Golden Tube SE-40 Specs
Dana Bunner
I'm sure many readers are familiar with the Golden Tube SE-40
power amp. I've looked one over and listened to it for a few
minutes and was impressed. For the $980 asking price, getting a
Class A, single-ended, 40WPC amp of this build quality seemed
one of the best buys in audio.
Solo Electronics claims that this amp does put out 40 watts per
channel in stereo mode, or 80 watts in mono. They also claim
a THD measurement of just 0.009% at 1 watt.
However the June, 1996 issue of "Hi-Fi News & Record Review," a
British publication, calls these numbers into question. According
to their bench tests, the SE-40 is nowhere near a 40WPC amp.
Pushing the amp up to a very audible 5% THD, they were
able to get all of 26 watts at 1000Hz. That number fell off
dramatically on the low end, all the way down to just under 7 watts
at 20Hz (again while allowing 5% THD).
To get a power bandwidth out to close to Golden Tube SE-40 specs
and to keep THD down to 1%, the output had to be kept down to only
5 watts. Allowing for some additional THD, they were able to
extend the amp up to around 10WPC across a moderately wide bandwidth.
At 1W and 1000Hz, THD was measured at 0.5%, or about 50 times what
Solo Electronics claimed. Other not-so-impressive measurements
included an Intermodulation reading of -35dB at clipping and 50dB
of channel separation. Output measurements when the amp was
loaded (using a Wilson WITT) showed a number of deviations from
0dB, most notably a couple of dB in the 30-40Hz region and another
2dB drop in the 2K-3K region (down 1-2dB from roughly 1600Hz to
4000Hz).
All in all, the output was much more typical of a 20WPC amp,
although some of the measurements are meager even for a 20 watter.
According to reviewer, listening tests revealed problems with complex
bass passages, with blurring of instruments (most likely the result
of high THD). The dropoff in output in the 2K-3K region was also
noted as "audible." Pushing volume levels up to over 20WPC
resulted in "it could be coaxed to play louder without
aggression, but with an audibly rapid loss of fidelity."
As to the sound itself, the review had many positive things to say
about the imaging, transparency, and microdynamics. And they noted
that the measurement deficiencies were not uncommon in a single-
ended valve amp design.
However, as a potential purchaser of the SE-40, I must say that I
feel there is an ethical issue here. I auditioned the SE-40 under
the Golden Tube-driven perception that this was a 40WPC amp with
impressive THD figures. If Hi-Fi News is correct, then Solo
Electronics is simply lying about the amp's output power and
measurements.
I'd read comments that some purchasers found the amp to have less
power than they suspected. Perhaps they were actually expecting
something with 40 watts of power?
I'm interested in learning if anyone has seen other test measurements
conducted on the SE-40 and if they differ from Hi-Fi News. Or if
Solo Electronics has issued any statements about the review or
their product claims.
Dana
Stewart Pinkerton
Dana Bunner <dbu...@doit.wisc.edu> writes:
>As to the sound itself, the review had many positive things to say
>about the imaging, transparency, and microdynamics. And they noted
>that the measurement deficiencies were not uncommon in a single-
>ended valve amp design.
>However, as a potential purchaser of the SE-40, I must say that I
>feel there is an ethical issue here. I auditioned the SE-40 under
>the Golden Tube-driven perception that this was a 40WPC amp with
>impressive THD figures. If Hi-Fi News is correct, then Solo
>Electronics is simply lying about the amp's output power and
>measurements.
Well, there is a kit amplifier available by mail order from World Audio
Design, the kit arm of Hi-Fi World, which also uses a pair of 5881/6L6s
in parallel single-ended configuration, but it's rated at 17 watts! This
is a more realistic value for this configuration, I find it hard to
believe that any more than 30 watts is reasonably achievable from a pair
of these tubes, plus the output transformers on the SE40 aren't big
enough for this kind of power, hence the fall away to 7 watts at 20Hz.
The WAD design, incidentally, costs rather more than $1,000 as a
mail-order kit and measures 30-25kHz at full power -1dB, with a midband
power output of 17 watts at 1 percent distortion, the distortion level
dropping to 0.16 per cent at 1kHz 1 watt, 1 per cent at 10 kHz 1 watt.
These are pretty decent figures for this sort of design - do you really
think Solo can put a fully-built amp into the retail market at less cost
and provide better performance?
>I'd read comments that some purchasers found the amp to have less
>power than they suspected. Perhaps they were actually expecting
>something with 40 watts of power?
>I'm interested in learning if anyone has seen other test measurements
>conducted on the SE-40 and if they differ from Hi-Fi News. Or if
>Solo Electronics has issued any statements about the review or
>their product claims.
I haven't seen any other measurements on the UK side of the pond, nor
any comment from Solo, but like Martin Colloms said, commercially
available single-ended amps do tend to have VERY optimistic specs! It's
unfortunately true that if you really want to get the supposed
advantages of single-ended tube amplifiers and have enough power for
conventional speakers, say 30 watts 20Hz-20kHz at 1 per cent distortion,
then you need a good low-ripple power supply, big output tubes with
powerful drive stages and VERY big output transformers. All of this,
especially the output transformers, does not come cheap!
OTOH, if you have reasonably sensitive speakers (90dB/W and a genuine 8
ohm load), you may find the SE40 is adequately powerful for your needs
and then the important thing is not the specs (which are poor for ANY SE
amp, even the grandaddy of them all, the Ongaku) but the actual sound
quality, which many people find extremely satisfying musically.
Dana Bunner
> >>>Well, there is a kit amplifier available by mail order from World Audio
> Design, the kit arm of Hi-Fi World, which also uses a pair of 5881/6L6s
> in parallel single-ended configuration, but it's rated at 17 watts! This
> is a more realistic value for this configuration, I find it hard to
> believe that any more than 30 watts is reasonably achievable from a pair
> of these tubes, plus the output transformers on the SE40 aren't big
> enough for this kind of power, hence the fall away to 7 watts at 20Hz.<<<
I agree that the SE40's measurements are not poor for its design and cost.
I have no problem with what it provides for the dollar. My gripe is with
the outlandish claims being made.
I think the same issue of Hi-Fi News took a look at a high-end single-
ended 300B-based unit (from Sparks) which claimed to have 32WPC, but
only measured like a 15WPC unit.
> As I recall, the SE40 uses *three* EL34s per side, not a pair of 6L6s.
> Someone please correct me if I'm wrong, but that's the way I recall seeing
> them.
It has 3 5881s per channel. And it has a total of 2 6SN7GTBs (Sovtek)
also. These are changable to 6SL7s for higher gain.
Dana
Lilleston
>>>Well, there is a kit amplifier available by mail order from World Audio
Design, the kit arm of Hi-Fi World, which also uses a pair of 5881/6L6s
in parallel single-ended configuration, but it's rated at 17 watts! This
is a more realistic value for this configuration, I find it hard to
believe that any more than 30 watts is reasonably achievable from a pair
of these tubes, plus the output transformers on the SE40 aren't big
enough for this kind of power, hence the fall away to 7 watts at 20Hz.<<<
As I recall, the SE40 uses *three* EL34s per side, not a pair of 6L6s.
Someone please correct me if I'm wrong, but that's the way I recall seeing
them.
--Randy
Stewart Pinkerton
lill...@aol.com (Lilleston) writes:
I'm looking at the illustration on page 32 of the June 1996 Hi-Fi News,
which is the review mentioned, and the tubes are marked Sovtek 5881/6L6.
It doesn't help that the text describes them as pentodes, however! I was
wrong about the number though, there are indeed three of them per side -
oops! This being the case, a genuine 40 watts output should have been
just about possible, though 25-30 would be more reasonable, so maybe the
design is less than ideal - certainly the results indicate that the o/p
transformers are way too small.
William Gode
In article <31EC05...@macc.wisc.edu> Dana Bunner <dbu...@macc.wisc.edu> writes:
>From: Dana Bunner <dbu...@macc.wisc.edu>
>Subject: Re: Golden Tube SE-40 Specs
>Date: Tue, 16 Jul 1996 16:09:43 -0500
>I agree that the SE40's measurements are not poor for its design and cost.
>I have no problem with what it provides for the dollar. My gripe is with
>the outlandish claims being made.
Who is making the "outlandish claims" regarding the SE-40? The factory?
If you look *carefully* at the specifications page in the SE-40 manual
you will see that the manufacturer states the following:
"T.H.D.: >0.009% @ 1W, 5% @ Full Output"
The symbol ">" means "greater than" and it seems to me that all the
various THD vs. power measurements support THD that is "greater than"
.009% at 1 watt and 5% at 40 watts, yes? (Anybody READ the specs?)
As satisfied SE-40 owners (listening, not measuring), my friend and I
telephoned the factory on 7-17-96 to get their comments on the power
output vs. THD issue. We were told that Golden Tube (Solo Electronics)
stands by their measurements which indicate "approximately 5% THD" at
40 watts per channel. They went on to state that all single-ended amps
have high distortion numbers and, if they spec'd the SE-40 at 10% THD
(the way Cary does with their single-ended amps) the SE-40 puts out
closer to 50 watts per channel.
Subjectively, the amps sound just wonderful on a variety of speakers
and seem to play as loud and clean and any other 40 watter we've heard.
BTW, the three 5881s are run in "Class A Ultralinear mode with an extra
cathode winding for enhanced bass control." The tubes are adjusted to
run at 58 mA cathode current (per tube) for a pure class A output power
of 13 to 14 watts per tube.
Happy listening!
Bill Gode
Tim Takahashi
Stewart Pinkerton <a...@borealis.com> wrote:
Dana Bunner <dbu...@doit.wisc.edu> writes:
>>However, as a potential purchaser of the SE-40, I must say that I
>>feel there is an ethical issue here. I auditioned the SE-40 under
>>the Golden Tube-driven perception that this was a 40WPC amp with
>>impressive THD figures. If Hi-Fi News is correct, then Solo
>>Electronics is simply lying about the amp's output power and
>>measurements.
>believe that any more than 30 watts is reasonably achievable from a pair
>of these tubes, plus the output transformers on the SE40 aren't big
>enough for this kind of power, hence the fall away to 7 watts at 20Hz.
Which is true..... and not to step on anyones toes (since I
do have a single-ended tetrode amp, in my 1937 RCA console radio)
but who on earth would consider a single ended tetrode amp
a desireable topology for high fidelity use?
From the transformer design standpoint, the problem of
core saturation is much worse when dissapating the idle
current for a 30w SE amp than for an 8w amp.
From the technical standpoint, the desireability of the
2A3 and 300B are due to their marvelous linearity (which
allows low distortion to be obtained with minimal or
no feedback). KT88s, 6L6s, etc. require considerable
feedback (by triode standards) to begin to compete
technically.
Maybe I need to listen to the SE40... but I've mused
over homebrewing this sort of amp numerous times
in the past and the disadvantages (need for feedback,
high open loop distortion, need for high-mu driver
stange, etc) outweigh the advantages (cheap and
common tubes) in my opinion.
-tim
StuartMcc
In article <4sfqdk$r...@newsgate.dircon.co.uk>,
pat...@popmail.dircon.co.uk (Stewart Pinkerton) writes:
>Well, there is a kit amplifier available by mail order from World Audio
>Design, the kit arm of Hi-Fi World, which also uses a pair of 5881/6L6s
>in parallel single-ended configuration, but it's rated at 17 watts! This
>is a more realistic value for this configuration, I find it hard to
>believe that any more than 30 watts is reasonably achievable from a pair
>of these tubes, plus the output transformers on the SE40 aren't big
>enough for this kind of power, hence the fall away to 7 watts at 20Hz.
Stewart, the Golden Tube SE-40 has three 5881 tubes in parrallel for each
channel. Still, I think that 40 watts is a bit of an ambitious
specification. Regarding GT's abillity to retail the product at $980, you
must take into consideration that GT is making its own transformers (the
biggest single item cost for SE amps) and that Chris and Joseph Lau and
the family and friends that work for them hardly have a life outside of
their audio business. These folks put in extremely long hours in a low
overhead operation.
Stuart
Stewart Pinkerton
t...@isaac.me.rochester.edu (Tim Takahashi) writes:
>Which is true..... and not to step on anyones toes (since I
>do have a single-ended tetrode amp, in my 1937 RCA console radio)
>but who on earth would consider a single ended tetrode amp
>a desireable topology for high fidelity use?
>From the transformer design standpoint, the problem of
>core saturation is much worse when dissapating the idle
>current for a 30w SE amp than for an 8w amp.
Obviously true, but simply a matter of spending enough money to pay for
a huge core. You do need to believe VERY strongly that single-ended
sounds better, cost is typically double for the same power, bandwidth
and distortion, compared to a class A push-pull design.
>From the technical standpoint, the desireability of the
>2A3 and 300B are due to their marvelous linearity (which
>allows low distortion to be obtained with minimal or
>no feedback). KT88s, 6L6s, etc. require considerable
>feedback (by triode standards) to begin to compete
>technically.
True, but in ultra-linear mode and with a small amount of NFB, they do
compete well - and 6L6s are a LOT cheaper than 300Bs, which some would
consider to have an excessively warm sound compared to the 211 or 845.
>Maybe I need to listen to the SE40... but I've mused
>over homebrewing this sort of amp numerous times
>in the past and the disadvantages (need for feedback,
>high open loop distortion, need for high-mu driver
>stange, etc) outweigh the advantages (cheap and
>common tubes) in my opinion.
Fair enough, engineering is all about balancing the various relevant
factors and weighting them to your personal tastes.
Stewart Pinkerton
wi...@interaccess.com (William Gode) writes:
>>I agree that the SE40's measurements are not poor for its design and cost.
>>I have no problem with what it provides for the dollar. My gripe is with
>>the outlandish claims being made.
>Who is making the "outlandish claims" regarding the SE-40? The factory?
>If you look *carefully* at the specifications page in the SE-40 manual
>you will see that the manufacturer states the following:
>"T.H.D.: >0.009% @ 1W, 5% @ Full Output"
>The symbol ">" means "greater than" and it seems to me that all the
>various THD vs. power measurements support THD that is "greater than"
>.009% at 1 watt and 5% at 40 watts, yes? (Anybody READ the specs?)
Nice one, but clearly a typo and not what the manufacturer meant to
write - if it is deliberate, that's even more worrying as it'd be an
obvious attempt at deception. Incidentally, if someone REALLY wants to
push this, legally the comma separates the '>' from the '5%' so they
have no excuse for less than 40 watts at 5%.
>As satisfied SE-40 owners (listening, not measuring), my friend and I
>telephoned the factory on 7-17-96 to get their comments on the power
>output vs. THD issue. We were told that Golden Tube (Solo Electronics)
>stands by their measurements which indicate "approximately 5% THD" at
>40 watts per channel. They went on to state that all single-ended amps
>have high distortion numbers and, if they spec'd the SE-40 at 10% THD
>(the way Cary does with their single-ended amps) the SE-40 puts out
>closer to 50 watts per channel.
Hmmmm. That's WAY off what Hi-Fi News measured, they only got 26 watts
at 1 kHz, dropping to 6.8 watts at 20Hz for the same 5% distortion level
- how 'approximate' do they mean?
>Subjectively, the amps sound just wonderful on a variety of speakers
>and seem to play as loud and clean and any other 40 watter we've heard.
Oh sure, no criticism of the sound intended, just that their quoted
figures seem to be VERY optimistic, to put it charitably.
>BTW, the three 5881s are run in "Class A Ultralinear mode with an extra
>cathode winding for enhanced bass control." The tubes are adjusted to
>run at 58 mA cathode current (per tube) for a pure class A output power
>of 13 to 14 watts per tube.
That's interesting. What's the anode voltage? I'd have thought a maximum
of around 350 volts for a 5881, which would give 20.3 watts quiescent
dissipation, hence a practical class A absolute maximum of around 9
watts per tube, or 27 watts for all three, pretty close to the measured
figure! Someone needs a new battery in their calculator.
Dana Bunner
William Gode wrote:
> What is your agenda in slamming probably the only company that makes
> a nice sounding single-ended tube amplifier for under $1000?
That's an easy one. I'm in the market to purchase an amplifier and am in
the process of comparing several.
My agenda for probing the claims of Solo Electronics is a simple, I want
the truth about their amp.
Dana
Stewart Pinkerton
Dana Bunner <dbu...@macc.wisc.edu> writes:
>I know this type of design has trouble at
>very low frequencies, so I'd even be receptive to the power figures being
>quoted across a diminished bandwidth. Say 32Hz to 17000Hz.
There is no inherent design feature of the single-ended tube amp that
makes low frequencies unachievable, the 'problem' is simply one of cost.
The generation of 40 watts at 20Hz in a single-ended tube amp requires a
VERY big core of expensive grain-oriented steel in the output
transformer to avoid magnetic saturation - take a look at a picture of
an Ongaku sometime, and it's only a 28 watt design!
Stewart Pinkerton
wi...@interaccess.com (William Gode) writes:
>>Plus, given that the Golden Tube is being marketed primarily on its
>overall
>>quality, I am amazed that they would cite its specifications based
>upon
>>a 5% THD figure. That's not quality, heck that's not even high fidelity.
>Go measure ANY single-ended tube amplifier and see what THD you get.
>For that matter, measure the THD in most loudspeakers if you want to
>see numbers like 15-20% in the bass. If you want low THD, buy a
>transistor amplifier (and NO speakers).
It's true that most SE tube amps are pathetically incompetent in
engineering terms, is this supposed to be a defence of the SE-40? Just
to set the record straight, there are many speakers which will take 40
watts at 30Hz and produce less than 5% distortion. generally they cost a
bit more than the SE-40, but they will do it.
>What is your agenda in slamming probably the only company that makes
>a nice sounding single-ended tube amplifier for under $1000?
I had the impression that she expected the amp to produce at least close
to it's published specification, doesn't seem that unreasonable to me!
Tim Takahashi
Stewart Pinkerton <a...@borealis.com> wrote:
>t...@isaac.me.rochester.edu (Tim Takahashi) writes:
>>but who on earth would consider a single ended tetrode amp
^^^^^^^
>>a desireable topology for high fidelity use?
>True, but in ultra-linear mode and with a small amount of NFB, they do
>compete well - and 6L6s are a LOT cheaper than 300Bs, which some would
>consider to have an excessively warm sound compared to the 211 or 845.
Now wait jusss a minute here. The 300B was supposed to be
the "ultimate," and now an offhand remark about the 211 and 845?
and then passing off that a ultra-linear tetrode "competes"
well with a pure tridoe.
what goes?
>>Maybe I need to listen to the SE40... but I've mused
>>over homebrewing this sort of amp numerous times
>>in the past and the disadvantages (need for feedback,
>>high open loop distortion, need for high-mu driver
>>stage, etc) outweigh the advantages (cheap and
>>common tubes) in my opinion.
>Fair enough, engineering is all about balancing the various relevant
>factors and weighting them to your personal tastes.
I know what my personal tastes are; I have a pretty good idea
about how equipment goes together; but I dont see the point
behind the SE40, other than to cash in on the single-ended
"cachet."
Yes. A 40 watt single-ended power amp will require a large
transformer (whether driven by 300Bs or 5881s makes no
difference there). That's a given.
An 845 based power amp will require an extremely expensive
power supply (B+ running at +1000V or above).
Among the rational voltage power triodes, the 300B offers
the greatest output (8 watts singled-ended).
I've measured the difference in open-loop distortion
between tetrodes operated in "ultra-linear" and strapped
as "triodes." It is substantial; the triode-mode is better.
However, the efficiency of say EL34s run as triodes is
inferior to a proper power triode (300B).... so if you're
designing a ground-up power triode amp, the 2A3 or 300B
makes sense.
Single-ended 300B amps make sense in terms of absolute
minimalism. You can not devise a simpler circuit. Period.
That the distortion is low, and that they sound sweet
are all plusses. And I'll build a pair when I have the room
for a second sset of loudspeakers, efficient enough for
only 8w of power amp. As it stands, P-P triode-configured
EL34s are insufficient.
Single-ended masssed ultra-linear tetrodes dont make
sense in terms of purity of design, minimalism or
other rational engineering reasons.
-tim
.
Dana Bunner
First, I want to state that I appreciate the spirit of those who are defending
the SE40 amp. Obviously they are doing so due to the belief in the amp's ability
to produce a wonderfully pleasing sound. And a belief in both the design and
construction quality of the unit. I hope my comments are not taken as an attack
on either Golden Tube's overall product quality.
William Gode wrote:
>
> In article <31EC05...@macc.wisc.edu> Dana Bunner <dbu...@macc.wisc.edu> writes:
> >From: Dana Bunner <dbu...@macc.wisc.edu>
> >Subject: Re: Golden Tube SE-40 Specs
> >Date: Tue, 16 Jul 1996 16:09:43 -0500
>
> >I agree that the SE40's measurements are not poor for its design and cost.
> >I have no problem with what it provides for the dollar. My gripe is with
> >the outlandish claims being made.
>
> Who is making the "outlandish claims" regarding the SE-40? The factory?
>
> If you look *carefully* at the specifications page in the SE-40 manual
> you will see that the manufacturer states the following:
>
> "T.H.D.: >0.009% @ 1W, 5% @ Full Output"
>
> The symbol ">" means "greater than" and it seems to me that all the
> various THD vs. power measurements support THD that is "greater than"
> .009% at 1 watt and 5% at 40 watts, yes? (Anybody READ the specs?)
I can hardly believe the above statements are being made as a DEFENSE of
Solo Electronics. It implies that there was a purposefully deceptive
campaign by SE to lure people into buying their product. That they
selected numbers that they knew to be erroneous and then marketed the
products on those numbers, using a little ">" sign as a legal shield
in case anyone protested.
Why select .009% if it is not an accurate representation of their product's
specifications. Why not .0000001% ? Is .009% a "perfect" number in that
is it possible that someone might actually believe it?
Even as one who is somewhat upset with Solo Electronics, I would not dare
to go so far as to suggest they are manipulating numbers this blatantly.
> As satisfied SE-40 owners (listening, not measuring), my friend and I
> telephoned the factory on 7-17-96 to get their comments on the power
> output vs. THD issue. We were told that Golden Tube (Solo Electronics)
> stands by their measurements which indicate "approximately 5% THD" at
> 40 watts per channel.
And I would like to believe them. I look forward to additional benchtests
of the SE40 to see if independment testers can verify their claims.
However the tests conducted by Hi-Fi News indicated that the 5% THD
figure was reached at 26 watts, not 40. And the 26 is available only in
the midband, not across the audible frequency range.
Plus, given that the Golden Tube is being marketed primarily on its overall
quality, I am amazed that they would cite its specifications based upon
a 5% THD figure. That's not quality, heck that's not even high fidelity.
If they are a quality-oriented company, then they should, IMHO, be more
upfront with their specifications. As a potential purchaser, I think I
have a right to know their power output and frequency range at a livable
distortion figure, say 1.5%. I know this type of design has trouble at
very low frequencies, so I'd even be receptive to the power figures being
quoted across a diminished bandwidth. Say 32Hz to 17000Hz.
I would like to see how many watts per channel is produced on a SE40 across
a 32-17K bandwidth at a maximum of 1.5% THD. I don't think this is an
unreasonable request at all. "Hi-Fi News" indicates that in order to get
a wide bandwidth at less than 1% THD, they had to keep the amp under 5 watts.
I don't know if they were requiring a low end extension all the way down to
20 cycles in this test, I wish they had been more explicit.
It still appears to me that the SE40 is more correctly classified as a
20-25 watt amp.
> Subjectively, the amps sound just wonderful on a variety of speakers
> and seem to play as loud and clean as any other 40 watter we've heard.
I've heard very positive feedback from many SE40 owners during this
conversation, certain customer satisfaction is an excellent indicator
of quality.
Dana
William Gode
In article <31EE58...@macc.wisc.edu> Dana Bunner <dbu...@macc.wisc.edu> writes:
>From: Dana Bunner <dbu...@macc.wisc.edu>
>Subject: Re: Golden Tube SE-40 Specs
>I can hardly believe the above statements are being made as a DEFENSE of
>Solo Electronics. It implies that there was a purposefully deceptive
>campaign by SE to lure people into buying their product. That they
>selected numbers that they knew to be erroneous and then marketed the
>products on those numbers, using a little ">" sign as a legal shield
>in case anyone protested.
Just trying to point out that Solo claims around 5% THD at 40 watts/chan.
>Even as one who is somewhat upset with Solo Electronics, I would not dare
>to go so far as to suggest they are manipulating numbers this blatantly.
Are you a lawyer? Nobody suggested manipulation of anything.
>Plus, given that the Golden Tube is being marketed primarily on its
overall
>quality, I am amazed that they would cite its specifications based
upon
>a 5% THD figure. That's not quality, heck that's not even high fidelity.
Go measure ANY single-ended tube amplifier and see what THD you get.
For that matter, measure the THD in most loudspeakers if you want to
see numbers like 15-20% in the bass. If you want low THD, buy a
transistor amplifier (and NO speakers).
>If they are a quality-oriented company, then they should, IMHO, be more
>upfront with their specifications.
Go borrow an SE-40 from your local dealer, hook it up in YOUR system
and see how is SOUNDS. Forget specifications. Look under the lid at
the build quality. Put it on your bathroom scale to check the 45 pound
net weight. Call the factory and have them tell you about the custom
transformers they build for this unit and the care taken in designing
and building these things. Ask them about the custom, computerized
distortion analyzer they use to test the amps. THEN, tell us they are
not "quality-oriented."
What is your agenda in slamming probably the only company that makes
a nice sounding single-ended tube amplifier for under $1000?
Bill
Dana Bunner
William Gode wrote:
>
> In article <4slq53$e...@newsgate.dircon.co.uk> pat...@popmail.dircon.co.uk (Stewart Pinkerton) writes:
> >Hmmmm. That's WAY off what Hi-Fi News measured, they only got 26 watts
> >at 1 kHz, dropping to 6.8 watts at 20Hz for the same 5% distortion level
> >- how 'approximate' do they mean?
>
> Just got off the phone with Chris Lau, President of Solo...He said
> that he met with Martin Colloms after the amp in-question had been
> tested and reviewed. Chris said that Martin agreed that something
> must have been wrong with either the input mains voltage applied to
> the amplifier, or the test procedures/equipment used.
Now this is what I have been looking for. Evidence that Solo is disputing Hi-Fi
News' measurements. Something that tells me that Solo is prepared to back their
claim of the SE40 truly being a 40WPC amp and meeting their THD specifications.
> Stewart, is it true that the *latest* issue of Hi-Fi News and Record Review
> has Martin Colloms using a PAIR of SE-40s to evaulate loudspeakers? I
> don't have access to the magazine, but have been told that's the case.
> If so, I guess Martin must not think too badly of Golden Tube.
In the last issue, Colloms stated that he would be evaluating the SE40 in monoblock
mode for the next issue. It is possible that this is the article being referenced
above, or maybe they are using them to evaluate speakers.
It should be noted the Colloms' criticisms of the SE40 were not solely confined to
measurements. In the text of the article he claims that during listening tests
(which he also claims were conducted prior to the bench measurements), he stated
that "heavier bass material quickly stretched the amplifier to the point where the
low-end weight evaporated, while the upper bass began to blur." Later in the
measurements section he states, "There is loss in the low bass as well as some mid
bass uneveness and a presence band [midrange] suckout. These errors were audible,
if not too objectionable in a musical context." He felt that transients and micro-
dynamics were first rate, with the qualification that they occur within the amp's
modest dynamic range.
Colloms rates amplifiers on a 0 to 30 scale. His overall score on the SE40 was a
19. However he did add that "single-ended fans could give it a truly audiophile 30"
but added that for "heavy metal fans it would score only a 10."
Bill, I guess you are one of those "single-ended fans."
Thus the review is certainly a mixed bag. Clearly he felt that there were some very
strong sonic attributes to the amp. In fact he wraps up the review with some
glowing phrases (delightful, natural, fluid, yet vital sounding midrange). Yet it
is peppered with caveats and poor measurements. In the end he recommends that
people give it a listen, but feels that "higher sensitivity speakers are recommended
if distortion is to remain at sub-audible levels." He used Wilson WITTs, Quad 63s,
and Spendor SP2s for the evaluation.
If Solo is correct that the SE40 unit tested was defective, then certainly the amp
should be retested with the results made well known.
Dana
William Gode
In article <4slq53$e...@newsgate.dircon.co.uk> pat...@popmail.dircon.co.uk (Stewart Pinkerton) writes:
>Subject: Re: Golden Tube SE-40 Specs
>Hmmmm. That's WAY off what Hi-Fi News measured, they only got 26 watts
>at 1 kHz, dropping to 6.8 watts at 20Hz for the same 5% distortion level
>- how 'approximate' do they mean?
Just got off the phone with Chris Lau, President of Solo...He said
that he met with Martin Colloms after the amp in-question had been
tested and reviewed. Chris said that Martin agreed that something
must have been wrong with either the input mains voltage applied to
the amplifier, or the test procedures/equipment used.
Stewart, is it true that the *latest* issue of Hi-Fi News and Record Review
has Martin Colloms using a PAIR of SE-40s to evaulate loudspeakers? I
don't have access to the magazine, but have been told that's the case.
If so, I guess Martin must not think too badly of Golden Tube.
>>BTW, the three 5881s are run in "Class A Ultralinear mode with an extra
>>cathode winding for enhanced bass control." The tubes are adjusted to
>>run at 58 mA cathode current (per tube) for a pure class A output power
>>of 13 to 14 watts per tube.
>That's interesting. What's the anode voltage? I'd have thought a maximum
>of around 350 volts for a 5881, which would give 20.3 watts quiescent
>dissipation, hence a practical class A absolute maximum of around 9
>watts per tube, or 27 watts for all three, pretty close to the measured
>figure! Someone needs a new battery in their calculator.
The SE-40 runs the Sovtek 5881s at an anode voltage of 475 volts.
(Remember that the Sovtek 5881 is more rugged than the conventional
5881, or 6L6 variants.) 475 Volts at 58 mA = 27.55 watts per tube.
At 50% efficiency, this results in 13.77 watts output, per tube.
At your estimated 44% efficiency, still over 12 watts output, per tube.
MY calculator says 36-40 watts output, per channel.
I love my SE-40. (How do you measure love?)
Bill Gode
David Beatty
Greetings all!
I'd like to make one comment.
What about the music?
I fear from the gist of this topic that the
key point has been lost!
What about the purpose of all this iron?
I've listened to ALOT of gear, and sometimes "audio ecstasy" occurs
in the strangest systems.....
The SE-40 is well made, sounds sweet and tubey. Too soft for my
liking, and alittle loss of detail in the upper mid/treble.
BUT!
That's just me.
The only gauge should be your own ears. F--- the reviewers. Most
of the brits (hey, i'm one!) are so biased to their own it's amazing!
Anyone listened to the KEF Coda? "Speaker of the decade" over there.
I think it sucks.
Anyway.....
The music is the point, after all!
DB
William Gode
In article <31EE7E...@macc.wisc.edu> Dana Bunner <dbu...@macc.wisc.edu> writes:
>From: Dana Bunner <dbu...@macc.wisc.edu>
>Subject: Re: Golden Tube SE-40 Specs
>My agenda for probing the claims of Solo Electronics is a simple, I want
>the truth about their amp.
Dear Dana,
At the risk of being redundant, why don't you borrow an SE-40 and LISTEN
to it in your own system. Trust your own ears and your own judgement.
Do not be so weak and insecure as to trust the opinions of total strangers!
On the other hand, perhaps you and Stewart Pinkerton should go into the
amplifier business and design your own power amplifier...produce well
over 1000 units at a retail price of under $1000...and get Martin Colloms
to grant you a favorable review. Sounds pretty simple to me!
Bye Bye
Tim Takahashi
Stewart Pinkerton <a...@borealis.com> wrote:
* True, but in ultra-linear mode and with a small amount of NFB, they do
* compete well - and 6L6s are a LOT cheaper than 300Bs, which some would
* consider to have an excessively warm sound compared to the 211 or 845.
Tim Takahashi <t...@isaac.me.rochester.edu> writes :
> Now wait jusss a minute here. The 300B was supposed to be
> the "ultimate," and now an offhand remark about the 211 and 845?
> and then passing off that a ultra-linear tetrode "competes"
> well with a pure tridoe.
* Well, the 300B is a good tube, but many consider the 211 and 845 to be
* superior. (snip) Compare the prices of these amps with the SE-40 however
* and you can see why people who are interested in what a single-ended tube
* amp sounds like might like to try the 5881 before committing the cost of a
* decent car to their power amp!
If we waive the requirement for specific output devices, why not use
FETs rather than Beam Power Tetrodes? I'm firmly in the tube camp
when it comes to audio, am an engineer by trade, and am absolutely
not a mystic.
I know what a 6v6 sounds like single ended (that old RCA radio again).
No thanks.
* The 5881 in ultra-linear mode is not all that far behind in linearity terms
* - let's not get TOO picky when we're talking about devices that struggle
* to put out 10 watts at 5% distortion!
Which is exactly my point. A 300B SE triode amp, may generate 5% distortion
at its maximum rated output; but functionally it is essentially distortion free.
The characteristic curves of the output triode let us predict this.
Unfortunately, beam power tetrodes aren't very linear. And when run
single ended, they dont have symmetry on their side to help out.
> I dont see the point behind the SE40, other than to cash in on the
>single-ended "cachet."
* That is the point - if SETs really do have a special magic
That's my point. There is NO magic. Soft clip, gently rising distortion
with output, extreme simplicity, lack of feedback related anomaly's
(transformer/speaker interaction). All these may be euphonic;
even a desireable design goal. But nothing here is magic.
*surely a 5881 will provide most of it, otherwise why not use a
*push-pull 300B amp
Which has crossed my mind on many an occasion. I have to investigate
phase inverters some more.... but the conventional topologies
strike me as being imperfect; a single ended topology eliminates
problem at the source (rather like a Newtonian telescope
avoids chromatic aberration).
>Single-ended 300B amps make sense in terms of absolute
>minimalism. You can not devise a simpler circuit. Period.
*The topology does not depend on the tube, you could use any triode or
*other triode-connected tube and get the same circuit.
But with dramatically less power (a 6L6 is good for 1-watt class-A,
triode strapped, single ended, +350v B+). +1000V B+ supplies are
extremely expensive; with parts sourcing troubles.
>Single-ended masssed ultra-linear tetrodes dont make
>sense in terms of purity of design, minimalism or
>other rational engineering reasons.
* They do to any rational engineer who's been trained to figure cost into
* the design equation - an engineer is someone who can do for a dollar
* what any fool can do for ten!
Then buy Sanyo.
While you might like the sound of your "SE-40," it isnt becuase of its low
distortion, or akin to the 300B/845/211 magic. It just aint so.
-tim
William Gode
In article <4sp0qr$s...@newsgate.dircon.co.uk> pat...@popmail.dircon.co.uk (Stewart Pinkerton) writes:
>From: pat...@popmail.dircon.co.uk (Stewart Pinkerton)
>Subtle difference, asshole!
My, my...did we hit a nerve? You don't have to be vulgar to make a point.
>Show me a commercially available design which meets those specs
>or pull your head in before it meets hot lead, pilgrim!
Already did. It's called the Golden Tube SE-40. With over 1000 sold
in less than two years. Sells used at 70% of new list. The *only*
"less-than-glowing" review comes from, uh, England. Musically wonderful.
>Single-ended 10 watt bipolar and MOSFET amps, push-pull class A bipolar
>and MOSFET amps from 30 to 100 watts, discrete class A preamps,
>high-speed op-amp preamps, passive control units, bipolar, FET and
>op-amp moving-coil headamps, sealed and reflex loudspeakers,
Nice list of accomplishments. No tube (valve) designing? Establishes
your obvious bias towards transistors very nicely for all to see. Thanks.
>What have YOU designed? And does it matter in defining our ability to
>LISTEN to music?
Doesn't matter what I've designed. I'm just glad that we finally have
*you* talking about "listening to music." Sorry you had to burst a
blood vessel in the process. The MUSIC was my point in the first place.
See ya...
Stewart Pinkerton
t...@isaac.me.rochester.edu (Tim Takahashi) writes:
>Stewart Pinkerton <a...@borealis.com> wrote:
>>True, but in ultra-linear mode and with a small amount of NFB, they do
>>compete well - and 6L6s are a LOT cheaper than 300Bs, which some would
>>consider to have an excessively warm sound compared to the 211 or 845.
>Now wait jusss a minute here. The 300B was supposed to be
>the "ultimate," and now an offhand remark about the 211 and 845?
>and then passing off that a ultra-linear tetrode "competes"
>well with a pure tridoe.
>what goes?
Well, the 300B is a good tube, but many consider the 211 and 845 to be
superior, despite the practical problems caused by the high anode
voltage. These would include the designers of the Audio Note Ongaku and
Cary 805, both of which use the 211, and the Unison Research Smart 845,
which of course uses the 845. The Jadis SE 300B uses a single tube and
the Audio Note Kassai uses a parallel pair of 300Bs, so you have a
choice of 'ultimate' power triodes in a range of world-class
single-ended amps, take your pick.
Compare the prices of these amps with the SE-40 however and you can see
why people who are interested in what a single-ended tube amp sounds
like might like to try the 5881 before committing the cost of a decent
car to their power amp! The 5881 in ultra-linear mode is not all that
far behind in linearity terms - let's not get TOO picky when we're
talking about devices that struggle to put out 10 watts at 5%
distortion!
>I know what my personal tastes are; I have a pretty good idea
>about how equipment goes together; but I dont see the point
>behind the SE40, other than to cash in on the single-ended
>"cachet."
That is the point - if SETs really do have a special magic, surely a
5881 will provide most of it, otherwise why not use a push-pull 300B
amp, which should retail at around the same cost for a 25-30 watt
design?
>Yes. A 40 watt single-ended power amp will require a large
>transformer (whether driven by 300Bs or 5881s makes no
>difference there). That's a given.
>An 845 based power amp will require an extremely expensive
>power supply (B+ running at +1000V or above).
>Among the rational voltage power triodes, the 300B offers
>the greatest output (8 watts singled-ended).
Er, what's irrational about a kilovolt power rail? Many solid-state fans
would consider 350 volts just as irrational!
>I've measured the difference in open-loop distortion
>between tetrodes operated in "ultra-linear" and strapped
>as "triodes." It is substantial; the triode-mode is better.
>However, the efficiency of say EL34s run as triodes is
>inferior to a proper power triode (300B).... so if you're
>designing a ground-up power triode amp, the 2A3 or 300B
>makes sense.
Only if you leave cost out of the equation - if you don't then the 211
or 845 could make even more sense, depending which designer you ask.
Most professional audio designers would suggest that the most important
part of a tube power amp is not the output tubes, but the power supply
and the output transformers.
>Single-ended 300B amps make sense in terms of absolute
>minimalism. You can not devise a simpler circuit. Period.
The topology does not depend on the tube, you could use any triode or
other triode-connected tube and get the same circuit.
>That the distortion is low, and that they sound sweet
>are all plusses. And I'll build a pair when I have the room
>for a second sset of loudspeakers, efficient enough for
>only 8w of power amp.
Ay, there's the rub!
>Single-ended masssed ultra-linear tetrodes dont make
>sense in terms of purity of design, minimalism or
>other rational engineering reasons.
They do to any rational engineer who's been trained to figure cost into
the design equation - an engineer is someone who can do for a dollar
Giri Iyengar
David Beatty <bea...@qb.island.net> writes:
> Most of the brits (hey, i'm one!) are so biased to
> their own it's amazing!
Is that what you call self-biasing?
..Giri
Stewart Pinkerton
David Beatty <bea...@qb.island.net> writes:
>> Most of the brits (hey, i'm one!) are so biased to
>> their own it's amazing!
Speak for yourself!
There is of course the problem of availability and then of course you
have to be careful about translating value for money judgements unless
you know the relative prices Stateside, but that's not the same as bias.
Stewart Pinkerton
wi...@interaccess.com (William Gode) writes:
>In article <31EE7E...@macc.wisc.edu> Dana Bunner <dbu...@macc.wisc.edu> writes:
>>From: Dana Bunner <dbu...@macc.wisc.edu>
>>Subject: Re: Golden Tube SE-40 Specs
>>Date: Thu, 18 Jul 1996 13:13:16 -0500
>>My agenda for probing the claims of Solo Electronics is a simple, I want
>>the truth about their amp.
>Dear Dana,
>At the risk of being redundant, why don't you borrow an SE-40 and LISTEN
>to it in your own system. Trust your own ears and your own judgement.
>Do not be so weak and insecure as to trust the opinions of total strangers!
>On the other hand, perhaps you and Stewart Pinkerton should go into the
>amplifier business and design your own power amplifier...produce well
>over 1000 units at a retail price of under $1000...and get Martin Colloms
>to grant you a favorable review. Sounds pretty simple to me!
Unfortunately, being an engineer I know it's not possible to retail a
genuine 40 watt at 5% over 20Hz-20kHz single-ended tube amp at less than
$2,000, so I guess it's not quite so simple after all! I'd use quadruple
5881s driven by another 5881, with a custom wound low-ratio output
transformer - would be a great looking chassis! Actually, that's not
true, I'd never put my name to a single-ended tube amp design.
OTOH, a REAL power amp with 60 class A watts per channel, less than 0.1%
distortion from 20-20kHz and superb sound is already available for
around $1,800. It's a push-pull MOSFET design called the Sumo Five. If
you insist on single-ended operation you can probably live with 30
watts, in which case buy the Pass Aleph 3. The truth is out there!
William Gode
In article <4sogfa$h...@newsgate.dircon.co.uk> pat...@popmail.dircon.co.uk (Stewart Pinkerton) writes:
>From: pat...@popmail.dircon.co.uk (Stewart Pinkerton)
>Unfortunately, being an engineer I know it's not possible to retail a
>genuine 40 watt at 5% over 20Hz-20kHz single-ended tube amp at less than
>$2,000, so I guess it's not quite so simple after all!
Didn't think you were up to the task.
What *have* you designed?
Stewart Pinkerton
wi...@interaccess.com (William Gode) writes:
>In article <4sogfa$h...@newsgate.dircon.co.uk> pat...@popmail.dircon.co.uk (Stewart Pinkerton) writes:
>>From: pat...@popmail.dircon.co.uk (Stewart Pinkerton)
>>Subject: Re: Golden Tube SE-40 Specs
>>Date: Fri, 19 Jul 1996 17:25:31 GMT
>>Unfortunately, being an engineer I know it's not possible to retail a
>>genuine 40 watt at 5% over 20Hz-20kHz single-ended tube amp at less than
>>$2,000, so I guess it's not quite so simple after all!
>Didn't think you were up to the task.
I didn't say I wasn't up to it, I said it couldn't be done. Subtle
difference, asshole! Show me a commercially available design which meets
those specs or pull your head in before it meets hot lead, pilgrim!
>What *have* you designed?
Single-ended 10 watt bipolar and MOSFET amps, push-pull class A bipolar
and MOSFET amps from 30 to 100 watts, discrete class A preamps,
high-speed op-amp preamps, passive control units, bipolar, FET and
op-amp moving-coil headamps, sealed and reflex loudspeakers, all of
these for the love of it (look up 'amateur' in your Funk & Wagnell).
Military test equipment and assorted other unfriendly hardware for
money.
Stewart Pinkerton
t...@isaac.me.rochester.edu (Tim Takahashi) writes:
>If we waive the requirement for specific output devices, why not use
>FETs rather than Beam Power Tetrodes? I'm firmly in the tube camp
>when it comes to audio, am an engineer by trade, and am absolutely
>not a mystic.
No problem, I'd rather use FETs any day!
>* The 5881 in ultra-linear mode is not all that far behind in linearity terms
>* - let's not get TOO picky when we're talking about devices that struggle
>* to put out 10 watts at 5% distortion!
>Which is exactly my point. A 300B SE triode amp, may generate 5% distortion
>at its maximum rated output; but functionally it is essentially distortion free.
>The characteristic curves of the output triode let us predict this.
>Unfortunately, beam power tetrodes aren't very linear. And when run
>single ended, they dont have symmetry on their side to help out.
No point in beating this one to death, can we agree the 300B is not an
order of magnitude better than the 5881 in ultra-linear mode?
>That's my point. There is NO magic. Soft clip, gently rising distortion
>with output, extreme simplicity, lack of feedback related anomaly's
>(transformer/speaker interaction). All these may be euphonic;
>even a desireable design goal. But nothing here is magic.
Agreed, that's why it stuns me that people will pay $10,000 and WAY
upwards for this kind of performance! Incidentally, the
transformer/speaker interaction might equally well be recorded under
'lack of feedback' PROBLEMS!
>*surely a 5881 will provide most of it, otherwise why not use a
>*push-pull 300B amp
>Which has crossed my mind on many an occasion. I have to investigate
>phase inverters some more.... but the conventional topologies
>strike me as being imperfect; a single ended topology eliminates
>problem at the source (rather like a Newtonian telescope
>avoids chromatic aberration).
Until you introduce an eyepiece to make the device useable!
>>Single-ended 300B amps make sense in terms of absolute
>>minimalism. You can not devise a simpler circuit. Period.
>*The topology does not depend on the tube, you could use any triode or
>*other triode-connected tube and get the same circuit.
>But with dramatically less power (a 6L6 is good for 1-watt class-A,
>triode strapped, single ended, +350v B+). +1000V B+ supplies are
>extremely expensive; with parts sourcing troubles.
So what? You didn't factor in cost, so what's with the 'kilovolt
supplies are extremely expensive'? There is NO parts sourcing problem,
all the bits you need to make a 2,000 volt supply rail are available off
the shelf, it's just that you normally use them for things like
microwave oscillators, not Hi-Fi amps.
>>Single-ended masssed ultra-linear tetrodes dont make
>>sense in terms of purity of design, minimalism or
>>other rational engineering reasons.
>* They do to any rational engineer who's been trained to figure cost into
>* the design equation - an engineer is someone who can do for a dollar
>* what any fool can do for ten!
>Then buy Sanyo.
Cop-out. Also buy Classe or Krell or Mark Levinson or Pass Aleph, they
don't come even close in price to the $52,600 300B Kassai!
>While you might like the sound of your "SE-40," it isnt becuase of its low
>distortion, or akin to the 300B/845/211 magic. It just aint so.
I don't own an SE-40, never would. I was just supplying some technical
answers to Dana Bunners questions regarding the SE-40s failure to meet
its published specs.
Jim Albano
Stewart Pinkerton writes:
>
>Subtle difference, asshole!
>
>
Geez, Stewart. Take a bhang hit and chill out. The point Bill was
trying to make is that the SE-40 has little to do with measurements
and everything to do with pleasure. The amp makes no pretense to
absolute neutrality, nor do I suspect was SOLO after specs and
measures as the end-all and be-all of the design. If the amp (or
its genre) ain't your cup o' tea, so be it. If it doesn't have
enough power for Dana Bunner or if Dana doesn't like the sound, so
be it. But I think Bill's point is that to evaluate the SE-40 in
purely technical terms is to miss the design goal of the amp. The
amp is obviously intended to appeal to that niche in the market
that favors beauty of sound over purely ascetic accuracy. If
"beauty of sound" isn't necessarily high-end, so what? The
aesthetic, artistic appeal of the amp precludes, for its faithful,
any guilt over the sacriligious departure from the hallowed grounds
of accuracy.
>
>[I've designed] Single-ended 10 watt bipolar and MOSFET amps,
>push-pull class A bipolar and MOSFET amps from 30 to 100
>control units, bipolar, FET and op-amp moving-coil headamps, sealed
>
Gulp. Well, Stew, I'm no engineer but that looks like an impressive
list of accomplishments to me. The audacity of Bill to question
your impeccable credentials! But in fact he was baiting you, and
you bit . . . . . big time.
Unfortunately it appears the objective/subjective debate rages
despite the truism that audio, like music and other art forms, is a
uniquely subjective experience. We all hear differently, value
different sonic phenomena, see and hear different things in great
works of art. Some people even like cubism, can you believe it?
Not to mention Coltrane and Kenny G. (Did I really use those two
names in the same sentence? Sorry, John.) And yes, Stewart, I
suspect some people even find your amplifiers satisfying.
But Bill's point is so simple: music is his aesthetic, and the
SE-40 has made his path purer. If exacting specification is your
aesthetic, then your amps might well make your path purer too. I
find it amusing, however, that you would dump on his path, because
ostensibly your goals are the same--the rendering of music. Unless,
of course, hardware and specs matter more than the music. Seems to
me that you engineers have never developed an accurate tool for
measuring emotional response, save perhaps the infamous polygraph
machine, the buzzing and whirring of which sounds horrible even in
the most accomodating environments.
Regards,
Jim A.
Stewart Pinkerton
wi...@interaccess.com (William Gode) writes:
>>Subtle difference, asshole!
>My, my...did we hit a nerve? You don't have to be vulgar to make a point.
You mean, like insulting someone's professional skills?
>>Show me a commercially available design which meets those specs
>>or pull your head in before it meets hot lead, pilgrim!
>Already did. It's called the Golden Tube SE-40. With over 1000 sold
>in less than two years. Sells used at 70% of new list. The *only*
>"less-than-glowing" review comes from, uh, England. Musically wonderful.
You haven't been reading the thread, have you? The SE-40 does NOT meet
its published specs, and by a wide margin! It does however, measure up
exactly as you'd expect of a single-ended amp retailing for less than a
grand. Incidentally, the 'less than glowing review' in Junes Hi-Fi News
criticised the technical results but was highly complimentary about the
sound. From the closing paragraph, "The SE40 enchants with a
delightfully natural, fluid, yet vital sounding midrange, with good
rhythm and timing, lovely transients and high transparency. These are
powerful qualities in a product of this modest cost, and I advise a good
listen for anyone desiring a closer approach to the heart of music
replay in this price range. There is more than a taste of audiophile
Nirvana here." Harsh words indeed :-)
>>Single-ended 10 watt bipolar and MOSFET amps, push-pull class A bipolar
>>and MOSFET amps from 30 to 100 watts, discrete class A preamps,
>>high-speed op-amp preamps, passive control units, bipolar, FET and
>>op-amp moving-coil headamps, sealed and reflex loudspeakers,
>Nice list of accomplishments. No tube (valve) designing? Establishes
>your obvious bias towards transistors very nicely for all to see. Thanks.
Very few designers work in both technologies, that doesn't mean they
don't recognise the strengths and weaknesses of the alternative
approach. If I were designing a powerful radio transmitter I would
certainly use tubes (that's the intended use of the 211 and 845), also
if I owned electrostatic speakers I would certainly audition some tube
amps with them. I have in fact tried a tube amp with my Duettas (the ARC
Classic 60) but it did not match the Krell KSA-50 - to my ears, of
course.
Stewart Pinkerton
j.al...@ix.netcom.com(Jim Albano) writes:
> Geez, Stewart. Take a bhang hit and chill out.
Grrrr! Snarl! Bad hair day, man, what can I say :-)
> The point Bill was
> trying to make is that the SE-40 has little to do with measurements
> and everything to do with pleasure. The amp makes no pretense to
> absolute neutrality, nor do I suspect was SOLO after specs and
> measures as the end-all and be-all of the design.
No argument there. Danas original point was that she started out with a
short list based on specs and I guess some reviews, and then she finds
that the SE-40 misses its specs by a mile, so she thinks they're being
dishonest. What do YOU think about a "40 watt" amp that puts out less
than 30 watts mid-band and less than 7 watts at 20 Hz?
My Krell KSA-50 puts out nearly 100 watts into 8 ohms, I'm not saying
that has any relevance to sound quality, but it does have relevance to
honesty in published specifications.
>>[I've designed] Single-ended 10 watt bipolar and MOSFET amps,
>>push-pull class A bipolar and MOSFET amps from 30 to 100
>>watts,discrete class A preamps, high-speed op-amp preamps, passive
>>control units, bipolar, FET and op-amp moving-coil headamps, sealed
>>and reflex loudspeakers . . .
>>
> Gulp. Well, Stew, I'm no engineer but that looks like an impressive
> list of accomplishments to me. The audacity of Bill to question
> your impeccable credentials! But in fact he was baiting you, and
> you bit . . . . . big time.
Didn't say any of 'em sounded good, did I? :-) Class A MOSFET power amps
are definitely the way to go though, and fast op-amps for everything
else! Helpful hint - the REAL skill is in the power supplies......
> But Bill's point is so simple: music is his aesthetic, and the
> SE-40 has made his path purer. If exacting specification is your
> aesthetic, then your amps might well make your path purer too. I
> find it amusing, however, that you would dump on his path, because
> ostensibly your goals are the same--the rendering of music. Unless,
> of course, hardware and specs matter more than the music. Seems to
> me that you engineers have never developed an accurate tool for
> measuring emotional response, save perhaps the infamous polygraph
> machine, the buzzing and whirring of which sounds horrible even in
> the most accomodating environments.
Ah yes, the 'you engineers' comment again. Actually, many of the
engineers who post in these groups are also musicians, and I started out
at University doing psychology, so I do have some grasp of the
measurement of emotional response :-). More seriously, I have no problem
with anyone who has a preference for technically inferior items such as
single-ended tube amps and LPs, the hissing matches usually start when
bogus 'proofs' are offered for why someones personal preference is
tecnically superior, when it plainly isn't. If you look at what I wrote,
I didn't dump on his path, I dumped on his rather snide attack on my
professional skills, subtle difference, sir :-). The thread originated
as a simple 'why are Solo lying about the SE-40s specs'. The actual
sound of the amp has never been criticised, only the fact that -
presumably for marketing reasons - Solo claim very impressive technical
specs for an amplifier whose design cannot come close to meeting them.