Semisouth R100 Circlotron?

[woofertester]

I have 2 pairs of Semisouth R100 JFETs. Having successfully breadboarded a J113 circlotron circuit, I am considering trying a point-to-point lashup of a pair of R100s in a circlotron configuration. Has anyone already tried this?

 

[Zen Mod]

certainly is, though I can't remember where I've seen it

however, if you find schm with IRFP, changes for SJEP are trivial

 

[Jacruzer787]

Not IRFP, but Lu…


https://www.diyaudio.com/community/...-power-buffer-description-230522-pdf.1177133/

Lateral Mosfet version

Thread 'Simple Circlotron with Lateral MOSFETs'

2010-01-04 5:25 pm

Being a good buddy as he is, Jacco shared some of his 2sk135s with me, and not having the counter-part (2sj50) I decided to use them for a nice circlotron amp.
Different topologies were tried and here is what gave the best sonic result - Source Follower ie. power buffer driven with opa1632. I really love this chip (it's not an OpAmp but a full differential amp) - it sounds most natural and most appealing and I didn't found better sounding circuit as long as you don't ask for more than 12-13Vpeak per phase (per output) which is all I needed to drive this circlotron to full power.
I used...

• juma
• Replies: 31
• Forum: Pass Labs

 

[woofertester]

Thanks guys. I believe that I just need to invert the polarity of the Bias Adjust in this circuit for the Semisouth R100 and any normal N-MOSFET as well. .. and reduce the value of the Source R.

 

[Jacruzer787]

Very nice, keep us posted!

 

[generg]

@woofertester

Thread 'The LU1014 Circlotron Power Buffer'

2023-05-24 11:02 am

We have published before, and also recently, the DAO circlotron headphone amplifier built by NicMac.
https://www.diyaudio.com/community/...a-zgf-headphone-amplifier.225577/post-7325913
This really have exceptional performace without applying any global negative feedback.
So why not a power amp version ?

For the last 2 years during Covid 19, we have been working quietly on a circlotron power buffer for loudspeakers.
It takes the same idea of the LU1014 Triode Cell from the Zen Variation 9, but is different in that the LU1014 is used in follower mode.
How...

• EUVL
• Replies: 49
• Forum: Pass Labs

• 

 

[woofertester]

Hello generg. Thank you for your reply. I am following Patrick's DAO power amp developments. I will experiment with it when he publishes. I have a large stash of LU/LD 1014 and some matched pairs waiting for something worthy to try. A DAO cirlotron seems to be a perfect project. It is more complicated than a simple Semisouth R100 circlotron.

I just checked my parts stash and I have matched pairs of 2SK182ES and THF51 that I also want to try in a circlotron. I also have a small population of 2SK2087 but the population is too small for matched pairs.

 

[EUVL]

Yes, this one from 2023 is more interesting :
www.diyaudio.com/community/threads/the-lu1014-circlotron-power-buffer.399639/

But maybe people are not interested in circuitry these days, and just want something easy to build.


Patrick

 

[EUVL]

Hello generg. Thank you for your reply. I am following Patrick's DAO power amp developments. I will experiment with it when he publishes......

But we have already published everything.


Patrick

 

[generg]

Yes, this one from 2023 is more interesting :
www.diyaudio.com/community/threads/the-lu1014-circlotron-power-buffer.399639/

But maybe people are not interested in circuitry these days, and just want something easy to build.


Patrick

This what I linked!

:--))

 

[woofertester]

But we have already published everything.


Patrick

My mistake. My apologies. I have said before and it bears repeating, I thoroughly enjoy and appreciate your contributions.