BTW, I have a batch of Sony 2SK82 and 2SJ28's coming in.
Does anyone know the pinouts on them?
NP, did you ever try these during the early Threshold years, when the Yamaha and Sony VFET amps first arrived at the scene? Or was these transistors totally inaccessible then?
And is this batch of Sony VFET transistors large enough to build 100 F-something amps with VFETs?
Rolv-Karsten
Vfet
I meant to say "thank you" of course.
The VFETs was the possible holy grail in the 70ties, lots of promise, but even though VFET-sympathizer today hold e.g. the Yamaha B1 in high esteem, I doubt these are a match for todays better amplifiers. But could almost 40 years old devices like these VFETs still hold? Maybe - the 300B still is a very good tube, and if one can get the Toshiba 2SK146 that is still a good input JFET for a MC-preamp (I think John Curl used these in the early 80ties (JC80)).
Anyway (meanwhile, back at the ranch...) , NP, back to VFETs, wasn't it true that these required very special/complicated driver stages? And they were quite vulnerable, especially compared to the then new Hitachi power MOSFETs. So they disappeared from the scene.
Could you perhaps tell us more about your views on VFETs - pros and cons and all that?
Best regds
RK
I meant to say "thank you" of course.
The VFETs was the possible holy grail in the 70ties, lots of promise, but even though VFET-sympathizer today hold e.g. the Yamaha B1 in high esteem, I doubt these are a match for todays better amplifiers. But could almost 40 years old devices like these VFETs still hold? Maybe - the 300B still is a very good tube, and if one can get the Toshiba 2SK146 that is still a good input JFET for a MC-preamp (I think John Curl used these in the early 80ties (JC80)).
Anyway (meanwhile, back at the ranch...) , NP, back to VFETs, wasn't it true that these required very special/complicated driver stages? And they were quite vulnerable, especially compared to the then new Hitachi power MOSFETs. So they disappeared from the scene.
Could you perhaps tell us more about your views on VFETs - pros and cons and all that?
Best regds
RK
I have a board sitting in my bedroom with some paralleled J110s cascoded with a MOSFET, intended to drive a load through a transformer. No way is it anywhere near as ambitious as Nelson's JFET monster, but maybe I should finish it and give it a spin. Maybe a more ambitious construction could be done, as I have lots of J110s. I was thinking of a B+ voltage of 150-160V, just using a rectified isolation transformer.
Wrenchone,
I have alway wondered if such an amp was feasible and how it would sound. I have drawn up two abstract schematics of p-p amps like this. I was just wondering what people think of the concept.
How many jfet wound it take to get realistic voltage and current swing out of such an amp to get 20W ?
I have alway wondered if such an amp was feasible and how it would sound. I have drawn up two abstract schematics of p-p amps like this. I was just wondering what people think of the concept.
How many jfet wound it take to get realistic voltage and current swing out of such an amp to get 20W ?
I have been working on ZV7-J
I will attach my block diagram. Let me know if this will work.
Perhaps we should start a new thread?
Aren't the Lovoltech JFETS unobtanium? Is there anything comparable to sub?
I have some ideas on how to raise power and remove the input capacitors. Nelson may even get a laugh from it.
By the way, my code name for this is Fe.
I will attach my block diagram. Let me know if this will work.
Perhaps we should start a new thread?
Aren't the Lovoltech JFETS unobtanium? Is there anything comparable to sub?
I have some ideas on how to raise power and remove the input capacitors. Nelson may even get a laugh from it.
By the way, my code name for this is Fe.
Attachments
Last edited:
I have been working on ZV7-J
I will attach my block diagram. Let me know if this will work.
Perhaps we should start a new thread?
Aren't the Lovoltech JFETS unobtanium? Is there anything comparable to sub?
I have some ideas on how to raise power and remove the input capacitors. Nelson may even get a laugh from it.
By the way, my code name for this is Fe.
I'll post few links in your new thread
or - I'm lazy - here they are ..... :
http://www.diyaudio.com/forums/showthread.php?p=1662435#post1662435
(look at last pages)
and here is Magura's Donut progression :
http://www.diyaudio.rs/topic/7-donut-a-la-overkill/
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.