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Magnavox AMP170 rebuild

BeerCan

BeerCan

Tá mé ar meisce.
klama2006 very kindly sold me his Magnavox amps recently as a project. I received them yesterday and now I am taking stock of what I have and deciding what to do with these.

I plan on doing a complete rebuild. I would like to remove all the components and clean/paint the chassis. This will be my first complete restoration on an audio product so I am looking for suggestions.

I am wondering if any one knows of any circuit modifications for these. I am also looking for suggestions for output transformers.

They are amp170's which area variation of the amp169. They have larger power transformers and a choke in the power supply. Otherwise they are identical.

magnavox1.jpg

magnavox2.jpg
 
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What's wrong with the output transformers they came with? Are you looking to restore or upgrade? I've found that on many of these old console amps, the power trannies run very warm if not hot. It depends how much you want to spend, I've found I'm best off keeping it stock or close to it... otherwise you might as well start from scratch and build yourself exactly what you want... the power supply could certainly be made stiffer, the power tranny higher VA, the OPT higher quality. Or strip it, clean it up, replace out of spec components, put it back together, and enjoy the music.

Just my 2 cents.
 
Mostly looking to do a restore but I am considering small modifications, nothing extensive. I am asking just in case there is some knowledge out there that corrects or enhances anything in this particular circuit. Regarding the OPT . . . well they don't match and that just bugs me. I am not against getting 2 matched vintage or just replacing them with new parts. Just as long as they match. I forgot to mention in my original post that these are slightly different amps. One is a 170aa and one is a 170bb. I am not 100% sure what the differences are but there are visibly a few. Both will be rebuilt using the 170aa circuit as a base.
 
Those outputs sound mighty nice, especially from 100hz and on up (not that they don't go low, they can just get a little loosy down there).:music:
 
BeerCan said:
Mostly looking to do a restore but I am considering small modifications, nothing extensive. I am asking just in case there is some knowledge out there that corrects or enhances anything in this particular circuit. Regarding the OPT . . . well they don't match and that just bugs me. I am not against getting 2 matched vintage or just replacing them with new parts. Just as long as they match. I forgot to mention in my original post that these are slightly different amps. One is a 170aa and one is a 170bb. I am not 100% sure what the differences are but there are visibly a few. Both will be rebuilt using the 170aa circuit as a base.
Click to expand...

Give me the TX numbers. I may have a match that I could swap ya.
 
Wow. . .sorry it took me so long to reply to this. My work load just exploded all at once and I was swamped for a few days.

It turns out that the transformers are sort of matched, kind of. One is a 3300388-1 and one is a 330038-1a. They look a little different so I assumed they were not the same. Hopefully I can start on these soon. I have already started ordering the parts.
 
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