Nice to see some Super IT talk again on Diyaudio! Do any of you know the part number of the original FETs?
Late 2020, I compared my SuperIt to the only rev. schematic I've ever seen online and found add'l circuitry not on the schematic...but I made a list of parts as well as I could.
Now I have to find it (I save everything...cartons of notepads, printouts, etc. They're not lost...they're just misplaced).
Now I have to find it (I save everything...cartons of notepads, printouts, etc. They're not lost...they're just misplaced).
I have not found my Super-IT notepad yet.
To a previous question about the NPN power transistor...mine has TIP50.
I am out-boarding a replacement power transformer and will have to use series voltage dropping resistors...so I might as well use a few RC filter stages and a bleeder resistor in the outboard chassis.
In a previous e-mail with George Kaye, he said the HV regulator produces 250 VDC, so if I am doing outboard pre-regulation, I would only need about 260 VDC into the regulator.
He didn't recall the current draw of the 3 tubes.
I thought I read somewhere 8 mA, but doubt I actually read that as I cannot find it again. more likely I remembered info from somewhere else...so I don't trust it.
Knowing the total plate current would allow me to pre-determine the dropping resistor values. Otherwise, I'll have to feed it a variable B+ & measure.
I'm curious if anyone has ever measured the cathode current or voltage drop.
Then we'd be assuming we have identical builds. My board has a different Rev. letter than the schematic circulating (sometimes) the internet.
Oh, I'll at least look at my SuperIT PCB for the JFET p/n's. I did determine they were all the same on mine...U-something...can't remember the number at the moment.
Thanks
To a previous question about the NPN power transistor...mine has TIP50.
I am out-boarding a replacement power transformer and will have to use series voltage dropping resistors...so I might as well use a few RC filter stages and a bleeder resistor in the outboard chassis.
In a previous e-mail with George Kaye, he said the HV regulator produces 250 VDC, so if I am doing outboard pre-regulation, I would only need about 260 VDC into the regulator.
He didn't recall the current draw of the 3 tubes.
I thought I read somewhere 8 mA, but doubt I actually read that as I cannot find it again. more likely I remembered info from somewhere else...so I don't trust it.
Knowing the total plate current would allow me to pre-determine the dropping resistor values. Otherwise, I'll have to feed it a variable B+ & measure.
I'm curious if anyone has ever measured the cathode current or voltage drop.
Then we'd be assuming we have identical builds. My board has a different Rev. letter than the schematic circulating (sometimes) the internet.
Oh, I'll at least look at my SuperIT PCB for the JFET p/n's. I did determine they were all the same on mine...U-something...can't remember the number at the moment.
Thanks