hessodreamy Posted June 16, 2010 Report Posted June 16, 2010 (edited) I've got this fender solid state amp but the reverb doesn't work. You turn the reverb level up and it just hums a bit, but no verb. Anyway, I opened things up. The cables from the main amp to the spring unit at the bottom of the chassis are ok. One thing I did notice when I checked inside the spring unit (a simple 3 spring unit, pic attached) is that there's no resistance between the inner and outer lugs of the input socket ie they're connected somehow. Is this right, or does it point to something being shorted? Edited June 16, 2010 by hessodreamy Quote
Paul Marossy Posted June 17, 2010 Report Posted June 17, 2010 Did you check that with the tank completely removed from the amp? And when you say no resistance, is it literally zero or is it like 8 or 10 ohms or something like that? Quote
hessodreamy Posted June 18, 2010 Author Report Posted June 18, 2010 Did you check that with the tank completely removed from the amp? And when you say no resistance, is it literally zero or is it like 8 or 10 ohms or something like that? Yup, I removed the tank from the amp and checked the resistance across the 2 lugs on the input. Absolutely zero. Also i measured just before where it gets to the transducer. Zero there, too. Quote
Geo Posted June 18, 2010 Report Posted June 18, 2010 Sounds like both the input and output transducers are shorted. Quote
hessodreamy Posted June 18, 2010 Author Report Posted June 18, 2010 (edited) I think I understand now. Never looked at these things before. Basically the resistance I measure across each of the connectors is the impedance of the in/out coils, right? When I said there was no resistance across the input, it was actually about 35 ohms. (must've set multimeter wrong) And where the output was showing infinite - further inspection shows the coil wire has snapped. So rather than a short, it's a break. Now let's see if I can get the bugger back on... Edited June 18, 2010 by hessodreamy Quote
Paul Marossy Posted June 18, 2010 Report Posted June 18, 2010 Sounds like you are close to getting it figured out... Quote
hessodreamy Posted June 22, 2010 Author Report Posted June 22, 2010 Sounds like you are close to getting it figured out... Figured it out. It's screwed. Can't seem to get enough of the wire free to re-solder. Unless anyone has any tips for this situation it looks like a dead duck. Quote
Geo Posted June 22, 2010 Report Posted June 22, 2010 Can't seem to get enough of the wire free to re-solder. I would try to unwind a turn or two of the coil. If it's well-potted though, that may be impossible. Worth a try, since you can't screw it up any more than it already is. Quote
Paul Marossy Posted June 22, 2010 Report Posted June 22, 2010 Can't seem to get enough of the wire free to re-solder. I would try to unwind a turn or two of the coil. If it's well-potted though, that may be impossible. Worth a try, since you can't screw it up any more than it already is. Or if the piece you have to work with is long enough, you can scrape off some of the coating on the transformer wire and solder an extension on it. Quote
hessodreamy Posted June 30, 2010 Author Report Posted June 30, 2010 I'm looking into replacing the tank and I've seen some on eBay. Are they pretty generic or do they need to be matched to the amp? Quote
Tim37 Posted June 30, 2010 Report Posted June 30, 2010 you will need to find out what the imput and out put impedance is and find one that matches it shouldnt be that hard to match up though. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.