I have no way to match small signal transistors unfortunately. I agree, it's a good possibility that transistors from the same batch might be matched close enough. I just want to make sure first that the amp works as it is before starting any upgrades/updates.
A quick update.
* Turned on the power supply, voltages for amp were spot on (+/- 73VDC); amp not installed; protection relay clicked.
* Reinstalled amp board. Output boards not installed yet (and small board that sits on the heasinks). Turned on the receiver. Protection relay clicked. All four driver transistors got very hot after 1 minute. Turned it off. (other parts were cool to the touch on the board - electrolytics and large ceramic resistors).
Trying to figure why drivers would get hot. Is that because the output stage is not installed? But at the same time, why would they fully open with no outputs connected?
Should I continue and install the output stages, or start troubleshooting at this stage?
A quick update.
* Turned on the power supply, voltages for amp were spot on (+/- 73VDC); amp not installed; protection relay clicked.
* Reinstalled amp board. Output boards not installed yet (and small board that sits on the heasinks). Turned on the receiver. Protection relay clicked. All four driver transistors got very hot after 1 minute. Turned it off. (other parts were cool to the touch on the board - electrolytics and large ceramic resistors).
Trying to figure why drivers would get hot. Is that because the output stage is not installed? But at the same time, why would they fully open with no outputs connected?
Should I continue and install the output stages, or start troubleshooting at this stage?