Burned fingers, I certaily can't argue with your choices, despite offering a few alternatives.
So here is an afterthought. If the CCS shunt regulator would cause the pre-regulator portion of the to see a constant current, then the frequency dependent impedance of the PS is eliminated from consideration.
So, my guess is that if you simply designed a constant current draw configuration (my second solution), you would achieve the same effect without regulation.
However, you would lose isolation from line variations as Frank reminded me.
I have yet to hear the kind of difference that you have heard, so I will believe them until I have this opportunity.
Have you paid a visit to Frank's tube pages to get info on the 5692? If you haven't, you may or may not want to go look.
So here is an afterthought. If the CCS shunt regulator would cause the pre-regulator portion of the to see a constant current, then the frequency dependent impedance of the PS is eliminated from consideration.
So, my guess is that if you simply designed a constant current draw configuration (my second solution), you would achieve the same effect without regulation.
However, you would lose isolation from line variations as Frank reminded me.
I have yet to hear the kind of difference that you have heard, so I will believe them until I have this opportunity.
Have you paid a visit to Frank's tube pages to get info on the 5692? If you haven't, you may or may not want to go look.
Hi,
The Red October series from RCA are nothing more than reduced rated ordinary tubes for industrial use.
By downrating the maximum ratings of the standard models longer life and higher reliability was projected, tubes were selected and were give a read amphenol-like base.
Other than that they're still ordinary SL, SN or SJ7 tubes...they're fine but certainly not worth the asking price for audio apps.
This same method of downrating on so called specail quality tubes is very often applied to US tubes, contrary to European Special Quality tubes (SQ series) which more often than not were truely exceptional in design and life expectancy, some of them were so conservatively rated that although they were rated for 10.000 HRS they actually didn't vary more than 10% throughout their useful life of close to 50.000 HRS.
At the risk of sounding chauvinistic, almost any European made SQ tube will be special quality indeed and if not abused will last a lifetime.
While audio use wasn't what the the engineers had in mind almost all of the SQ tubes do offer all of the desiderata we look for and more; low noise, long life, low distortion, you name it and they tend to maintain those qualities throughout their life.
Cheers,
The Red October series from RCA are nothing more than reduced rated ordinary tubes for industrial use.
By downrating the maximum ratings of the standard models longer life and higher reliability was projected, tubes were selected and were give a read amphenol-like base.
Other than that they're still ordinary SL, SN or SJ7 tubes...they're fine but certainly not worth the asking price for audio apps.
This same method of downrating on so called specail quality tubes is very often applied to US tubes, contrary to European Special Quality tubes (SQ series) which more often than not were truely exceptional in design and life expectancy, some of them were so conservatively rated that although they were rated for 10.000 HRS they actually didn't vary more than 10% throughout their useful life of close to 50.000 HRS.
At the risk of sounding chauvinistic, almost any European made SQ tube will be special quality indeed and if not abused will last a lifetime.
While audio use wasn't what the the engineers had in mind almost all of the SQ tubes do offer all of the desiderata we look for and more; low noise, long life, low distortion, you name it and they tend to maintain those qualities throughout their life.
Cheers,
burnedfingers said:
Most CD players, except for perhaps the more esoteric ones have a cap on their output so I would say that the chance of damage to the pot from stray DC is small. On the other hand if you are going to regulate the supply and build it to the hilt do it right and put in a stepped attenuator and you won't have any worries. As far as regulation goes I have avoided it to this day simply because I have a nasty perfectionist tilt to my psyche and if it changes the sound to the better as drastically as you say then I would no longer be able to build simple circuits with resistors, capacitors, chokes and transformers and be satisfied with the sound. Then the powerful appeal of something so simple, so out of date, that sounds so nice (overstated warmth, distortion and power sags and all) would cease to be such an interesting and rewarding enterprise and would turn into a full blown obsession for the absolute perfect measurements and the most pure signal that I could afford to achieve. That as opposed to the semi-obsessed state I have been in since I tasted sweet success with my first project. Were I to go down that road of personal torture and discontent, were I to venture into that complex and arcane world of formulas and intuition (black magic?), I would soon be divorced and lonely and generally a waste of good oxygen. I'll stick with the romance and ignorant bliss. Perfectionism is the road to madness for me personally......sigh. I would build a nice CLCL filter with good stiff caps of the best quality I could afford and enjoy the fruits of my labor. Of course if you are already on the audio insanity search for the ultimate sound and technical perfection then you are on your own. Contentment is priceless and willful and selectively maintained ignorance is the key to a happy life.
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