2. amps-preamps
  3. 185617-152491

Did my preamp short kill my Mark Levinson amps and Infinity Beta servo ?

My solid state preamp ( prefer not to name as maybe I am completely wrong in my thinking) that without warning developed a short in the right channel output due to some type of "leak" killl my wonderful vintage system?  Both ML No23 amps and the Infinity Beta bass crossover servo unit all stopped working - non of which had any external fuses blow.

I am able to get my  high end preamp fixed by the maker, but living in rual Minnesota makes it basically impossible to find a place that can look at all my other now non-functioning equipment.   (No lightening strikes and everything on high quality heavy duty line conditioners that did not trip).  The Infinity Beta servo is the unit I really hope to save because those speakers are mint and my wife actually accepts them.  Anyone know who might service that piece?

jerry_b2
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cleeds
5,682 posts
 

Have you tested the amps and xover/servo using another preamp? It's possible they weren't damaged at all.

jerry_b2 OP
15 posts
 

I am afraid so.

Hooked up a heavily modified but sweet soundng Hafler 500 to the servo and new pre-amp....and that killed a channel in the Hafler....so I am thinking something went very bad with that servo as well.

After everything working perfectly for over a quater of a decade, it all goes bad in a day.  Yikes.  Other than the Hafler, everything seemed to be military grade....and military grade prices originally.  Hate to think of similar replacement costs.

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cleeds
5,682 posts
 

I am really sorry to hear this. I am not sure who will service the Infinity xover/servo. I know they were built by PS Audio, so maybe they can help with that. As you know, the Beta woofers really need the xover/servo to perform their best. Good luck to you, @jerry_b2 !

panzrwagn's avatar
panzrwagn
455 posts
 

OK, a 'short' means that somehow the preamp leaked DC voltage into the Infinity crossover/servo box and the power amp? But if the Infinity is a Low Pass/High Pass setup, which I think it is, the high pass section would block DC from the HP output feeding your Hafler, wouldn't it?

I'm just trying to understand.

Maybe the short was in the power supply of the preamp and DC or worse, a rectifier diode failed, and it was AC that got on the chassis ground? In that case it may have fried the ground traces off the circuit boards in both down stream devices. That's not really fixable, and you'd be looking at replacements. Either way, bummers, Best of luck with your repairs.

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