HDTenEightyP/NetNews huggingface dataset:
From: peterca@ento.csiro.au
Subject: Re: Re:leaking cap and dirty pot
Originator: tjk@csd4.csd.uwm.edu
Organization: University of Wisconsin - Milwaukee
Date: Mon, 31 Aug 1992 13:18:06 GMT

>redfreak@ecn.purdue.edu (Thomas Lobonc) writes:
>>Last night I was looking inside my Counterpoint SA-1 (old!) preamp,
>>and I discovered a whiteish crystalline lump growing out of the end
>>of one of my capacitors. The capacitor said: Sprague Atom TVA-1716
>>80uF-450VDC 85(deg)C 7904L USA 5205. The cap is bypassed by two 
>>Rel-Caps (3 in parallel), of .10uF and .001uF. There are two of these
>>cap units in the preamp, located near the power supply regulation and
>>caps on the PCB.
>
>>If anyone could answer my questions, I would appreciate it.

I agree with the answers 99% and have deleted most

>>2. Where can I find a replacement cap?
>
>Most any electronics store, including Radio Shack. Since this 
>component is almost certainly part of the power supply, most any
>equivalent component (i.e. same or higher capacitance, same or
>somewhat higher voltage rating) will do OK.

If the preamp uses valve rectification (I don't know-probably doesn't) then
don't exceed the max. uF specified for the rectifier valve.

>>5. Would it be worth it to replace with a higher grade cap?
>
>If it makes you feel better to know that you have the greatest
>dielectric in the world right there in your power supply filter
>capacitors, do. It won't affect the sound, though.
I'm not so sure.

I would try to find a capacitor which specifies low ESR and low ESL
(equivalent series resistance and inductance) or a high ripple current or
mentions use for switch-mode power supplies.  What you want is for the
power supply to your circuit to have the minimum impedance at all
frequencies.  The designers have done the right thing to bypass the
electrolytic with smaller film caps to reduce the impedance at high
frequencies. Any two caps in parallel will necessarily have a lower
impedance than one of them alone-the more paralleled the better but
diminishing returns will set in eventually.  Some designers use 10, 50 or
100 mid size caps rather than a few large ones for their pre and power
amps.  Some make the mistake of having one enormous cap with no bypasses. 
Some of the British tweakers claim that the addition of a larger cap with
poor high frequency performance can "introduce chronic inertia" but I find
it hard to see how- at worst adding a large cap with high impedance should
do nothing.
Having said all that you may be OK with an ordinary grade cap because of
the bypasses- if nothing else it will work OK till you find a fancy cap(s).
 Why not report back if there is or isn't a difference.  If you're not yet
handy with a soldering iron now is a good time to start.

----------------------------------------
Peter Campbell
C/O Div. Entomology, C.S.I.R.O.
Box 1700 Canberra A.C.T. 2601
Australia  (peterca@ento.csiro.au)
Ph.61-6-2464158 (w), 61-6-2516213 (h)
----------------------------------------


Newsgroups: rec.audio.high-end
From: philg@zurich.ai.mit.edu (Philip Greenspun)
Subject: Re: Driving ELS Directly
Originator: tjk@csd4.csd.uwm.edu
Reply-To: philg@martigny.ai.mit.edu
Organization: M.I.T. Artificial Intelligence Lab.
Date: Wed, 2 Sep 1992 12:52:39 GMT



I believe that in the 1960s, a fair number of direct drive amplifiers
for electrostatic loudspeakers were constructed.  However, it was
apparently the case that better sound, or at least better sound per
dollar, was achievable by using

1) really huge transformers

2) separate transformers for bass and treble -- covering 10 octaves
with one transformer is too tough

3) big conventional amps

You can see this system today in a typical audiophile system.  Sound
Lab electrostatics, for example, employ two bass transformers in
parallel and one treble transformer with total weight of over 50 lbs.
(20+ kg to you).

If you are really interested in this, you should talk to Peter
whats-his-name who designed the Quads and/or Roger West, who designed
the Sound Labs and many of the earlier American electrostats.  They
can probably tell you why direct drive failed.

I remember a conversation with Roger West, who is a Stanford Ph.D. in
EE by the way (an astonishing rarity in American high-end audio), and
he said that the transformers weren't limiting the sound to an extent
that he wanted to design a high voltage amp.  He has designed plenty
of amps in his day (mostly for high power Evans & Sutherland video
projectors) and could probably do it if anyone could.

Anyway, the long and the short of it is that you might save money by
going direct drive, but you wouldn't necessarily open up new sonic
frontiers over today's heavy-duty electrostats.

Philip Greenspun
MIT Department of Electrical Engineering

Newsgroups: rec.audio.high-end
From: bit!grego@ogicse.UUCP (Greg Sanguinetti)
Subject: Re: house grounding (was Power conditioners,...)
Originator: tjk@csd4.csd.uwm.edu
Organization: University of Wisconsin - Milwaukee
Date: Fri, 28 Aug 1992 13:03:17 GMT
	id <m0mNq4i-0004omC@ogicse.cse.ogi.edu>; Thu, 27 Aug 92 13: 04 PDT


In: Article 3391 of rec.audio.high-end:paul@gaitlab1.Uwaterloo.ca (paul j guy)
writes>

>       I would take issue about the ground being connected to
>neutral at the fuse panel. There should be a grounding bus to
>which the ground line is connected. In fact to counteract local
>ground differences, the Canadian Electrical Code recommends that
>local ground busses, or even daisy-chaining be used if that's
>what is needed to reduce ground potential differences. ...

I don't know about Canada (or maybe I'm missing something here?) but
in the US, all the service boxes have the neutral service entry wire
terminated at the ground bus. All neutral wires comming in to the
breakers are tied to the grounding bus right along with the ground wires.
The ground is connected to the neutral at all service boxes in the system.

All standard home circuit installations have daisy chained grounding
schemes, i.e. each run between boxes on a given circuit has the ground
tied to the previous run. You can run a direct ground from a given
outlet to the corresponding service box (star grounding scheme) and
see some improvement due to a cleaner, and shorter, ground. This can get
tricky to do if the service box isn't close by with good access from crawl
space, attic, or basement. Also in the US, electrical inspectors aren't use
to seeing single wires running around in the walls, except low voltage
stuff. They don't like it.

>       The major barrier to hospital grade stuff is the PRICE ! 
>For the hundred or so dollars, you would get better results with
>the more conventional audio tweak products.
>
Hospital grade outlets are not so expensive (about 30 US$) if you only
need a couple. However considering you can get a good quality standard
outlet for less than 1 US$, you wouldn't want to do your whole house
in hospital grade stuff!
-grego
---------------------------------------------------------------------------
Grego Sanguinetti, Bipolar Integrated Technology | Water, water everywhere,
grego@bit.uucp or grego%bit%ogi.cse.edu          | but I'd rather drink
or bit!grego@ogi.cse.edu or ...!ogicse!bit!grego | beer.

Newsgroups: rec.audio.high-end
From: redfreak@ecn.purdue.edu (Thomas Lobonc)
Subject: Capacitors
Originator: tjk@csd4.csd.uwm.edu
Organization: University of Wisconsin - Milwaukee
Date: Thu, 3 Sep 1992 13:04:55 GMT

Thanks to everyone who replied to my post about capacitors for my SA-1
Counterpoint has all parts in stock, but I am looking for better prices.

My question: Would it be better to replace the 80uF with a 75uF or 85uF
if I can't find an 80? Or is it just best to pay more to get the 80?

Thanks,
Tom

Newsgroups: rec.audio.high-end
From: allegra!jj@allegra.att.com (James Johnston)
Subject: Re: 5881 Tube Questions
Originator: tjk@csd4.csd.uwm.edu
Organization: AT&T Bell Laboratories, Murray Hill, NJ
Date: Thu, 27 Aug 1992 13:03:18 GMT

In article <1992Aug25.133619.14830@sei.cmu.edu> rsd@sei.cmu.edu (Richard S D'Ippolito) writes:
>
>|> What sort of tube is [the 5881], and what relationship (if any)
>|> does it bear to the KT-66?  A pointer to a reference is
>|> fine here.  In fact, if such a reference exists, I'd be 
>|> grateful to learn of it.

>It's equivalent to the 6L6, 6L6G, 6L6GB, and 6L6GC, which are beam power tubes

Um, the 6L6, 6L6G, and 6L6GB have  much lower plate dissipation than
the 6L6GC, so I would be very careful in calling them equivelent.

I'm also thinking that the 5881 had a slightly lower Pd than the GC
version, but I don't have my tube manual at hand, it's stored in 
nitrogen in a vault :-)

[Mine aren't. The 5881 is a special 6L6-G, which means that you can sub a
6L6-GC for it, but not the other way around. In general, you can sub a later
model tube in for an earlier model tube, but not the other way around.  -tjk]

Newsgroups: rec.audio.high-end
From: biesel@javelin.sim.es.com (Heiner Biesel)
Subject: Re: Follow up on power conditioners, fuses, and such.
Originator: tjk@csd4.csd.uwm.edu
Organization: Evans & Sutherland Computer Corporation
Date: Wed, 2 Sep 1992 12:51:03 GMT

tcheung@gandalf.rutgers.edu (Tak Cheung) writes:


>(2) Replacing original fuses with much higher amp ratings, such as 
>replacing the 1A fuse in my Classe' preamp with a 8A one improves the
>BASS and DEPTH perception  (I have already replaced the 18 gauge Belden 
>power cord with a 14 gauge Belden cord).  Some fuses can introduce brightness,
>some don't.  I use some Radio Shack fuses I had and sound better than the
>1A slow-blow stock fuse.

Please, if you value your safety, don't follow this advice!

Replacing a fuse with one of a higher rating is foolhardy, and just
invites an electrical fire. It completely defeats the purpose of having
a fuse in the first place. So, if in your search for the perfect
auditory orgasm you should be tempted to mess with the fuses: *DON'T*!

Regards,
       H. Biesel


Newsgroups: rec.audio.high-end
From: rsd@sei.cmu.edu (Richard S D'Ippolito)
Subject: Re: 5881 Tube Questions 
Originator: tjk@csd4.csd.uwm.edu
Organization: The Software Engineering Institute
Date: Wed, 26 Aug 1992 13:06:16 GMT


In article <1992Aug18.202727.14871@husc3.harvard.edu>, rice@scws6.harvard.edu (Ken Rice) writes:

|> What sort of tube is [the 5881], and what relationship (if any)
|> does it bear to the KT-66?  A pointer to a reference is
|> fine here.  In fact, if such a reference exists, I'd be 
|> grateful to learn of it.

It's equivalent to the 6L6, 6L6G, 6L6GB, and 6L6GC, which are beam power tubes
for audio output stages.  My manual states "Power output at all levels has low
third- and higher-order harmonics."  It then lists the following:

CIRCUIT                                    THD      PWR OUTPUT

CLASS A1 AMPLIFIER (Triode connection)      5%         1.4W
PUSH-PULL CLASS A1                          2%        17.5W
PUSH-PULL CLASS AB1                        1.8%       55W
PUSH-PULL CLASS AB2                         2%        47W

In the AB1 circuit, the driving voltage required is 70vp-p, and each tube is
dissipating about 35W.  The output swing is about 525V across 5600 Ohms,
giving a voltage gain of approximately 7.5.

This was real hi-fi in the early 60s.

Rich


   "Please keep in mind that the ultimate goal [of hi-fi] is the
   reproduction of art, and that the invocation of science, while a neat
   parlour trick, is often unnecessary, flawed, and unreasonable."
   --  name mercifully withheld...                            rsd@sei.cmu.edu

Newsgroups: rec.audio.high-end
From: bit!grego@ogicse.UUCP (Greg Sanguinetti)
Subject: Re: Carver preamp/tuner, good or bad?
Originator: tjk@csd4.csd.uwm.edu
Organization: University of Wisconsin - Milwaukee
Date: Fri, 28 Aug 1992 13:03:08 GMT
	id <m0mNq4h-0004okC@ogicse.cse.ogi.edu>; Thu, 27 Aug 92 13: 04 PDT


In Article 3404 of rec.audio.high-end: exulme@exu.ericsson.se
(Michael Englund, T-TDT, x0996) writes:

>I have been looking for a preamp for some time and have noticed that the Carver
>CT17 seems to have the "features" I'm looking for, like:
>
I have owned a CT17 for a few years. I recomend it.
The feature set is excellent. The direct CD path is very clean.
I really like having the pro-logic decoder, tuner, and preamp in the
same unit. I have not experienced any cross talk problems (yet anyway).
The remote/manual servo actuated volume control is a really handy and
nice feature that I use ALOT.

>However, I don't know much about Carver and I'm  worried about all that
>hype in his ads. I'm an EE engineer and I don't understand half of the
>terms used in the ads, like Sonic Holography!! Magnetic Field
>Amplification! Soft Equalization etc. etc.  This really makes me
>worried, did I miss some Eletronic revolution or something, or are the
>use of these terms just an attempt to sell an inferior product.
>
Yup, total garbage marketing hype lingo, you guessed that right. The
engineering and quality are not necessarily at fault, just Bob Carver's
love for major hype.
For instance the Sonic Holography circuit does add some sound stage
expansion. It is room and listening position sensitive. It is NOT worth
paying extra money for but it was already on the box. The Asymetric
Charge Coupled thingamajig circuit on the FM tuner does work rather well
although once again the name is missleading. I have often wondered if
they don't sit around and drink mass quantities of beer and joke about
what stupid name they should attach to the newest circuit to piss off
the audiophiles!

>The cabinets also appear somewhat plastic to me.
>
It is actually pretty solid. Hard to rack mount though.

>The question: is Carver a High end product, or would I be just as well
>off bying that Oshimmurayaki brand at Sears :-) (Note: I have nothing
>against japanese products, have a few good ones myself)

I really do like THIS PARTICULAR Carver product. I think they did a good
job on this one. I have had no problems with it at all. My only complaint
is the wierd user interface. Setting up the pro-logic surround system
requires the use of BOTH front pannel settings AND remote control settings!?
Oh well, sigh.

In summary, I would not hesitate to make the same purchase again. I don't
own any other Carver gear and so far have not seen any that made sense for
me, but this one was just what the doctor ordered.
-grego
---------------------------------------------------------------------------
Grego Sanguinetti, Bipolar Integrated Technology | Water, water everywhere,
grego@bit.uucp or grego%bit%ogi.cse.edu          | but I'd rather drink
or bit!grego@ogi.cse.edu or ...!ogicse!bit!grego | beer.
From: SJKlyne@exua.ex.ac.uk (S.J.Klyne)
Newsgroups: rec.audio.high-end
Subject: Re: Power conditioners, e.g. Tice, PowerWedge,...
Date: 26 Aug 92 13:07:10 GMT
Distribution: rec.audio.high-end
Organization: Computer Unit. - University of Exeter. UK
          id <sg.29958-0@ben.uknet.ac.uk>; Tue, 25 Aug 1992 21: 11:58 +0100
          id <19303-0@eros.uknet.ac.uk>; Tue, 25 Aug 1992 21: 11:53 +0100
Originator: tjk@csd4.csd.uwm.edu


In article <Aug.13.15.09.11.1992.27006@gandalf.rutgers.edu>
tcheung@gandalf.rutgers.edu (Tak Cheung) writes: [...]
   from the street to their abodes) ??  If so, then how about those
   in-line fuses or circuit breakers ??

When I bought my Naim Nait about 5 years ago a tweak i was recommended
Wto try was to replace the internal 1A fuse with a 10A, which after
Winstallation and listening for a few days I did and yes it was
Wbetter...

simon

[The technician in me says if you do this, kiss your warranty good-bye, 
 and if the amp blows up, you can't say I didn't warn you. -tjk]

--
Simon Klyne, Department of Mathematics, University of Exeter, England
email :    SJKlyne@vortex1.exeter.ac.uk
Newsgroups: rec.audio.high-end
From: HENSONSA%WHITMAN.BITNET@CORNELLC.cit.cornell.edu
Subject: Armor All?  Records????  Records????  Sheesh!
Originator: tjk@csd4.csd.uwm.edu
Organization: University of Wisconsin - Milwaukee
Date: Fri, 4 Sep 1992 14:10:23 GMT
   with BSMTP id 0032; Thu, 03 Sep 92 23: 01:45 EDT
 <01GOCZ1626ZC000C37@WHITMAN.BITNET>; Thu, 3 Sep 1992 20: 02 PDT

The Armor All "scandal" came about back in 1989 or 90 (or maybe even 91--short
term memory is the first to go) when Sam Tellig reported on a tweek that he
heard about through various sources--essentially spraying CD's with Armor All
to clean up the surface.  Many readers tried this and many reported audible
improvements in their digital front ends.  However, soon after this, other
reports of problems with Armor All began to surface.  It seemed that after a
few weeks (months), the surface of the treated CD's began to go opaque,
rendering them unplayable.  Some people had treated their entire systems, and
were naturally starting to panic.  It was discovered, much to the relief of ST
and Stereophile, and thousands of gullable audiophiles that washing the CD's
off in warm water and Lemon Joy managed to remove the worst of the Armor All.

Have we learned any valuable lessons on the dangers of semi-permanent tweeks,
boys and girls?

Records and Armor All???

Derek


Newsgroups: rec.audio.high-end
From: hans@smab.se (Hans C Larsson)
Subject: Re: Questions on Digital Cable
Originator: tjk@csd4.csd.uwm.edu
Organization: Saab Missiles AB, RLD-Gbg, Sweden
Date: Thu, 3 Sep 1992 13:08:21 GMT

Andy Sheen <sheen@src.bae.co.uk>           Fri, 28 Aug 92 10: 47:16 BST writes:


>p0p4018@zeus.tamu.edu (PREMTHAMKORN, PRAKIT) writes:

>>> 3)  Can I use ordinary cable as digital cable?  If not, why?

>and electron@waikato.ac.nz replied:

>>I can't see any problem with using coax cable as long a you match the impedance
>>of the input/output impedance of the equipment you are trying to connect
>>together.  If the length of cable is not too long any cable will probably do.
>>(the lenth of a miss-matched cable can "round off" the sharp corners of the
>>digital information and could produce errors.)
>>brucee

[...]

>So in summary, I know what I'd do if I were connecting digital systems together
>- buy a decent quality matched coax cable. If funds didn't permit, then cheap
>coax (perhaps aerial down cable) would be my next choice, but then I'd have
>to attach suitable connectors at either end (if my local friendly hi-end
>store wouldn't do it). I personally wouldn't use "ordinary" cable since the
>side by side construction of most cables seem to increase the impedance seen
>by the drivers considerably. 

>I'd love to try this theory out, but I don't have access to an external
>DAC to try it. Has anyone out there tried specialist coax vs cheap coax vs 
>ordinary cable ? I'd love to know if what I'm saying here holds for practice
>as well as theory :-)  It has for all non-audio electronics that I've been

I have an -87 Sony CDplayer with coaxial digital out connected
to a -90 (1-bit) Sony DATrecorder. Since the DAC in the DAT is superior
to the one in the (otherwise excellent) CD I use the DAT as standalone
DAC when playing CD's (and not playing tapes...).

First I used a standard RCA-type cable (one channel) and it worked
fine. I then tested a 0.5 m length of coaxial RG 59 cable which 
had a characteristic impedance of 75 ohms. With this cable I got
quite frequent loss of signal/sync in the DATmachine ! Something
like once or twice per CD played ! The drop-out was about 1 secs.

I now use a high quality RCA-type video cable (75 ohms)
without problems.

I *know* that the "real" coaxial cable *should/ought* to 
be the best but (my) reality was of a different opinon...

Anyone wants to offer an explanation ?
-- 
------------------------------------------------------------
        Hans C Larsson			Email:	hans@smab.se
	Saab Missiles, Sweden		Motto:	"keep it short"

Newsgroups: rec.audio.high-end
From: kerr@convex.com (Jim Kerr)
Subject: Re: Carver preamp/tuner, good or bad?
Originator: tjk@csd4.csd.uwm.edu
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.
Date: Thu, 27 Aug 1992 13:01:56 GMT


Carver isn't officially a "high-end" product, but they do make good 
equipment. I bought a CT-17 along with a Krell KST amp and Apogee Duettas,
and have been very pleased with it. My main requirement that drove me
away from the true "high-end" gear was my need for a remote control.
Krell makes a remote control pre-amp, but it's *real* expensive (like $6K
if I remember correctly).

The salesman (Audio Insight - I mention this since the original poster
is right down the street from me in Richardson, TX) told me he was skeptical
about the sonics of the CT-17 because of all the features it has in such
a small box, but they tested it out and found it quite good, therefore
they carry it. A "CD direct" path is included. This allows you to bypass
the entire pre-amp except the volume control. The way the manual is written,
it appears to me to be Bob Carver's challenge to you to see if you can
hear a difference, and thus impress you with the clean sound of the 
pre-amp. I couldn't hear a difference myself.

The ACCD tuner feature is a plus - it's much stronger than my previous
tuner. The "sonic holography" is a waste in my book, especially with the
Duettas. The CT-17 manual states that you have to do serious speaker 
placement gymnastics to get the full effect.

The other big plus of the CT-17 is its video capabilities. I have my
laser disk and VCR run through it and the video out driving the TV. This
is real handy with the remote. It makes for a well integrated audio-video
system. The CT-17 also has Dolby Pro-Logic surround sound built in,
which I intend to experiment with in the future.

One negative is that the CT-17 doesn't have balanced input connections,
so I can't use this feature available on my Krell.

If you do decide to buy one, I wouldn't recommend Audio Insight as the
best price. I bought mine there with the system. They sell basically retail,
so I paid around $800 for it. I've seen it mail order for $650. Audio Insight
is a "high end" store, and with that comes retail pricing. You can probably
find it at other stores for less.

Jim Kerr
Convex Computer Corporpation
Richardson, TX
kerr@convex.com

Newsgroups: rec.audio.high-end