64 Deluxe Service Question

[ojaverde]

I have a 64 deluxe and I want to service it myself. Where can I get info on what to check? I know the filter caps are original so they probably need replacing. I am pretty handy with a soldering iron, and am aware of the high voltage dangers and know how to drain the caps, so I want to try and give this thing a tune up myself. Other than the filter caps, what should I be checking? I have a digital multi meter but I'm not sure how to use it to measure whether any resistor values have drifted. Also, Which resistors should be checked?

[Silverface]

I know the filter caps are original so they probably need replacing.

That's an understatement.

You are in danger of losing your output transformer (the heart of the amp) and/or power transformer - those caps are 20 years past their life-cycle replacement date. I would not even turn on a '64 with original caps - it could play fine, or it could cook off before you have a chance to flip the power switch. It's a time bomb.

If you do not know what caps to replace I really suggest taking it to a professional amp tech. That's a classic, valuable vintage amp and NOT something you want to take your first stab at servicing. It's good you know the dangers...far too many players open amps and start poking around not realizing an amp can kill you when it is off, unplugged and hasn't been turned on for a month. But if you are not familiar with the circuit and don't know the basics of the power supply, you could make a very, very expensive mistake very easily. It happens all the time. ONE filter cap installed backwards and your amp could be cooked - and they do not ALL go the same way, so many have made the mistake of thinking "oh, got this one backwards"...then BOOM.

If you absolutely insist on doing it yourself (which I really think is foolish...I'm not trying to be insulting, I'm trying to save you money and from potential disaster) you need to get a few books about guitar amps - Kevin O'Connor's books are probably the best out there; Geald Weber's fist one is where a lot of players got started working on their own amps and is OK, but a lot of money for schematics and information you can get for free on the internet - it IS handy, although it's packed with opinions and some oddball suggestions. Dan Torres' book is only useful if you know what you're doing - his description of the different stages of the amp is good, but things like his bias charts are in left field.

Really, you need about $150 worth of solid amp service and repair books and electronics manuals (especially when you go poking around the preamp and phase inverter - you don't just replace resistors because they are off-spec without knowing hat other parts are affected, and you need to be able to check all the bypass caps for leakage), another 3-4 hundred in equipment (a good Fluke multimeter, a signal generator, a load box (which you are better off building) and if you've never done this before a used 'scope so you learn what to look for (later on you may be able to do without it - I don't use one any longer - but at first it's essential to understanding what's going on)...so you can dump between $500 and a grand to do it yourself, or pay $250 or so for a full service from a pro, which it won't need for another 15 years or so.

Of course, it's your call - but it's logically a pretty simple decision. If you DO want to mess around with a tube amp find a beat-up silverface that's been modded and hacked, and use that as a learning experience as you restore it. You won't be in danger of wrecking a stock vintage amp and you can learn far more rebuilding one than trying to learn how to do just a "normal" service.