Choosing and Using Vacuum Tubes
Includes information on replacement tubes
for hundreds of amplifiers!
4th Edition • $14.99

About Groove Tubes®

For over 30 years, Groove Tubes have been trusted and demanded by touring professionals and their techs
around the world. Groove Tubes started in southern California, and through innovative design, rigorous
selection and testing, GT-powered amps have rocked the world in some of the most famous rigs everplayed from studio to stage. Combining our passion for music with the science of sound, the Groove Tubes
team still employs the same testing, grading and matching disciplines that continue to deliver flawless
performance every time.

Tube Cross Reference Basics

There have been a myriad of tubes types and styles made over the years for industrial, military andcommercial use. Many of these use European nomenclature. A cross reference is included here:
Groove Tubes

Industrial

EuropeanGroove Tubes

Industrial

GT-12AT7

6679

ECC81

GT-6CA4-

European
EZ81

GT-12AU7

6189

ECC82

GT-ECC83

7025

ECC83

GT-12AX7

7025

ECC83

GT-6L6

5881

KT66

GT-5AR4-

GZ34 / GZ37 / U54 / U77

GT-6V67048 / 5871-

GT-5U4-

GZ32 / GZ31 / U51 / U52

GT-6550

6550

KT88

GT-5Y36853

GZ30 / U50

GT-EL34-

6CA7 / KT77

GT-7025

7025

ECC83

GT-EL84-

6BQ5

Table of Contents
About Groove Tubes and Introduction to Vacuum Tubes....................................................................................... 2-3
Biasing, Groove Tubes Power Tubes Overview............................................................................................................4
Tube Replacement – When and Why? How?...............................................................................................................5
Preamp Tubes................................................................................................................................................................. 6-7
Specialty, Rectifier and Special Applications Group Tubes.......................................................................................8
6V6 and 6L6 Power Tubes.................................................................................................................................................9EL34 and EL84 Power Tubes...........................................................................................................................................106550/KT88 Power and Special Order Tubes.................................................................................................................11
Silver Series Preamp, Rectifier and Power Tubes.....................................................................................................12
Tube/ Amplifier Reference (manufacturers listed in alphabetical order)........................................................ 13-31
Groove Tubes Process.............................................................................................................................................. 32-35
My Amplifiers / Tubes Reference Pages................................................................................................................ 36-38
For the latest information on Groove Tubes, visit our web site at www.groovetubes.com

GROOVE TUBESHEAR THE DIFFERENCE™

© 2012 FMIC. GROOVE TUBES® is a registered trademark of Fender Musical Instruments Corporation.
All rights reserved. Amplifier and model names contained herein are the property of their respective
owners and are provided for reference only. Specifications subject to change without notice. 5550114112
2

Groove Tubes • Tube Reference Guide

Introduction to Vacuum Tubes
Electric guitar and bass players over the past 50 years have been linked by a single critical piece ofequipment: The tube amp. With all of the advances in transistor and digital technology, professionals still
prefer tube amps as part of their musical arsenal from studio to stage. There are many reasons for this, andwe will explore many of these factors in plain language, throughout in this guide.
Tubes have provided the foundation for musical and audio circuits that have produced much of the worlds’
greatest rock, jazz, blues and country music during the last century. Ironically, tube-driven circuits are notnecessarily a perfect “reproducer” of sound. They are actually a “producer” of part of the musical output
by adding definite, subtle, tactile and sonic characteristics to the signal path of instrument amps.
So, why do tube amps sound and feel different?
First, tubes are imperfect. They each have unique performance characteristics and designs. They respondto signal input in a softer, slower and less precise manner than digital circuits. This provides the soft feel,or touch that many players enjoy in great tube amps. This is due to the natural “compression” that tube
inefficiency creates. Unfortunately, they also degrade over time and use, which is why many professionals
re-tube their amps before each tour and maintain spares for road use.
Second, tubes tend to distort in a very non-linear way. If you look at tube circuit distortion on test
equipment, you would see a slightly rounded waveform as the tube starts to distort. This is different from asolid-state or digital waveform which tends to appear square, distorting all frequencies at the same time.
In tube circuits, low frequencies tend to distort first, and higher frequencies stay clean longer. Becauseof the way we hear sounds, this is more pleasing, less harsh. The harmonics that tend to distort in a tube
circuit are also more musical and are the reason that when you “grab” a note on a guitar at high volumes
and the amp distorts, it will feed back in a musically useful and pleasing way.
Finally, even though tubes are made of glass, and have little metal parts inside, they are actually pretty
durable, and with proper testing, rather predictable. Over the years, there are many specific amp designs
that have been associated with an “American” sound, a “British” sound, etc… Many high-end boutique
products use these reference sounds from tubes in their circuit designs to achieve signature tones.

What is a Tube?
A tube is an electronic gain producing device consisting of a minimum of four active elements: a heater(filament), a cathode, a grid and a plate. These are all sealed in a vacuum glass enclosure to prevent parts
from burning. Once heated, the cathode begins to emit electrons, which flow from the cathode (which is
negatively charged) toward the plate (which is positively charged). The grid’s purpose is to control thisflow, in effect, acting as a “valve”. This is one reason that tubes are called “valves” in the UK.

What is the difference between preamp tubes and power tubes?
When the guitar’s pickup produces a small voltage (the result of the string vibrating in the pickup’s
magnetic field), this signal goes into the “preamp” part of an amp circuit. It is applied to the grid, whichcauses a larger current flow from the cathode to the plate. Preamp tubes are usually the main tone
generators in an amp circuit and you can experiment with the gain and tone of you amp easily by trying
different preamp tubes. GT makes it easy by providing clear, intuitive descriptions of these tubes.
Power tubes provide the major horsepower in an amp circuit, and will have their greatest impact on tone
as they distort. This means you have to run amps pretty loud to get the maximum benefit from the tube
distortion in the power amp section. That explains the popularity of small, lower power tube amps which
distort nicely at lower volumes. Keep in mind, there are several styles of power tubes available. You must
use the specific style (EL34, 6V6, 6L6, etc…) that the circuit was designed to accommodate.

Groove Tubes • Tube Reference Guide

3

What is “biasing”?
Bias refers to the adjustment (generally in the power tube section) that controls the voltage of the gridof a tube. When the grid bias is properly set, the tubes are balanced in the circuit and produce a clean,
powerful signal. It is like matching the engine RPM to the proper gear in a race car to achieve optimum
performance for the desired speed.
If the bias is not set correctly, the amp may not perform properly, or the tubes may wear out more quickly.
If you install a set of tubes with very different outputs or strengths from each other, it may not be possible
to adjust the bias to achieve maximum performance from all power tubes. You will get a compromise on all
tubes, and none will perform to their proper potential or specification.
Fortunately, many manufacturers use power tubes that fall in the same specification as “Medium” (4-7 finescale) of Groove Tubes as their stock tubes. The amplifier’s bias control is adjusted at the factory for tubes
in this power range. Tubes in this power range are widely available at all times from Groove Tubes.
If you want to change the performance of your amp to distort more quickly, or stay clean longer, you canuse Groove Tubes in the Low (1-3 fine scale), or High (8-10 fine scale). If so, you should have a qualified
service tech re-bias your amp for the new tubes. The good news, is that once this is done, you should be
able to replace your power tubes with Groove Tubes of the same type and rating without bias adjustment.
Preamp circuits and many tube power amp designs today feature an “auto’biasing” circuit. You can checkwith the amp manufacturer to see if your amp has “auto-bias”. If so, no further adjustments are needed.

Groove Tubes® Power Tubes – Dynamically Energized™
and Performance Matched™
These pass every Groove Tubes premium certification for micro-phonics, hum, noise floor, physicaloperation and performance characteristics. We also analyze and match the gain-to-distortion ratio on a
dynamic basis, assuring a powerful, singing tone that is rich in harmonics and balanced for longer sustain,
wider frequency response and a more musical amplification experience.
Groove Tubes are quite simply the best tubes you can buy that are specifically designed and tested formusical instrument amplification. Sold as single tubes, matched duets, quartets and sextets, Groove Tubes
are standard equipment on professional Fender® tube amps.
Matching power tubes has been part of tube history since the beginning. Power tubes usually work inpairs, and we have developed proprietary selection and matching procedures. This includes special
fixtures, processes and software, exclusive to Groove Tubes.
Many companies test power tubes for POWER output only. In reality, the POWER output of tubes varies
little, so testing strictly for power output is a rather meaningless exercise. What we do at Groove Tubes is amuch more involved test of the distortion and TONAL characteristics of the tube. Surprisingly, this is wheretubes can vary quite a bit, even within the same model, factory and production run.
Groove Tubes has developed a procedure that combines valid, scientific comparison and exclusive
methods that take into account the tonal characteristics of tubes for use in instrument amplification.

The Groove Tubes Warranty
Preamp Tubes - Warranted to be free of burn out for 180 days from date of purchase.
Power Tubes - Warranted to be free of burn out for 90 days from date of purchase.

4

Groove Tubes • Tube Reference Guide

Tube Replacement? When, Why and How?
Glass, metal, lots of little parts... tubes are subject to mechanical problems and are not meant to last alifetime. The harder you work your tubes, the faster they wear out. Plus, there are a number of other factorsthat make tubes one of the easiest and least expensive “fixes” for your tube amp.
1. Tubes are subject to vibration damage. The inside of a combo tube amplifier is a super-abusive
environment for tubes because you crank up the volume, create a huge amount of sonic vibration, directly
couple the tubes to the chassis of your amp and then stick the chassis inside the speaker cabinet!
2. When tubes operate, the metal parts on the inside of the tube begin to glow. That means that they arereally hot, like molten metal. When metal is heated enough to glow, it gets soft. Excessive vibration cancreate a situation where the metal becomes fatigued or stressed.
3. If you are at a gig with your amp, you run it hard and then take it outside and place it in the back of yourcar while the internal components are still warm and soft, the bouncing around while you are driving cancause damage to the tube.
4. The reason that it is called a “vacuum tube” is that the air is sucked out of the inside of the tube when it
is manufactured. This creates a “vacuum” inside the tube and this lack of oxygen allows the metal parts toheat up without actually burning. If the tube develops a leak, or the seal is broken air will leak back into thetube and the components could smoke, smolder or burn.
5. Tubes are inexpensive compared to transformers, speakers, etc…and a lot easier to replace!
6. When one tube starts to go, it drags the others down with it, decreasing the overall efficiency of the amp,
which adversely changes the tone and reduces sustain.
7. You can keep spare tubes with you in case something happens at a gig. With Groove Tubes you can evenmake sure that you have a spare power tube set with the exact same rating.
8. Many manufacturers have started producing small, inexpensive tube amps. While many of these arereally cool, sometimes a manufacturer will cut corners on the tubes that come in the amp. Groove Tubes
preamp and power tubes can really punch up the performance of these amps.
9. With the easy-to-understand descriptions of GT preamp tubes, you can experiment with different styles
and types to achieve a wide variety of different gain structure and tone.
10. Audio troubleshooting. Change tubes if your amp experiences any of the following:a. Loss of tone, clarity, sustain and harmonic richness.
b. Poor output-level balance.
c. Lack of midrange punch and definition.
d. Rattling, whistling or humming.
e. Feedback or metallic sound on certain notes
f. Weak sound and power loss.
g. To experiment and change amp tone characteristics.
11. When you have decided to change tubes in your amp, go to www.groovetubes.com.

Groove Tubes • Tube Reference Guide

5

Preamp Tubes

These pass every Groove Tubes premium certification for microphonics, hum, physical characteristics
and function. Quite simply the best preamp tubes you can buy — specifically designed and tested formusical instrument amplification and standard equipment on Fender amps. Outstanding and consistent
performance for mixing and matching to get a signature tone from your amp.

GT-12AX7-C Preamp Tube

GT-12AX7-M Preamp Tube

GT-12AX7-R Preamp Tube

GT-12AX7-R2 Preamp Tube

Great chiming tone with sweet, warm midrange excellent
for Marshall and Fender amps. Smooth distortion
characteristics and one of the highest-output preamp
tubes in the GT 12AX7 line, with very consistent quality.

The most widely used design in new amplifiers today.
Extremely rugged, consistent and forgiving, it’s a great
all-around replacement given its inherently darker tone
and relatively low gain. Can be slightly harsh when
overdriven, but its warmth makes it a good choice forhigher-gain and brighter amps and for keeping unwanted
feedback and over-the-top overdrive under control.

Dual-triode vacuum tube based on the highly soughtafter Mullard 12AX7, which went out of production in
the late 60’s. Some consider the Mullard one of theultimate vintage 12AX7 tubes, and this reissue gives
you the chance to get “that tone.” Its unique triple
mica design reduces tube hum and microphonics, andgives performance stability under the most demanding
conditions, such as high gain tube guitar amps sitting on
4x12 cabs. This tube delivers rich, harmonically complex
tone and midrange warmth.

Longer-plate-structure version of the standard “R” seriestube, which produces brighter tone. Larger plate makes
this tube slightly more prone to microphonic issues whenused with high-gain amps. Suggested for use in darker
amps to brighten tone. Very live and responsive, withgood clarity.

GT-12AX7-R3 Preamp Tube

The highest-gain output tube in the “R” series, this tube
is similar to the R2 and has similar output, but with ashorter plate, higher gain, and a more consistent quality
variance score. An extremely consistent tube useful inmost applications.

6

Groove Tubes • Tube Reference Guide

Preamp Tubes (Continued)

GT-ECC83-S Preamp Tube

GT-12AU7 Preamp Tube

GT-12AT7 (ECC81) Preamp Tube

GT-12AY7 Preamp Tube

Our highest-gain preamp tube, this tube has a hugeamount of gain, with terrific output that makes it a great
choice for driving modern, complex high-gain circuits.
It has a relatively high quality variance (making Groove
Tubes pre-testing procedures especially important in thiscase), with a tight, strong and relatively bright tone thatcan really liven up a weak or tired old vintage amp or a
new amp with grade-quality tubes.

Durable phase splitter or driver tube. Excellent in vibrato
or reverb circuits where consistent, high output power
is desired.

Our lowest-gain preamp tube. Can sub for a 12AX7 tolower gain and produce a very creamy, warm tone.
Great for harp or blues when softer, more compressed
distortion at lower volumes is desired. Very low gain andvery mellow output.

Low-gain tube used in very early Fender amps. Can
sub for a 12AX7 to lower gain and produce a slightly
warmer tone. Great for harp or blues where softer, morecompressed distortion at lower volumes is desired.
Medium / soft gain.

Groove Tubes • Tube Reference Guide

7

Rectifier/Specialty Tubes

These pass every Groove Tubes premium certification for microphonics, hum, noise floor, physicaloperation and characteristics. Includes rectifier tubes, phase inverters and specialty kits specificallydesigned and tested for musical instrument amplification applications as noted.

GT-5AR4-R
Rectifier Tube

GT-5U4 Rectifier Tube

Our highest-output rectifier tube.
Originally used in early higherpowered Fender amps (40 watts
or more) with tube rectifiers; also
used in the Vox AC30.

Medium-output rectifier tube
originally used in early mediumpower Fender amps with tube
rectifiers.

GT-5Y3 Rectifier Tube

GT-6CA4
Rectifier Tube

Low-output rectifier tube originally used in early low-power
Fender amps with tube rectifiers(Champ, Princeton and Deluxe).
May also substitute for a 5AR4 or
5U4 for lower output levels.

The lowest-output rectifier tube
in the GT line; commonly usedduring the ’60s in student andpractice amplifiers.

Special Applications Group – High Performance
Exclusive GT Testing, Matching, Grading

SAG-AT7-MPI
Specialty Tube
Selected and matched for criticalaudio and guitar/ bass amplifieruse, where a match of the twosides of the triode are desired forphase inverter or driver use.

SAG-MHG Marshall Hi Gain Kit
Two selected high gain ECC83 tubes optimized for the
preamp stage of Marshall amplifiers which use a dual
triode in the first gain stage. Includes two preamp tubes
and one SAG-AT7-MPI matched phase inverter.

SAG-FHG Fender Hi Gain Kit
SAG-AX7-MPI
Specialty Tube
Selected and matched for criticalaudio and guitar/ bass amplifieruse, where a match of the twosides of the triode are desired forphase inverter or driver use.

8

Two selected high-gain ECC83 tubes optimized for the
preamp stage of Fender amplifiers that use a dual triodein the first gain stage. Includes two preamp tubes andone SAG-AT7-MPI matched phase inverter.

SAG-FST Fender Soft Touch Kit
Two selected lower-gain, slow rise time 12AX7 tubes optimized for the preamp stage of Fender amplifiers that use
a dual triode in the first gain stage. Includes two preamp
tubes and one SAG-AT7-MPI matched phase inverter.

Groove Tubes • Tube Reference Guide

6V6 Power Tubes

The 6V6 is a low-output power tube (12-18 watts) often used in Fender amplifiers, including the Champ,
Deluxe, Dual Professional, Vibro-King, Princeton, Vibrolux and others. It has a very warm, round and soft
response with rich harmonics, and distorts easily. One of the best choices ever produced for rehearsal andrecording amplifiers. Available as singles, pairs and quartets; stocked in “medium” power ratings. Also
available by special order with “low” and “high” power ratings and fine scales ranging from 1 through 10.

GT-6V6-S
Power Tube

GT-6V6-C
Power Tube

Our most premium design, for longlife and professional performance.
The choice for many pro players
who use Groove Tubes in theirfavorite amps for recording andrehearsal; fully captures the spirit
and sound of tube amps from the’50s and ‘60s to the present.

Classic design and the mostaffordable choice in the GT 6V6
line. Warm overdrive and soft
distortion character.

GT-6V6-R
Power Tube
Solid, predictable performance,
the most used widely used tube
design in stock amplifiers frommajor manufacturers in the
6V6 line.

6L6 Power Tubes

A medium-output power tube (generally 20-25 watts) often used in Fender professional amplifiers including
the Bassman, Bandmaster, Concert, Dual Showman, Hot Rod Series, Pro Series, Super Reverb, Tremolux,
Twin, Vibrolux, Super Sonic, Blues Deluxe, Blues DeVille and others. Available in many variations, its
response is round, with a pronounced midrange character; strident and chesty with a super-bright andclean, powerful punch. Perhaps the most recognized signature tone for U.S. guitar music of all styles fromthe ’60s onward.

GT-6L6-CHP
Power Tube
EXCLUSIVE GT design.
This black-plate (carbonized nickel)
design features extended heatsink
wings. Has strong and focused
output, and is highly recommended
for enlivening any stock Fender orMarshall that uses a standard 6L6.
High-performance design delivers
30 watts, with very high performance/headroom. An outstanding
replacement for any tube amp with
6L6 power tubes.

GT-6L6-GE
Power Tube
EXCLUSIVE GT design. The GE is afaithful reproduction of the original“clear top” 6L6. The flagship of theGT 6L6 line, it looks and sounds
exactly like the original G.E. tube
used by Fender in the ‘50s and ‘60s.
It took more than four years todevelop, and has stunning clarityand power.

GT-6L6-S
Power Tube

GT-6L6-R
Power Tube
Solid and consistent performance;very sturdy and reliable. AKA 5881.

Groove Tubes • Tube Reference Guide

Great dynamics and a very sweet,
punchy tone with enhanced power
rating and performance. Morebrilliant top end and a very full, pronounced and round low-frequency
output. A solid replacement for
stock performance.

9EL34 Power Tubes

The original power platform behind most high-powered British guitar stacks from the ’60s onward. Output
is generally between 20 and 25 watts, with pronounced midrange punch, tight low end and crisp top end
that breaks up relatively smoothly and gets a little crunchy when pushed hard. It provides a great voicethat stands out in a band mix as the mids tend to power their way through an overall mix. Big brother to theEL84. Stocked in “medium” power ratings; also available as special orders with “low” and “high” power
ratings and fine scales ranging from 1 through 10.

GT-E34L Power Tube

GT-EL34M Power Tube

EXCLUSIVE GT design. The heat wings attached to theplate give our version of the original EL34 15-20 percent
more power. Interchanges in any EL34 applicationand stays tight and robust all the way up to full power.
Highly dynamic, big low end and runs cooler for longer
life. Amazing headroom, killer tone and all of the greatfeatures and characteristics of the EL34 design.

The GT EL34 is based on the original Mullard EL34 of the‘60s — the stock tube in all early Marshall and Hiwatt
amps. Mullard produced it for about 15 years, and thisis a faithful reproduction of the classic XF2 dual-getter
version. It has a big, fat and well-defined tone and really“wakes up” reissue amps to perform like the originals.
As close as you can get to vintage Marshall power tube
heaven.

GT-EL34R Power Tube
A more modern implementation of the original at anaffordable price, and currently standard issue on many
U.K. amps. Very durable and consistent, which is goodfor manufacturing, but the distortion can be slightly harsh,
and it lacks a little high end. This makes it more forgiving,
but can sound a little dull.

EL84 Power Tubes

Exhibits many of the same characteristics as the EL34, but with a power output of roughly 5-8 watts. Very
creamy and smooth; used in many modern class “A” amps. Nearly every modern tube amp company
produces a small amp, and Groove Tubes EL84s are a perfect upgrade for any stock tube in these amps.
Great for recording and rehearsal; with a soft and tactile touch, rich harmonic response and pleasingly
musical top end. Stocked in “medium” power ratings; also available as special orders with “low” and“high” power ratings and fine scales ranging from 1 through 10.

GT-EL84-S Power Tube

GT-EL84-R Power Tube
A solid performer — good quality and long lasting. Tends
to be a little more aggressive and edgy when pushed into
overdrive. This version is a little brighter, but still has anice smooth top end. Unique character with moderate
output.

10

The warmest Groove Tube in this family. It remains very
buttery, with relatively high power output and very evenresponse. A great replacement for many modern stock
amps, overcoming a variety of design issues and limitations in inexpensive tube amps. A great way to upgrade
your amp and step up to Groove Tubes tone with one ofour best sellers.

Groove Tubes • Tube Reference Guide6550 / KT88 Power Tubes

One of the highest-output pentodes available. Originally manufactured in the United States by G.E., itdelivers 35 to 50 watts per tube and was original equipment in Ampeg SVT and Marshall amps during the’70s and early ’80s. A big, clean, tight tube with amazing headroom and performance and great power anddynamics. A similar tubes is the KT88 (used by Sunn and others). The highest-output power tube in thisfamily. Stocked in “medium” power ratings; also available as special orders with “low” and “high” power
ratings and fine scales ranging from 1 through 10.

GT-6550C Power Tube

GT-6550R Power Tube

Our softest 6550 is easier to push into distortion than the“R” version or the original. Has a nice character thatbreaks up slightly earlier, which some players prefer in a
Marshall. A 6550 standard, this tube will produce a stock
signature distortion at lower levels than the “R” version.

Our highest-output 6550 is slightly easier to push into
distortion than the original G.E. version and has a harder
response than the “C” for tighter, quicker response. Goodfor bass amps and metal, when more pronounced note
definition is desired with just a touch of distortion.

GT-KT88SV Power Tube
EXCLUSIVE GT design. This is the highest-output power
tube in the 6550/KT88 family, with special heat dissipation
wings on the plate that let it reach the same power
specs as the original Gold Lion KT88 of the ’60s. The best,
most durable and most powerful tone in the family, withoutstanding dynamic response and big bottom end. The
definitive tube for bass amps, country, jazz, metal andany situation in which most of the tone shaping occurs in
the preamp, pedals or effects. Amazing high-horsepower
delivery of clean tone.

Tube Amp Book
This deluxe revised edition of Aspen Pittman’s The
Tube Amp Book contains 40% new material. Features
a CD-ROM with 800 available schematic and layout
diagrams. Hardcover with convenient enclosed spiralbinding.

SPECIAL ORDER TUBES
Matched Power Tube Sets

Our stock matched-power tubes sets are offered in the “medium” range. We use a 10-point scale (10 being
the highest output ); “medium” tubes fall in the 4-7 range and are most similar to stock tubes for many
amplifiers, especially Fender. For amp service techs or those wishing to customize amplifiers to achieve
specialized tone, “high” (8-10) and “low” (1-3) tube sets are available. These may require amp re-biasing
by a qualified service technician. Please contact your Groove Tubes Retailer to purchase matched setswith ratings other than “medium.”

Non-Stock Tubes

There are many other tubes in the Groove Tubes lineup that are non-standard for use in ampifiers today
and are not included on this pricelist. These include preamp, rectifier, power amp and microphone tubes
such as the 6205, 6922, 7027, 7591, 5881C, KT66, KT77, etc. Please contact your Groove Tubes Retailer tocheck availability of these tubes and for information on your other special-order needs.

Groove Tubes • Tube Reference Guide

11

SILVER Series
In a world of “Good, Better, Best” choices, Silver Series tubes are the “Better” choice. They are excellent
workhorses in many amplifier circuits in reverb driver, phase inverter or other applications, and can also be
an excellent choice in the audio chain in most positions. Silver Series tubes are fully functional and pass
many of the same exhaustive tests of premium Groove Tubes. They exceed all basic industry specifications
for performance and provide a very affordable alternative for use in non-critical applications. Silver Series
power tubes are perfect for single power tube (non-matched) use, as spares or use in project amplifiers.
Silver Series preamp tubes are great for “sampling” different preamp tube performance characteristics
and to experiment with your sound. Please contact your Groove Tubes Retailer for information on current
availability, pricing and special opportunities to purchase Silver Series tubes.
PRODUCTSTOCK NUMBER

Silver Series preamp tubes - various

Call for Availability

Silver Series rectifier tubes - various

Call for Availability

Silver Series power tubes - 6550

Call for Availability

Silver Series power tubes - KT88, KT66

Call for Availability

Silver Series power tubes - KT77

Call for Availability

Silver Series power tubes - EL34R, 6L6S, 6L6R

Call for Availability

Silver Series power tubes - 6L6CHP, 6L6C, 6L6GE, 6L6R, 6V6S, E34LS, EL34M

Call for Availability

Silver Series power tubes - 6V6R, EL34C, EL84R, EL84S

Call for Availability

Warranty

Warranted to be free of burn out for 30 days from date of purchase.

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Groove Tubes • Tube Reference Guide

TUBE/AMPLIFIER REFERENCE

To use this guide, locate the manufacturer of your amplifier or other tube-based audio product (listed in alphabeticalorder),and then search for the model. The full complement of Groove Tubes replacement tubes will be listed next tothe model name. if you can’t find your amplifier model in this guide, contact Groove Tubes for more information.

65ampsLondon2-12AX7, 1-EF86,EL84 Duet, EZ81

Marquee Club

2-12AX7, 1-EF86,EL84 Quartet, GZ34

SoHo

2-12AX7, 1-EF86,EL84 Duet, EZ81

Royal Albert

3-12AX7, KT77 Duet or 6V6 Duet, SS plugin or 5Y3 or 5U4 or GZ34/5AR4

Acoustic
160

2-12AX7, 2-12AT7, 6L6 Quartet

160

3-12AX7, 1-12AT7, 6L6 Quartet

164/165

2-12AX7, 2-12AT7, 6L6 Quartet

164/165

3-12AX7, 1-12AT7, 6L6 Quartet

G-100T

3-12AX7, 1-12AT7, 6L6 Quartet

G-60T

2-12AX7, 2-12AT7, 6L6 Duet

Tube 60

2-12AX7, 2-12AT7, 6L6 Duet

ADA
MB-1

2-12AX7

MP-1

2-12AX7

T-100S

2-12AX7, 6CA7 Quartet

Alembic
Preamp2-12AX7

F/X

1-12AX7

Ampeg
Jet-12 - early

2-6K11, 7591 Duet

Note: some older Jet-12s used 6BK11s instead of 6K11s. This tube is no longer available, and there is no adequate substitute.

Jet-12

2-12AX7, 7591a Duet

Jet-12R

2-12AX7, 1-6U10, 7591a Duet

GS-12R Rocket II

3-12AX7, 1-6U20, 7591a Duet

G-12 Gemini 12

3-12AX7, 1-6CG7, 1-7199, 7591a Duet

G-15 Gemini 12 - early

4-12AX7, 1-6CG7, 1-7199, 7591a Duet

G-15 Gemini 12

4-12AX7, 1-6CG7, 1-7199, 7027 Duet

GV-22 Gemini

4-12AX7, 1-6CG7, 1-7199, 7027 Duet

SB-12

2-12AX7, 6L6 Duet, 5AR4

B-25

2-12AX7, 1-7100, 7027 Duet, 5AR4

B-22X

4-12AX7, 1-6CG7, 1-7199, 7027 Duet, 5AR4

B-42X

4-12AX7, 1-6CG7, 1-7199, 7027 Duet, 5AR4

GV-12

1-12AX7, 1-6U10, 1-12DW7, 7591

AC-12

1-12AX7, 1-6U10, 1-12DW7, 7591

AX-44C

1-12AX7

AX-70

1-12AX7

B-12XT

4-12AX7, 7027 Duet, 5AR4

VT-40 - later

1-12AX7, 2-12DW7, 1-6AN8, 1-6CG7, 7027 Duet

VT-40

3-12AX7, 1-6K1 1, 1-12DW7, 1-6AN8, 1-6CG7, 7027 Duet

VT-22 - later

1-12AX7, 3-12DW7, 1-6CG7, 1-6AN8, 7027 Quartet

Groove Tubes • Tube Reference Guide

13

Ampeg (Continued)
VT-22

3-12AX7, 1-6K11 1, 1-12DW7, 1-6AN8, 1-6CG7, 7027 Quartet

VT-60

4-12AX7, 1-12AU7, 6L6 Duet

VT-120

4-12AX7, 1-12AU7, 6L6 Quartet

V-2

3-12AX7, 1-12DW7, 1-12AU7, I-6K1 1,1-6CG7, 7027 Duet

V-3

4-12AX7, 1-12AT7, 6550 Duet

V-4

3-12AX7, 1-12DW7, 1-12AU7, I-6K1 1,1-6CG7, 7027 Quartet

V-4B

2-12AX7, 1-12DW7, 1-12AU7, I-6K1 1, 7027 Quartet

V-5

3-12AX7, 6550 Quartet

V-7

4-12AX7, 1-12AT7, 6550 Quartet

V-9

1-12AX7, 4-12DW7, 1-6CG7, 2-12BH7, 6550

B-15 - early

2-6SL7, 1-7199, 6L6 Duet, 5AR4

B-15N

3-6SL7, 6L6 Duet, 5AR4

B-18

2-6SL7, 1-7199, 7027 Duet

Audio ResearchSP-3 Series

8-12AX7

SP-6 A and B

6-12AX7

SP-6E

4-12AX7, 2-ECC88

SP-8

4-12AX7, 2-ECC89, 1-12BH7

SP-10

12-ECC88, 1-ECC81, 2-6L6OS Duet

D75A and D76

4-12Ax7, 8-6CG7, 1-6550A, 1-6550 Quartet

D79, D150, D-70/115/250

Call the Groove Tubes Sales Department with your serial number

Bedrock
1200

5-12AX7, 1-EL34 Duet

1400

3-12AX7, 1-EL34 Duet

1600

6-12AX7, 1-EL34 Quartet

Benson300

3-12AX7, EL34400

3-12AX7, EL34

BognerShiva

7-12AX& EL34 or 6L6 Duet depending on output transformer

Ubershall

6-12AX7 EL34 Quartet

Ecstacy

6-12AX7 EL34 or 6L6 Quartet depending on output transformer

Metropolis 15

5-12AX7, 1-EL84 (reverb) EL84 Duet

Metropolis 30

5-12AX7, 1-EL84 (reverb) EL84 Quartet

Duende5-12AX7, 6V6 Duet, 5AR4 or 5Y3 Rectifier

Budda Super Drive Series
18

2 x 12AX7, 2 x EL84, 1 x 5U430

2 x 12AX7, 4 x EL84, 1 x 5U4

45

3-12AX7, 1-5U4 Rectifier, 2 x KT66

80

3-12AX7, 1-5U4 Rectifier, 4 X 6L6Twin Master2 x 12AX7, 2 x EL84, 1 x 5U4

Carr
Raleigh14

2 X 12AX7, 1 X EL-34

Groove Tubes • Tube Reference Guide

Carr (Continued)
Mercury

2 X 12AX7, 1 X 12AT7, 1 X EL34

Viceroy

3 X 12AX7, 1 X 12AT7, 2 X 6L6

Rambler

3 X 12AX7, 1 X 12AT7, 2 X 6L6

Slant 6V

4 X 12AX7, 2 X 12AT7, 4 X 6V6, 1 X 5AR4

Hammerhead

2 X 12AX7, 2 X EL34

CarvinVTR 2800 50-watt

1-12AT7, 6CA7 DuetVTR 2800 100-watt

1-12AT7, 6CA7 Quartet

VTX 100

3-12AX7, 6L6 Quartet

X-B12 30-watt

3-12AX7, 6L6 Duet

X-T12 60-watt

3-12AX7, 6L6 Duet

X-V112 100-watt

3-12AX7, 6L6 Quartet

X-VI12 - later

3-12AX7, EL34 Quartet

X-V212 100-watt

3-12AX7, 6L6 Quartet

X-V212 - later

3-12AX7, EL34 Quartet

X-V212E 100-watt

3-12AX7, 6L6 Quartet

X-60 60-watt

3-12AX7, EL34 Quartet

X-60B 60-watt

3-12AX7, 6L6 Duet

X-100 100-watt

3-12AX7, 6L6 Quartet

X-100B 100-watt

3-12AX7, 6L6 Quartet

X-100B - later

3-12AX7, EL34 Quartet

Note: Some Carvin amps may not be able to use EL34 tubes since pin 1 and 8 were not always wired together. Check your amp if it’san older model. See the 6L6-to-EL34 mod: Service and Mod Section under Fender amps in Aspen Pittman’s The Tube Amp Book.

Champion
R&R 10-watt

1-12AX7, 6V6 Duet

R&R 20-watt

1-12AX7, EL34 Duet

Conn
Strobe Tuner

2-6AQ5, 1-6X4, 1-5879, 1-12AT7, 1-12AU7

Conrad Johnson
Premier One

4-6CG7, 1-5751, 2-6550 Sextets

Premier Three

2-12AX7, 5-5751, 2-5965

MV-75A

2-6CG7, 1-5751, 6550 Quartet

CornfordHarlequin

2-2AX7, EL84 Single

Hellcat

5-12AX7, EL84 Quartet

Hurricane

4-12AX7, EL84 Duet

M.K.50 H

4-12AX7, 6L6 Duet

R.K. 100

4-12AX7, EL34 Quartet

Crate
V5

1 X EL84

V18

2 X EL84

V33

4 X EL84

V50

2 X 6L6

Groove Tubes • Tube Reference Guide

15

Crate (Continued)
V100

4 X 12AX7, 4 X EL34

Demeter
TGA-3

6-12AX7, 6550 Quartet

TGP-3

6-12AX7

VTBP/201

6-12AX7

VTDB-2

1-12AX7

Diaz
CD-100

3-12AX7, 1-12AT7, 6L6 Quartet

Diezel
VH4 & VH4S

4-12AX7, 4 X 6L6, KT66, KT88, 6550, EL34

HERBERT

4-12AX7, 6 X 6L6, KT66, KT88, 6550, EL34

EINSTEIN

4-12AX7, 4 X 6L6, KT66, KT88, 6550, EL34

SCHMIDT

4-12AX7, 4 X 6L6, KT66, KT88, 6550, EL34

Divided by 13
LDW 17/39

12AX7, 2 X EL34

EDT 13/29

12AX7, 12AT7, 2 X KT66, 1 X 5AR4

CJ 11

2 X 12AX7, 2 X 6V6, 1 X 5AR4

FTR 37

12AX7, 4 X 6V6, 1 X 5AR4

SJT 10/20

12AX7, 2 X 6V6, 1 X 5AR4

TBL 200

12AX7, 4 X KT88

JTR 9/15

12AX7, 2 X EL84 2 X 6V6, 1 X 5AR4

RSA 23

12AX7, 2 X KT88, 1 X 5AR4

RSA 31

12AX7, 4 X EL84, 1 X 5AR4

JJN 50/100

12AX7, 4 X EL34

Dr. Z AmpsCARMEN GHIA

1 X 12AX7, 1 X 5751, 2 X EL84, 1 X 5Y3

EZG 502 X 12AX7, 2 X 12AT7, 2 X 6L6

GALAXIE

3 X 12AX7, 2 X 6L6, 1 X 5U4

JAZ 20/40

5 X 12AX7, 1 X 12AT7, 4 X 6V6

MINI Z1 X 12AX7, 1 X EL84

REMEDY

3 X 12AX7, 4 X 6V6

DynacoPAS Series

4-12AX7, 1-12X4

Stereo 70

2-7199, 1-5AR4, EL34 Quartet

MKIII

1-6AN8, 1-5AR4, 6550 Quartet

Fender16

1959 Bassman - reissue

3-12AX7, 6L6 Duet

Bandmaster VOS

1-12AY7, 2-12AX7, 6L6 Duet, 5U4

Bandmaster OS

6-12AX7, 6L6 Duet

Bandmaster NS

3-12AX7, 1-12AT7, 6L6 DuetGroove Tubes • Tube Reference Guide

Fender (Continued)
Bandmaster/Reverb

4-12AX7, 2-12AT7, 6L6 Duet, 5U4

Bantam Bass

2-12AX7, 1-12AT7, 6L6 Duet, 5U4

Bassman 4x10 OS 1

1-12AY7, 2-12AX7, 6L6 Duet, 5U4

Bassman 4x10 OS 2

1-12AY7, 2-6925, 6L6 Duet, 2-5U4

Bassman 4x10 OS 3

2-12AY7, 1-12AX7, 6L6 Duet, 2-5U4

Bassman 4x10 OS VOS

1-6SC7, 1-6SL7, 6L6 Duet, 5U4

Bassman Top 50-watt

3-12AX7, 1-12AT7, 6L6 Duet, 5U4

Bassman Top 70-watt

3-12AX7, 1-12AT7, 6L6 Duet

Bassman Ten 70-watt

2-12AX7, 1-12AT7, 6L6

Bassman 100

2-12AX7, 1-12AT7, 6L6 Quartet

Bassman 135

2-12AX7, 1-12AT7, 6L6 Quartet

Champ OS

1-6SJ7, 6V6, 5Y3

Champ OS

1-12AX7, 6V6, 5Y3

Champ 12 - 1990

1-12AX7, 6L6

Concert

6-12AX7, 6L6 Duet, 5U4

Concert

6-12AX7, 6L6 Duet

Concert 1983

5-12AX7, 2-12AT7, 6L6 Duet

Deluxe 5C3

1-6SC7, 1-12AY7, 6V6 Duet, 5Y3

Deluxe 5D3

1-12AY7, 1-12AX7, 6V6 Duet, 5Y3

Deluxe 5113

2-12AX7, 6V6 Duet, 5Y3

Deluxe Brown

3-12AX7, 6V6 Duet, 5Y3

Deluxe Reverb

4-12AX7 (12AX7), 2-12AT7, 1-5AR4 6V6 Duet

Deluxe Reverb - 1983

5-12AX7, 1-12AT7, 6V6 Duet

Dual Showman

3-12AX7, 1-12AT7, 6V6 Quartet

Dual Showman Head - 1990

4-12AX7, 1-12AT7, 6V6 Quartet

Dual Showman Reverb

4-12AX7, 2-12AT7, 6V6 Quartet

Fender 30

4-12AX7, 2-112AT7, 6L6 Duet, 5U4Fender 75

3-12AX7, 2-112AT7, 6L6 Duet

Fender 100 PA

4-12AX7, 2-112AT7, 6L6 Duet

Fender 160 PS

3-12AX7, 1-12AT7, 1-12AU7, 1-6CA8, 6L6 Sextet

Fender 300 PS

2-12AX7, 1-12AT7, 6V6, 6550 Quartet

Fender 400 PS

6-12AX7, 1-12AT7, 6L6, 6550 Sextet

Fender Blues Jr

3-12AX7, 1-EL84 Duet

Fender Dual Professional

5-12AX7, 1-6V6GT, 6L6 Quartet

Fender Hot Rod Deluxe

3-12AX7, 6L6 Duet

Fender Hot Rod Deville

3-12AX7, 6L6 Duet

Fender Tonemaster3-12AX7, 6L6 Quartet

Fender Pro Series Twin

7-12AX7, 1-12AT7, 6L6 Quartet

Fender Pro Series Concert

7-12AX7, 1-12AT7, 6L6 Duet

Fender Pro Series Pro
Reverb

7-12AX7, 1-12AT7, 6L6 Quartet

Fender Vibrosonic

4-12AX7, 2-12AT7, 6L6 Duet

Fender Vibro-King

5-12AX7, 1-6V6 (EL-84 early models), 6L6 Duet

Fender Vibrolux Reissue

5-12AX7, 1-12AT7, 6L6 Duet

Fender 63 Vibroverb Reissue

5-12AX7, 1-12AT7, 6L6 DuetGroove Tubes • Tube Reference Guide

17

Fender (Continued)

18

Harvard

1-12AX7, 6V6, 5Y3

Harvard

1-12AX7, 1-6AT6, 6V6 Duet, 5Y3Musicmaster Bass

1-12AX7, 6V6 Duet

Princeton VOS

3-6SC7, 6L6 Duet, 5U4

Pro OS

2-12AY7, 1-12AX7, 6L6 Duet, 5U4

Pro Brown

6-12AX7, 6L6 DuetPro

3-12AX7, 1-12AT7, 6L6 Duet, 5AR4

Pro Reverb

4-12AX7, 2-12AT7, 6L6 Duet, 5AR4

Quartet Reverb

4-12AX7, 2-12AT7, 6L6 Quartet

Rack Amp RPWI

2-12AX7, 1-12AT7, 6L6 Quartet

Rack Guitar Preamp

2-6C10, 4-12AX7, 2-12AT7

Rack Bass Preamp

2-6C10, 4-12AX7

Rack 200-watt amp

2-12DW7, 2-12BH7, 2-12AX7, 6550 Sextet

Reverb Unit OS

1-12AX7, 1-12AT7, 1-6K6

Reverb Unit

1-12AX7, 1-12AT7, 6V6

Showman OS

6-12AX7, 6L6 Quartet

Showman

3-12AX7, 1-12AT7, 6L6 Duet, 5U4

Super 2x10 V front

2-12AY7, 6V6 Duet, 5U4

Super 2x10

1-12AY7, 2-12AX7, 6L6 Duet, 5U4

Super VOS

3-6SC7, 6L6 Duet, 5U4

Super OS

1-12AY7, 10-12AX7, 6L6 Duet, 5U4

Super Brown

5-12AX7, 6L6 Duet

Super Reverb

4-12AX7, 2-12AT7, 6L6 Duet, 5U4

Super Reverb

4-12AX7, 2-12AT7, 6L6 Duet

Super Champ - 1983

1-12AX7, 1-12AT7, 1-6C10, 6V6 Duet

Super Twin

2-12AX7, 1-12AT7, 1-6CX8, 1-6C10, 6L6 Sextet

Super Six

4-12AX7, 2-12AT7, 6L6 Quartet

Super 60 - 1990

2-12AX7, 1-12AT7, 6L6 Duet

Super 112 - 1990

2-12AX7, 1-12AT7, 6L6 Duet

Super 210 - 1990

2-12AX7, 1-12AT7, 6L6 Duet

Tone Master - new model

3-12AX7, 6L6 Quartet

Tremolux VOS

1-12AY7, 2-12AX7, 6L6 Duet, 5AR4

Tremolux OS

4-12AX7, 6L6 Duet, 5AR4

Twin Cream/Brown

6-12AX7, 6L6 Quartet

Twin Reverb

4-12AX7, 2-12AT7, 6L6 Quartet

Twin Reverb - 1983

5-12AX7, 2-12AT7, 6L6 Quartet

Vibrolux VOS

2-12AX7, 6V6 Duet, 5Y3

Vibrolux OS

3-12AX7, 1-12AT7, 6L6 Quartet

Vibrolux Brown

4-12AX7, 6L6 Duet, 5AR4

Vibro Champ

2-12AX7, 6V6, 5Y3

Vibroverb Brown

4-12AX7, 2-12AT7, 6L6 Duet, 5U4

Vibro King - new model

5-12AX7, 1-EL84, 6L6 Duet, 5AR459 Bassman LTD

3-12AX7, 6L6GC Duet, 5AR4

Bassman 300 Pro

1-12AX7, 1-12AT7, 1-6550 Sextet

Pro Junior

2-12AX7, EL84 DuetGroove Tubes • Tube Reference Guide

Fender (Continued)
Super-Sonic

6-12AX7, 2-12AT7 6L6 Duet

Super-Sonic (head)

5-12AX7, 1-12AT7 1-6550 Sextet

57 Deluxe (reissue)

2-12AX7, 6V6 Duet, 5Y3

57 Twin (reissue)

4-12AX7, 6L6 Duet, 2-5U4

Blues Deluxe

3-12AX7, 6L6 Duet

Blues DeVille

3-12AX7, 6L6 Duet

64 Vibroverb Custom

4-12AX7, 2-12AT7 6L6 Duet, 5AR4

Princeton Recording Amp

3-12AX7, 1-12AT7 6V6 DuetEC Twinolux

4-12AX7, 6L6 Duet, 2-5U4

EC Tremolux

3-12AX7, 6V6 Duet, 5Y3GT

EC Vibro-Champ

2-12AX7, 6V6, 5Y3GT

Machete Combo & Head

5-12AX7, 1-12AT7, 6L6 Duet

Super Sonic 22 Combo

3-12AX7, 2-12AT7, 6V6 Duet

Super Sonic 60 Combo

6-12AX7, 2-12AT7, 6L6 Duet

Super Sonic 60 Head

5-12AX7, 1-12AT7, 6L6 Duet

Super Sonic Twin Combo

7-12AX7, 2-12AT7, 6L6 Quartet

Super Sonic 100 Head

7-12AX7, 2-12AT7, 6L6 Quartet

Super Champ X2 Combo & Head 1-12AX7, 6V6 Duet
Greta

1-12AX7, 12AT7

Excelsior

2-12AX7, 6V6 DuetChampion 600

1-12AX7, 6V6’65 Princeton Reverb Reissue

3-12AX7, 1-12AT7, 6V6 Duet, 5AR4Super Champ XD

1-12AX7, 6V6 Duet

Vibro-Champ XD

1-12AX7, 6V6

Bassman 100T Head

2-12AX7, 1-12AT7, 6L6 Quartet

Super Bassman Head (2012)

3-12AX7, 1-12AT7, 6550 Sextet’65 Twin Reverb Reissue

4-12AX7, 2-12AT7, 6L6 Quartet’65 Deluxe Reverb Reissue

4-12AX7, 2-12AT7, 6V6 Duet, 5AR4

’94 Twin Amp

5-12AX7, 3-12AT7, 6L6 Quartet

The Twin

5-12AX7, 2-12AT7, 6L6 Quartet’65 Super Reverb Reissue

4-12AX7, 2-12AT7, 6L6 Duet, 5AR4

Princeton Reverb II

3-12AX7, 1-12AT7, 6V6 Duet

Bandmaster VM Head

2-12AX7, 6L6 Duet

Deluxe VM Combo

2-12AX7, 6L6 DuetTwin Custom 15

4-12AX7, 2-12AT7, 6L6 Quartet

TBP-1

2-12AX7

GibsonAtlas Medalist

2-6EU7, 1-6C4, 6L6 Duet

Atlas IV

2-6EU7, 1-6C4, 6L6 Duet

BA-15RV

3-6EU7, 1-12AU7, 6V6 Duet, 5y3

Bass 30

2-6EU7, 7591 Duet

Bass 50

2-6EU7, EL34 Duet

BR-3

2-7B4, 1-W5, 6V6 Duet, 5Y3

BR-6

1-6SL7, 1-6SN7, 6V6 Duet, 5Y3

Groove Tubes • Tube Reference Guide

19

Gibson (Continued)

20

BR-6F

1-6SJ7, 1-6SN7, 6V6 Duet, 5Y3

BR-9

1-6SN7, 6V6 Duet, 5Y3

Duo-Medalist

3-6EU7, 1-12AX7, 2-12AU7, 7591 Duet

Falcon3-6EU7, 1-12AX7, 2-12AU7, 7591 Duet

Falcon4-12AX7, EL84 Duet

GA-Custom

3-6SJ7, 2-6SQ7, 2-05, 6L6 Duet, 5U4

GAART-1

1-12AX7, 1-6BM8, 5Y3

GA-IRVT

1-7100, 1-6EU7, 1-6BM8, 5Y3

GA2-RVT

4-6EU7, 1-12AU7, 6V6 Duet, 5Y3

GA-4RE

2-6EU7, 1-12AU7

GA-5

1-12AX7, 6V6, 5Y3

GA-5T

2-6EU7, 1-6AQ7, 6X4

GA-6

1-12AY7, 1-6SL7, 6V6 Duet, 5Y3

GA-6 newer

2-12AX7, 6V6 Duet, 5Y3

GA-8

1-6EU7, 1-6C4, 1-6BQ5, 6CA4

GA-8T

1-12AX7, 2-6BM8, 5Y3

GA-9

1-6SJ7, 6V6 Duet, 5Y3

GA-14

2-12AX7, 6V6 Duet, 5Y3

GA-15

1-12AX7, 1-6SL7, 6L6 Duet, 5Y3

GA-15RVT

2-6EU7, 1-12AU7, 1-EL84 Duet

GA-16T

1-12AX7, 6V6 Duet, 5Y3

GA-17RVT

2-6EU7, 1-12AX7, 2-6AQ5, 6CA4

CA-18T

2-6EU7, 1-6CA4, EL84 Duet

GA-19RVT

3-6EU7, 1-7199, 6V6 Duet, 5Y3

GA-20

1-6SL7, 2-6SJ7, 6V6 Duet, 5Y3

GA-20T

1-12AY7, 1-12AX7, 1-5879, 1-6SQ7, 6V6 Duet, 5Y3

GA-20RVT

3-6EU7, 2-12AU7, EL84 Duet, 5Y3

GA-25

1-6SJ7, 2-05, 6V6 Duet, 5Y3

GA-25RVT

4-6EU7, 1-12AU7, 6V6 Duet, 5Y3

GA-30

1-6SC7, 2-6SJ7, 6V6 Duet, 5Y3

GA-30 Invader

2-12AX7, 1-12AU7, 6V6 Duet, 5Y3

GA-30RV Invader

3-6EU7, 1-12AU7, 6V6 Duet, 5Y3

GA-30RVT Invader

4-6EU7, 2-12AU7, 7591 Duet, OA2

GA-30RVT Lancer

1-12AX7, 2-6EU7, 2-12AU7, 7591 Duet, OA2

GA-40 early

1-6SN7, 3-6SJ7, 6V6, 6V6 Duet, 5AR4

GA-40 Les Paul2-5879, 1-12AX7, 1-6SQ7, 6V6 Duet, 5Y3

GA-40T

3-6EU7, 1-12AU7, 7591 Duet, 5AR4

GA-45RVT Saturn

4-6EU7, 1-12AU7, 1-6CG7, 6L6 Duet, OA2

GA-46 Accordion Pre

3-12AX7, 2-5879

GA-46 Accordion Amp

1-6SN7, 6V6, 6550 Duet, 5AR4

GA-50

2-6SJ7, 2-W5, 6L6 Duet, 5AR4

GA-50T

3-6Si7, 1-6SN7, 1-6SL7, 6L6 Duet, 5V4

GA-55

2-12AY7, 1-6SC7, 6L6 Duet, 5V4

GA-55RVT Ranger

4-6EU7, 1-12AU7, 1-6CG7, 6L6 Duet, OA2

GA-60

2-6EU7, 7591 Duet, 5AR4

Groove Tubes • Tube Reference Guide

Gibson (Continued)
GA-70 Country-Western

1-12AX7, 1-12AY7, 1-12AU7, 6L6 Duet, 5V4

GA-75 Recording

2-6EU7, 1-6CG7, 6L6 Duet, 6C4

GA-75W

1-12AX7, 2-6SC7, 1-6W7, 6L6 Duet, 5V4

Super Medalist

2-6EU7, 2-12AU7, 1-6AU7, 1-12AX7, 7591 DuetThor Bass Amp

2-6EU7, 1-6CA7 Duet

Titan 1, 11 and 111

3-6EU7, 2-12AU7, 1-OA2, 1-6FQ7, 6L6 Quartet

Titan Medalist

3-6EU7, 2-12AU7, 1-OA2, 1-6FQ7, 6L6 Quartet

Hawk

3-12AX7, 1-EL84 DuetLes Paul TV or JR

1-6SJ7, 6V6, 5Y3

Skylark T

1-6X4, 2-12AX7, 1-EL84

Skylark

1-12AX7, 1-6X4, 1-EL84

SG Systems 100

1-12AX7, 1-8417 DuetSG Systems 200

1-7015, 1-8417 Sextet

EH-1503-6SQ7, 1-6N7, 1-5U4, 6L6 Duet

Echoplex

2-6EU7, 1-6C4

XFL-3

2-12AX7, 1-12AT7

XFL-60/60

4-12AX7, 2-12AT7, 6L6 Duet r EL34 Duet

Greer
THUNDERBOLT 30

2-12AX7, EL34 Duet (some with 6L6 Duet), 5AR4

CAM 18

2-12AX7, 6V6 Duet (some with 6L6 Duet), 5AR4

Special 20

2-12AX7 (some w/5879 in V1), 6V6 Duet (some w/5881 Duet), 5AR4

Rev 50

3-12AX7, EL34 Duet, 5AR4

NTG 15

2-12AX7, EL84 Duet, 5Y3

MARAUDER 35

2-12AX7, 6L6 Duet, 5AR4

UNDERDOG 15

2-12AX7, 6V6 Duet, 5Y3

Groove Tubes
STP-B

1-12AX7

NOTE: The following Groove Tubes Electronics products accept a wide variety of tubes without modifying the amp. The owner cancustomize his/her own amp and change the sound characteristics as desired.

TRIO

5-12AX7

STP-G

4-12AX7, 6V6 Duet or EL34 Duet

STA-1 Preamp

6-12AX7, 2 output Duets - EL34, 6L6, 6550, KT88

D-75 Dual amp

4-12AX7, 2 output Duets - 6L6, EL34, 6550, KT88

D-120 Dual amp

4-12AX7, 2 output Duets - 6L6, EL34, 6550, KT88

D-75 Studio

4-12AX7, 2-Duets - 6550, KT88 or KT90

Soul-o 75

5-12AX7, Duet - 6L6, EL34, 6550, KT88 or KT90

Soul-o 150

5-12AX7, Quartet - 6L6, EL34, 6550, KT88 or KT90

Soul-o 45

3-12AX7, 1-12AU7, 1-12AT7, Duet - 6L6, EL34, 6550, KT88

Soul-o Single

2-12AX7 or any combination of 12AX7, 12AT7, 12AU7, 12AY7,Single output tube - 6V6, 6L6, EL34, 6550, KT88, EL84 in 928 adaptor

Soul-o 30

5-12AX7, 6L6 Duet

Soul-o 50

5-12AX7, 6L6 or EL34 Duet

Hammond
B-3 Preamp

1-12BH7, 2-6AU6, 2-6C4, 1-6X4, 1-12AX7, 1-12AU7

Groove Tubes • Tube Reference Guide

21

Hiwatt
30W

4-12AX7, EL84 Quartet

30WR

4-12AX7, EL84 Quartet

50

4-12AX7, EL34 Duet

100

4-12AX7, EL34 Quartet

200

4-12AX7, EL34 Sextet

400

5-12AX7, KT-88 (6550) Sextet

C520

4-12AX7, EL84 Duet

D50L

4-12AX7, EL34 Duet

D50LR

4-12AX7, EL34 Duet

D50LRC

4-12AX7, EL34 Duet

D100L

4-12AX7, EL34 Quartet

D100LR

4-12AX7, EL34 Quartet

PRE-1

3-12AX7PW50

4-12AX7, EL34 Quartet

S50

4-12AX7, EL34 Duet

S50LC

4-12AX7, EL34 Duet

S100L

4-12AX7, EL34 Quartet

Jim Kelly
Single Channel

2-12AX7, 6V6 Quartet

Single Channel Reverb

3-12AX7, 1-12AT7, 6V6 Quartet

Foot-Actvtd Channel-Switching

3-12AX7, 1-12AT7, 6V6 Quartet

Kasha
KA-150

3-12AX7, 6550 Quartet

Rockmod-1

4-12AX7

Rockmod-2

5-12AX7

Rockmod-3

5-12AX7

KMD
GV-60

Transistor preamp with 6L6 Duet

GV-100Transistor preamp with 6L6 Quartet

GV-100S

Transistor preamp with 6L6 Quartet

Korg
SV1

1 X 12AX7

TRITON EXTREME

1 X 12AU7

EMX1

2 X 12AX7

ESX1

2 X 12AX7

TP2

2 X 12AU7

TPB2

2 X 12AU7Krank
KRANKENSTEIN 50

3 X 12AX7, 2 X 6L6

REV. STANDARD AND PRO

3 X 12AX7, 2 X 6L6

REV. SST

3 X 12AX7KRANKENSTEIN +4 X 12AX7, 4 X 6550

REV. +

4 X 12AX7, 4 X 6550

Groove Tubes • Tube Reference Guide

LaneyA50

4-12AX7, EL34 Duet

A100

4-12AX7, EL34 Quartet

PT-50

4-12AX7, EL34 Duet

PT-100

4-12AX7, EL34 Quartet

PT-30

3-12AX7, 6V6 Duet

PT-50 MV

3-12AX7, EL34 Duet

PT-50 AOR

4-12AX7, EL34 Duet

PT-100 MV

3-12AX7, EL34 Quartet

PT-100 AOR

4-12AX7, EL34 Quartet

ST-30

4-12AX7, 6V6 Duet

LegendG-50 and G100

3-12AX7 with transistor amp

LeslieModel 147

1-12AU7, 1-OC3, 6550 Duet

Model 122

2-12AU7, 1-OC3, 6550 Duet

Marantz
Model 7

6-12AX7

Model 82-6CG7, 2-6BH6, EL34 Quartet

Model 91-6CG7, 2-ECC88, 2-EL34 Quartets

Markley
40 SR

1-12AX7 with transistor amp

80 SR

1-12AX7 with transistor amp

40 DR

1-12AX7 with transistor amp

80 DR

1-12AX7 with transistor amp

150 DR

1-12AX7 with transistor amp

T 60-watt

3-12AX7, 6L6 Duet

T 120-watt

3-12AX7, 6L6 Quartet

CD-40

3-12AX7, 6L6 Duet

CD-60

3-12AX7, 6L6 Duet

CD-120

3-12AX7, 6L6 Quartet

CD-212

4-12AX7, 6L6 Quartet

RM100 MT

2-12AX7, 6L6 Quartet

Preamp DR

1-12AX7

Preamp DB

1-12AX7

MarshallJVM 410 H & C

5 X 12AX7, 4 X EL34

JVM 210 H & C

5 X 12AX7, 4 X EL34

JVM 205 H, C

5 X 12AX7, 2 X EL34

JVM 215C

5 X 12AX7, 2 X EL342466

4 X 12AX7, 4 X KT66

226 & 2266C

4 X 12AX7, 2 X KT66

1923 & 1923 C

4 X 12AX7, 2 X EL34

DSL 100, DSL 100MLB

4 X 12AX7, 4 X EL34

DSL 50

4 X 12AX7, 2 X EL34

Groove Tubes • Tube Reference Guide

23

Marshall (Continued)
DSL 401

4 X 12AX7, 4 X EL84

DSL 201

4 X 12AX7, 2 X EL84

TSL 100

4 X 12AX7, 4 X EL34

TSL 122

4 X 12AX7, 4 X EL34

TSL 60

4 X 12AX7, 2 X EL34

TSL 601

4 X 12AX7, 2 X EL34

TSL 602

4 X 12AX7, 2 X EL34

1959 SLP, SLPX

3 X 12AX7, 4 X EL34

1959 HW3 X 12AX7, 4 X EL34

1959 RR

3 X 12AX7, 4 X EL34

1987 X, XL

3 X 12AX7, 2 X EL34

2245 (JTM 45)

3 X 12AX7, 2 X 6L6, 1 X 5AR4

JTM45100 (40TH ANNIVERSARY) 3 X 12AX7, 4 X KT66
JTM45OS3 X 12AX7, 2 X KT66, 1 X 5AR4

1962

3 X 12AX7, 2 X 6L6, 1 X 5AR4

SUPER 100 JH

3 X 12AX7, 4 X KT66

2203 X

3 X 12AX7, 4 X EL34

2203 KK

3 X 12AX7, 4 X KT88

MF 3502 X 12AX7

CLASS 5

2 X 12AX7, 1 X EL84

MA100H, C

3 X 12AX7, 4 X EL34

MA50 H, C

3 X 12AX7, 2 X EL34

MHZ40C

3 X 12AX7, 2 X EL34

MHZ15C

3 X 12AX7, 2 X 6V6

AVT SERIES (HEADS & COMBOS) 1 X 12AX7
MB 60

1 X 12AX7

MB150

1 X 12AX7

MB42101 X 12AX7

MB44101 X 12AX7MB450H1 X 12AX7

VBA 400

3 X 12AX7, 1 X 12AU7, 8 X 6550

EL34100100

2 X 12AX7, 2 X 12AT7, 8 X EL34

EL345050

2 X 12AX7, 2 X 12AT7, 4 X EL34

EL842020

2 X 12AX7, 1 X 12AU7, 4 X EL84

JMP1

2 X 12AX7

1992LEM

3 X 12AX7, 4 X EL34

McIntosh24

C-22

6-12AX7

MC-30

1-12AX7, 1-12AU7, 1-12BH7, 6L6 Duet, 5U4

MC-40

1-12AX7, 1-12AU7, 1-12BH7, 6L6 Duet, 5AR4

MC-60

1-12AX7, 1-12AU7, 1-12BH7, 6550 Duet

MC-75

1-12AX7, 1-12AU7, 1-12BH7, 6550 Duet

MC-240

3-12AX7, 2-12AU7, 2-12BH7, 6L6 Duet, 2-5U4

MC-260

3-12AX7, 2-12AU7, 2-12BH7, 2-6550 Duets, 2-5AR4

MC-275

3-12AX7, 2-12AU7, 2-2-12BH7, 2-6550 Duets

MC-3500

2-12AX7, 2-6DJ8, 1-6CG7, 1-6BL7, 6L6 Octet

Groove Tubes • Tube Reference Guide

Mesa/Boogie
Studio 22

5-12AX7, EL84 Duet

Studio Preamp

4-12AX7, 1-12AT7

Quartet Preamp

8-12AX7

MK-1 60 - early

2-12AX7, 1-12AT7, 6L6 Duet

MK-1 60 Reverb - early

4-12AX7, 1-12AT7, 6L6 Duet

MK-1 60 EQ - early

2-12AX7, 1-12AT7, 6L6 Duet

MK-I 60 Reverb/EQ - early

3-12AX7, 2-12AT7, 6L6 Duet

MK-I 10t - early

2-12AX7, 1-12AT7, 6L6 Quartet

MK-I 100 Reverb - early

2-12AX7, 2-12AT7, 6L6 Quartet

MK-I 100 EQ - early

2-12AX7, 1-12AT7, 6L6 Quartet

MK-I 100 Reverb/EQ - early

3-12AX7, 2-12AT7, 6L6 Quartet

MK-I 100 Reverb - reissue

4-12AX7, 1-12AT7, 6L6 Quartet

MK-II 60

4-12AX7, 6L6 Quartet

MK-II 60 Reverb

4-12AX7, 1-12AT7, 6L6 Duet

MK-II 100

4-12AX7, 6L6 Quartet

MK-II 100 Reverb

4-12AX7, 1-12AT7, 6L6 Quartet

MK-IIB 60

4-12AX7, 6L6 Duet

MK-IIB 60 Reverb

5-12AX7, 6L6 Duet

MK-IIB 100

4-12AX7, 6L6 Quartet

MK-IIB 100 Reverb

5-12AX7, 6L6 Quartet

MK-IIB 300

2-12AX7, 2-12AT7, 6L6 Sextet

MK-IIB 300 Reverb

2-12AX7, 3-12AT7, 1-6FQ7, 6L6 Sextet

MK-IIB 300 Cascode 60

4-12AX7, 6L6 Duet

MK-IIB 300 Cascode 60 Reverb

4-12AX7, 1-12AT7, 6L6 Duet

MK-IIB Cascode 100

4-12AX7, 6L6 Duet

MK-IIB Cascode 100 Reverb

4-12AX7, 1-12AT7, 6L6 Quartet

MMIC 60

4-12AX7, 6L6 Duet

MMIC 60 Reverb

5-12AX7, 6L6 Duet

MK-IIC 100

4-12AX7, 6L6 Quartet

MMIC 100 Reverb

5-12AX7, 6L6 Quartet

MMIC Simul 75 Reverb

5-12AX7, 1-EL34 Duet, 6L6 Duet

MMIC 300

3-12AX7, 1-12AT7, 1-6FQ7, 6L6 Sextet

MMIC 300 Reverb

4-12AX7, 1-12AT7, 1-6FQ7, 6L6 Sextet

MK-II 300 Simul Reverb

4-12AX7, 1-12AT7, 1-6FQ7, 1-EL34 Duet, 6L6 Quartet

MK-III 60

4-12AX7, 6L6 Duet

MK-III 60 Reverb

5-12AX7, 6L6 Quartet

MK-III 100 Reverb

5-12AX7, 6L6 Quartet

MK-III Simul 75 Reverb

5-12AX7, 6L6 Duet, EL34 Duet

MK-IV

4-12AX7, 1-12AT7, 6L6 Quartet

Satellite 60

2-12AX7, 6L6 Duet

Simul-Satellite

2-12AX7, 6L6 Quartet

Simul-Class 290 Stereo

3-12AX7, 2-6L6 Quartets

Simul-Class 295

4-12AX7, 6L6 Quartet and EL34 Quartet

Simul-Class 395 Stereo

4-12AX7, 2-6L6 Quartets

Strategy 400

4-12AX7, 6L6 Octet and EL34 Quartet

Strategy 500 Stereo

4-12AX7, 1-6550 Quartet and 2-6L6 Quartets

SOB 60 - early

2-12AX7, 1-12AT7, 6L6 DuetGroove Tubes • Tube Reference Guide

25

Mesa/Boogie (Continued)
SOB 60

3-12AX7, 6L6 DuetSOB 60 Reverb

4-12AX7, 6L6 Duet

SOB 100 Reverb

4-12AX7, 6L6 Quartet

D-180 - early

2-12AX7, 2-12AT7, 6L6 Sextet

D-180

3-12AX7, 1-12AT7, 6L6 Sextet

Bass-400

4-12AX7, 6L6 Sextet

Bass-400 Plus

4-12AX7, 2-6L6 Sextet

50150 Power Amp

2-12AX7, 6L6 Quartet

TriAxis Preamp

5-12AX7

Dual Rectifier Solo Head

5-12AX7, 2-5U4 6L6/EL34 Quartet

Triple Rectifier Solo Head

5-12AX7, 3-5U4 6L6/EL34 Sextet

Dual Rectifier Trem-O-Verb

6-12AX7, 2-5U4 6L6/EL34 Quartet

Dual Caliber 50

6-12AX7, 6L6 Duet

Dual Caliber 30

6-12AX7, 1-6BQS/EL34 Quartet

NOTE: MK-11C and early MK-III Simul-Class models were shipped with a Quartet of 6L6s. MESA/Boogie recommends that these
Simul-Class units be retrofitted with two 6L6s and two EL34s. The EL34s should be placed in the outer-left and outer-right tube sockets, with the 6L6s in the middle. No mods required when making this change. Early Strategy 400 amps used twelve 6L6s. Some Bass
400s were shipped with a sextet of 6550s. 6550s and 6L6s are compatible with the early Bass 400s - no modifications are required.

20/20

3 - 12AX7/12AX7/12AX7 2 Duets EL84

Metalhead
Elan MK 11

5-12AX7

Elan MK III

5-12AX7

Mitchell
Pro 100

4-12AX7, 6L6 Quartet

Pro 100 EQ/Reverb

5-12AX7, 6L6 Quartet

Pro 100 EQ/Reverb

3-12AX7, 1-12DW7, 6L6 Quartet

Deluxe

4-12AX7, 6L6 Duet

Mojave Amps
Coyote

3-12AX7, GZ34/5AR4, EL84 DuetSidewinder

3-12AX7, GZ34/5AR4, EL84 Quartet

Plexi 45

3-12AX7, GZ34/5AR4, 6L6 / KT666 Duet

Scorpion 50 watt

4-12AX7, EL34 Duet

Peacemaker 100 watt

4-12AX7, EL34 Quartet

Musicman

26

RD 50

1-127, 6L6 DuetRD 65

6L6 Duet (transistor preamp)

RD 100

6L6 Duet (transistor preamp)

RD 112

6L6 Duet (transistor preamp)

RD 120

6L6 Duet (transistor preamp)

RP 65

6L6 Duet (transistor preamp)

RP 100

6L6 Duet (transistor preamp)

RP 115

6L6 Duet (transistor preamp)

Seventy-Five

1-12AX7, 6CA7 Duet

One-Thirty

1-12AX7, 6CA7 Quartet

75

6L6 Duet (transistor preamp)

Groove Tubes • Tube Reference Guide

Musicman (Continued)
150

6L6 Quartet (transistor preamp)

NOTE: Early model used 6CA7, check amp.

MusitechStereo 240

5-12AX7, 1-12AT7, 1-5AR4, 6L6 Duet, EL34 Duet

Stereo 215

5-12AX7, 1-12AT7, 6V6 Duet, EL84 Duet

Nomad
50-watt Channel-switching

4-12AX7, 1-12AT7, EL34 Duet

100-watt Channel-switching

4-12AX7, 1-12AT7, EL34 Quartet

50 Reverb

6-12AX7, 1-12AT7, EL34 Duet

100 Reverb

6-12AX7, 1-12AT7, EL34 Quartet

Orange40TH ANNIVERSARY

2 X ECC83, 2 X EL84

ROCKER 30 & 30 COMBO

3 X ECC83, 2 X EL84

ROCKER VERB 50

4 X ECC83 2 X 12AT7, 4 X 6V6

ROCKER VERB 50 COMBO

3 X ECC83, 2 X 12AT7, 4 X 6V6

ROCKER 100

4 X ECC83, 2 X 12AT7, 4 X EL34

THUNDERVERB 50

4 X ECC83, 2 X 12AT7, 2 X EL34?????

THUNDERVERB 200

4 X ECC83, 2 X 12AT7, 2 X 6550 / KT88

AD5

1 X ECC83, 1 X EL84

AD30 HTC & TC

4 X ECC83, 2 X EL84, 1 X 5AR4

DUAL TERROR

4 X ECC83, 4 X EL84

TINY TERROR COMBO & HEAD

3 X ECC83, 2 X EL84

TERROR BASE 500

2 X ECC83

AD 200B MKIII

2 X ECC83, 1 X 12AT7, 4 X 6550 / KT88

AD 50 H2 X ECC83, 2 X EL34

RETRO 50

2 X ECC83, 2 X EL34

PeaveyClassic 60

2-12AX7, 6L6 DuetClassic 60/60

3-12AX7, 2-6L6 DuetClassic 120

3-12AX7, 6L6 Quartet

Classic 120/120

4-12AX7, 2-6L6 Quartet

Classic and VTX

6L6 Duet (transistor preamp)SDuce

6L6 Quartet (transistor preamp)

Heritage

6L6 Quartet (transistor preamp)

Mace

6L6 Sextet (transistor preamp)MX

6L6 Quartet (transistor preamp)

Roadmaster - early

6550 Quartet (transistor preamp)

Roadmaster - later

4-12AX7, 2-12AT7, 6L6 Sextet

Rockmaster3-12AX7, 6L6 Quartet

Rockmaster - later

3-12AX7, 6L6 Quartet

Encore 65

3-12AX7, 1-12AT7, 6L6 DuetTG RAXX

4-12AX7TB RAXX

4-12AX7

Triumph 60

4-12AX7, 1-12AT7, 6L6 DuetGroove Tubes • Tube Reference Guide

27

Peavey (Continued)
Triumph 120

4-12AX7, 1-12AT7, 6L6 Quartet

Butcher

3-12AX7, 6L6 Quartet

Vintage - early

2-6C10, 6L6 Quartet

Vintage - later

6L6 Quartet (Transistor Preamp)

VTA 400

3-12AX7, 1-6AN8, 6550 Quartet

VTA 800

3-12AX7, 1-6AN8, 6550 Octet

VTB 300

2-12AX7, 1-6AN8, 6550 Quartet

VTG 300

2-12AX7, 1-6AN8, 6550 Quartet

Classic 30

3-12AX7, EL84 Quartet

Bravo

3-12AX7, EL84 Quartet

XXX

3-12AX7, 6L6 Quartet (Option of EL-34 Quartet)

5150

5-12AX7, 6L6 Quartet (NOTE: V4 is the phase inverter in this amp - not V5)

Polytone
Fusion4-12AX7, 1-12AU7, 1-12AT7, 6L6 Quartet

Randall
RGTES

4-12AX7, 1-12AT7, 6L6 Quartet

RGT100

4-12AX7, 1-12AT7, 6L6 Quartet

RGT100HT

4-12AX7, 1-12AT7, 6L6 Quartet

RiveraTBR-1 - Rudolf Schenker

8-12AX7, 2-KT77 Duet

TBR-1 - Ted Nugent

6-12AX7, 1-12AT7, 2-KT77 Duet

TBR-1

7-12AX7, 2-EW4 Duet

TBR-1M

7-12AX7, 2-EW4 Duet

TBR-ISL

7-12AX7, 2-EW4 Duet

TBR-2

7-12AX7, 2-6550 Quartets

TBR-2M

7-12AX7, 2-6550 Quartets

TBR-2SL

7-12AX7, 2-6550 Quartets

TBR-2 - John Sykes

7-12AX7, 2-6550 Quartets

TBR-2 - Jerry Garcia

5-12AX7, 2-12AU7, 2-6550 Quartets

TBR-2B

5-12AX7, 2-12AU7, 2-6550 Quartets

TBR-3 Hammer 120

4-12AX7, 2-6550 Quartets

TBR-4 Preamp

6-12AX7, EL84 Duet

TBR-5 Hammer 320

4-12AX7, 2-6550 Duets

TBR-6 Preamp

4-12AX7

TBR-7 Power Amp

4-12AX7, 2-5881 Duets

M60 Combo

5-12AX7, 2-EL34 Duets

M100 Combo

5-12AX7, EL34 Quartet

M100 Combo - Jerry Garcia

5-12AX7, 6550 Quartet

S120 Combo

6-12AX7, 2-EL34 Duets

Roland28

Bolt 30

1-12AT7, 7391 Duet

Bolt 60

1-12AT7, 6L6 Duet

Bolt 100

1-12AT7, 6L6 Quartet

Groove Tubes • Tube Reference Guide

Seymour Duncan
60-watt Combo/head

3-12AX7, 2-12AU7, EL34 Duet60-watt Convertible

3-12AX7, 2-12AU7, EL34 Duet

100-watt Combo/head

6-12AX7, 2-12AU7, EL34 Quartet ,5U4

100-watt Convertible

6-12AX7, 2-12AU7, EL34 Quartet ,5U4

8440

3-12AX7, EL34 Duet

KTG-1

2-12AX7, 1-12AU7

KTG-2100

2-12AX7, 2-12AU7, KT88 Quartet

Silvertone
50-watt Reverb

4-12AX7, 2-6CG7, 6L6 Duet

100-watt Reverb

4-12AX7, 2-6CG7, 6L6 Quartet

Sound City
Bass 150

2-12AX7, 1-12AT7, 6550 Quartet

Concord

3-12AX7, 2-12AT7, EL34 Quartet

GT-50

1-12AX7, 1-12AT7, EL34 Quartet

PA-400

3-12AX7, 2-12AT7, EL34 Quartet

PA-200

3-12AX7, 2-12AT7, 6550 Quartet

MK-IV 120

4-12AX7, 1-12AU7, EL34 Sextet

LB-50 Plus

3-12AX7, 1-12AT7, EL34 Duet

LB-200 Plus

4-12AX7, 1-12AT7, 6550 Quartet

50 watt

3-12AX7, EL24 Duet

100 watt

3-12AX7, 1-12AT7, EL34 Quartet

200 watt

3-12AX7, 1-12AT7, 6550 Quartet

Spectra30 T

3-12AX7, 6V6 Duet

60 T

3-12AX7, 6V6 Duet

120 T

3-12AX7, 6L6 Quartet

2-12 T

4-12AX7, 6L6 Quartet

Sundown
Formula 50

4-12AX7, 6L6 Duet

Rebel 50

3-12AX7, 6L6 DuetArtist Combo

5-12AX7, 6L6 Quartet

Rebel 100

3-12AX7, 6L6 Quartet

Artist 30 Combo

5-12AX7, 6L6 Duet

SD1012C

5-12AX7, 6550 Duet

SD1000H

5-12AX7, 6550 Duet

Sunn
Coliseum PA

3-12AX7, 1-6AN8, 6550 Quartet ,5AR4

Model A

4-12AX7, 6550 Quartet

Model A212

4-12AX7, 6550 Duet

Model T

4-12AX7, 6550 Quartet

Sceptre1-12AX7, 1-12AU7, 1-6AN8, 6550 Duet

Sentura1-12AX7, 1-12AU7, 1-7199, 6CA7 Duet

Sonic

1-12AX7, 1-12AU7, 1-6AN8, 6550 Duet

Solos I

2-12AX7, 1-12AU7, transistor-powered

Groove Tubes • Tube Reference Guide

29

Sunn (Continued)
Spectrum I

1-12AX7, 1-7199, 6CA7 Duet

Solarus (190L)

1-12AX7, 1-12AU7, 1-6AN8, 6550 Duet

100S

1-12AX7, 1-12AU7, 1-6AN8, 6550 Duet

20OS (190B)

1-12AX7, 1-6AN8, 6550 Duet

1000S

1-12AX7, 1-12AU7, 1-6AN8, 6550 Quartet

120OS (350L)

1-12AX7, 1-12AU7, 1-6AN8, 6550 Quartet

2000S (350B)

1-12AX7, 1-6AN8, 6550 Quartet

NOTE: Later models may use 7199. Earlier models may use 6CA7.

THD
4-10

1-12AY7, 3-12AX7, 6L6 Duet

2-10

1-12AY7, 3-12AX7, 6L6 Duet

V-Front

1-12AY7, 3-12AX7, 6L6 Duet

Tweed Head

1-12AY7, 3-12AX7, 6L6 Duet

4-10 Reverb

1-12AY7, 3-12AX7, 1-12AT7, 6L6 Duet

2-10 Reverb

1-12AY7, 3-12AX7, 1-12AT7, 6L6 Duet

V-Front Reverb

1-12AY7, 3-12AX7, 1-12AT7, 6L6 Duet

Tweed Head Reverb

1-12AY7, 3-12AX7, 1-12AT7, 6L6 Duet50-watt Rack Head

1-12AY7, 4-12AX7, 1-12AT7, 6L6 Duet

100-watt Rack Head

1-12AY7, 4-12AX7, 1-12AT7, 6L6 Duet

NOTE: 12AX7 can be substituted for 12AYs for increase in gain. EL34s, 6CA7s, KT88s and 6550s can be substituted for 6L6s with asimple bias-voltage adjustment.

Thunderfunk
50B

5-12AX7, 1-12AT7, 6550 Duet

100B

5-12AX7, 1-12AT7, 6550 Duet

SOELS

6-12AX7, 2-12AT7, EL34 Duet

100ELS

6-12AX7, 2-12AT7, EL34 Quartet

50LS

6-12AX7, 2-12AT7, 6550 Duet

100LS

6-12AX7, 1-12AT7, 6550 Quartet

Trace Elliot
Hexavalve

3-12AX7, 6550 Sextet

Quatravalve

3-12AX7, 6550 Quartet

Twinvalve

3-12AX7, 6550 Duet

VA350

3-12AX7, 6550 Sextet

VR350

3-12AX7, 6550 Sextet

GP12XV

3-12AX7

Trainwreck
Liverpool 30-watt

3-12AX7, EL34 Quartet

Express 22-watt

3-12AX7, 6V6 Duet, some with EL34 Duet

Liverpool Rocket

3-12AX7, EL84 Quartet, 1-5AR4

Two Rock

30

CUSTOM REVERB V2 50

4-12AX7, 1-12AT7, 2 X 6L6

CUSTOM REVERB V2 100

4-12AX7, 1-12AT7, 4 X 6L6

10TH ANNIVERSARY

4-12AX7, 1-12AT7, 4 X 6L6

Groove Tubes • Tube Reference Guide

Victoria
518-T

1-12AX7, 6V6, 5Y3

20112-T

1-12AY7 or 5751, 1-12AX7, 6V6 Duet, 5Y3

DOUBLE DELUXE

1-12AY7 or 5751, 1-12AX7, 6V6 Quartet, 5Y3 or 5AR435210-T

2-12AY7, 1-12AX7, 6L6 Duet, 5U435115-T

2-12AY7, 1-12AX7, 6L6 Duet, 5U435310-T

2-12AY7, 1-12AX7, 6L6 Duet, 5U445410-T

1-12AY7, 2-12AX7, 6L6 Duet, 5AR480410-T

1-12AY7, 2-12AX7, 6L6 Quartet, 5AR450212-T

1-12AY7, 2-12AX7, 6L6 Duet, 5AR480212-T

3-12AX7, 6L6 Quartet, 5AR4

VICTORI-ETTE

3-12AX7, 2-12AT7, EL84 Duet, 5AR4

VICTORILUX

3-12AX7, 2-12AT7, EL84 Quartet or 6L6 Duet, 5AR4

SOVEREIGN

2-12AX7, 1-12AT7, 1-EF86, 1-6BM8, EL34 or 6L6 Duet, 5AR4

Regal

3-12AX7, 1-12AT7, Use any octal based output tubes or rectifier

Trem de la trem

3-12AX7, 6V6 Duet, 5U4

Voodoo Amps
V-Plex 25

3-12AX7, 6V6 Duet

V-Plex 50

3-12AX7, EL34 Duet

V-Plex 100

3-12AX7, EL34 Quartet

WITCHDOCTOR 10 watt

2-12AX7, 6V6 (single), 5Y3 Rectifier

V-Rock 50

3-12AX7, KT77 Duet

V-Rock 100

3-12AX7, KT77 Quartet

V-Reck 50

3-12AX7, KT77 Duet

V-Reck 100

3-12AX7, KT77 Quartet

Vox
AC15TB & TBX

5 X ECC83, 2 X EL84, 1 X 5Y3

AC15CC1 & AC15CC1X

2 X 12AX7, 2 X EL84

AC15H1TV & AC15HTVH

3 X 12AX7, 1 X EF86, 2 X EL84, 1 X 6CA4

AC30/6TB & AC30/6TBX

5 X 12AX7, 1 X 12AU7, 4 X EL84, 1 X 5AR4

AC30HW AC30HWH

5 X 12AX7, 4 X EL84, 1 X 5AR4

AC30CCH,CC1, CC2, CC2X

3 X 12AX7, 4 X EL84, 1 X 5AR4

AC30H2, HH

3 X 12AX7, 4 X EL84, 1 X EF86, 1 X 5AR4

AC50CPH, CP2

4 X 12AX7, 2 X EL34

AC100CPH

4 X 12AX7, 4 X EL34

VALVTRONIX (MOST MODELS)

1 X 12AX7AD120VTX

2 X 12AX7

TONELAB SERIES1 X 12AX7

COOLTRON SERIES1 X 12AU7

V9159 (CAMBRIDGE 15)

1 X 12AX7

V9130 (CAMBRIDGE 30 REVERB)

1 X 12AX7

V9320(CAMBRIDGE REVERB 30 TWIN)

1 X 12AX7

Groove Tubes • Tube Reference Guide

31

Groove Tubes Process
Acquisition• There are very few tube factories in the world,
GT only sources from the best

• GT only purchases raw tubes that meet specs for
low hum, noise and microphonics• Tubes are shipped to GT global facilities for further
selection and grading

Preamp Tubes• The first step is a burn-in period which lasts
approximately 2 hours• This “settles the tubes”, burns off impurities
and stabilizes components• All processes and computer programs areproprietary to Groove Tubes• “House of Pain” - The Human Element• Tubes placed in amplifiers hooked tohum/volt meters and speakers• Amps run at very high levels of Gain, EQ
and “ping” tested for microphonics• “The Brain / Black Box” - Scientific evaluationof overall tube performance• Tone Generator runs a frequency sweep throughan amplifier into the Black Box• Output from Black Box signal is connected
to GT software and monitor

32

Groove Tubes • Tube Reference Guide

Groove Tubes Process

Pass - GT Tube

Preamp Tubes Continued• GT proprietary program tests for smooth
frequency response, gain and output• Tubes are tested for hum and noise level,
results are displayed in graphic form

• The Kennedy Amplitrex AT-1000 Internal tube function revealed• GT proprietary program further dissects
and measures tube performance• Evaluates plate resistance, current, voltage,
bias draw, transconductance• Provides numeric values for gain andvoltage for each triode• The Hagerman Vacu-Trace and 465-B
Oscilloscope - the final refinement• Tubes are matched for Special Application
Group kits during this phase• Matched Phase Inverter (MPI) tubes
must pass this test

• Provides visual reference matching fortwo sides of triode• The two curves must visually lay on topof each other to be a perfect match

Groove Tubes • Tube Reference Guide

33

Groove Tubes Process
Power Tubes• Groove Tubes features proprietary matching
and grading of power tubes• Tubes must meet the same rigorous
manufacturing specs as preamp tubes• Tubes are placed in a fixture and“Dynamically Energized™”• Only Groove Tubes does “DynamicallyEnergized™” testing of power tubes• Measures cathode filament voltage, plate
voltage, wide variety of other specs• The GT “Mothership” contains all coding
information on unique GT testing• Tubes are graded according to distortionlevels on a scale from 1 to 10• Tubes with similar distortion levels arematched in pairs, quartets and sextets• This creates opportunity to properly bias
amp to maximize tube performance• High graded tubes have more headroom andless distortion - fine scale is 8 - 10

• Medium graded tubes most commonly usedin stock amps - fine scale is 4 - 7• Low graded tubes are softest and quickest
into soft clipping - fine scale is 1 - 3

34

Groove Tubes • Tube Reference Guide

Groove Tubes Display
Look for this display at your local Groove Tubes retailer
to find the tubes that are right for you and your amp!

My amplifiers / tubes reference:(use pencil)
Amplifier One
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
Groove Tubes • Tube Reference Guide35

My amplifiers / tubes reference:(use pencil)
Amplifier Two
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
Amplifier Three
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
36

Groove Tubes • Tube Reference GuideMy amplifiers / tubes reference:(use pencil)
Amplifier Four
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
Amplifier Five
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
Groove Tubes • Tube Reference Guide37

My amplifiers / tubes reference:(use pencil)
Amplifier Six
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
Amplifier Seven
Date tubes changed:______________________________Amp Brand______________________________________
Model_________________________________________
Serial Number___________________________________
Year___________________________________________
Preamp tubes (QTY / TYPE)_________________________
Rectifier tubes(QTY / TYPE)_________________________
Power tubes (QTY / TYPE )__________________________
POWER RATING__________________________________
38

Groove Tubes • Tube Reference Guide

For the latest information on
Groove Tubes, visit our website atwww.groovetubes.com

GROOVE TUBESHEAR THE DIFFERENCE™

© 2012 FMIC.
GROOVE TUBES is a registered trademark of
Fender Musical Instruments Corporation. All rights
reserved. Amplifier and model names contained herein
are the property of their respective owners and areprovided for reference only. Specifications
subject to change without notice.
5550114112®

Groove Tubes • Tube Reference Guide

39

This comprehensive quick guide provides
complete and accurate information on replacement tubes
for hundreds of amplifiers from vintage classics
through the newest and coolest models!
We have also included a section on tube basics,
from troubleshooting to biasing. Also included aredescriptions of the performance characteristics of themost commonly used tube types and the Groove Tube
versions of these tubes.

©2012 Groove Tubes