echoes Posted June 18, 2006 Report Posted June 18, 2006 (edited) i had my dad buy me this amp back in march at a guitar store. when i played it at the store, it worked fine, but ever since i picked it up at from my dads house, it doesnt work. for some reason, i think it might be the tubes, but who knows... i sure dont. it has four 12AT7's and one 12AU7 as well as 2 6V6's. it turns on, but makes no noise at all. thats about all i know, but if you need more info, let me know and ill tell you. please help me get this thing working again, its like my dream amp Edited June 18, 2006 by echoes Quote
George Brown Posted June 18, 2006 Report Posted June 18, 2006 do you hear any noice at all? if you cant even hear background hiss that the amp may usualy produce give it to a tech to check out, if you dont know what your doing with valve amps you can easily get worse than a small shock. if you can hear background hiss check the rest of your signal chain, start by removing any pedals and go direct to the amp, try this with al your cables. if this works with all your cables add your pedals one by one finding the one that may be causing the problem. if you stil have no sound either try another guitar going into your amp or the same guitar going into another amp to see if its the wirring in your guitar Quote
crafty Posted June 18, 2006 Report Posted June 18, 2006 If it's new, it's probably under warranty. Like was said, there are very lethal currents inside that amp and if you've never handled high-power AC electronics before, it can and will hurt or kill you. Let the store or the manufacturer take care of it. Quote
echoes Posted June 18, 2006 Author Report Posted June 18, 2006 nah, this is an old school 60s amp, and i dont use pedals at all. i plugged it into a cabinet and turned it up to 10 and you still dont hear anything... ive plugged it into about 3 different cabs and used a handful of cables im really hoping its just like preamp tubes, because thats about all the money i will have until christmas to pay for anything with Quote
crafty Posted June 18, 2006 Report Posted June 18, 2006 Check the power tubes first--the 6V6's. Preamp tubes rarely need replacement. Quote
echoes Posted June 18, 2006 Author Report Posted June 18, 2006 how can i tell if its the power tubes that need replacing Quote
George Brown Posted June 18, 2006 Report Posted June 18, 2006 im not an expert but this really seems like a more serious problem then tube failure as tube faliure is usualy more gradual, crafty you are right to sugest only changing power tubes but id suggest checking the ones already in place. when your amp is on do you see a dim glow comming from your tubes (this shouldnt look like stuff you see in ads in guitar mags there way to bright) if there is no glow change tubes. i think a capacitor may have gone, if so its probably electrolitic which means your power section (after the rectifier) need a look at. it is also posible that another component may have "blown" but i still recomend for a tech or someone with good electronic skills take a look at it Quote
echoes Posted June 18, 2006 Author Report Posted June 18, 2006 well thank you both for your help hopefully i can scrape together some money to get it checked out Quote
George Brown Posted June 18, 2006 Report Posted June 18, 2006 what i said about the electrolics in the power section of you amp may have been a bit over the top after giving it a bit more thought, does the standy-by light come on? this would indicate if the problem was in the main power section or in the amplification stage Quote
echoes Posted June 18, 2006 Author Report Posted June 18, 2006 alright, so i turned it on and looked at the tubes. 3 of the preamp tubes arent glowing at all, its the last 3 Quote
thegarehanman Posted June 18, 2006 Report Posted June 18, 2006 Seems like you should still get a mild hum with all of your power tubes working and some preamp tubes out. Anyhow, does it say anywhere on the back of the amp what each of the preamp tubes function as? Somewhere on there you should see a word or two describing each of the tubes' functions(i.e. reverb tank, etc). peace, russ Quote
JoeAArthur Posted June 18, 2006 Report Posted June 18, 2006 Looks to me like it is a head version of a Deluxe Reverb. Sure, the tube complement is all wrong, but that mix of tubes sounds all wrong for any guitar amp. The place that sold it could have just put in whatever tubes they had handy - so look for a tube chart or some kind of markings and on the bottom of the chassis wouldn't be unusual for a 1960s amp. Quote
echoes Posted June 18, 2006 Author Report Posted June 18, 2006 well i guess whoever owned it before took out the reverb tank and disconnected the footswitch input for it and rerouted the speaker output in place of it. the tremolo is disconnected too. i dont know if these help... but heres some inside pics Quote
crafty Posted June 19, 2006 Report Posted June 19, 2006 Looks to me like it is a head version of a Deluxe Reverb. Sure, the tube complement is all wrong, but that mix of tubes sounds all wrong for any guitar amp. The place that sold it could have just put in whatever tubes they had handy - so look for a tube chart or some kind of markings and on the bottom of the chassis wouldn't be unusual for a 1960s amp. There's nothing at all wrong with that mix of tubes for a guitar amp. Also, chances are good you won't see a glow off of your preamp tubes even if they're good, anyway. I'd be willing to bet the problems are having to do with the hot rodding that was done by a previous owner. Especially if they were futzing with the speaker output and reverb/trem system. Quote
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