From: META000 <META@UNB.CA>
Subject: Re: Stupid Marshall/Bassman tricks???
Organization: The University of New Brunswick
Date: Sun, 20 Dec 1992 21:25:25 GMT

In article <1992Dec18.135538.2094@cbfsb.cb.att.com> kew@cbnewsg.cb.att.com (steve.w.askew) writes:
>In article <mike.18@vm1.mcgill.ca>, mike@vm1.mcgill.ca (Mike Woo) writes:
>> In article <1992Dec17.175025.12741@verity.com> dnj@barbeque.verity.com (Dave Johansen) writes:
>>
>> >Last night while purchasing a Marshall Bluesbreaker (JTM 45)
>> >the guy I bought it from had an interesting setup. He had the
>> >cord going into input I, but had a short lead running from the
>> >second lead I into the upper input of II. This appearred to increase
>> >gain/saturation/something which I found pretty cool.. well anyway
>> >I also have a Bassman ('59 reissue) and I was curious if anyone
>> >has tried this trick w/o adverse effect on the Bassman.. I use the
>> >old turn up the second volume (normal) while plugged into the
>> >bright for a slight gain effect.
>>
>> >advTHANKSance
>>
>> >-dnj
>>
>>      I've read about this setup (I think it was in GP Magazine) and it's
>> perfectly fine for a Bassman.  I believe it increases the gain for a
>> crunchier sound.  I wonder if you could put a footswitch between the
>> the two inputs and get a pseudo-channel switching effect?  Anybody out
>> there ever give that a try?  Just curious...
>>
>>                                        Rockin' In The Free World,
>>                                               Mike (Dr.) Woo
>> a
>
> This is a Fender trick that goes back to the 50's. Also remember
> input 1 on the bright has 6db more gain than input 2. You can also
> plug into the Bright 1 only and use the normal volume as a tone
> control. Try this setting with a Strat.
> 1. Cord plugged into Bright 1
> 2. Start with all tone controls (Presence Middle Treble Bass) on 6.
> 3. Bright Volume on 5
> 4. Normal volume on 6.5.
>
> Vary tone to taste. Use the "Normal" volume to fatten tone.
> 
>
> There is also a buch of things you can do with tubes.
> 1. Replace the solid state rectifier with a tube.
> 2. Replace all the 12AX7 with varios combonations
>    of 12AY, 12AT tubes.
> 3. Try the Sovtek 5881 in stead of 6L6's
>
>
>
> Steve
> Doin That Blues ThAng!
>
>.
>.
Actually, the two channels on the Bassman appear to have exactly the
same amount of gain.  What differs between them is that one has a
bypass capacitor hard-wired to the volume control to give a "bright"
channel instead of a a normalchannel with a bright switch, while the
other one has no such capacitor - a normal channel with the bright
switch "off".  The two channels are mixed together at the next stage
before going to the tone controls.

I stumbled onto the patching trick about 20 years ago with another
amp that shall remain nameless, butalso had 4 jacks.  The net effect
is to get a beefier sound since there is some high end loss
resulting from "passive y-ing" of the signal.  If one used an active
splitter box and fed each channel separately, you could get the
overdrive benefits without the high end loss. In the case of the
Bassman, depending on which channel, bright or normal, is treated as
theprimary channel, this high end lossmay be offset to some degree.

A more elegant solution is to use an active splitter (e.g., the Spluffer
from Craig Anderton's EPFM book, available from PAiA, is a decent
littleunit). I built one for a friend using an early 60's Strat and
late 60's Super Reverb, so that he could select one orthe other
channel remotely. The splitter also buffered the highimpedance
output ofthe guitar so thathe got a much crisper single-coil sound
than he had gotten before.  Highly recommended!

Some players do "the Bassman trick" across amps as well.  If memory
serves, before wehad Bob Bradshaws in the world, people like Jimi
and Pete would simply run guitar cords from the extra input jack to
the next Marshall head over, and daisy chain 'em.  A little voice
inside of me,however, says this is not likely the safest, or most
hum free arrangement, although it will do in a pinch.  Bear in mind,
though,that theBassman trick results in two input channels bearing
down on the same mixer while the Jimi trick sends the same inputto
another head.  A quick glance at the schematic indicates that the
signal available at the extra jack is attenuated, relative to the
primary one.  Maybe this is where Steve gets the 6db difference
from. The gain structure of each channel is identical, but the signal
each is receiving, using the patch cord trick, is not.

Mark Hammer