SET Asylum

Posted by Ralph (M) on October 15, 2021 at 11:25:51

In Reply to: RE: Properly designed SE amps posted by tube wrangler on October 04, 2021 at 22:30:15

I don't use a CCS in single-ended circuits so I can't comment, but I use them in differential amps all the time and I do have this to say:

Most CCS circuits I've seen are detrimental, because they leave performance on the table and often have linearity problems. I solved that issue about 25 years ago by implementing a 2-stage CCS in our circuits. By having 2 stages it could be referenced to ground at one end- so it knew what 'quiet' was supposed to be; at the other end it was referenced to the power supply, so it could suppress noise from the power supply as well. You really do need a 2-stage CCS to get the job done.

In our amps the power supplies were not regulated. So the performance was affected by line voltage. With the CCS installed as described, the performance of the voltage amplifier circuit was unmeasurable with the line voltage variable from 105VAC up to 130VAC. The CCS over that range varied in performance by 17 parts per million. That's pretty sweet- works really well to reduce noise and distortion while increasing gain.

I can't speak to use in single-ended circuits.