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Old 10th July 2007, 11:52 PM   #31
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BigRed,

I'm sorry if it seems as though I'm communicating directly with Chris - he just has been the primary person thats been helping me (at least on a level that I can currently understand/operate). I haven't had a chance to check your recommendation yet, I will respond after I get my meter on those.

Thanks,
Brian
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Old 11th July 2007, 12:20 AM   #32
anatech is offline anatech  Canada
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Hi Brian, All,
I thought it was time for a reality check, that's all.

In other words, what do you actually want to do with it Brian?

It would be silly to end up with a working mono PA amp if Brian wanted stereo.

So don't bow out fellas, your hints are valuable and I'm no more right than anyone else here. I'm going to hang back a bit.

-Chris
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Old 11th July 2007, 06:50 AM   #33
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Hi All,

Quote:
There is undoubtedly a 70V/25V output transformer in this thing as well if it is for pa work. Does this unit have connections for high voltage lines - usually marked 25V or 70V out?
Yes - there is a 70v output on the rear.

Ok, so here is what I'm thinking - ditch the PA direction, strip what can be stripped and build up a LM3886 or ??

I checked on ebay and there are several "chip/s" for sale. I also did a search here and waded through as many posts as I could. Should I desolder the transformers and check them? (so that I don't create any more "issues" by popping fuses etc.)
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Old 11th July 2007, 06:51 AM   #34
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Also, to answer your last ? Chris - I would like this to function in "stereo"...
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Old 11th July 2007, 05:31 PM   #35
anatech is offline anatech  Canada
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Hi Brian,
Now let's examine if that is a reasonable way for you to go.

First, you need to repair or clear the short so that you can measure your supply voltages. I'm hoping they are too low for a 100 W amplifier. You'll see why in a few posts.

Measure the rectifiers for shorts, same for your output transistors and drivers. With a transformer output, even a DC offset will cause extremely high current to flow, so please disconnect the transformer and try using the ballast lamp Andrew suggested to power your amp up.

Now for the big question. Assuming you can make a circuit board, or buy them, you will need to build an amplifier. It may be possible to reuse the power supply, case and heat sink. So, before we pursue the "swapping of the amp guts", you need to be sure you can do the work. In the meantime, try to find the reason for the high current so you can at least measure your supply voltages.

-Chris
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