Tube Amp Archive

The Garolite CE must be something other than bakelite, which isn't and hasn't been produced since the 60s, or 70s. Bakelite was very bad stuff too. I forget the exact formula, but I seem to remember formeldahyde (sp) being in the mix. There is or was a similar product, but the name of that escapes m...

If you don't really need that much power, tube life will be longer with the dissipation that Vacuum Voodoo mentioned. Just under the red plating current would still be a bit high.

I've done a few from the schematic. Mostly Valco designs. The way I do it is to View the board ( I use turrets) from what would be the control side of the chassis, with the tube sockets on the opposite side. Many schematics have the input/pre-amp end on the left, as viewed. In which case I start wit...

Today I picked up two of the Unibit types from Harbor Freight. The bigger of the two goes to 1 1/4" diameter holes, and works very good for the 1 1/8 holes I used it for. I already had the smaller ones and use them all the time. I wouldn't recommend using the big one with a hand drill, it's safer wh...

The plumbing flux is an acid based flux. It would require a good cleaning to get any residue of the acid off, like a little scrubbing with water/baking soda mixed. Seems like less hassle to toss the no-good eyelets and get some good ones.

PILA

With the tubes going into thermal meltdown, it would seem that there is no bias at all to control plate current . There needs to be negative volts on the grids in relation to the cathodes of the power tubes.

PILA

The inter-action between the controls is part of the 5E3. Some different tonal effects are possible with that. Looking at the schematic, it's hard to figure why it works that way, but it does. Regarding your squeel/oscillation, try reversing the plate leads from the primaryof the output transformer,...

It may be time to take the covers off and check thier wiring. I'm an aircraft tech, and we have to put a filter cap on the alternators on piston engined small airplanes, even though it's rectified to DC. ADF receivers have a whine from the alternator, but I'm not sure if it's from the brushes on the...

VERY VERY NICE!!

PILA

I personally think a scope is over-kill for building amps. Like someone above said, it either works/sounds good or it doesnt. Good meters are a must though. I would personally spend money on tools to build chassis' as opposed to in-depth type test equipment. I have all that stuff, this is just my op...

I know what you mean by addictive Steve... I built my first amp in 1953 in Germany while in the military. I did it because of thier 220 volt ac line voltage, and got tired of lugging an auto-transformer around to reduce to 110 volts. Then, it was about three years ago I built a Valco clone. (shoulda...

DZR400 Do you think it's OK to ground the backs of the pots separately to ground? The tabs on the back of the pots aren't always that great a ground. I know that grounding them in guitars helps.

PILA

Hey Ryan, you should be piloting a corporate jet, tons of switches!! I used to have to fix all that stuff!~!

Pila

I was reading on another forum that the rectifier tube data tells you the max size for electrolitics. Don' remember if it's only for the first stage after the tube, or are you using a SS rectifier?

I see Antique Electronics has them for 10 bucks, same as 6Q11. Sounds like an old TV tube.