DYNACO PAS-4?
Tony Fafoglia
or had any experience with the new Dynaco Pas4 tube preamp.How does
it compare with the more recent Panor Dynaco pas3 which I had heard
wasn't so great(from a dealer who sold them no less!). Also any opinions
on the Audio Van Alstine Pas3 and 4 preamps?People I talk to have
varied opinions on AVA, either a great bargin or overhyped!(they must have seen the catalogs!).Thanks for the help.
Tony Fafoglia
Mark Thompson
: A non netting friend of mine wanted me to ask if anyone has heard
: or had any experience with the new Dynaco Pas4 tube preamp.How does
: it compare with the more recent Panor Dynaco pas3 which I had heard
no tubes!
I think the best PAS3 mods are the ones that do the least. Just upgrade
the tubes, caps and resistors get rid of the selector and put in a noble
volume control. Don't go overboard with the powersupply. If you try
to build the ultimate preamp in the pas chassis... well why bother.
Mark
Russ Button
> A non netting friend of mine wanted me to ask if anyone has heard
>or had any experience with the new Dynaco Pas4 tube preamp
Dyna PAS4???? Is Dynaco back in business? Where have *I* been?
Are you sure your friend hasn't gotten this confused with the old
Dynaco PAT4, one of the worst sounding transistor pre-amps ever made?
Ahhhh.... Whadda *I* know?
Russ Button
Toma Elton E
Just replace the electrolytics in the power supply and all the circuit
board components, or use a diode pair and even more capacitance (I
don't know if the transformer could handle it though) in the power
supply
When I got my PAS2 it was broken, but all it needed was a new heater
rectifier (see above post).
Anyone out there have the PAS3 faceplate and knobs? The PAS2 is the
same except for a very ugly brown front and knobs, and replacing them
would be nice.
Elton Toma
Steven Abrams
(Russ Button) writes:
> Dyna PAS4???? Is Dynaco back in business? Where have *I* been?
>
I don't know where you've been! The PAS-4 is a new preamp available
from the Audio Advisor, and perhaps other places. And Dynaco also has
their name on a surround-sound processor. And I've heard that there
are ST-70 reissues available.
Now, I don't know if Dynaco the company is back, or if someone has
bought their name. Perhaps someone Out There knows and can enlighten
us. I read something about it, but it has slipped my brain.
~~~Steve
--
/*************************************************
*
*Steven Abrams abr...@cs.columbia.edu
*
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#include <std/dumquote.h>
#include <std/disclaimer.h>
Brock Hannibal
>
>Are you sure your friend hasn't gotten this confused with the old
>Dynaco PAT4, one of the worst sounding transistor pre-amps ever made?
>
>Ahhhh.... Whadda *I* know?
>
I have listened to this little pre-amp through almost every conceivable
type of speaker--Quad electrostatics, JBL L-100's, AR-3a's, Advents, big
Magneplanar's, Infinity Reference series, Dahlquist DQ-10's, RTR towers,
Tannoy something or others. It has also been paired with a multitude of
power amps and phono cartridges. I have compared the Pat4 to Audio Research,
Mark Levinson, Apt-Holman and other "high-end" preamps in "in home" extended
listening and found that yes indeed each pre-amp had its characteristic
sound. In fact though one would be hard pressed to ascribe the terms
"better" or "worse" to these preamps, although with a given set of other
equipment a preference might be formed. Anyway, calling the PAT4 "one of
the worst sounding transistor pre-amps ever made" is the worst form of
ignorant name-calling and the type of thing that makes ordinary people
cringe when confronted with rabid audiophiles.
Brock Hannibal
Design Engineer
Tektronix, Inc.
Mithat Konar
>Tony Fafoglia (fafo...@medicine.wustl.edu) wrote:
>: A non netting friend of mine wanted me to ask if anyone has heard
>: or had any experience with the new Dynaco Pas4 tube preamp.How does
>: it compare with the more recent Panor Dynaco pas3 which I had heard
>I don't know about the Panor PAS3 but i do believe that the PAS4 hand
>no tubes!
>
>I think the best PAS3 mods are the ones that do the least. Just upgrade
>the tubes, caps and resistors get rid of the selector and put in a noble
>volume control. Don't go overboard with the powersupply.
I kinda' disagree on this point. At the very least I think you'll want
to rebuild the heater supply with modern components as the selinium rectifiers
age poorly (causing the heater voltage to drop) and the electrolytic caps could
be larger (for better hum isolation). Use standard silicon rectifier diodes in
place of the seliniums and large value modern electrolytics in place of the
old ones. This change alone can breathe new life into a petering PAS.
___________________________________________________________________________
Mithat Konar, Engineer
Korg Research and Development
1629A South Main Street
Milpitas, CA 95035
USA
___________________________________________________________________________
Dan Normolle
|> >Tony Fafoglia (fafo...@medicine.wustl.edu) wrote:
|> >: A non netting friend of mine wanted me to ask if anyone has heard
|> >: or had any experience with the new Dynaco Pas4 tube preamp.How does
|> >: it compare with the more recent Panor Dynaco pas3 which I had heard
|> >I don't know about the Panor PAS3 but i do believe that the PAS4 hand
|> >no tubes!
|> >
|> >I think the best PAS3 mods are the ones that do the least. Just upgrade
|> >the tubes, caps and resistors get rid of the selector and put in a noble
|> >volume control. Don't go overboard with the powersupply.
|>
(although I'd never do it again, better to just build from scratch), but it
was kind of expensive. One might buy the plans and PC boards from them and
source the parts oneself. My feeling is that one could obtain improvements from:
1) Replacing the input jacks, if they're really ugly.
2) Bypassing the tone controls or at least replacing the pots.
3) Replacing the volume control.
One should be careful in just swapping in a rectifier bridge for the selenium
rectifiers; the voltage drop across the silicon is lower. IF you're going
to fool with the power supply at all, you should probably rebuild it completely.
dpn
--
-----------------------------------------------------------------------------
Daniel Normolle Department of Biostatistics
(313) 936-1013 School of Public Health
(313) 763-2215 (FAX) University of Michigan
mo...@umich.edu Ann Arbor, MI 48109-2029
-----------------------------------------------------------------------------
Mark Thompson
which would be nice to keep. I guess my point is that if you
try to go too radical with modifying a PAS then the question becomes; why.
Here's one scenario (be it, extreme?):
Get an old PAS3X. Strip it down, take out the boards transformer switches
and rectifier. Get new boards which have a totally different tube component
and topology. replace the whole back panel so you can put in those Tifiny
jacks. Now replace all the switches and pots with Alps and Shalcross. Ok
now the powersupply. External would be nice, no AC in the chassis. But that
little PAS transformer is sooo wimpy it can't power my regulated power supply.
Replace it too. Wire the thing up with the best wire i can find and im done.
Oh, one more thing. The face plate looks so funny with all those extra holes
in it. Maybe i'll get a new one made up.
Now you might have a wonderful sounding preamp, but it ain't no pass. The
thing you have created could have just as well been built the thing in a bud
box.
My point is that PAS mods should be improvements to the PAS basic design
not a reimplementation. So many try to make it into an SP6 or something
when it really doesn't have even the basic requirements for such large project.
Mark
Frank Geick - INGRES/ADVISOR x3558
: In article <2pj26b$q...@introl.introl.com> Russ....@Eng.Sun.COM writes:
: >
: >Are you sure your friend hasn't gotten this confused with the old
: >Dynaco PAT4, one of the worst sounding transistor pre-amps ever made?
: >
: >Ahhhh.... Whadda *I* know?
: .................................... Anyway, calling the PAT4 "one of
: the worst sounding transistor pre-amps ever made" is the worst form of
: ignorant name-calling and the type of thing that makes ordinary people
: cringe when confronted with rabid audiophiles.
Here's your chance to be a *definitive voice* in this debate:
For sale: Dynaco PAT-4 (unmodified) $25 + shipping from San Francisco.
While I don't use it anymore it does have some nice features (stereo
blend for headphones, etc).
BTW:
On the whole, the company produced very cheap but musical components in
the 60's and 70's. I think their design philosophy and engineering
approach (simple designs, intelligent parts selection, listening) are
the same basics used by good designers today. The little solid state
Dynaco amp I bought with the PAT-4 (the 40W/channel unit), I still
listen to frequently.
I use it with a $50 DIY passive pre-amp against a $600 mass market
integrated amp in AB comparisons to show people what good sound is
about.
Frank Geick | fr...@Ingres.COM
| The ASK Group /\
| 1080 Marina Village Parkway, Alameda CA 94501-1095 ///\
| Phone: (510) 748-3558 /////\
--------------------------------------------------------------
Mithat Konar
>What about the tube restifier for the high voltage supply? Should I
>Just replace the electrolytics in the power supply and all the circuit
>board components, or use a diode pair and even more capacitance (I
>don't know if the transformer could handle it though) in the power
>supply
>
DO NOT replace the tube rectifier with a pair of diodes as the voltage drop
across the tube rectifier elements is significantly greater than that across
a silicon junction. This means that you could raise the B+ in the supply
to a point where you exceed the ratings of various components (esp. power
supply caps) particularly when you fire the preamp up. (Since the tubes
are not yet conducting, there will be no voltage drop across the series
resistances in the power supply.)