zenith amp

[diesel_tech]

A friend gave me this amp from an old tv.

http://techpreservation.dyndns.org/schematics/59/59_Zenith_SRS10_178.djvu

I think it has some potential, i haven't powered it up yet, needs some new filter caps. I was thinking os using a better O/P transformer, the current one is , well, small. Also thinking of trying it in UL. Any other thoughts on it?

Thanks
Jeremy

 

[planet10]

what are you going to use it for?

The amp can be simplified,,, and the phase splitter improved. I'd play with the circuit before i swaped OPTs...

dave

 

[diesel_tech]

I'm going to be listening to a little of everything, but more rock than anything. What would you suggest to simplify it?

An externally hosted image should be here but it was not working when we last tested it.

 

[planet10]

First you make sure it works (clean up the PS, replace dud parts)... then you could try tapping the input to the grid of the 1st 'AU7 (bypassing the tone controls). Next i'd change the phase splitter.

dave

 

[diesel_tech]

I'll give it a try, i'm hoping to have it monday.

Thanks
Jeremy

 

[diesel_tech]

Well i did get th amp, and i replaced the filter caps, and the foil caps with new ones. I still have a sporadic crackling noise. THe only caps i did not change were a couple of ceramin disc caps, and tubular style ceramic caps. The tubular caps i know from expirience do not go bad very often, i have a radio from 1932 that still has them, and are still dead on for value, the disc caps i'm not so sure about. Any suggestions?

Thanks
Jeremy

 

[adason]

sporadic crackling noise

that is most likely coming from poor contact between tube pins and sockets, see if deoxying it helps