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maxhifi maxhifi is offline
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Default Tube amplifier poll

I'd like to take a simple poll. I don't really want to make it into a debate
about the merits of various configurations, I'm just curious about what's in
use. What is the configuration of the amplifier you most commonly listen to?
I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical



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Peter Wieck Peter Wieck is offline
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Default Tube amplifier poll

On Aug 10, 12:15 am, "maxhifi" wrote:
I'd like to take a simple poll. I don't really want to make it into a debate
about the merits of various configurations, I'm just curious about what's in
use. What is the configuration of the amplifier you most commonly listen to?
I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical


6550 in PP, 75W, 86dB, mostly classical, bluegrass and international
(Celtic).

Peter Wieck
Wyncote, PA

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MarkS MarkS is offline
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Default Tube amplifier poll


"maxhifi" wrote in message
news:dDRui.46876$rX4.36476@pd7urf2no...
I'd like to take a simple poll. I don't really want to make it into a
debate about the merits of various configurations, I'm just curious about
what's in use. What is the configuration of the amplifier you most
commonly listen to? I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical



KT88 PP 75 W. 6SJ7GT Input, 6SN7 LTP, fixed bias
Dyna PAS w/ custom line stage, no tone controls, triode feedback pair with
subsonic filter.
Jazz & Rock
Mark


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Id ita Id ita is offline
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Default Tube amplifier poll





What is the configuration of the amplifier you most commonly listen

to?

Output Tube: RCA Cunningham 45
Configuration: single
NFB: 0
Power Output: ~2 watts
Speaker Efficiency: 95dB/m
Music Type: blues, jazz, R&B

Recent live music:
Jeff Gautier, Patti Smith







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John Byrns John Byrns is offline
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Default Tube amplifier poll

In article dDRui.46876$rX4.36476@pd7urf2no, "maxhifi"
wrote:

I'd like to take a simple poll. I don't really want to make it into a debate
about the merits of various configurations, I'm just curious about what's in
use. What is the configuration of the amplifier you most commonly listen to?
I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical


Mine is:

Output Tube: 25L6GT
Configuration: Push Pull, cathode bias, pentode
NFB: none
Power Output: 7 Watts per channel, continuous rating
Speaker Efficiency: 96dB/m
Music Type: Classic/Traditional Jazz


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/


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Ian Iveson Ian Iveson is offline
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Default Tube amplifier poll

4 x 6CH6 per monobloc PP distributed load (30% screen, 10% cathode),
12W, ~0.3ohm, no global feedback, E88CC direct coupled voltage amp /
concertina.

Old Mission plastic-coned standmounts efficiency not known but
probably highish 80s and a fairly benign load compared to more modern
stuff. Small room. Some day I'll make something better. I'm more
concerned with clarity and coherence than precision per se.

Any good music, but symphonies upset the neighbours and they shout
through the quiet bits.

cheers, Ian


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Sander deWaal Sander deWaal is offline
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Default Tube amplifier poll

(Id ita) said:


What is the configuration of the amplifier you most commonly listen

to?



Mid/high amps:
Output Tubes: JJ KT88 PPP in triode.
Configuration: push pull .
NFB: local only, around the power tubes and in the unbypassed cathode
resistors.
Drivers: 12BH7 RCA.
Phase splitters : ECC81/12AT7 AEG Telefunken.
Power output: 40 watts/ 2-4-8 ohms.

Low amp:
Output MOSFETs 4 x 2SK135 and 2SJ50.
Driver : E288CC Philips in SRPP.
NFB : local only, source- and unbypassed cathode resistors,
Biased in high AB, power output approx. 100 watts in 8 ohms.

Pre-amp:
Active filtering @ 120 Hz with LM4562 opamps, Noble pot, external
power supply.
MC preamp: lots of 2SA970 and 2SC2240 in a balanced configuration.
MM preamp: 2 x 6072 EH and 1 x 6CG7 unknown origin.

Turntables : Thorens TD160-II, Audioquest arm and Denon DL103R,
modified : subchassis, platter and plinth, electronic motor drive.
Denon DP-60L with stock arm and AT OC9 cart.
Denon DP-51F with Denon DL160 HO-MC.

CD players:
Sony CDP-XA20, modified.
Philips CD960, modified.
Teac P700 and homebrew DAC delta-sigma Crystal CS4329 and discrete
output stage.
Pioneer PDS-06 modified.

Tuner:
Kenwood KT1100.

Speakers/ Efficiency :
2 * mid-high panels Magnepan MG1C, 84dB/w/m / ch.
Low panels : 4 * Magnepan MG1 improved, total 87 dB/w/m / ch.

Other systems:
2A3 PP, 12BH7, ECC83.
6BX7 PP, 6SN7, 6SN7.
Various solid state amps and projects.
Leak Sandwich 300, homebrew infinite baffles with Philips 9710AM.


Music Type : blues, jazz, jazzrock, fusion, '60-'70-'80s pop and
rock, baroque.


Recent live music:
My own hobby-band. Jazzrock, of course. ;-)

--

- Maggies are an addiction for life. -
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reyer reyer is offline
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Default Tube amplifier poll

KT88 PP UL + CFB (aka Super Triode by Menno van der Veen), 30 Watt
driven by a ECC99 LTP phase splitter
ECC186 anode follower, grounded cathode preamp
No global feedback.
Speakers are old and small Philips, no data, sound fine.

Cheers!

Reyer


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Peter Wieck Peter Wieck is offline
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Default Tube amplifier poll

On Aug 10, 11:57 am, Sander deWaal wrote:

A neat list of equipment.


In *active* use in our households (2, main and summer houses) a

Amplification:

Scott LK-150 **
Dynaco ST-70 *
Dynaco ST-35 **
Harmon-Kardon Citation 16 *

Integrated:

Dynaco SCA-35
AR AU amp **
Revox B251 *
Dynaco SCA-80Q
HK Citation integrated tube amp on the bench being restored.

Pre-Amp:

Dynaco PAS-3 *
HK Citation 17
Revox A720 **
Dynaco PAT-4
Dynaco PAT-5bifet

Receiver:

AR Model W and model R Receivers (one *)

CD:

Yamaha 5-disc changer *
Philips (Holland) 5-disc changer
Revox B225 **
Original 'very first' Sony discman w/transformer pack adaptor.
(bench-
test unit) **

Cassette:

Revox B215 *
HK2000
Tascam 3-head

TT:

Rabco ST6 *
Rabco ST8
Revox B790 **
Revox B795

R/R

Revox A77 "road deck" (amp & speakers included). *

Speakers:

AR3a **
AR4x
AR M5
AR Athena sub-sat (vanishingly few were made before AR was shut down
by Jensen). **
Revox Picollo sub-sat
AR TSW 110 *
AR 622 active sub-sat system (bench-test unit) *

Tuners:

AR tuner **
Dynaco FM-3 heavily modifed *
Dynaco FM-3 full-factory
Dynaco FM-5
Dynaco AF-6
(repeat) Revox A720 **
HK-500
HK Citation 15
Grundig Satellit 700 (OK, a full-band portable radio with a very nice
stereo FM 'front end'). **

* = Likely to be still in service 6 months from now.
** = will be pried from my cold, dead fingers. Note that some of these
** choices are somewhat irrational and sentimental and/or for the
purposes of "completeness" rather than for any particularly great
sound as may come out of or through them.

No reference is made (except once) as to any modifications or changes
that may or may not have been made.

The rest of the stuff comes and goes as do the tides based on whim,
better offers or trades. And the list of "what once was" is far too
long for this venue.

Peter Wieck
Wyncote, PA



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Default Tube amplifier poll

Peter Wieck said:

snip nice list


The rest of the stuff comes and goes as do the tides based on whim,
better offers or trades. And the list of "what once was" is far too
long for this venue.



That goes for most of us, I think. ;-)

How's your homebrew-tube amp project going, Peter?

--

- Maggies are an addiction for life. -


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Default Tube amplifier poll

On Aug 10, 3:48 pm, Sander deWaal wrote:

How's your homebrew-tube amp project going, Peter?


Slowly. I am loath to bend sheet-metal until I have a firm circuit.
Each circuit I try has its advantages and disadvantages... right now,
I am investigating a PP 6L6/5881 configuration, each channel using a
single 12AX7 as driver w/a very simple SS power-supply. It sure takes
a load off the power-transformer, appears to be very stable while
breadboarded on the bench, makes nice sound and is quite simple.
Everything gets to be a little bit lazy, a good thing for stability
and longevity. My test speakers for this are the AR Athenas, the
satellites are tiny (1.5"dome mid & 3/4" dome tweet) and the sub ( 2
x 8" long-throw) makes a nice footrest under the bench. And those
speakers would likely be the permanent mates.

I also tried a near-duplicate of the Dynaco ST-35 circuit with a fixed-
bias circuit and based on 6BQ5 outputs, and I am tempted to try the
original 7591A output tubes as Fisher configured for the original
iron... So many things to try, so little time.

I think I rejected the 6BQ5 option as I want a bit more than 13 watts,
but I would settle for a reliable 20, well within the range of the
5881 in PP Class A. And I prefer to be able to use readily available
(to me) NOS; or vintage tubes already in hand.

I am contemplating a very simple black-box type cosmetic layout with
the transformers concealed and the tubes caged behind the front
panel. Just an LED or neon pilot on the front panel, the on/off switch
being a momentary-contact relay-system so that any interruption of
power would cause complete shut-down... no possibility of automatic re-
start.

Cats and grandkids preclude exposed tubes, but suchlike was never a
big thing of mine, eyewash does not sound much, good or bad.

But all that is the easy part. It's the circuit that is taking the
time and making me waffle...

Peter Wieck
Wyncote, PA

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Andre Jute Andre Jute is offline
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Default Tube amplifier poll

On Aug 9, 9:15 pm, "maxhifi" wrote:
I'd like to take a simple poll. I don't really want to make it into a debate
about the merits of various configurations, I'm just curious about what's in
use. What is the configuration of the amplifier you most commonly listen to?
I'll start with mine,


I switch one of three amps when I arrive in my study, and a fourth one
when my family goes to bed:
Output Tube: trioded EL34; 300B; Quad silicon; 6SN7 for electrostatic
headphones
Configuration: Push Pull; SE; PP; balanced PP
NFB: adjustable, usually none; none; I don't ask about the NFB in the
Quad SS amps!; none
Power Output: 20W; 3.7W; 140W; maybe one watt
Speaker Efficiency: Quad ESL-63 86dB/m, Lowther type horns 103dB/m
Music Type: Classical (and classic rock'n'roll) -- I play mostly
chamber music and voices

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

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Andre Jute Andre Jute is offline
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Default Tube amplifier poll

On Aug 10, 8:08 am, John Byrns wrote:

Mine is:

Output Tube: 25L6GT
Configuration: Push Pull, cathode bias, pentode
NFB: none
Power Output: 7 Watts per channel, continuous rating
Speaker Efficiency: 96dB/m
Music Type: Classic/Traditional Jazz

Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/


Is this your notorious "Amplifier without Transformer"?

BobC
LOL


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John Byrns John Byrns is offline
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Default Tube amplifier poll

In article .com,
Andre Jute wrote:

On Aug 10, 8:08 am, John Byrns wrote:

Mine is:

Output Tube: 25L6GT
Configuration: Push Pull, cathode bias, pentode
NFB: none
Power Output: 7 Watts per channel, continuous rating
Speaker Efficiency: 96dB/m
Music Type: Classic/Traditional Jazz


Is this your notorious "Amplifier without Transformer"?


Hi Andre,

No, it is my notorious "Power Amplfier without Power Transformer", it is
hardly without transformers as it has four.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/
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Peter Wieck Peter Wieck is offline
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Default Tube amplifier poll

On Aug 10, 6:16 pm, Bret Ludwig wrote:
Slowly. I am loath to bend sheet-metal until I have a firm circuit.


Why? A genenric box accommodates many circuits.





Each circuit I try has its advantages and disadvantages... right now,
I am investigating a PP 6L6/5881 configuration, each channel using a
single 12AX7 as driver w/a very simple SS power-supply. It sure takes
a load off the power-transformer, appears to be very stable while
breadboarded on the bench, makes nice sound and is quite simple.
Everything gets to be a little bit lazy, a good thing for stability
and longevity. My test speakers for this are the AR Athenas, the
satellites are tiny (1.5"dome mid & 3/4" dome tweet) and the sub ( 2
x 8" long-throw) makes a nice footrest under the bench. And those
speakers would likely be the permanent mates.


I also tried a near-duplicate of the Dynaco ST-35 circuit with a fixed-
bias circuit and based on 6BQ5 outputs, and I am tempted to try the
original 7591A output tubes as Fisher configured for the original
iron... So many things to try, so little time.


I think I rejected the 6BQ5 option as I want a bit more than 13 watts,
but I would settle for a reliable 20, well within the range of the
5881 in PP Class A. And I prefer to be able to use readily available
(to me) NOS; or vintage tubes already in hand.


Build around whatever's handy, change later.



I am contemplating a very simple black-box type cosmetic layout with
the transformers concealed and the tubes caged behind the front
panel. Just an LED or neon pilot on the front panel, the on/off switch
being a momentary-contact relay-system so that any interruption of
power would cause complete shut-down... no possibility of automatic re-
start.


Cats and grandkids preclude exposed tubes, but suchlike was never a
big thing of mine, eyewash does not sound much, good or bad.


Easy to fab a cover.



But all that is the easy part. It's the circuit that is taking the
time and making me waffle...


Bull****. You're stalling. Build something, any goddamned thing.
Anything actually built-even single ended triodes, as hard as it is to
believe-sounds better thatn the best idea not built.

If you want an amp to listen to build any of several known good
circuits. If you want to tinker, build a GOOD power supply for bench
or static use and then breadboard the circuits.

Known good basic designs include the Williamson, Marantz, several RCA
and MO/GEC tube manual designs, and many others. Build, listen, test,
rework, whatever suits your fancy. But don't spend a lot of time on
thinking without building.- Hide quoted text -

- Show quoted text -


Bret, with all due respect (none), eat **** and die.

Peter Wieck
Wyncote, PA



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maxhifi maxhifi is offline
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Default Thanks everyone for your responses!

There's quite a variety represented here - most foreign to me are the push
pull 845s, and the fact that speakers actually exist to make an SE 45
useful!

"maxhifi" wrote in message
news:dDRui.46876$rX4.36476@pd7urf2no...
I'd like to take a simple poll. I don't really want to make it into a
debate about the merits of various configurations, I'm just curious about
what's in use. What is the configuration of the amplifier you most
commonly listen to? I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical





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maxhifi maxhifi is offline
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Posts: 164
Default Tube amplifier poll

I am investigating a PP 6L6/5881 configuration, each channel using a
single 12AX7 as driver w/a very simple SS power-supply. It sure takes
a load off the power-transformer, appears to be very stable while
breadboarded on the bench, makes nice sound and is quite simple.


I have an old ST70-II carcass (it looks like the circuit board caught fire)
which I've often thought of rebuilding into something similar.

My thoughts are as follows

6L6 in p-p, pentode, local feedback around the output stage, regulated
screen voltage, cathode bias, and a 6SL7 driver.





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Peter Wieck Peter Wieck is offline
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Default Thanks everyone for your responses!

On Aug 10, 7:08 pm, "maxhifi" wrote:
There's quite a variety represented here - most foreign to me are the push
pull 845s, and the fact that speakers actually exist to make an SE 45
useful!


That "useful" is an exceedingly small universe, pretty much limited to
extremely efficient speakers and signal with a PA average of about
10dB or so and for those who wish to listen either to very limited
repertoire and/or at very low volume.

Not to say that such do not exist, but that they are not particularly
adapted to the way that most of us use our systems in the real world.

It is only a certain sort of person that can convince themselves that
90hz to 15,000hz down 6dB or more at anything outside those limits can
be mistaken for "full frequency".

Peter Wieck
Wyncote, PA

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John Byrns John Byrns is offline
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Default Tube amplifier poll

In article om,
Peter Wieck wrote:

On Aug 10, 3:48 pm, Sander deWaal wrote:

How's your homebrew-tube amp project going, Peter?


Slowly. I am loath to bend sheet-metal until I have a firm circuit.
Each circuit I try has its advantages and disadvantages... right now,
I am investigating a PP 6L6/5881 configuration, each channel using a
single 12AX7 as driver w/a very simple SS power-supply. It sure takes
a load off the power-transformer, appears to be very stable while
breadboarded on the bench, makes nice sound and is quite simple.
Everything gets to be a little bit lazy, a good thing for stability
and longevity. My test speakers for this are the AR Athenas, the
satellites are tiny (1.5"dome mid & 3/4" dome tweet) and the sub ( 2
x 8" long-throw) makes a nice footrest under the bench. And those
speakers would likely be the permanent mates.

I also tried a near-duplicate of the Dynaco ST-35 circuit with a fixed-
bias circuit and based on 6BQ5 outputs, and I am tempted to try the
original 7591A output tubes as Fisher configured for the original
iron... So many things to try, so little time.

I think I rejected the 6BQ5 option as I want a bit more than 13 watts,
but I would settle for a reliable 20, well within the range of the
5881 in PP Class A. And I prefer to be able to use readily available
(to me) NOS; or vintage tubes already in hand.

I am contemplating a very simple black-box type cosmetic layout with
the transformers concealed and the tubes caged behind the front
panel. Just an LED or neon pilot on the front panel, the on/off switch
being a momentary-contact relay-system so that any interruption of
power would cause complete shut-down... no possibility of automatic re-
start.

Cats and grandkids preclude exposed tubes, but suchlike was never a
big thing of mine, eyewash does not sound much, good or bad.

But all that is the easy part. It's the circuit that is taking the
time and making me waffle...


I don't understand why you are waffling, reading between the lines you
wrote above it is clear you already have your circuit.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/
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Id ita Id ita is offline
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Default Thanks everyone for your responses!




Group: rec.audio.tubes Date: Fri, Aug 10, 2007, 6:02pm From:
(Peter*Wieck)
On Aug 10, 7:08 pm, "maxhifi" wrote:

There's quite a variety represented here - most foreign to me are

the push pull 845s, and the fact that speakers actually exist to
make an SE 45 useful!



Not to say that such do not exist, but that they are not particularly

adapted to the way that most of us use our systems in the real world.
It is only a certain sort of person that can convince themselves that

90hz to 15,000hz down 6dB or more at anything outside those limits can
be mistaken for "full frequency".


An SE enthusiast faced with a limited choice of drivers is no less
prone than anybody else to mistake such a limited range for "full
frequency". And the real situation is not so dire.
(We) are prone, however, to gerrymander our priorities to fit the
limitations of the gear, in order to receive a singular blessing. I've
built clean PP amps that were subjectively blameless, but always lacked
the ineffable qualities of "involvement" and "presentation" that even a
casual SE design would bring right back. The strengths in each approach
are not mutually exclusive, and can be combined in the right
implementation, but I'm still getting there.

So, the current fave 45 is suited to meet current real-world facts: my
modest SPL
requirement, a preference for small-ensemble music, an acceptable driver
on hand, and a willingness to take the narrow path through a deeper
experience than that which can be measured and quantified by pedestrian
means.

Horses for courses, as some living saint once said.

Regards,
Barry Bialos



Peter Wieck
Wyncote, PA








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maxhifi maxhifi is offline
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Default Thanks everyone for your responses!


"Id ita" wrote in message
...

So, the current fave 45 is suited to meet current real-world facts: my
modest SPL
requirement, a preference for small-ensemble music, an acceptable driver
on hand, and a willingness to take the narrow path through a deeper
experience than that which can be measured and quantified by pedestrian
means.



What kind of driver is it? I built a stereo 2A3 amplifier, using EF37A
drivers, and a 6CA4 rectifier, and love the sound of it, however, it's too
weak to use full time with my main speakers.


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Default Thanks everyone for your responses!



Group: rec.audio.tubes Date: Sat, Aug 11, 2007, 4:01am (PDT+7) From:
(maxhifi)

"Id ita" wrote in message
...

**So, the current fave 45 is suited to meet current real-world

facts: my modest SPL
requirement, a preference for small-ensemble music, an acceptable

driver on hand...


What kind of driver is it? I built a stereo 2A3 amplifier, using

EF37A drivers, and a 6CA4 rectifier, and love the sound of it,
however, it's too weak to use full time with my main speakers.


It's a driver from Frankenstein's lab. A Jensen 855A 8" with the outer
two-thirds of the cone and untreated paper surround removed, and
replaced with the outer cone and cloth surround of a Radio Snack
(40-2086?), carefully glued to the remaining inner cone.

A whizzer was removed. The inner cone and
dust cap were treated with an acrylic sealer. Strips of 1" carpet felt
were glued to the inside of the basket struts. The result is
considerably smoother than the stock Jensen, but the top octave is
pretty much gone. I've used a small horn tweeter to fill it in, and
gotten an even match, but the horn is too aggressive no matter how it is
adjusted. With the horn gone, it's back to "better than hi-fi" despite
the soft highs.

The enclosure is a 3.6 cu. ft. sealed box. A port would extend the
lows, but complicate the impedance curve to the distress of my SET. I
prefer smooth rolled bass to a "thump" anyway.

A good match to this kind of driver might be an SE pentode with no loop
feedback, working as a constant-current amplifier. The voice coil Z
typically starts to rise at the frequencies where the cone mechanically
rolls off. A current source puts higher voltage across the higher Z, and
compensates the roll-off. But then the bass is utterly undamped, and an
open baffle will likely work better.

Regards,
Barry







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Peter Wieck Peter Wieck is offline
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Default Tube amplifier poll

On Aug 10, 8:08 pm, John Byrns wrote:
In article om,
Peter Wieck wrote:





On Aug 10, 3:48 pm, Sander deWaal wrote:


How's your homebrew-tube amp project going, Peter?


Slowly. I am loath to bend sheet-metal until I have a firm circuit.
Each circuit I try has its advantages and disadvantages... right now,
I am investigating a PP 6L6/5881 configuration, each channel using a
single 12AX7 as driver w/a very simple SS power-supply. It sure takes
a load off the power-transformer, appears to be very stable while
breadboarded on the bench, makes nice sound and is quite simple.
Everything gets to be a little bit lazy, a good thing for stability
and longevity. My test speakers for this are the AR Athenas, the
satellites are tiny (1.5"dome mid & 3/4" dome tweet) and the sub ( 2
x 8" long-throw) makes a nice footrest under the bench. And those
speakers would likely be the permanent mates.


I also tried a near-duplicate of the Dynaco ST-35 circuit with a fixed-
bias circuit and based on 6BQ5 outputs, and I am tempted to try the
original 7591A output tubes as Fisher configured for the original
iron... So many things to try, so little time.


I think I rejected the 6BQ5 option as I want a bit more than 13 watts,
but I would settle for a reliable 20, well within the range of the
5881 in PP Class A. And I prefer to be able to use readily available
(to me) NOS; or vintage tubes already in hand.


I am contemplating a very simple black-box type cosmetic layout with
the transformers concealed and the tubes caged behind the front
panel. Just an LED or neon pilot on the front panel, the on/off switch
being a momentary-contact relay-system so that any interruption of
power would cause complete shut-down... no possibility of automatic re-
start.


Cats and grandkids preclude exposed tubes, but suchlike was never a
big thing of mine, eyewash does not sound much, good or bad.


But all that is the easy part. It's the circuit that is taking the
time and making me waffle...


I don't understand why you are waffling, reading between the lines you
wrote above it is clear you already have your circuit.

Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/- Hide quoted text -

- Show quoted text -


John:

I have tried (breadboarded) two circuits. Both had their merits, but
the 6BQ5 circuit was just too 'little'. I am tempted to try one or two
more including one based on the 7591A, and one possibly with different
drivers before I bend and punch sheet metal.

That's really all there is to it. I am not in a hurry, and I am trying
to learn rather than assemble by rote.

Peter Wieck
Wyncote, PA

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Default Thanks everyone for your responses!

On Aug 10, 10:07 pm, (Id ita) wrote:

An SE enthusiast faced with a limited choice of drivers is no less
prone than anybody else to mistake such a limited range for "full
frequency". And the real situation is not so dire.
(We) are prone, however, to gerrymander our priorities to fit the
limitations of the gear, in order to receive a singular blessing. I've
built clean PP amps that were subjectively blameless, but always lacked
the ineffable qualities of "involvement" and "presentation" that even a
casual SE design would bring right back. The strengths in each approach
are not mutually exclusive, and can be combined in the right
implementation, but I'm still getting there.

So, the current fave 45 is suited to meet current real-world facts: my
modest SPL
requirement, a preference for small-ensemble music, an acceptable driver
on hand, and a willingness to take the narrow path through a deeper
experience than that which can be measured and quantified by pedestrian
means.


If you say so... It really reads in a perverse sort of way along the
lines of the statement: "It feels so good when I stop banging my
head".

Again, I have heard flea-powered SE systems with various sorts of
drivers that sound etherially beautiful... with very limited signal
such as solo voice, or Gregorian Chant as two examples. But not with
much else.

Peter Wieck
Wyncote, PA

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Andre Jute Andre Jute is offline
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Default Tube amplifier poll

On Aug 10, 3:30 pm, John Byrns wrote:
In article .com,
Andre Jute wrote:

On Aug 10, 8:08 am, John Byrns wrote:


Mine is:


Output Tube: 25L6GT
Configuration: Push Pull, cathode bias, pentode
NFB: none
Power Output: 7 Watts per channel, continuous rating
Speaker Efficiency: 96dB/m
Music Type: Classic/Traditional Jazz


Is this your notorious "Amplifier without Transformer"?


Hi Andre,

No, it is my notorious "Power Amplfier without Power Transformer", it is
hardly without transformers as it has four.

Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/


Not much of a revolutionary you are! Mind you, I've just done an OTL
amp for my electrostatic headphones (only two power transformers if
you don't count the two chokes), so between the two of us we're
halfway there!

Up the winders!

Andre Jute
A little inaccuracy sometimes saves tons of explanation. --H.H.Munro
("Saki")(1870-1916)

Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review



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Andre Jute Andre Jute is offline
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Default Thanks everyone for your responses!

On Aug 10, 5:08 pm, "maxhifi" wrote:
There's quite a variety represented here - most foreign to me are the push
pull 845s, and the fact that speakers actually exist to make an SE 45
useful!


Check out The Impresario speaker and the High Wife Acceptance Factor
Lowther bicor horn at
http://members.lycos.co.uk/fiultra/JUTE%20ON%20AMPS.htm
They also have associated low-power amps, respectively the 'SEntry'
and 'Minus Zero'.

Andre Jute


"maxhifi" wrote in message

news:dDRui.46876$rX4.36476@pd7urf2no...

I'd like to take a simple poll. I don't really want to make it into a
debate about the merits of various configurations, I'm just curious about
what's in use. What is the configuration of the amplifier you most
commonly listen to? I'll start with mine,


Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical



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Default Tube amplifier poll

On Aug 10, 6:08 pm, John Byrns wrote:
In article om,
Peter Wieck wrote:

..........
It's the circuit that is taking the
time and making me waffle...


I don't understand why you are waffling, reading between the lines you
wrote above it is clear you already have your circuit.

Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/


I imagine every janitor, even one as worthless as Wiecky, knows not to
stick his hands in electricity but to telephone for someone competent
to do the job.

Andre Jute

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Default Tube amplifier poll


Output Tube: 6V6GT
Configuration: Push Pull,cathode bias..
NFB: Yes;adjustable
Power Output: 8W per channel before any signs of distortion on the 'scope.
Speaker Efficiency: unknown.(sorta lowish,but in a small room)
Music Type: Any,and everything..(Except Country! Blech!)

Schematic and pic. (Dynaco ST-70 beside it)
It's from a Sears "Silvertone" console of some sort.
http://www.users.qwest.net/~ptaylor/...e_amp_Mods.gif
http://www.users.qwest.net/~ptaylor/...PP-6V6_amp.jpg

(And again,Thanks to Brian McAllister for the Sams info!) :-)



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Peter Wieck Peter Wieck is offline
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On Aug 11, 10:29 am, Andre Jute wrote:

I imagine every janitor, even one as worthless as Wiecky, knows not to
stick his hands in electricity but to telephone for someone competent
to do the job.

Andre Jute


So, the stroke victim resurfaces? Can Mr. McCoy and its sockpuppets be
far behind? Clearly a nice long supervised rest did not have the
desired results?

I would suspect, Andre, that I have been around and further with
electricity and its applications (in audio and elsewhere) than you
have been even in your wildest pretenses.

If your wiring skills... even in breadboarding... are as you have
already illustrated with your non-functioning "ultra-fi" amp as
displayed in this venue are indicative of your overall skills, you
would be the last creature on earth to be the critic.

But, don't lose any sleep over it, Andre. My preliminary designs
actually work. Not that they are anything much more than derivative of
and refinements of designs that have been out there for 40 years or
more, but at least I have the grace to admit that rather than
pretending that what I am doing is either revolutionary or unique. But
that they work must be acutely frustrating to you. Sorry about that. I
promise to blow up a $0.05 Chinese electrolytic capacitor in your name
the next time I am at the bench. Will that make you feel better? But I
will not offer a design that burns controls... that is your particular
domain and level of expertise.

I run all the test-beds through an isolation transformer with the
output side on a 3A dual-element fuse. No loses so far. How about you?
Is that "Ultra-Fi" playing yet? Even passing signal (however briefly)?

Peter Wieck
Wyncote, PA

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On Aug 11, 10:35 am, Bret Ludwig wrote:
John:


I have tried (breadboarded) two circuits. Both had their merits, but
the 6BQ5 circuit was just too 'little'. I am tempted to try one or two
more including one based on the 7591A, and one possibly with different
drivers before I bend and punch sheet metal.


So tell us, what drives you to fool with such an undesireable tube
such as the 7591, expensive, not terribly available?


That I have a bunch in hand... no more.

Peter Wieck
Wyncote, PA



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Andre Jute Andre Jute is offline
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Default Thanks everyone for your responses!

First Worthless Wiecky twitched his net curtain to give us his worn-
out prissy-mouthed omnidirectional disapproval of everything outside
the narrowest norm of the lowest common denominator, a true janitor's
out-of-the-toilet, puckered bottom-up view of audio:
:
On Aug 10, 7:08 pm, "maxhifi" wrote:

There's quite a variety represented here - most foreign to me are the push
pull 845s, and the fact that speakers actually exist to make an SE 45
useful!


That "useful" is an exceedingly small universe, pretty much limited to
extremely efficient speakers and signal with a PA average of about
10dB or so and for those who wish to listen either to very limited
repertoire and/or at very low volume.


This is untrue.

Not to say that such do not exist, but that they are not particularly
adapted to the way that most of us use our systems in the real world.


So why say what you next admit is a lie, Worthless?

It is only a certain sort of person that can convince themselves that
90hz to 15,000hz down 6dB or more at anything outside those limits can
be mistaken for "full frequency".


This too is nonsense. What is true is that it is only a certain class
of fascist who believes he can prescribe what other people should use
and enjoy. As I've said before, Worthless, you are genetically, and by
your condition and ineradicable envy of your betters, a fascist.


Peter Wieck
Wyncote, PA


Sounds more like Salem in the days of Cotton Mather to me every time I
am unfortunate enough to see someone replying to your pompous
witterings.

Then Barry Bialos wrote:
An SE enthusiast faced with a limited choice of drivers is no less
prone than anybody else to mistake such a limited range for "full
frequency". And the real situation is not so dire.


Right. He doesn't need to make any such adaptation except by choice.
It is only fashion victims, parroting the latest street gossip, like
Worthless Wiecky, who haven't yet discovered that it is no problem
making an SE amp with audio range output, and powerful enough to drive
any speaker with any range you desire or prefer. I built 80W SE amps,
and we have an example right now of Patrick building 50-60W SE amps,
but the idiot Wiecky mutters on about low power being a necesary
condition of SE. The little janitor isn't only stupid, he's blind and
deaf as well.

What's more, if low power tubes sound sweetest, and some very sweet
tubes have very low power, all it takes to build or buy a horn that
will give full audio spectrum on vanishingly small power is money and
the balls to face down idiots who will say your horn is too big for
their houses -- then they needn't have it! It is absolutely no
technical problem building a full-range horn all the way down to 16Hz,
and a very modestly sized horn, as horns go, can easily with the aid
of woofer give 20Hz-22kHz. But people secure in their own taste have a
right to reserve to themselves alone the choice of balanced natural
sound, as distinct from the engineering wet dream of an arbitrarily
chosen "audio range". (Not even to mention that the idiots who decry
everyone else's choices on investigation are in 99 per cent of cases
discovered not to own speakers that can manage their wet dream, or
speakers even anywhere near as good are already owned by those they
decry. Or, to mention only the specifics of Worthless Wiecky's
stupidities, he is of an age when he has long since ceased to hear
that 15kHz he now jeers is too low for everyone else. Now watch the
outburst of rage when someone applies a modicum of logic to his
spiteful vomitings: the little man likes handing it out but he can't
take it.)

(We) are prone, however, to gerrymander our priorities to fit the
limitations of the gear, in order to receive a singular blessing.


And we have a perfect right to do so. However, as it happens, I love
chamber music and vocal music, including Gregorian Chant, and I choose
the gear accordingly. For some fascist mentality to come tell us that
we made a mistake in choosing our gear and are depriving us of
whatever his favourite music might be (you can spot the tenth-raters
on RAT easily -- they never speak of the rapture of music) is simply
intolerable. Hey, I have the money and the space and intellectual
ability, so I once built special speakers for Gregorian chant, but I
feel no need to apologize for them by saying that of course I also
have other speakers for more general purposes.

I've
built clean PP amps that were subjectively blameless, but always lacked
the ineffable qualities of "involvement" and "presentation" that even a
casual SE design would bring right back.


It's tough to design a really good PP amp because the mentality we
inherit -- as Worthless Wiecky has just demonstrated again -- is the
engineering paradigm of maximum power for minimum cost. Once you lose
that depressing burden, which only requires putting your mind in gear,
it becomes much easier to make a good PP amp. It should be built of
triodes or trioded pentodes (which sound quite as good as DHT if you
limit the operating range to the most linear part of the transfer),
and it should be strictly Class A and have zero or very little NFB
(which three things together make the sound that is mistaken called
"single-ended sound").

The strengths in each approach
are not mutually exclusive, and can be combined in the right
implementation, but I'm still getting there.


Hallelujah. Stick around Barry; we can do with another positive
outlook; sometimes it seems as if the congenitally negative creeps
like Worthless Wiecky are all that is on RAT, which is a view that
does an injustice to the many open-minded strivers after truth and
glee who contribute to or lurk on RAT.

So, the current fave 45 is suited to meet current real-world facts: my
modest SPL
requirement, a preference for small-ensemble music, an acceptable driver
on hand, and a willingness to take the narrow path through a deeper
experience than that which can be measured and quantified by pedestrian
means.


Nothing pedestrian about a banksa6550 PP amp with so much NFB that
ever-diminishing, of course, harmonics numbers must be given in
superscripts of magnitudes: "and the 513^10^3 harmonic is umpteen
thousand decibels below audibility..." A lot of topclass engineering
hours went into it and many are willing to pay for the bragging
rights. We should respect that too.

Horses for courses, as some living saint once said.


Let a thousand flowers bloom, and one will smell sweet. The trick is
knowing which one that is. A Class A ZNFB triode amp of very
conservative design coupled to high-sensitivity point source speakers
multiplies the audiophile's predictive abilities by at least two or
three magnitudes.

Regards,
Barry Bialos


Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

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"PhattyMo" wrote in message
...

Output Tube: 6V6GT
Configuration: Push Pull,cathode bias..
NFB: Yes;adjustable
Power Output: 8W per channel before any signs of distortion on the 'scope.
Speaker Efficiency: unknown.(sorta lowish,but in a small room)
Music Type: Any,and everything..(Except Country! Blech!)


Those look like my fav. sylvania 6V6's - and nice paint job!


  #33   Report Post  
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Default Tube amplifier poll

iv got a citation 5 harman/kardon 40watt p/ch rms.
a citation 1 harman/kardon preamp.
home made mixer/preamp with 5.1 output
tube sound simulator built in and tube
headphone amp built in, has 16 inputs
and 5 line outputs, 2 cannon 3pin inputs, 2
cannon outputs for pro audio, guitar input
for marshall amp, 2 power suppies 1 for
headphone amp the other is a 200watt
pc/power supply modified for rest of it.
and a marshall 9200 2/ch 100watt rms p/ch
1 rack case server with mp3 music, a radio
card,automation software for controll of
power and controll of audio and reel/reel
controll- etc.
marshall amp has 8 5881 tubes and 4 12ax7 tubes.
harman/kardon has 4 7581 tubes 2 12by7 and 2 6cg7.
harman/kardon preamp has 4 12ax7 5 12at7.
i have some home made tube amps and a
200watt NTS power amp it has 4 kt66 gec
and 4 6sj7 2 6au4 tubes.
other amps i have need work.

"maxhifi" wrote in message
news:dDRui.46876$rX4.36476@pd7urf2no...
I'd like to take a simple poll. I don't really want to make it into a
debate about the merits of various configurations, I'm just curious about
what's in use. What is the configuration of the amplifier you most
commonly listen to? I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical





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Nothing as fancy or exotic as what most of you all have:

1959 Zenith console Model SF2580 dubbed the "Schubert" by Zenith.

Output Tube: EL84 (4)
Configuration: Push Pull, I believe
NFB: (not a clue what that means)
Power Output: 40W according to the instruction manual. I presume they
mean 20W per channel.
Speaker Efficiency: I dunno - the ones that came with the console...
Music Type: mostly Soundtracks, Showtunes, Country. A little bit of
everything exept Rap, Hip hop, etc.

Another I listen to just as much:

1964 Sears Silvertone receiver, Model 7408
All original works - not one cap or tube replaced so far.

Output Tube: EL84 (4)
Configuration: Push Pull, I believe
NFB: (not a clue what that means)
Power Output: I dunno
Speaker Efficiency: I dunno. Currently using modern KLH speakers.
Music Type: mostly Soundtracks, Showtunes, Country. A little bit of
everything exept Rap, Hip hop, etc.

Gerry

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Default Tube amplifier poll

My system:

Sony DVD changer, well broken in.

P-P EL34, dioded-triode, 6DJ8, 6SN7.

Mission bookshelves and Edgarhorn 80Hz woofers.

Music: Often

Happy Ears!
Al




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John Byrns John Byrns is offline
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Default Tube amplifier poll

In article om,
tubegarden wrote:

My system:

Sony DVD changer, well broken in.

P-P EL34, dioded-triode, 6DJ8, 6SN7.


"dioded-triode", sounds interesting, can you tell us more about this?


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/
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Default Tube amplifier poll

On Aug 10, 12:15 am, "maxhifi" wrote:
I'd like to take a simple poll. I don't really want to make it into a debate
about the merits of various configurations, I'm just curious about what's in
use. What is the configuration of the amplifier you most commonly listen to?
I'll start with mine,

Output Tube: 807
Configuration: Push Pull Parallel, cathode bias, pentode, monoblocks
NFB: local only
Power Output: 70W
Speaker Efficiency: 91dB/m
Music Type: mostly Rock and Classical


Several... all pentodes in P-P, cathode bias, mono, quite large NFB
used, various quality OPT's - the least, but still OK, being a Hammond
125E.
Three with 2 x 6V6, max 10 to 12 watts each (one max 8 watts, lower B
+)
Two with 2 x 6L6, max 18 to 20 watts each
A couple with 2 x 6BM8's in P-P (receivers), circa max 6 wpc each.
Planned: stereo, 4 x 6BQ5 (for 10 o 14 wpc) or 6L6 or EL34 (for 18-20
wpc)... to be advised, still thinking about it ands no time to start
the project yet.
Cheers,
Roger

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Default Tube amplifier poll

On Aug 12, 7:13?am, John Byrns wrote:


"dioded-triode", sounds interesting, can you tell us more about this?

Regards,

John Byrns


It is using a SS diode between the plate and the screen, or the screen
R. When I posted somewhere I had done the triode mod, some good soul
emailed me privately and suggested using diodes. I eventually got four
of the same diodes and tried it. It is one of those simple mods that
have improved my listening.

Happy Ears!
Al


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Andy Evans Andy Evans is offline
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On Aug 10, 5:15?am, "maxhifi" wrote:
I'd like to take a simple poll. I don't really want to make it into a debate
about the merits of various configurations, I'm just curious about what's in
use. What is the configuration of the amplifier you most commonly listen to?


Balanced Push Pull all DHT amplifier on 2 chassis, driven from a
balanced DAC

Mains transformer 0-300v Actual voltage 312v
Resistance of secondary 39R
First cap: 47uF electrolytic Voltage:366
Choke: 10uF 91R
Second cap: 80uF polyprop Voltage:354
Choke 10uF 150R
Third cap: 40uF polyprop Voltage:350
Resistor: 1.6k measured, probably 1.5k
Fourth cap: 40uF polyprop Voltage:341

Input stage = differential pair, DC coupled to driver stage
Valve type: 30 globe Mu=9.3 Anode resistance 10.3
Anode resistor = 60k Anode Voltage = 156
Cathode resistor = CCS Bypass = none
Cathode Voltage = 9.7 Current each valve = 3mA

Driver stage = differential pair, push pull
Valve type: 112A globe Mu=8.5 Anode resistance 5.1k
Anode resistor = Transformer 1:1 Anode Voltage = 350
Cathode resistor = 11.5k shared Bypass = none
Cathode Voltage = 172 Current each valve = 7.5mA

Output stage = differential pair, push pull
Valve type: 2a3 Mu=4.2 Anode resistance 800R
Anode resistor = Transf. 6.6k Anode Voltage = 354
Cathode resistor = 622 shared Bypass = 100uF Polyprop
Cathode Voltage = 58 Current each valve = 46mA



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