old Marshall 30w transistor schematic please

[pinkjimiphoton]

I stand corrected, I could see a darkness in that area, but I could not see if it was a trace or not on the photos I was checking.
Thanks for the new photos pinkjimiphoton, it cleared it right up.
I have updated the schematic to draft 3, but I had already made the inputs as stereo jacks and I can't be bothered to change them back right now.
If I make up a PCB I always use stereo jacks just for the added strength so the solder is less likely to crack with use.
It might be silly, but I feel why not add the extra 50% solder connections to hold the jacks steady.
Once we have the schematic correct, I will post it up as a final.

Then the fun might start, what mods could be made if I make up the PCB and go to get some made ?
Effect loop for sure, but what circuit do I add, reverb ?
But that's for later
Here is Marshall 5010 PCB 78-2 Schematic draft 3 :

bro, i forgot to mention, the measurements for the jack spacings are from the bottom, from the left edge to pin one of each of the switching jacks.

i agree, switching jacks make way more sense, and are way more robust.

i really like the guitarpcb.com paramix for adding loops to this circuit, it works well, is cheap and easy, and ya get a series loop as well as an adjustable parallel one.

proper reverb tank for the 30 watt or 12 watt reverb circuit appears to be the P-RMOD 8FB3C1B is a very close reverb pan that will work well with the circuit, antique electronic supply has them, if anyone else contacts you about it... should also work with the 12 watt reverb combo, which is what i used to replace mine. the stock 30 watt reverb and the marshall 12r both use a crappy spring unit that mounts right on the pcb and is prone to feedback if it works at all

excellent work. you rock, bro!

very stoked. with your permission, when all ends off, if its cool i'll send a copy to marshall for their archive, as they do NOT have this circuit archived.

[pinkjimiphoton]

hey tassieviking, i think i found one other mistake...  i guess i was unclear in my description, and i just noticed it.

pin 1 of the gain pot connects to node of 10k and 47n on the 2.2uf tantalum side. so it's still off by that one connection. the 10k r4 and 47n c1 are in parallel. ONLY one side of them connects to pin 3 of the jelly bean.
the gain pot pin 1 connects to the other node, where the "input" of the rc network connects to the 2.2uf tant.

i did a q&d paint fix on it, this is how it needs to be:

[Rob Strand]

pin 1 of the gain pot connects to node of 10k and 47n on the 2.2uf tantalum side. so it's still off by that one connection. the 10k r4 and 47n c1 are in parallel. ONLY one side of them connects to pin 3 of the jelly bean.
the gain pot pin 1 connects to the other node, where the "input" of the rc network connects to the 2.2uf tant.

i did a q&d paint fixon it, this is how it needs to be:

That doesn't look right.

The R4 and C1 connections on Draft 3 look ok to me.

The tracks fork off at R4 and C1.  One path goes to IC1 pin 3 the other goes to VR1 pin 1.

The two parts,
https://postimg.cc/mPpbH6PT

On the right is R4 and C1 then a bit to the left is IC1, below IC1 and to left a bit more  is VR1
https://postimg.cc/t1W3ZK8Y

[pinkjimiphoton]

nope. it's exactly as i changed it to on the last schematic. the gain pot doesn't connect directly to pin 3. it connects on the other side of the r4/c1 network. i checked it against the actual board, unless i'm losing my mind, which IS possible.

i'll look again at it, but r4/c1 are in parallel. one side connects to the neg side of the 2.2u tant. that's where pin 1 of the gain pot goes. the other side of the r4/c1 network connect directly to pin 3 of ic 1.

i'll beep it out to be sure when i get back to my bench. but that was also what i drew when i first started drawing it out myself. its one of the differences between this and the other two boards that are out there.

gimme a bit, stay tuned...

[Rob Strand]

nope. it's exactly as i changed it to on the last schematic. the gain pot doesn't connect directly to pin 3. it connects on the other side of the r4/c1 network. i checked it against the actual board, unless i'm losing my mind, which IS possible.

i'll look again at it, but r4/c1 are in parallel. one side connects to the neg side of the 2.2u tant. that's where pin 1 of the gain pot goes. the other side of the r4/c1 network connect directly to pin 3 of ic 1.

i'll beep it out to be sure when i get back to my bench. but that was also what i drew when i first started drawing it out myself. its one of the differences between this and the other two boards that are out there.

gimme a bit, stay tuned...

I can see the connections very clearly on the PCB on your earlier pic and the follow the Draft 3 connections.

Lower side (ie. side closest to the pots) of R4/C1 go to IC1 pin 3 and VR1 pin 1 (counter-clockwise).
Should be able to buzz it out with continuity.

[pinkjimiphoton]

looking at it, yer right i think

i will beep just to be sure, cuz sometimes pics can be decieving i find with pcb pix

[Rob Strand]

looking at it, yer right i think

i will beep just to be sure, cuz sometimes pics can be decieving i find with pcb pix

Those trace lines are how I see it.

The fork in the PCB tracks puts you off.

[pinkjimiphoton]

too much crap on my bench. yes, i AM brIAn dead.

somehow i was confusing myself. pin 1 of gain r4 and c1 in parallel at pin 3 of ic, other side to c2 to pin 7.

rev 3 is the one. sorry for the confusion.

2 marshalls, a tube works head, my ps systems power tool and a bx13 24 pin to 13 pin midi guitar adapter kinda all going at once....

yikes! 

[Rob Strand]

too much crap on my bench. yes, i AM brIAn dead.

somehow i was confusing myself. pin 1 of gain r4 and c1 in parallel at pin 3 of ic, other side to c2 to pin 7.

rev 3 is the one. sorry for the confusion.

2 marshalls, a tube works head, my ps systems power tool and a bx13 24 pin to 13 pin midi guitar adapter kinda all going at once....

yikes!

No worries, thanks for checking all the stuff.  Tracing PCBs never gets any easier.  Many eyes certainly helps knock out the bugs.

[Tassieviking]

Fingers crossed that it is right this time.

[pinkjimiphoton]

confirmed!
working schematic for the marshall 5010 pcb78-2, thanks tassieviking and rob strand!
gotta get measurements still, they're written on my bench buried somewhere i have to find it, had to dig thru bags of parts
looking for other parts

the pcb i had "for parts" has had the power supply rebuilt, and works great. got it mounted in a hammond aluminIum box of 17x3x6" with the proper transformer, a real power supply jack and lighted switch, thanks to a nibbler i got that i don't believe i've lived without for all these many years...

drove me literally bat-shit insane last nite. it was kinda passing signal, poorly, motorboating like crazy, etc...
found a bad solder  on the ground side of a filter cap, fixed that, the hum continued.

i was bringing it up on my variac. it was humming horrible. and sounded like it was gonna blow up, so i didn't juice it ...
then it hit me... dumbass... its transistors, NOT TUBES.
TUBES may fire at 20 or 30 volts, at least a little.
transistors that are designed to be run at 28v ptp wanna see 28v to bias. not, like, 4 or 6.
i rebuilt it twice before i figured out the damn thing was completely misbiased.
whipped it up to 110 and suddenly the damn thing worked perfect.



anyways, its in a box and functional. the "presence" control would make a great treble booster, i may add it to some of the other amps.




video0-no

part 1

part deux

[Tassieviking]

I have nearly completed the PCB now, the way I like it.
It' as close as I can get it without actually holding it in my hands.
pinkjimiphoton, Rob Strand -
Is it ok if I include your names on the finished PCB for when I post all the KiCad files.
Like this PDF document shows.

[pinkjimiphoton]

that is beautiful!!!

hell yes, i'd be honored, bro!!

i'd definitely buy a couple boards when you get some if ya need an investor!

thank you so much for doing this!

[Rob Strand]

I have nearly completed the PCB now, the way I like it.
It' as close as I can get it without actually holding it in my hands.

The whole PCB, that's impressive!

pinkjimiphoton, Rob Strand -
Is it ok if I include your names on the finished PCB for when I post all the KiCad files.

It's OK with me but I don't feel worthy  .  You did 99.9% of the hard work.

[Tassieviking]

I think I got it close, here are my files on it.
















I can't work out how to post ZIP files, so if you want the KiCad file or Gerber files you have to go to the Solid Stat Guitar forum to get them.
https://www.ssguitar.com/index.php?topic=5124.msg40134;topicseen#new

[Tassieviking]

[/quote]
It's OK with me but I don't feel worthy  .  You did 99.9% of the hard work.
[/quote]

Rob.
The Circuit would be useless with even 0.1% wrong.
I think your input was more then 0.1% anyway.

[pinkjimiphoton]

thanks Michael, that's some beautiful work, bro!!
i'm hoping to build a couple of these just for shits n grins.
i am super appreciative of your hard work on this project, and yes, rob's too damn humble sometimes