Tube Amp Archive

What Martin means is that the 5F6A Bassman doesn't have adjustable fixed bias. The bias voltage is set by a resistor in that circuit. Most amps now have adjustable fixed bias. You adjust the bias via a potentiometer when the tubes are idle (no input), thats what he means by "idle current". A lot has...

Doveman,

If you can't find one that fits, PM me with the dimensions and I'll custom make you one on my lathe for free. Takes all of about 5 min. using a nylon rod.

Try the handkerchief trick: You take a handkerchief (or bandana) and work one edge under the knob. Then you wrap the edge around the knob and start twisting the handkerchief until it gets tight. Grip the twisted part in your hand and put your thumb on the knob. Pull firmly and straight up and the kn...

That is some fine looking woodworking. I don't use gorilla glue any more. Tests have shown it is not nearly as strong as regular old wood glue. You need every bit of strength you can get with a miter joint, even with biscuits, plus a thin film of glue makes the strongest joint. I use plain yellow al...

Taylor, Try different speeds on some scrap. Sheet aluminum is always "gummy" and doesn't cut very easily as it tends to stick to the cutting edges. Sometimes it will cut better at a certain speed, and chatter at others. 3 in 1 is not a very good cutting fluid. Try a mix of half dish soap and half w...

For what it's worth regarding how hot the EL84's are biased, my Blues Jr. came stock from Fender biased at 12W per tube. I crank it all the time, and so far no redplating, and no burnt-out tubes. I've had it a couple of years, now. Granted, it's got the stock Fender chinese EL84's, but it sounds fin...

Taylor, Try different speeds on some scrap. Sheet aluminum is always "gummy" and doesn't cut very easily as it tends to stick to the cutting edges. Sometimes it will cut better at a certain speed, and chatter at others. 3 in 1 is not a very good cutting fluid. Try a mix of half dish soap and half wa...

It appears that JB Weld is an insulator; it says so on their web site. You can also thin it with acetone or laquer thinner (I'd use a few drops per batch) to make it flow. It can handle temps up to 500 F. Next time I'll use it instead of nail polish (even though that worked). This place is great for...

You can flow a little clear nail polish between the tube and the base. I put it in a syringe and ran it between the base and the tube body, or you can use the brush to flow it around. If you are concerned about heat, try some kind of high temp adhesisve. It's just difficult to get it in between the ...

I'll vote for the humble 5F1 Champ. This was the first amp I built, and I was not happy with it UNTIL I took out the recommended cathode bypass cap, used a NOS 5Y3, and 6V6 and traded the C8R jensen reissue I put in for an old Jensen alnico speaker from an organ pull (a '57 P8PS smooth cone I got fo...

The handles are ALWAYS the weakest part. I know someone who had the handle fly off his Twin Reverb at the top of a flight of metal steps after a gig. He said nothing broke, but the one corner got a little mushy. He mentioned seeing the whole slo-mo roll thing, too. LOL! I have the cheapo, leather An...

I've had problems with the eyelet spinning when drilling them out, so I turn the board over and place the eyelet over a mill file, or a piece of sandpaper so it grips the eyelet and doesn't let it spin.

That D-style chassis is def from the guy in Thailand. It is quite sturdy, but a lot of the holes are in awkward locations, and/or the wrong size. It has a nice anodized finish, though. I'd seriously consider it at $100. I paid the $167 for mine. Came all the way from Thailand in a carboard box tied ...

Thanks for the info on that capacitor, UHOP! I've seen caps like that in several builds so far, and couldn't figure out what it was. And thank you for the info on the suede. Some people are reluctant to share their sources. So how do I get in touch with Jelle? When I mentioned to my son that I was c...

This is one of the nicest builds I have ever seen. The pictures are excellent. Thank you for posting them. You obiously spent hours sourcing and planning this build, and it shows. I am currently building my own 183, and I will use this build as my standard. I hope mine comes out looking half as good...