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Old January 27th 08, 06:52 AM posted to alt.binaries.pictures.radio
Brian Hill[_2_] Brian Hill[_2_] is offline
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First recorded activity by RadioBanter: Oct 2007
Posts: 62
Default marantz 250 amp early 70s


"Buck Frobisher" wrote in message
...

"Brian Hill" wrote in message
...

Here it is almost done.

--
Regards
B.H.
Hill Amplification
http://hillamplification.com

Brian's Radio Universe
http://webpages.charter.net/brianhill/500.htm



wow, looks like lots of work, despite the fairly open look of the various
boards. You had to completely take one out?



Yea I had to go over it all. The main failure was that a number of carbon
comp resistors went south in the HV circuits and the voltage went way up
frying a few transistors etc... So I replaced all the carbon comps and most
of the capacitors minus the mica types which all tested good. The circuit
boards are all very robust being about 3/16" thick with heavy trace. It's a
nice well designed amp. I rebuilt the power supply relay too and hope it
works? I give it the smoke test tomarrow!

BH