Hello again,
i think i made a mistake... The A1715 is a darlington Transistor with 5 Amps, the MJE has only 3 Amps....cant find so many transistors with the same package and as darlington. Its only for drive the PS Fets...maybe somebody has an alternative, or can i use the MJE? Will the withstand the current?
i think i made a mistake... The A1715 is a darlington Transistor with 5 Amps, the MJE has only 3 Amps....cant find so many transistors with the same package and as darlington. Its only for drive the PS Fets...maybe somebody has an alternative, or can i use the MJE? Will the withstand the current?
That's a lot for a 494 to drive. What's the pulldown resistor value on terminals 9 and 10?
What about any of these:
TO-126 Darlington Transistors Darlington Transistors | Mouser
On an amp like this, can you charge enough to justify warrantying it if the owner blows it after you repair it?
What about any of these:
TO-126 Darlington Transistors Darlington Transistors | Mouser
On an amp like this, can you charge enough to justify warrantying it if the owner blows it after you repair it?
I don't know but for many of the larger amps, I know other shops were charging $400-500 to repair the amps. Most quit taking them after a while because they didn't want to have to deal with warranty repairs on those amps. I would not take in amps like this except for a few possibly to learn what I wanted to know. My customers would become violent if I didn't warranty their stupidity/ignorance so I avoided large amps that would cost more than about $150 to repair. About $40-50 of that would be parts.
For all of those FETs and the 494 with 180 ohms of pulldown, it's probably best to stick with darlingtons.
For all of those FETs and the 494 with 180 ohms of pulldown, it's probably best to stick with darlingtons.
So, i received the original transitors from Vibe. They were bery helpfull.
Now another Problem.
Renewed the Audio Section. Everything fine, amp plays music. But, when i switch the amp off, and in a short time on again, it blows a bank of fets in the output, also one IRS21844s is open. Happened two times now. Iam going to take out all fets aggain for recheck, but maybe somebody had this problem allready and know what to do?
Now another Problem.
Renewed the Audio Section. Everything fine, amp plays music. But, when i switch the amp off, and in a short time on again, it blows a bank of fets in the output, also one IRS21844s is open. Happened two times now. Iam going to take out all fets aggain for recheck, but maybe somebody had this problem allready and know what to do?
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Does the rail voltage build completely before you get r-r oscillation, like this:
http://www.bcae1.com/temp/ampstartup01.mkv
http://www.bcae1.com/temp/ampstartup01.mkv