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Posted by wolfy on
08-26-2018
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Paul McGowan is a regular poster on youtube. I have to take his presentations with a grain of salt as they always conform to sales pitch for PS Audio products, but they are interesting. Recently, he asserts that tubes in preamp stage will provide higher resolution. Ok, great, but if that is the case I would like to better understand why. Romy asserts that tubes belong in the power amplifier and not in preamp section. Ok, great too, and that makes more sense to me.
Really, tubes are more transparent that solid state? It's my understanding that tubes are inherently producing more distortion of the signal, so how is resolution or transparency going to be better with tubes?
https://www.youtube.com/watch?v=AlyJVhUykug
W.
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Posted by Romy the Cat on
08-26-2018
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Wolfy, first of all your
question is based upon wrong supposition. I never asserted that tubes belong in
the power amplifier and not in preamp section. I never remember made this comment
and why I know it is because it is never was a part of my believe system. I generally
do not think that SS circuitry can much in term of quality to a properly implements
tube circuitry but this thinking has a LOT of contingents. I am not circuit
specialist and I am rather a brutal end user and I can only judge form the examples
that I witnesses. I have seen remarkable
SS and tubes amps but generally I feel that tube amplifiers as class are more
cables then SS amps. The mistaken supposition that you took was probably because
I use SS preamp in my own playback. First of all what I use for my playback is
not coupled with my believe system. Second, I use it mostly because for the topology
of the playback I use I need an ultra-low output impedance in my preamp. The
third is because I did not have a preamp that would beat my active Placette in term
of transparency and dynamics. I do not claim that they do not exists, they might,
I just do not have it.
Regarding, the Paul
McGowan: it tend do not watch his films as some kind of intellectual challenge.
I have seen a few of his films, it was entertaining and his is a very comfortable
with himself man. He still in his wisdom, in my estimation, do not rise to the
level of demands that I impose to Sound.
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Posted by wolfy on
08-27-2018
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I had in mind a few comments made on your forum which I had in mind when I listened to Mr. McGowan:
"Vacuum Tubes the Vacuum Tubes must not be used in line level outputs. In audio Vacuum Tubes meant for power amplifiers, preferably for out stages, that where they do job."
"14) A preamplifier shall not use vacuum tubes as output devises. Come on, get real! No one yet built an absolutely transparent tubes buffer. The output stages of an Ultimate preamplifier shall be DC-coupled SS devise."
I must have misunderstood your points.
Still, I do think Mcgowan's assertion is interesting. Maybe it does not matter whether tube or solid state, but more so how they are implemented.
W.
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Posted by Romy the Cat on
08-27-2018
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Well, the conflict you pointed might sound reasonable but not completely.
The First quote is taken from a thread “Disregard Digital with Vacuum Tube
output”. In there I advocated do not look into D/A converters with tube output stages.
In was in 2005 and at that time there were tones of DACs with tube output stage
that did the DAC’s “humanization”. I very much did not like it then and do not
like it now. Again, not because it is topologically impossible but because any single
DAC that I had/heard at that time was not good in my estimation and the best
DACs I have heard used SS outputs. So, in context of the thread the comment was
appropriate in my view.
The second comment is from 2009, the “The 15 Commandments of
Ultimate Preamp” thread. It said exactly what read: “No one yet built an
absolutely transparent tubes buffer”. I do stand with the observation that up
to the time I very actively was monitoring what the best was done out there I
did not see any tube preamp that I find to be transparent. I built a few my one
transparent tube buffers and I commissioned some people who I have high respect
to build buffers for me, not one was able to do it transparent enough. That
lead to my choses but I do not deny that it is possible to have a very transparent
buffer, there is nothing in tubes that theoretically limits it.
In my case I did not possible it as I was needed an ultra-low
output impedance whish in case tube preamps means an extra state … not good in
my books…
Again, regarding McGowan. I kind of discard those
talks because he was taking about “resolution” and I have no idea what it is.
Well, unfortunately I know what he and his audiences mean and I do not care
about this characteristic at all as they do not talk about “proper” resolution but
rather about transients contrasts – a bogues distinguishing of Audio confusion.
PS: With all it said, I agree that I have to be less “resolute”
in my judgment. I think nowadays I am possessing slightly softer judgment then
10 years back. I know that nowadays I would not spend another $100K and 4 year
of my life to chaise an ultimate tube buffer. I do applaud the people who would
and I would like to use it if it was discovered. I feel that a proper SS buffer
can do what make person do not want to look for tube buffer as the ultimate
tube of SS buffers would produce unethical results. The tube implementation
would be MUCH more expressive and exotic.
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Posted by gordan on
11-13-2018
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in the last years there was lots of development in field of DHT preamps. new circuits, or old circuits becoming practical and useful - especially related to hum inducing DHT heating issues that used to affect the sound. now you can basically have a superior full-DHT layout throughout amplification (both pre and output) much easier than before.
This YT video is strange. This topic can't be summed in 5 minutes talk, unless it's a sale pitch type, stating PS Audio knows the best. Sorry.
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Posted by Amir on
11-13-2018
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I have listened to AMR DP-777 DAC (SE versio and upgraded nos tubes) many times.in my idea the best sound of AMR dac come from "Bit-Perfect I" filter if you listen to good records. if i put bad records then there is no difference between filters and even i may prefer other filters.
https://www.stereophile.com/content/abbingdon-music-research-dp-777-da-processor-measurements
Bit-Perfect I filter means there is no filter in signal path (no digital and no analog filter).the time domain response of this mode has no overshoot and the time domain response is perfect.
Audionote UK removed Brickwall low pass analog filter after 2003 and all new AN dacs have no digital no analog filters in signal path. I have Audio Note DAC 5 Special.
these NOS tube DACs may have problem in low frequency extension (in a bass extended system) and processing complex music like classical orchestra (these DACs could not drive low impedance pre-Amplifiers) but in my two way system they are better than other DACs.
I have listened to many many expensive solidstate DACs (dcs scarlatti , CEC da0 3.0 , accuphase 100/101 and ...) but non of them give me the true sound.all of those ss dacs use digital and analog filters.
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Posted by Amir on
11-13-2018
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In loudspeaker and amplifier design we could use more channels to have better result (like 12 channel DSet concept) but i never seen any DAC/Pre to have more channels.It seems i am speaking about moronic idea but it is interesting to me think about that.For example designing 6 stereo channel DAC/Pre for a 6 channel of loudspeaker . It means we will have 6 separated stereo dac/pre.Crossover filters are not in digital domain.
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Posted by gordan on
11-14-2018
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 Amir wrote: | | In loudspeaker and amplifier design we could use more channels to have better result (like 12 channel DSet concept) but i never seen any DAC/Pre to have more channels.It seems i am speaking about moronic idea but it is interesting to me think about that.For example designing 6 stereo channel DAC/Pre for a 6 channel of loudspeaker . It means we will have 6 separated stereo dac/pre.Crossover filters are not in digital domain. |
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Of course there are, for example this is a very specialized product in this field - Najda DSP: http://www.waf-audio.com/products.php?pos=1&lang=en
8 analogue channel outputs with volume control so you can feed for example 4 x 2 channels of multi way horns.
i dont have any experience so someone else need to write how good and useful it is.
for sure there are other products like this today.
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Posted by Romy the Cat on
11-14-2018
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Gordan, this is slightly different
concept. The presence of multiple
outputs
with volume control does not assure that each of the channel has own time delay
circuitry. Plus it look like Najda
does volume at digital level, which is not so good. I personally
do not know any GOOD DACs that would incorporate multiple output buffers with individual
time delays made properly at digital level. Ironically a lot of very cheap pro
audio equipment have this option but I did not see in High-End audio anybody
went to it. There was a guy, I think it was in Moscow or in Poland who has two identical
DACs running and one of them run time delay. If you use only digital playing then
it is good direction to go to time synchronize the base horns with the rest of
the channels.
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Posted by gordan on
11-14-2018
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| Romy the Cat wrote: | | Gordan, this is slightly different
concept. The presence of multiple
outputs
with volume control does not assure that each of the channel has own time delay
circuitry. Plus it look like Najda
does volume at digital level, which is not so good. I personally
do not know any GOOD DACs that would incorporate multiple output buffers with individual
time delays made properly at digital level. Ironically a lot of very cheap pro
audio equipment have this option but I did not see in High-End audio anybody
went to it. There was a guy, I think it was in Moscow or in Poland who has two identical
DACs running and one of them run time delay. If you use only digital playing then
it is good direction to go to time synchronize the base horns with the rest of
the channels.
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Najda volume control is analogue in each channel. The rest I don't know, especially I don't know how DSP is implemented and if individual time delays are possible. But if you are able to physically time align your setup, I think this is very useful.
You are right about pro audio, I've been at few demos aimed to pros and was shocked with options that exist today. Actually if you want full control on what is happening in your room, you can go with smallest setups from L Acoustics, d&B, Nexo, or similar. They are far ahead of home audio and totally reasonable with prices in comparison...
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Posted by Paul S on
11-14-2018
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Well, so far, this has been the problem, that someone "solves" an audio problem in a way that takes the life and deeper meaning from the sound of evolved Music. What Romy said about digital sound processing was put kindly, but only because he was looking at the problem simplistically, in the context in which it was presented. For sure, if ever recorded sound can yield evolved results through multi-layered DSP, including during playback, then many of us will be rushing to implement these solutions! I hope anyone who thinks they have found a viable solution will share examples!
Best regards,
Paul S
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Posted by Romy the Cat on
11-15-2018
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| gordan wrote: | | Najda volume
control is analogue in each channel. The rest I don't know, especially I don't
know how DSP is implemented and if individual time delays are possible. But if
you are able to physically time align your setup, I think this is very useful. |
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Do not want to derail the thread about the magnificent Paul
McGowan, and it is despite that Amir has fucked it up, but I would disagree
with you, gordan. About Najda. It is good for them
that they went with analog out, if they did but in context of multichannel
output it is wasteful and an indication that they have one extra and completely
necessary buffer stage. A volume control should be at input but at output, otherwise
you would need an active stage to drive the cable after the volume control. A
good analog output stage is expensive and to waste it for not used channels is
very expensive. So, if they go with analog output stage for each channel then
it is a very simple and cheap adjusting a feedback in opamp or in some kind of
integrated chip where the functionality has built-in. So, I would vote for no
volume controls in DAC outputs, would it be a single channel or multichannel…
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Posted by gordan on
11-26-2018
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Frankly I don't need this explanation about Najda, I know it all - only wanted to point at its existence which can not be denied. For some people it will work. For us snobs loyal to our PLLXO solution, this device can be used for some basic experiments to check options on the fly, not as a final solution. What we need can only be DIY-ed so far.
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