Received this amp with burned power supply. Mosfets and drivers are gone.
Removed all Fets and Gate resistors.
Fet drivers are C2383
and A1013.. Same Pinout as BD139/140 ECB
Two problems:
First:
TL494 and drive card is ok. But one Drivewave has 8V Amplitude, the other 12V Amplitude.... All parts are removed, but it seems, that the problem occurs from mainboard.
Second Problem: Somehow the driver configuration is strange, and doesnt work.
Normally it is E/F follower pair.
But this one got B+ and B- at the base of the transistors.
collectors are collected and goes to the mosfets.
Emitters are collected together and get the drive signal from the TL494.
Has someone infos about that, or ever seen such a configuration?
Removed all Fets and Gate resistors.
Fet drivers are C2383
and A1013.. Same Pinout as BD139/140 ECB
Two problems:
First:
TL494 and drive card is ok. But one Drivewave has 8V Amplitude, the other 12V Amplitude.... All parts are removed, but it seems, that the problem occurs from mainboard.
Second Problem: Somehow the driver configuration is strange, and doesnt work.
Normally it is E/F follower pair.
But this one got B+ and B- at the base of the transistors.
collectors are collected and goes to the mosfets.
Emitters are collected together and get the drive signal from the TL494.
Has someone infos about that, or ever seen such a configuration?
It seems, that i have opened the amp for the first time. I removed A1023 and C2383.
The first problem with the different Amplitude seems to be normal. There is a resistor between, E2 and B- which drops the amplitude.
The first problem with the different Amplitude seems to be normal. There is a resistor between, E2 and B- which drops the amplitude.
There could be a pulldown resistor between the emitters and ground but you should have them for both banks of drivers.
Ok, there are two resistors tied to B-. One for each bank.... So only left the configuration of the drive transistors... Very strange
