Amir, I have already received the power supply that he advised buying (he plans to make some modifications to it now). Yet I am still scared that it might damage THX, as I am no engineer myself. Could you kindly advise on how dangerous it would be just to try as an experiment using a linear power supply with THX? I understand that it would void the warranty, but what are exact risks if I use the same voltage PS?
The power supply I intend to use has the following specs:
Output voltage from 2 to 30 V adjustable.
Current-carrying capacity - 2 A.
Nominal power - 200 V·А.
Maximum output voltage discharge - 2V.
Full output resistance - 10 Ohm.
Since this is a variable supply, you need a voltmeter to measure and set its output. Multimeters are pretty cheap. Get one from amazon, ebay, etc. Get one with auto-ranging so don't go to less than $10 meters.
Next you measure the THX power supply, putting the positive/red cable from multimeter in the center hole and the black on the outside. Note what that voltage is, and importantly if you see a negative for the shown value. Oh, the meter needs to be in DC volts. Maybe someone else can do this and report so you can skip this step.
After that, you do the same measurement with the supply you bought. Before powering on the new supply, plug it into the THX amp to make sure it fits and is snug. There are different sized connectors. Again, do this *before* you turn on the power supply.
Then disconnect the cable from the THX amp on the new power supply to the multimeter, connect the wires per above, and adjust the variable voltage potentiometer until it reads the same value as the original THX amp. And importantly, with the same polarity (i.e. if THX is positive, make sure it is positive with the new supply too).
Getting the polarity right is *far* more important than getting the voltage right! Get a battery and test it with the meter, swap the wires back and forth and you see what I mean with polarity.
One the polarity and voltage are the same, then you can connect them to the THX amp. Turn the supply on, power on the THX amp and be ready to quickly disconnect if you smell anything burning, and/or popping sound.
If you like you can post pictures of measurements for each step we can help you with that too.
Chances of something going wrong is small if you blindly plug it in but if it does, given the shortage of units and cost of THX, you will have a lot of regrets.