2. amps-preamps
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Does my Pass amp dislike my Meridian preamp?

My Meridian G68 (preamp/processor) has been acting up, and my Meridian dealer suggested that the symptoms might be caused by an interaction with my amp, a Pass Labs XA30.5. I have consulted with a trusted Audiogon member, who doubts this theory. So I would like some more input. Here are the symptoms:

1. Meridian G68 freezes up. Neither the remote nor the front panel buttons are responsive. Must be unplugged and plugged back in to work again.

2. After it freezes and I power it down, sometimes a loud “popping” noise is emitted by the speakers.

3. In August, the Meridian G68 stopped working altogether. It was repaired by Meridian America. They replaced the power button and the power supply. But now the symptoms are back.

Thoughts?
bryoncunningham
atmasphere's avatar
atmasphere
12,138 posts
 
Bryoncunningham, the fact that it sounds better suggests that someone (not you) has not done their homework... I think your approach here is a good move.

If it seems to be OK- you might have the cause narrowed to the computer and the power supply, but the possibility also exists that it could be a defect in one of the modules that is locking up the computer or draining the power supply. FWIW, just because the power supply has been replaced is no guarantee at all that it works right!
bryoncunningham OP
903 posts
 
...the possibility also exists that it could be a defect in one of the modules that is locking up the computer or draining the power supply.

With that in mind, I think I am going to remove more excess circuitry from the unit. The fewer modules in place, the better the odds that the defective module, if it exists, will be out of the loop. If this works, it will be the solution to the Gordian Knot.

Thanks again, Ralph.

Bryon
bryoncunningham OP
903 posts
 
Update: I have left the G68 powered up for several days and retaken the measurements at the outputs. There is no AC or DC voltage coming from the outputs.

The G68 has not frozen up since I removed half the circuitry and left the lid off. That is consistent both with the heat theory and with the bad PCB theory.
atmasphere's avatar
atmasphere
12,138 posts
 
Bryoncunningham, try rotating the modules back into the preamp one at a time- let it run for 2 days each. If its one of those boards, you will know which one this way.

If nothing happens, then the power supply possibility is increased and the idea that its one of the removed boards is eliminated.
bryoncunningham OP
903 posts
 
That is a good idea, Ralph. Before I do it, I'm going to let it run continuously for a longer period of time - maybe a week - and see if it freezes. Thanks again for all your help.

Bryon
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