New 5E3 build - great sound; at unamplified guitar level...

[MWJB]

V2-B - a 12AY7 will always return a lower plate voltage than a working 12AX7 in the same circuit, yours doesn't. Your JJECC83 is broken, or it is a JJECC832 not an ECC83.

All voltages except V2-B look ball park.

Output jack wiring looks OK.

Grounds at pot bodies & preamp ground at chassis wall do not. Remake these, shiny pools of solder on the pot bodies, stake down the ground wire whilst the solder cools. Use the input jack ground as the preamp ground point, unless you are using isolated jacks, then use the chassis mounting bolt & a ring terminal.

Remount the 0.022 uf coupling cap from V2 pin 1 to pin 7 actually on the tube socket, eliminiate that log wire from the current top of the cap to the 1Meg at pin 7.

To drain your caps in 30 seconds, unplug the amp from the wall and put a jumper from ground to pin 1 or 6 of V1.

[Jazz P Bass]

R8, 9 & 14 do not seem to be adding up.
If R8 is 100K, why is R26 & 27 not being added to it? (22K + 5K)
Plus, where is R15 & 16 shown as connected to the B+ on the schematic?
I read it as not.
Unless....
C7 is short circuited.
Or something around there is miswired.

[FreddieRay]

Thanks for the new input!

Jazz P Bass, I'm not sure I understand what you are saying.. But I think the 'problem' here is that I measured resistances with the meter leads on both sides of each resistor as opposed to everything vs 1 common point. Is that a 'wrong' way of checking resistances here?

MWJB, I'll do those modifications you suggested somewhere next week and report back! And I'll put the JJ ECC83 away for now.

[Jazz P Bass]

I was hoping for an overall resistance check from the raw B+ point.
Like a chain.
While also checking different points to ground (an anomaly would hog current & throw off everything)

[FreddieRay]

Ok I see! I'll do that too, and post all the results as soon as I've recovered somewhat from New Year's Eve

[FreddieRay]

Well, turns out the OT replacement & GZ43 to NOS 5Y3 I did some time ago did fix the amp entirely; the problem this time was just the bad second half of V2. With the new 12AY7 in V2, I probed, as before, several points in the signal path with a 100 mV sine wave at the input. As expected, the overall signal voltages were lower with the 12AY7, but nothing out of the ordinary. I plugged in the guitar, played it; the amp sounded very good and most importantly, it was LOUD.

I tried some things while I was soldering those ground wires to the pots, but never really got good joints there, nor on the chassis. I figured that making good joints there, would be impossible with my unregulated 40W iron. So I settled for mediocre joints that stuck and tested out fine with the multimeter.. I'll try redoing them as described above.

I can't thank all of you enough for teaching me and helping me out Hopefully, this thread and this amplifier can remain closed for some time to come.. Cheers and a happy new year!

[rien]

hi!
Does the thread stop here? I have exactly the same problem as Freddy Ray has or had...