"Fiddy" 50-watt build log

[Reeltarded]

Rockin! Love it!

Watch that people don't plug them in without cabinets. Uhh.. I lost two original 50wtrs to consignment at the same time.

[xtian]

Received all parts, and started Fiddy v3. Each time, my layout, using the Weber 6Mx chassis, gets more elegant. I'm especially proud of the rectifier and bias circuit layouts. This one gets a 100 watt Drake PT and a ClassicTone OT, 1-watt Xicon carbon films, and Mallory 150s. Not high-end, but a step above my last two Fiddys in component quality.

I hope all this adds up to a better amp!

[xtian]

Hello, DIY plexi kit!

The Vishay/Dale 2-watt CPF 2 resistors are tiny, compared to the 1-watt carbon film Xicons.

And get a load of the beefy, 3 amp rectifier diodes!

[xtian]

Populated turret board.

[Colossal]

Populated turret board.

Tasty.

[Structo]

Nice work!

[xtian]

Thanks, guys! Here is the chassis, fully loaded.

[xtian]

Progress.

[ChrisM]

Looking good.
What's the 2.1mm DC jack off to the side for? Powering pedals?

[xtian]

What's the 2.1mm DC jack off to the side for? Powering pedals?

Power for LED strip lighting for the head cab. Leaving it out until the amp is finished and sounding good. Don't want to add complexity until circuit is working well.

[Bob S]

Looks great - you've got it down to a fine art.

[xtian]

Thanks, Bob!

Finished and sounds great!!

Had a bad hum; turned out to be Cliff jacks not grounded to chassis, so had to run a ground wire. Duh.

[M Fowler]

You big dummy

[xtian]

You big dummy

Oh, yeah, forgot my other wtf!?! My heaters were reading 6.5vac one leg, and 3.3vac other leg. *scratches head* Finally checked my notes on the Drake PT, and sure enough, BROWN is the heater CT, not BLACK.

[xtian]

I'm trying to fine tune my grounding scheme to reduce the minor hum remaining.

Check this: with amp in standby, that is, no HT going to the circuit, I am hearing hum out of the speakers! How is this possible? I pulled the power tubes and I still hear the hum, so I guess it must be the PT (the huge Drake bastard) inducing hum in the OT (the sweet, vulnerable Classic Tone).

Thanks for listening to me blabber while I work this thru.