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johnnycom · 08-07-2009, 05:57 AM

Hey Marty. I recently had some problems with my JCM900 Model 4100 Dual Reverb 100 watt head and we decided I had a bad tube. My head has Sovtec 5881 power amp tubes and I bought a matched quartet of Tung Sol 5881 tubes from Musicians Friend. They were a lot shorter than the originals but the tech thought they would be OK. He put them in and turned it on to bias them and they got real hot and now the head has no output at all. Could this have blown the PT? Are these the tubes you were referring to that we should stay away from?

Thanks.

08-07-2009, 05:57 AM	#5 (permalink)
johnnycom Junior Member Join Date: Aug 2009 Posts: 19	Re: Tube brands in JVM410h Hey Marty. I recently had some problems with my JCM900 Model 4100 Dual Reverb 100 watt head and we decided I had a bad tube. My head has Sovtec 5881 power amp tubes and I bought a matched quartet of Tung Sol 5881 tubes from Musicians Friend. They were a lot shorter than the originals but the tech thought they would be OK. He put them in and turned it on to bias them and they got real hot and now the head has no output at all. Could this have blown the PT? Are these the tubes you were referring to that we should stay away from? Thanks. __________________ John Guitars: Rockin' 1989 Fender Strat USA Ovation Celebrity CC44S Electric Acoustic Amps: Marshall JCM 900 High Gain Dual Reverb Marshall JCM 2000 DSLMLB 100 Marshall 1960B 4X12 Cab