Killed my T-Amp?

[JWFokker]

I got a new SI T-Amp after my first one died mysteriously, and now my second one isn't working either. The only modification I did to it was to wire it to my 12V power supply and now when I turn it on, the LED lights up, but no sound comes out. When I hook it up to my TCC preamp/switch box, if I turn the T-Amp on, the LED on the TCC channel indicator (Phono/Aux1/Aux2/Aux3) goes out regardless of what channel I have selected. Is the T-Amp dead or is something just not hooked up correctly?

 

[BWRX]

Is your 12V power supply actually 12VDC? Do you have a multimeter or oscilloscope you can use to probe around the circuit? Specifically, measure each output with respect to power supply ground. Each output should be floating around 6VDC. Also, look for 2.5V on the chip side of the inputs.

 

[JWFokker]

Inexplicably, at least to me, if I use a separate DC power supply for the T-Amp, everything now works. This is confusing though, because I had always used the single power supply previously.

 

[poynton]

Strange !

Could be a ground problem ?