New split panel JTM45 build

[coldengray]

Yes I believe they are zip tied together. Should I separate them? Might be hard now due to available length but I can do my best.

[Doug H]

opinions vary, I think the prevailing wisdom is that at the very least it's easier to twist the primaries if they are separate.

It's also recommended to run the ground wire from the speaker jack close to the PI ground point.

Not sure if any of that will really help, the question would be, how quiet can a jtm45 get? Or any smaller box 50 watter for that matter.

[coldengray]

I certainly appreciate the insight, I am always learning more to do it better the next time.

Looking at some other nice build pictures I have saved I see people have twisted them back to the chassis and down to the output sockets. I'll try that on my next build. These are twisted but break off sharply about halfway up...and are bundled.

[coldengray]

I shifted my green wire lead dress and separated the OT wires and now the amp is MUCH more quiet. Thanks everyone for the help.

[coldengray]

Got some popping and crackling, I think I know the problem...

[coldengray]

The more I think about it, the more I realize I need to examine my mixer section and hookup wires after changing the resistor values a few times. I bet that is the issue.

[coldengray]

Turns out I had a leaky Mustard cap on the High Treble channel. Lifted the leg, problem gone. Swapped for a Mallory I had o hand and HOLY BRIGHT. It sounds awful and sterile. I'll be swapping for another Mustard today.

[neikeel]

Turns out I had a leaky Mustard cap on the High Treble channel. Lifted the leg, problem gone. Swapped for a Mallory I had o hand and HOLY BRIGHT. It sounds awful and sterile. I'll be swapping for another Mustard today.

Thai is very unusual but glad you found it!

[coldengray]

Turns out I was wrong...the problem is back. I suspect the plate resistor. It's hitting the bench in an hour!

[bill bokey]

This wasn't a kit but it is a JTM45 so I am posting this here...M e r r e n OT, MM PT, NOS mustards, McMurdo octal sockets, custom made head and 2x12 cabinet. I'm really happy with how it turned out, even though I ran out of wire and had to use orange in some spots.

Next up is a Marstran spec OT and PT build with NOS Mustards, Pihers and a Bulgin...

Fantastic !!!!

[coldengray]

Well, I checked everything and finally realized it HAD to be the mixer bypass cap....and sure enough it was.

[coldengray]

And now I have an even more bizarre problem - when the amp is upside down on my chassis stand, I have a very quiet amp. I chopstick around and no problems, wiggle the tubes and no problems. I flip the amp over with the guts facing down and I get pops and cracks if I tap the amp.

Any ideas? Gravity causing contact between two parts or wires?

[neikeel]

And now I have an even more bizarre problem - when the amp is upside down on my chassis stand, I have a very quiet amp. I chopstick around and no problems, wiggle the tubes and no problems. I flip the amp over with the guts facing down and I get pops and cracks if I tap the amp.

Any ideas? Gravity causing contact between two parts or wires?

Probably a wire pushed into a turret that has a dry joint (did you hook the wire over the turret?)

Problem is if you try to reheat from above the wire will probably drop back. May need to undo the pots after removing the knobs and input jacks and inspect from below at same time (a dental mirror can be really helpful in this circumstance )

[coldengray]

90% of my hookups are on the turrets, wrapped back through the board. I only have a couple connections underneath the board, but everything will be inspected.

I regret changing the mixer values 3 times - this is when my problems began so I will start in that area. I need to determine if the issue is still only on channel 1.

Neil - keep an eye on this thread, I need you as a sounding board for my troubleshooting!

[coldengray]

One thing to check out - jumper leading from the plate resistors. I swapped a 100 watt resistor during my troubleshooting and it could have caused the under board connection to partially come out.

Also need to rule out the tubes again, just to be certain.