Gristo Gigmaster

[Gris]

This is my single channel AA763 Lux w/ verb (no trem) on a PR chassis project. Just about finished it. everything barely fits on the chassis w/ ZERO wasted space. was up til 2 am last night trying to work out the kinks. still getting some 'motor-boating' when i dime the midrange or bass. think part of the problem is used too big a pot for midrange, going for the max boost, but instead let in too much bass...?. Wonder if leaving the grid snubbers off did anything to contribute to this. Also may have shot myself in the foot by using a PT i got cheap that's kinda overpowered for this project. had about 520 on the plates til subbed in a 5U4 which dropped it down to 475. also a PITA as the PT had no bias tap & had to rob it off the recto. next time i'll use the correct PT fo-sho, may even spring for one for this amp. hey, this is a super-duper loud little beast. wont really have time to finish the shakedown on this one til i get back in a week. flying up to vermont Wed a.m. to do an all expenses paid spring break ski party gig, next Fri-Sat, woohoo ... :-)

[Don]

No pics???

[Gris]

No time, til i get back.

[Gris]

Pics coming tomorrow night after I put the knobs on. Ever so slightly disappointed in the not completely final result. Shot myself in the foot by trying to save a few bucks by using a slightly over powered PT. Think I'm gonna spring for David Allen's Lux PT. There is just a hint of brittleness in the clean sound and the voltages are above spec even with the 5U4 recto. It is also loud as f*ck. Killer overdrive sound though. The idea for this one was a 30 watt-ish spanky mini-super reverb sound in a small footprint head (PR head box) to be paired with a 15 watt tweed-ish head via head switcher into same cab. As is it sounds like 45-50 hot watts. Not quite the subtle warm but clear clean tone I'm going for. Not worried though, the last amp I built took months to get right and ended up as a holy grail amp. I'll be patient and keep tweaking.

[Cygnus X1]

I've had no problems so far with Ted Weber's 35-40 dollar PT's.
They run cool, and don't seem to drop much under load.

Used a total of 5 of them so far, both center tapped International and 25130's for diode rectification.

Only thing to watch for is the bolts-sometimes they are loose when they are delivered.

EDIT: I just double checked the prices-the WGTGP that I use for the SEL's is still 35, but the others have jumped quite a bit-the Tweed Deluxe is now 50. I also noticed speaker prices are bumping up. Arg. Well, I shouldn't complain, the service and quality has been excellent on everything. And I still like those speakers. I think the Sig's are great bang for the buck.

[Gris]

I'll likely end up grabbing whichever one (Allen or Weber) fits my existing bolt pattern. I already wallowed out the holes and don't wanna do enlarge them any more.

[Gris]

I finally got around to trying a 5R4. It dropped the voltage down to 479, LOL. (Actually was 489 with the 5U4, not 475 as prev reported). It did soften up/round out the sound a little bit.

The bigger surprise was that I was actually able to figure out why the amp was dark and gainy, even with high voltage. Turns out a certain supplier mistakenly sent me a gaggle of 50 uf/25 volt caps instead of the usual 25 uf 50V. I liked to have never found this, but I was sitting there last night staring at the circuit board with that puzzled WTF look on my face when the tiny writing on the closest black bypass cap suddenly came into focus. I couldn't believe my eyes. Haven't had time (or caps) to fix it yet.

[Cygnus X1]

Glad I'm not the only one that has these epiphanies.

[gooman]

Guru Gristo,sounds like a cool amp I misread the uF volt thing me understand now

[yankeerob]

Glad I'm not the only one that has these epiphanies.

I had a 470K where the 470Ω cathode resistor goes on the PI in the HRDx conversion I did last week - couldn't figure out why there was nothing getting through it like a

[Gris]

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[Gris]

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[Gris]

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[Cygnus X1]

Very nice work, Gris!
What kind of 6L6's do you have there?

And where did you get that faceplate done?

[Gris]

Very nice work, Gris!
What kind of 6L6's do you have there?

And where did you get that faceplate done?

Just some of those winged C Svelts that everyone raves about (I don't see it).

The control plate was from Weber's girl Sandy. She messed up the sizing. Be sure and give her measurements, don't rely on a model type match.

No wasted space on this amp, 45 watt Super/Lux Reverb on a PR chassis!

Check out the guts amigo... ;-)

[Cygnus X1]

Oh, I have a gut shot I need to get a pic of.
Besides that PTP Spitfire I made, it's the tightest I have ever built.

Good stuff!

[jerryjg]

Youll want Mercury magnetics or heyboar. Thoe are the best new transformers.Or just buy an old handwound Hammond.

[gooman]

Gris whats the guitar picks on the grill cloth for washers?

[Gris]

Gris whats the guitar picks on the grill cloth for washers?

Oh, that my 'Fender clock,' need to post a pic. The pics are the hours on the face of the clock... :-)

[phantomman]

Mighty schweet there, Mark!

That amp is gonna be a killer.

[Gris]

[Gris]

[Franklin]

Is nice! :)

[Cygnus X1]

It needs a drip edge to look right.


Cool work, Gris.
Could be a market for those clocks.
Er, well...FMIC might have an issue with it.

[Gris]

It needs a drip edge to look right.


Cool work, Gris.
Could be a market for those clocks.
Er, well...FMIC might have an issue with it.

Damn, I just mailed off my last drip edge to Roger dodger.

Seriously man, what planet are you from? The blue silver sparkle era never had drip edge!

[Cygnus X1]

LOL.

Just thinking different styles for the clock.
Tweed, Vox, SF, BF, Plexi...

[phantomman]

Damn, I just mailed off my last drip edge to Roger dodger.

LOLOL!

Seriously man, what planet are you from? The blue silver sparkle era never had drip edge!

Twew dat. But some corners would be kewl!