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Ampeg SVT 3 Pro output has DC
 11/5/2005 12:01 PM |
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| Erik Miller | Ampeg SVT 3 Pro output has DC I've got a tough one on the bench right now, an Ampeg SVT 3 Pro, which is a hybrid tube/solid state bass amp. The output has 8 IRFP240's, all of which measured dead short when it came in. Most of the .47 Ohm resistors had blown open, but I replaced the bad ones. I've replaced all of the IRFP240's and the driver transistors test OK, but when I power it up with a load on it, as soon as the relay clicks in, it blasts dc across the output and shuts down. At one point it melted down the voice coil on my 80 watt Celestion test speaker. I understand why I am one of the few techs in this area willing to work on solid state amps. Wendy's pays a better hourly rate. Any ideas? St. Louis Music usually wants money to mail a printed copy of schematics, so I don't have one. |
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| Replies: |
| R.G. C'mon, Erik, you've been around her... -- 11/6/2005 12:51 PM R.G. Now that I got that out of my syste... -- 11/6/2005 1:04 PM Enzo The driver transistors test OK. Fa... -- 11/7/2005 5:40 PM Erik Miller Before I go off to bed: the gates a... -- 11/8/2005 5:10 AM Enzo Let us know...... -- 11/8/2005 9:53 PM Erik Miller Knowing when to quit? -- 11/15/2005 3:51 AM Rick Erickson Re: Ampeg SVT 3 Pro output has DC -- 11/23/2005 3:47 PM |