Rerurn to Romy the Cat's Site

Thanks, jk

I have given a lot of thoughts to this topic lately and have a number of conversations with various people about the subject. A friend of mine from Europe, who is currently at fitness protection program, suggested that:

“.. in my "real" systems (that is not commercial) I have been running "electrolytic free" for the last nearly a decade and if I had to use them [commercial gear] I have always minimized their influence on the signal circuits as much as possible...”

He offers quite a few techniques how small film caps still might be used and does not screw sound. There were some other proposals and suggestions from different sources, which made me to think: why I ever need capacious? The single-stage Melquiades is as close to cap-free solution as it could be so why do not take it more racial – making PS capacitance free?

I spoke with Dima and asked him to suggest me solutions how it might be accomplished.  The PS caps do two duties: short signal to ground and kill ripples.  After a long conversation he came up with numerous options including those the Steve Bench proposes. The solution one is to use choke, then 600R series resistor (or a choke with 660R DCR) then a shunt of two back-to-back VR 105 tubes.  The 0B2 has very low impedance and will do a perfect path to ground for signal and will kill quite a lot of ripples. My idea was to run the Fundamental and HF channels from my current B+ and to use “no-caps supply” only for MF channel what 30mA the gas tubes will be able marginally to handle. The second that Dima proposed was to run 6C19P as default shunt regulator.

http://www.goodsoundclub.com/pdf/6C19p.pdf

.. having it’s cathode on ground, anode driving the output transformer and having approximately -33V on it’s grid. Of course we got carried away considering application a feedback from amp to drive the regulator’s grid. There were some further solutions that would keep private for now.

I most likely will try it all on my MF but I have an “ethical” problem with it. My usual rule is to make any changes ONLY if I specifically identified a specific sonic problem with the sound that I already have:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=432

To be honest, I was playing the amp today with new dedicated power supplies on the single-stage channels and it was remarkably good, with me complaining about nothing. So, I might have some intellectual objectives to get rid of caps but I have no natural sonic temptation to pursue this direction. I know myself and I know that it is not the environment where my mind operates productively. So, I do not know where I will be staying on it.  The gas tube might be good, the shunt regulator might be good… but if the current cap sounds “properly” then what would be a definition of “better” for me? I am not a Moron from DiyAudio web site. Perhaps instead of experimenting with no-cap shunt I need to listen more my current MF channel and wait until I will be able to identify it’s weakness… and THEN to see if the no-cap solution would address those specific sonic faults.

Rerurn to Romy the Cat's Site