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get a standard IEC power cable, like the one that your computer uses. cut off the female end. connect the black and white leads to where the power cord is attached right now and the green wire to the chassis of the amp, assuming the chassis is metal.

in addition to the tubes you want (right here), Triode Electronics will also sell you a gounded power cord, which has an eyelet connected to the green (ground) wire, so you can screw it onto your chassis with any screw that's, well, screwed into the chassis. it avoids the issue of soldering a wire to your chassis, which is somehow different from normal soldering or something, or so i've heard. that's the cable i put into my '64 ampeg reverberocket when i fixed it up.

i also bought a couple new sets of tubes from them for both my reverberockets. they have brand new 6SL7, 6SN7, and 7591A power tubes, along with all kinda other tubes... they had some NOS 6SL7 and 6SN7 tubes just strewn about in bins mixed with all kinda other tubes. it was a pretty crazy dig, scrounging for NOS ones. and in the end, i got a couple sylvania's and that's it. the 7591's that were stock in the amp, the original tubes, tested so strongly that they were offering to buy them from me.

www.triodeelectronics.com

I'm sure you already know this, but be careful when working inside of a tube amp.. It's pretty dangerous if you don't discharge it.

(Nitpick alert) If you're going to go to the trouble of adding a three-prong plug, you should rewire the switch and fuse wiring so both are in series with the HOT wire.

toomanyhelicopters wrote:it avoids the issue of soldering a wire to your chassis, which is somehow different from normal soldering or something, or so i've heard.

Soldering a wire to the chassis is nearly impossible with a soldering iron since the chassis acts like a big heat sink and absorbs all the heat. Soldering to the chassis usually requires a high-wattage soldering gun. Even then, you run the risk of melting the insulation off your wire while you're trying to solder it, which then requires expensive Teflon insulated wire...

The screw tab is a fine solution!

As a very general rule, you are usually safe after about an hour of the amplifier being switched off. I usually connect a screwdriver between the plug prongs just to make sure though.

Rodabod wrote:As a very general rule, you are usually safe after about an hour of the amplifier being switched off. I usually connect a screwdriver between the plug prongs just to make sure though.

an hour? is that really enough?

i use a screwdriver or alligator-clip wire to short the leads from the big caps straight to ground.

or alligator-clip wire from pin 1 on the V1 tube to ground.

Rodabod wrote:As a very general rule, you are usually safe after about an hour of the amplifier being switched off.

This may be true, but it's probably a bad thing to tell someone who is asking how to deal with high voltage electronics. Not all amps have bleeder resistors, and the ones that don't can hold the charge for DAYS, literally.

Rodabod wrote:I usually connect a screwdriver between the plug prongs just to make sure though.

??

Shorting out the primary winding of the power transformer will not drain high voltage DC from the filter caps.

BadComrade wrote:I'm guessing this isn't an item Radio Shack would have.

Probably worth a try... I've seen them there before, although they did seem go through another parts-downsizing episode within the last year or so.

If you feel like driving to Mount Prospect, you can visit these guys. Then the $5 you'll save in shipping charges will be spent on gas instead.

you can always just do it ghetto-style and spend $0. before soldering the power cable connections (undsolder them if you've already connected), feed the cable through the opening in the amp, into the chassis, and then tie the thing in a knot. a knot inside the chassis will prevent the cable from being tugged outside the head in a way that will stress the solder joints. granted, it will, if tugged hard enough and frequently enough, cause a short in the cable. i suspect it's not likely, but it's possible. but i've seen this technique employed, and i've employed it myself, and it's never resulted in a short. ghetto-style, yo. free.

A quick,easy and cheap strain relief can be found at most local hardware stores. Don't go to a "big box", but yer local Tru-Value or Ace should be able to set you up. Find the aisle with the drawers full of nuts, bots, and other assorted odds and ends. Look for rubber bushings (sometimes labled as "grommets"). I've found some at my local Ace that fit 18/3 cable. These things have a groove in their circumfrence and a hole in the middle (naturally...). You force the grommet into the hole in the chassis far enough for the sheet metal to sit in the groove. Then you force the cable through the hole and solder it up. Used this solution many a time with no problems. Hope I described that good enough for you to find what I'm talking about. Check the local place, and you should be able to figure it out...