Garnet Gnome

[mr_rye89]

It’s single ended in pentode mode so not much to go wrong, if it doesn’t red plate then the cathode current is probably ok. Those voltages seem high though, 350 on the screen grid of the output tube might be excessive. Hopefully Blue Crab will chime in

 

[AngrySailor]

Messing with this this morning, cleaned the pots and tube sockets. Sounds better but has some hum which is most noticeable at mid volume, it’s quiet at low and full volume. Tagged the new caps in temporarily in parallel with the old ones and no change. Trying to figure a good way to use the terminal strip to hold the new caps but almost wondering if the original is ok and that noise is just the nature of the beast and I’m just being too fussy? Think I’m going to completely eliminate the old transformer electrically and use the filament windings from the toroidal, the old transformer has an open high voltage winding and hums so I don’t want it to short eventually either... I can put these caps in easy enough, leave the old transformer and filter cap in place and the amp will look original until take the top off. Thoughts?

 

[J!m]

My thoughts are I’m not a fan of tubes.

 

[AngrySailor]

My thoughts are I’m not a fan of tubes.

 

[mr_rye89]

It’ll never be all that quiet, guitar amps are supposed to be kinda noisy, especially tubed ones.

My thoughts are I’m not a fan of tubes.

How else am I supposed to turn electricity into heat?!

 

[AngrySailor]

Recapped, we’re “Jason JJ Cruzin’” over here. Exactly the same with the new caps, just have to mount the new transformer in the bottom of the speaker cabinet and wire up permanently. Played a little bass through it, sounds like what you’d expect.

 

[AngrySailor]

Putting the finishing touches on this amp so he can pick it up this weekend. Just wanted to confirm the the “static shield” lead on the toroidal transformer is simply connected to chassis ground correct?

 

[Gepetto]

Putting the finishing touches on this amp so he can pick it up this weekend. Just wanted to confirm the the “static shield” lead on the toroidal transformer is simply connected to chassis ground correct?

Normally, yes, if the chassis is safety grounded. If the chassis does not have a path to earth ground, then I doubt the static shield will serve its intended purpose.

 

[AngrySailor]

Fuck, had it all working with jumpers, now I’ve installed the transformer, switched the heaters over to the new transformer and harnessed it all up, power up and NOTHING. Got filament voltage, 6.3vac, got my 300-0/300vac, and just shy of 500vdc. Not sure what I missed or fucked up. Not a sound at all from it. Had to move on to shop jobs, back at this later this evening. Something dumb I’m sure.

 

[AngrySailor]

Working now, ima. Dummy and wired the secondary center tap to the wrong terminal and it wasn’t attached to anything, wired to chassis ground now and works normally. Putting it back in the case and dunzo. Think buddy coming today to test it out and take it.

 

[AngrySailor]

She’s gone down the dusty trail. Buddy came by, brought his guitar and played through it a bit. He was tickled pink.

 

[AngrySailor]

Success. He played a show tonight with it. Rocked the church hall I’m sure. He’s a hell of a player too.