Well, thank you Nelson. My little stash of K170's and J74's just got even more interesting (as if they weren't before)...
well, it would be revelation to find a way of using lesser xconductance JFets instead of higher xconductance ones, without additional gimmicks
but, that sort of miracles are ........ well, just wishes
but, that sort of miracles are ........ well, just wishes
Looks like ill have to buy some lower grade Jfets before the prices go up from this article haha
Here is a link to the Erno Borbely Jfet article.
https://audioxpress.com/assets/upload/files/Erno BorbelyJFETs The New Frontier Part 1and 2.pdf
https://audioxpress.com/assets/upload/files/Erno BorbelyJFETs The New Frontier Part 1and 2.pdf
Switched-mode power supplies in class A, GR gerade jfets, biasing past Idss...just when you think you've seen it all...
(For the record, I don't think I have seen it all, it's just a saying 😉 )
(For the record, I don't think I have seen it all, it's just a saying 😉 )
If my memory is correct the DiyAudio Store LSK170 /LSJ74 Grade A was the most expensive grade and not the cheapest?
Before I knew anything about Idss I just purchased some JFETs together with various kits (ACA, M2X etc.) just to have some for future projects and because the A-grade was the most expensive I thought that they were probaby the best and had less noise figures. Later I understood that GR and BL grade was the ones that was used to all projects and I wondered why the A-grade was so expensive and it probably was a mistake to get those 🙂
Before I knew anything about Idss I just purchased some JFETs together with various kits (ACA, M2X etc.) just to have some for future projects and because the A-grade was the most expensive I thought that they were probaby the best and had less noise figures. Later I understood that GR and BL grade was the ones that was used to all projects and I wondered why the A-grade was so expensive and it probably was a mistake to get those 🙂
The good news is that between Linear Systems and purchases of some Toshibas
the supply situation is improving.
Now I understand your comment.
If the lower Idss spec JFETS' operate so well under greater stress, does this mean the V grade JFET's might make a nice power amplifier without having to use one thousand in parallel?
the supply situation is improving.
Now I understand your comment.
If the lower Idss spec JFETS' operate so well under greater stress, does this mean the V grade JFET's might make a nice power amplifier without having to use one thousand in parallel?
The essence of the Beast is to use a lot of small signal fets biased so they do not require additional heat sync. If the additional cost of the devices is offset by the elimination of the heatsink, you have a unique solution. Once you leave the SOA in free air, the project becomes less compelling.
I'm not saying it can't be done. I'm just pointing out the chalanges.
Just 2 pence.
This was a really helpful read. Clarified a few things that hadn’t sank in for me. Thanks NP! And you can send the surplus K370’s to me - I’ll make sure to get them to OPLDF 😀
