Your transformers are about half of the absolute minimum VA rating. They are probably hot as hell, and they will fail prematurely.
Bill
Bill
Only one pair and 30 volts rails! This is not reliable.
I suggest to lower the bias current to match the small transformer and the unique pair.
I suggest to lower the bias current to match the small transformer and the unique pair.
Why would he want to lower the bias, it's much too low now.
It would be best to start over with the right rail voltage.
You haven't given any info for us to be able to help you. Pics, drawings, sketches ?
Hi Everyone
maybe here is not the right place to ask my question but I take my shoot to ask anyway.
I already looking all over the place possible locally for 2SJ109 without no luck so if I insist to build J Aleph I must order it from overseas, before I do that I can find IRF9610 very easily and here my question to all of you who has changed from Aleph to J Aleph is that a worthy expense to me to order 2SJ109 from overseas shop or You think no big difference with just plain Aleph
Thanks
maybe here is not the right place to ask my question but I take my shoot to ask anyway.
I already looking all over the place possible locally for 2SJ109 without no luck so if I insist to build J Aleph I must order it from overseas, before I do that I can find IRF9610 very easily and here my question to all of you who has changed from Aleph to J Aleph is that a worthy expense to me to order 2SJ109 from overseas shop or You think no big difference with just plain Aleph
Thanks
If you cannot find the 2SJ109, a pair of well matched 2SJ74 will do the job
Using IRF9610 it's almost a downgrade to the Aleph 30
Using IRF9610 it's almost a downgrade to the Aleph 30
I already looked for almost any kind of P-channel no luck either
is upgrade from "normal aleph" to J Aleph is significant ?
looks like your IRF devices will be on the located on the heatsink in the same fashion as the board will be. Meaning that the board will be mounted on the sink by holes 1, 2, 3 and 4. It looks like ground goes to one of the 4 mounting screws for the board. If you ground that screw/bolt and then put it into the sink and then if you attach the IRF devices to the same sink you may short the mosfets. Maybe I am seeing it wrong, but thats what it looks like to me. Even if I was insulating the mosfets this would make me nervous.
Uriah
Did you try ebay? thera some vendords offering MP of 2SJ74
Yes, according to Nelson Pass 😉
xr000,
you are complaining about a hum but you tell nothing about your PSU.
Do you still have it when shorting the inputs?
you are complaining about a hum but you tell nothing about your PSU.
Do you still have it when shorting the inputs?
1st rule of pcb design : do not run a high current trace directly in parallel with one that leads to/from a high resistance load.
R11 is low resistance, but the input impedance of Q7 is definitely not.
You'd be in knee deep doodoo if Q7 was a lateral MOSFET device. (in particular with gate stopper R11 at such a distance from Q7)