Author Topic: please help me  (Read 2988 times)

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Offline mr.sunn

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please help me
« on: January 06, 2008, 08:31:43 pm »
I have a 1972 sunn 2000s amp and I cant get any info on it. I have tried all the forums I need to find a matching cab for it and I have gotten nowhere. when I turn the amp on, the breaker pops and the power transformer gets hot so that would lead me to believe that its bad. it reads 606. so that would make it a  Woodward-Schumacher transformer, right? where can I get a replacement? Please help me. You can contact me at scott18bass@yahoo.com
Thank you
FEEL THE SUNN
-Scott

Offline basiklybass

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Re: please help me
« Reply #1 on: January 07, 2008, 03:00:56 pm »
Sounds like bad power caps to me. There is a reason the transformer gets hot...and in my experiance, it's not that the transformer has gone bad, it's nothing but some iron and some wire. But the caps...now those have limited life, go bad and cause problems. Look for the cause, not the effect. What breaker pops? The house breaker? If so, you probably do have a smoked transformer....caused by bad caps.

This site has lots of info abou  the amps including schematics and many many postings about transformers and part. Search this site and you will find nearly everything you need...except possibly the money to pay for your Sunn habit. There is a correct 200S cabinet on Ebay right now, ends in 5 or 6 days. Somewhere on the east coast I think.

Offline JoeArthur

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Re: please help me
« Reply #2 on: January 07, 2008, 03:28:43 pm »

Power transformers do get hot in normal operation. Blowing the breaker is more than likely shorted electrolytic capacitors - at least I would replace them first before the power transformer...

Offline mckinnon audio

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Re: please help me
« Reply #3 on: January 08, 2008, 01:30:17 pm »
  Hi there,pull all the tubes out of the amp and unsolder the 2 red wires from the trans. that go to the rectifier(diodes or tube).Put some tape on them so they don't short and fire up the amp.If the breaker blows,you have a bad tranny,good luck,Mel.

Offline Soundmasterg

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Re: please help me
« Reply #4 on: January 08, 2008, 03:52:48 pm »
Quote
Hi there,pull all the tubes out of the amp and unsolder the 2 red wires from the trans. that go to the rectifier(diodes or tube).Put some tape on them so they don't short and fire up the amp.If the breaker blows,you have a bad tranny,good luck,Mel.

+1 on that.

If the PT is bad, good luck finding a new one. I would probably have Mercury Magnetics rewind the transformer if it is indeed bad, but that woul dbe spendy. Do the above test and that will tell you if it is bad or not.

Greg

Offline basiklybass

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Re: please help me
« Reply #5 on: January 09, 2008, 04:13:47 pm »
I picked up a replacement PT from Triode. A bit smaller but works just fine. I think it was around $80.00.

Since the PT is before the capacitors, it would seem to me that a bad PT would blow the breaker where as bad caps will cause other problems not the least of whichcould be a burned out PT. A burned out PT does not have to mean it is shorted. It could just be an open wire right at the connection point....the weakest point frequently. Bad caps could cause a bad transformer and that may pop the breaker....but in nearly all cases, a bad power transformer is caused by something after the transformer. Yes, there are exceptions...there always are.

Can't you just use a good DVM and meter it? The primary should be around 1.8 ohms if I recall correctly.