2. amps-preamps
  3. 1289231839

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

Showing 4 responses by atmasphere

atmasphere's avatar
atmasphere
12,099 posts
 
Bryoncunningham, its almost impossible to damage a crossover without also damaging the drivers. If there is indeed a crossover failure and the drivers OK, you can be assured that the problem was just in there waiting to happen and it has nothing to do with the amp or preamp.

How do you know that the amp driving the speaker is OK? Did you try it on a different speaker or the speaker on a different amp?
atmasphere's avatar
atmasphere
12,099 posts
 
A loud pop can certainly do damage to the speakers, without necessarily damaging the amplifier.

*All* the drivers damaged is a little weird- unless we are talking a smaller 2-way speaker. If it was heavily over-powered by one of these pops, it could have been toasted in a heart-beat.

I would run the G68 for 2 days non-stop and then see what sort of voltages are at the output. My guess though, based on what I have seen in this thread, is that the power supply is failing intermittently and is the source of the pops and freeze-ups. If that is true then you may never see anything unusual at the output unless you have some sort of event recorder rather than a simple voltmeter.
atmasphere's avatar
atmasphere
12,099 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!
atmasphere's avatar
atmasphere
12,099 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.
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