Starting to populate the chassis....

[dbharris]

That's good progress. Yes, disconnect the FET board and take voltages again. You should have a lower voltage at each successive B+ node. Is it the 22K dropping resistor on the power board that is smoking or something on the preamp board?

Good quality solder and the proper size definitely makes it easier to make clean solder joints.

-Dan

[BrianL]

22K on the power brd....
BrianL.

[erwin_ve]

Your dropping resistor on the FET board is 150 ohm instead of 150k. That is your current and smoke suspect.

[martin manning]

Well spotted, Erwin. I would bet money that will resolve the issue.

[BrianL]

Oops, big mistake, I'll fix it and let you know.
Thankx, BrianL.

[BrianL]

OK, changed the 150 resistor on the FET brd. to a 150K resistor and guess what.......no smoke. Yah!
Thanks for catching that....
Also cleaned all the rosin junk off the brd, both sides...
Let it run for about an hour while I watched it.....flipped all the switches, no pops, no sparks, no smoke...
no buzz, no hum, very quiet.
This is all without speaker output or guitar input...
I'm very happy....
Next step:
Install the tubes hook up the speaker, plug in a guitar and try again....
Thanks for helping,
BrianL

[GAStan]

...
This is all without speaker output...

Is anything connected to the speaker out?

[GAStan]

...
This is all without speaker output...

Is anything connected to the speaker out?

Never mind I see no tubes

[BrianL]

So moving forward:
After replacing the 150 ohm resister with the correct 150K resistor the22K resistor stopped smoking and the voltages have come down on B+5 and B+4. B+3 stayed the same. I have had the amp fired up with no tubes, no speaker output and no guitar input. Ran it for an hour with no smoke, no smells, flipped all the switches, no noises or smells or smoke there either......Now moving forward I put all the tubes in, matched set of four JJ's 6L6GC's and three JJ's 12ax7's. Plug in the speakers, set impedence for 16 ohms to match my old Univox 2-12" cabinet, plug in a guitar, turn the amp on(on is up on the toggle switch) to warm the tubes for a minute, tubes have a nice low glow to them. I don't know how to describe the glow. it's pleasant, not screaming at you... turn the standby switch to "on" and amazingly.... nothing...now that I think of it I'm gon'na try the standby switch in the down position, maybe the amp isn't really on!!!! Ok I tried it in both positions and nothing in either. (nothing means no guitar sounds from speaker, moved all the pots, flipped all the switches, nothing. I have a normal tube or transformer hum as to be expected. Silk screening on chassis says up is operate.

Tube voltages:
6L6GC's
All four tubes measure the same,
PIn1 -47VDC
Pin2 2.6VAC for heater
Pin3 435VDC
Pin4 298VDC
Pin5 -47VDC
Pin6 434VDC
Pin7 2.6VAC for heater
Pin 8 to no voltage AC or DC I wired to Ground

12ax7's
tube 3:
Pin1 311VDC
Pin2 25VDC
Pin3 80VDC
Pin4 - 5 2.6VAC for heater
Pin6 320VDC
Pin7 80VDC
Pin8 80VDC
Pin9 2.6VAC for heater
Don't know if I can post pics here or not. If I can get to the site I have pics.....


Anybody else having issues with the site?
When I go here it gives me a kind of DOS system look, tells me I got too many cookies or something. If I go out an in a bunch I can finally get to the site but it doesn't stay, sometimes DOS, sometimes site...
Brian L.

[GAStan]

I've been having a bunch of issues with the site too...

Looks like your heater voltages are a bit low. I like to measure the heaters on a 9 pin tube while in Standby using pins 4/5 to 9. 6.3 vac is ideal.

[BrianL]

OK, I'll recheck to see what's going on.
5.7 to 6.9 VAC are the specs for this tube.
Transformer data sheet says 3.15VAC or 6.3 VAC. together.

How would I get more voltage out of the transformer if it only wants to give me 5.7VAC.

So I've been spending all my spare time reviewing the schematics and drawings and info
to find out what I missed or did wrong. Doing my research so I'm not always reliant on you guys.
Trying to figure it out myself......

Looking at these, are they wired correctly???
Assuming the view is from inside the amp like the rest of the switches on this face.
Why would I run ground to power on the back left lugs???
Or do I have the wrong jacks???
Checking the jacks I have the "P" lugs are connected and the "GRND" lugs are connected.
(P) = power
(GRND)= ground
Thns,
BrianL

[erwin_ve]

OK, I'll recheck to see what's going on.
5.7 to 6.9 VAC are the specs for this tube.
Transformer data sheet says 3.15VAC or 6.3 VAC. together.

How would I get more voltage out of the transformer if it only wants to give me 5.7VAC.

So I've been spending all my spare time reviewing the schematics and drawings and info
to find out what I missed or did wrong. Doing my research so I'm not always reliant on you guys.
Trying to figure it out myself......

Looking at these, are they wired correctly???
Assuming the view is from inside the amp like the rest of the switches on this face.
Why would I run ground to power on the back left lugs???
Or do I have the wrong jacks???
Checking the jacks I have the "P" lugs are connected and the "GRND" lugs are connected.
(P) = power
(GRND)= ground
Thns,
BrianL

Brian, your terminology and drawing attempts are very confusing. In this case we have tip and sleeve at the main speaker jack, the tip is switched to that 3rd lug(tip shunt) when no jack is inserted in the jack connector, effectively wired to ground(when no jack is in).
The original unedited drawing of the 2nd gen hybrid has correct jack connectors layout.
For clarification, these jacks are used;
main - Closed tip (Switchcraft 12A)
ext. - Open tip (Switchcraft 11)

[BrianL]

Thanks Erwin
So its protecting it and you when not in use.
Brian

[erwin_ve]

Thanks Erwin
So its protecting it and you when not in use.
Brian

Yes correct

[timrobertson100]

Congrats on the progress.

Assuming the speaker jacks are fine, and the heaters are at the right voltage then you’re down to finding where the signal is getting dropped.

I’d suggest as a first test, plug guitar into the return of the effects loop and play. If nothing comes out the speaker, then you know there is problem after that point (and maybe before). If you do get noise, the problems lie in the preamp.

Do you have a scope?