Marshall ish build issues

[Captain chunkulus]

Pics

[Captain chunkulus]

Pics

[Captain chunkulus]

Pics

[Captain chunkulus]

Pics

[sluckey]

That is the most impressive cut and paste job I've ever seen. Ritchie has you covered now. 

[Captain chunkulus]

That is the most impressive cut and paste job I've ever seen. Ritchie has you covered now. 

I know it's funny right! I don't know if it will help or give everyone a brain aneurysm.

[Ritchie200]

WTF!  With all due respect, I was hoping for something a little more traditional?    Thanks Sluckey, my buddy....

You may want to actually draw it out.  Then revisit your layout and connections.  Something might jump out at you.

Jim

[shooter]

I would try this change, probably won't help, but hey, I can color also

[Captain chunkulus]

You guys are killing me. Lol. 

[shooter]

This is a working amp, just hums?
if yes;
can you post voltages, looking for bias, how hot you're running, I've seen tubes running hot hum, biased correctly they sing.

just re-looked and noticed the change I suggested "assumed" incorrectly , they were 2 halves of the same tube

[Captain chunkulus]

2 separate tubes used for the directly coupled stage. Bias is at 35 milli amps per side. Or -45ish at the  bias point.

[Captain chunkulus]

This is a working amp, just hums?
if yes;
can you post voltages, looking for bias, how hot you're running, I've seen tubes running hot hum, biased correctly they sing.

just re-looked and noticed the change I suggested "assumed" incorrectly , they were 2 halves of the same tube

Okay, v1 tube reads 162v and 241v
V2 reads 312v and 128v
V3 reads 377v
Phase inverter reads 280v and 275v
Bias at the 220k resisters is -43v
Each tube in the power amp is reading individually between 32.6mv and 35mv

Also here is a video of the amp.

[Captain chunkulus]

Also, thought i'd give a rundown of my grounding.
All preamp cathodes and preamp filter caps are grounded near the input on a buss wire with the exception of the phase inverter filter circuit  which is grounded to the center of 2 100ohm resisters on the heater supply. All tone controls including first stage gain pot are grounded at the busswire as well. The presence control is also grounded there. The output transformer common is run to the speaker jack sleeves and then grounded at the phase inverter common ground which is also tied to the buss wire. This was done after reading info on Aikens sight about grounding. Doesn't  seem to matter where I ground it, it makes no difference in hum. The power tubes are grounded to chassis through 2 watt 1ohm resisters. The main power supply is grounded to the center of the 2 100ohm resisters on the heater supply. The negative bias voltage supply  is grounded also to the heater artificial Center tap.

[Captain chunkulus]

WTF!  With all due respect, I was hoping for something a little more traditional?    Thanks Sluckey, my buddy....

You may want to actually draw it out.  Then revisit your layout and connections.  Something might jump out at you.

Jim

Sorry, I thought since I have musicians short hand this would be more usefully but since it's not, I will try to do a hand drawn schematic as soon as I can.

[shooter]

since I have musicians short hand

I can't tell you an A from E
look at your original schematic, it is drawn well, emulate that like you'd "cover" a song
If you're gonna do this long term, get yourself a drawing program, on the free side, expressSCH works fine, on the $side, Visio guys can do some amazing work.

As you're drawing, try and keep in mind which parts set up the tubes "operating" conditions, and which parts set up the tubes "tone or flavor".  The DC and AC paths through the maze.  China does well with mass quantity , you are striving for individual quality

[Captain chunkulus]

since I have musicians short hand

I can't tell you an A from E
look at your original schematic, it is drawn well, emulate that like you'd "cover" a song
If you're gonna do this long term, get yourself a drawing program, on the free side, expressSCH works fine, on the $side, Visio guys can do some amazing work.

As you're drawing, try and keep in mind which parts set up the tubes "operating" conditions, and which parts set up the tubes "tone or flavor".  The DC and AC paths through the maze.  China does well with mass quantity , you are striving for individual quality

Thanks for this info, I downloaded a copy of the express pcb. I'm going to try to figure it out and see if I can do a decent schematic. In the mean time, the only real issue I'm currently having is signal bleed when the gain pot and channel volume is down and hum. I searched the forum and the only thing that came up was this,
"A common high-resistance ground could cause some strange problems. The cathode of a triode has a low input impedance, but it also has a larger gain than the grid input. If there is a shared ground path that is poor quality (appreciably bigger than 0Ω), it is conceivable that the input signal develops a small voltage across the poor ground which serves to inject a signal into the cathode of a later stage. However, hum usually results from this cause, as power supply current are likely to be much bigger than signal currents.

So just a question, anyone ever have this problem? Any possible solutions?