Components do indeed make a difference, but definitely heed the wise words of the experienced members here - (if nothing more) for the sake of your wallet!
Everyone knows that DIY audio costs more than buying off the shelf.
In theory - should it? No.
In practice - does it? Yes.
Why? Because we're too caught up in the subjective aspects of our hobby.
As a certain great philosopher once said - "My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless, when he has climbed out through them, on them, over them. (He must so to speak throw away the ladder, after he has climbed up on it.)"
Likewise....great audio seems (unfortunately for our wallets), to be achievable only after spending so much money that one realises one didn't need to spend anywhere near the spent amount.
Everyone knows that DIY audio costs more than buying off the shelf.
In theory - should it? No.
In practice - does it? Yes.
Why? Because we're too caught up in the subjective aspects of our hobby.
As a certain great philosopher once said - "My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless, when he has climbed out through them, on them, over them. (He must so to speak throw away the ladder, after he has climbed up on it.)"
Likewise....great audio seems (unfortunately for our wallets), to be achievable only after spending so much money that one realises one didn't need to spend anywhere near the spent amount.
Hi and thanks for the advice.
I cannot explain why but i like the zero feedback designs, one that i have experience of being the Pass Bride of Zen.
A friend of mine built it following the original schematic with generic parts and it sounded ok.
Then i tried to modify a ps based on a lm317 to get the needed 60V
It lasted some minutes and then stopped working.
But the sound was better than with the original schematic.
As also the article of Mr Pass stated, the sound is very dependent from the PS quality.
And it was not an issue of parts quality but design that was wrong.
But the transparency was impressive indeed. Great design.
I think i will try it again even if the gain was too high for my power amp.
Thanks again,
gino
Thanks a lot for your valuable advice.
I am looking for a regulated 0-60V power supply circuit.
I was thinking of using this one ...
http://www.ti.com/lit/ds/symlink/tl783.pdf
what is your opinion ? better other options ?
The circuit is extremely sensitive to the quality of the power supply
and i now that is potential is spectacular but my result was only so so for the quality of the power supply. I am sure of this.
Thanks a lot,
gino
Hi i can testimony that this is completely true.
I had this Bride of Zen working ... and i was not completely satisfied with the sound ... a little lackluster.
So i started playing with the power supply.
The sound was even worse in most of the cases but very very different.
I think that this circuit has low PSRR being zero feedback.
So i am looking for a regulated 60V power supply for it that should still be in my cellar.
This circuit is amazing ... let everything through.
I do not know why is not more popular.
Thanks, gino
Hi and yes and no.
As someone has told me already a good understanding of the circuit at least is mandatory. Design one for me is magic ... completely beyond my ability.
Understanding a circuit means also to spot the parts more influencing the sound, for which a little more money can give sensible improvements in sound.
I have to little circuits to try ... both need 60V single supply to work.
So i m hunting for a suitable schematic.
Thanks, gino
Hi and yes and no.
As someone has told me already a good understanding of the circuit at least is mandatory. Design one for me is magic ... so beyond my ability.
Understanding a circuit means also to spot the parts more influencing the sound, for which a little more money can give sensible improvements in sound.
I have to little circuits to try ... both need 60V single supply to work.
So i m hunting for a suitable schematic.
Can the tl783 be a good solution for a regulated power supply ?
I need something easy to use and this regulator seems perfect.
Thanks, gino
Just to echo the other comments about power supplies - this is the heart of the amplifier: a superb power supply and ordinary amplifying circuit will subjectively far outstrip an ordinary power supply and superb amplifying circuit combo, especially if realistic sound levels are the goal - the other way round will only work if you listen always at very 'polite' levels ..
Hi and sorry to jump in but i am interested.
If i understand rightly zero feedback designs have poor PSRR. Do you think that they are also poorly performing ?
I am just asking because i think to rebuild a Mr.Pass Bride of Zen or similar concept with a single mosfet/bjt.
My impression has been that the BOZ has indeed a tremendous potential to sound really great.
Of course a high PSRR would be also nice but i am interested in the best possible approach to get good sound.
Even if this approach puts some challenges on the PS design and building.
Thanks a lot,
gino
P.S. by the way ... why PSRR and not PSNRR (power supply noise rejection ratio) ?
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Hi i am not sure if i understand what you intend with ordinary amplifying circuit
Maybe simple ? I mean, a zero feedback amp can have a very simple circuit, basic circuit. Maybe its PSRR is very poor and this puts consequently many challenges on the PS execution.
But someone think that Zero feedback is the way to go.
Otherwise a more complex high feedback circuit can have a very high PSRR but no hopes to sound superb.
This is an old but fundamental debate i think.
Mine is only a feeling but i am very fascinated by no feedback designs.
I have had a glimpse of their potential with the BOZ.
I never tried single ended tube amps but i think the situation is similar.
Thanks, gino
No, it is not a fundamental debate. It is not an old debate. It is a modern debate founded on misconception.
Some people prefer zero feedback because they prefer some distortion with their music.
Some people prefer zero feedback because they have tried adding a little feedback to a circuit not designed for feedback and they don't like the result so they wrongly conclude that feedback is a bad thing.
Some people think they prefer zero fedback because they think they are listening to zero feedback when in fact they are listening to significant feedback (e.g. via a follower circuit, or emitter/cathode/source degeneration, or a triode).
You do not understand rightly. A "zero feedback" design can have very poor or very good PSR, depending on the design and how much attention the designer paid to it.
Hello and thanks for the valuable advice.
I hope i am not wrong when i say that the Bride of Zen is a zero feedback design. So i read in the article describing it.
Thanks, gino
It appears to have a 100R degeneration resistor. That is feedback. It will reduce gain and raise output impedance. Usually, the latter is exactly opposite to what you need in a line stage.ginettot61 said:
Some people try to argue that degeneration is not feedback. I can only assume they do this so they can maintain their myth that they prefer zero feedback. It is exactly analogous to someone who says he never eats fruit but likes oranges, so he claims that oranges are not fruit.
Good point. People just aren't precise in their language when discussing feedback. Eg. "I don't like GNFB" quickly becomes "I don't like feedback."
SY's response has the ingredients of the answer: it's a circuit where the designer has not paid much attention to the details of its behaviour - in other words, a copy and paste of a standard, textbook approach, say ...
Thanks again for your valuable explanation.
I have been clearly misled by the article.
Just to understand better could you give me an example of very simple zero feedback circuit ? Now my curiosity is very high.
At this point i wonder if really zero feedback circuits do exist
To be honest i start to hate this zero feedback thing
Thanks again and kind regards,
gino
Hi and thanks.
I understand that the issue is completely beyond my ability to understand.
I am obviously sad for this because i have to trust someone when he says that his creations are the best ones.
Just think that someone say that even textbook design can sound spectacular ...
I have no hope to understand if he is saying the truth or he is only marketing his products.
Something more similar to religion/voodoo than science ...
I think i have to live with that.
Thanks to everyone.
Have a nice day,
gino
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