I am looking for a power follower like Andrea Ciuffoli's versions under
http://www.audiodesignguide.com/my/Follower_99c.gif (single ended class A)
http://www.audiodesignguide.com/my/Cool_Follower1.GIF (push-pull complementary)
http://www.audiodesignguide.com/my/Hot_Follower2.GIF (push-pull complementary)
but in a circlotron version with only two transistors (MOSFETs) and a balanced input.
Are such a diy project already started here ?
Thanks for an advice.
P.S.: this threads describes all versions with front end and voltage gain:
https://www.diyaudio.com/community/threads/current-feedback-mosfet-circlotron.345287/
https://blog.audiomaker.tech/pdf/antimatter.pdf
https://www.diyaudio.com/community/...t-circlotron-by-mike-rothacher.130810/page-15
https://www.diyaudio.com/community/threads/vssa-circlotron.261515/
https://www.diyaudio.com/community/threads/circlotron.353301/
https://www.diyaudio.com/community/threads/vssa-circlotron.261515/page-7#post-5789121
https://www.diyaudio.com/community/threads/joe-berrys-circlotron.384070/
https://www.diyaudio.com/community/threads/simple-circlotron.356473/
https://www.diyaudio.com/community/threads/jfet-only-circlotrons-without-negative-feedback.350904/
http://www.audiodesignguide.com/Hybrid2011/index.html
https://www.diyaudio.com/community/threads/d3a-mosfet-hybrid-circlotron.233152/
http://www.audiodesignguide.com/my/Follower_99c.gif (single ended class A)
http://www.audiodesignguide.com/my/Cool_Follower1.GIF (push-pull complementary)
http://www.audiodesignguide.com/my/Hot_Follower2.GIF (push-pull complementary)
but in a circlotron version with only two transistors (MOSFETs) and a balanced input.
Are such a diy project already started here ?
Thanks for an advice.
P.S.: this threads describes all versions with front end and voltage gain:
https://www.diyaudio.com/community/threads/current-feedback-mosfet-circlotron.345287/
https://blog.audiomaker.tech/pdf/antimatter.pdf
https://www.diyaudio.com/community/...t-circlotron-by-mike-rothacher.130810/page-15
https://www.diyaudio.com/community/threads/vssa-circlotron.261515/
https://www.diyaudio.com/community/threads/circlotron.353301/
https://www.diyaudio.com/community/threads/vssa-circlotron.261515/page-7#post-5789121
https://www.diyaudio.com/community/threads/joe-berrys-circlotron.384070/
https://www.diyaudio.com/community/threads/simple-circlotron.356473/
https://www.diyaudio.com/community/threads/jfet-only-circlotrons-without-negative-feedback.350904/
http://www.audiodesignguide.com/Hybrid2011/index.html
https://www.diyaudio.com/community/threads/d3a-mosfet-hybrid-circlotron.233152/
obviously there are no project as "CIRCLOTRON COOL FOLLOWER" - but maybe a push-pull circlotron hot follower ? - go to post #83 under
https://www.diyaudio.com/community/...-for-no-feedback-classab-buffer.174126/page-5
https://www.diyaudio.com/community/...-for-no-feedback-classab-buffer.174126/page-5
Circlotron power buffer can be very simple. The circuit in attachment (20W @ 8R) is biased with voltage dividers R13/R1 and R14/R9 to about 1A (Vgs = 2V). Changing the ratio of voltage dividers changes the bias - it's a push-pull circuit so it can work in class AB or A.
If more power is wanted the PSU voltage has to be higher - in that case the values of R13 and R14 have to be proportionally higher (in order to keep the same bias current).)
If Mosfets are not matched, a 5k pot connected in series with R1 or R9 can adjust the offset at the output.
Lateral Mosfets (k1058, k134/5 or Exicons) need no temperature compensation and no Source resistors (so we can enjoy higher cl. A envelope thanks to square law transfer characteristic) and, not to be forgotten, they sound very nice, especially in cl A. Since no global feedback is not present in this circuit, the damping factor is not high but I don't think it will bother you.
PSRR is not bad (about 70dB), just make sure that PSU has enough capacity say 2 x 33mF per channel (or less if you decide to go cl. AB).
If more power is wanted the PSU voltage has to be higher - in that case the values of R13 and R14 have to be proportionally higher (in order to keep the same bias current).)
If Mosfets are not matched, a 5k pot connected in series with R1 or R9 can adjust the offset at the output.
Lateral Mosfets (k1058, k134/5 or Exicons) need no temperature compensation and no Source resistors (so we can enjoy higher cl. A envelope thanks to square law transfer characteristic) and, not to be forgotten, they sound very nice, especially in cl A. Since no global feedback is not present in this circuit, the damping factor is not high but I don't think it will bother you.
PSRR is not bad (about 70dB), just make sure that PSU has enough capacity say 2 x 33mF per channel (or less if you decide to go cl. AB).
