Newbie looking for help on 5E3 hybrid

[JHow]

Here is a picture of what I am trying to say. In my picture, red is in, yellow is out (not shielded like yours) and black is chassis ground, orange is jumper. I put wire insulation on the leads of the caps before I soldered them, which makes them look yellow.

EDIT: .0005 goes to the middle lug of the volume pot - its not so clear in picture.

The pots are by CTS, incidentally, manufacturers of Toyota throttle parts!

[Jetav8r]

Your picture helps a lot, thanks. I'll get on this tomorrow, it looks much cleaner and simpler this way.

[Jetav8r]

Update

Finished rewiring my pots, bought some new power tubes and pre amp tubes. I found out the power tubes the designer sold me are not made any more, Motorola and GE. They did look old and worn, but what do I know? A lot more after frequenting this forum.

[Jetav8r]

New tubes did not make a difference in operation, still no sound at all, not even a hum. I took some DC voltage measurements with tubes out and came up with the following:

12AX7 (TUBE 1) Pin (1) 454 (2) 0 (3) 0 (6) 454 (7) 0 (8) 0

12AX7 (TUBE 2) Pins (1) 450 (3) 0 (6) 450 (7) 0 (8) 0

6V6 (TUBE 3) Pins (3) 460 (4) 458 (5) 0 (8) 0

6V6 (TUBE 4) Pins (3) 460 (4) 458 (5) 0 (8) 0

B+1=459 , B+2= 459 , B+3= 454, B+4= 454

One other thing I discovered, according to my schematic, there should be a 100k resistor at the second resistor spot on the preamp stage where B+4 connects, it looks and test to be only 1k. Could this be my problem?

[Enzo]

Maybe, I cannot open your schematic at the present. I'll try it after the next system reset here.

SOme thoughts. Your power tube cathode cap blew up. It could have been in backwards or underrated for voltage, but I fear a shorted tube. Are either of your 6V6 tubes missing the plastic center post on the base? That would allow you to unsert the tube in the socket the wrong way, and that often connects things together that ought not be.

And whatever damaged that cap could also have damaged the resistor next to it. Is that 270 ohm 5w cathode resistor intact? Check its resistance. Or with power off, just measure resistance to ground from pin 8 of either power tube socket.

With tubes removed you should always get zero volts on pin 8, and you would whether that resistor was healthy or not. But when tubes are installed, if that resistor is open, then nothing will come out the speaker.

If you have a 100k plate resistor in a preamp stage replaced by a 1k, that will have a serious effect onthe operation, but I think you would still hear some background hum in the speaker. Is the speaker utterly silent or is there some little sign of life in the background sounds?

[Jetav8r]

Hi Enzo, thanks for your help. To answer your questions:

Are either of your 6V6 tubes missing the plastic center post on the base?

Center post are keyed and intact for all power tubes new and old.

Is that 270 ohm 5w cathode resistor intact?

Resistor shows no damage and measures 270 ohm.

If you have a 100k plate resistor in a preamp stage replaced by a 1k, that will have a serious effect on the operation, but I think you would still hear some background hum in the speaker. Is the speaker utterly silent or is there some little sign of life in the background sounds?

I do believe this is the case and will replace this today with correct resistor. My speaker is eerily silent, but it did pass the 9 volt battery test, so I suspect it's not the brand new speaker.

[Enzo]

Did you test the speaker through its cord, or right at its terminals? A faulty cord can silence a speaker.

ANd check for a shorted output jack.

[Jetav8r]

Did you test the speaker through its cord, or right at its terminals? A faulty cord can silence a speaker.

ANd check for a shorted output jack.

Yes, I checked it through the chord, and it made a light crackle sound. Not sure how to go about checking output jack shorting, can you educate me? The jack is grounded, I checked it with my ohm meter. I read something about ground loops, could a situation such as this cause my problem. I've checked ground continuity and wiring continuity with my ohm meter and believe all is intact. However, I've read it's better to ground in one central location, I have three chassis ground locations, so I was planning on consolidating, keeping the mains in one spot and the circuit board in another near the input. I will daisy chain them together, all terminating in the spot at the input.
I'm getting close to taking this to a technician, but my pride won't let me. I want the satisfaction of having built an amp. My guitar is weeping! Gently.
Cheers!

[Jetav8r]

Update

I changed out my resistor 1k to 100k. Fired up the amp and it is producing sound from my guitar yet very faint nearly inaudible, you have to stick your ear right up to the speaker. Still dumbfounded