help with superlead board

johnnyeggz · Post by **johnnyeggz** » Thu Apr 28, 2005 12:17 pm

ok.im no tech...i got a pc board 73 super lead.....i got one of georges boards.....i put it in....all went well till the end....the old pc board had after the diodes a big cap...and then ...like 5 or 6 turretts....with all these wires going into it from i think the pt....the diagrams dont show where they go...plus the diagram dont show where the lil white wire from what i think is the pt goes either....help...im reocrding saturday....thanks

Flames1950 · Post by **Flames1950** » Thu Apr 28, 2005 1:04 pm

The white wire from the power tranny is your bias tap. It hooks to a turret joining to a 27K resistor which joinsthe bias diode, just to the right of the two bias caps, and to the left of the rectifier diodes.
All those turrets on the end are for the different voltages the power tranny could work off of, and you'll need to know which two were hooked up before you started......I don't have the Marshall 100 watt power transformer color codes here in front of me.......but two will need to be soldered and shrink wrapped together, the remaining ones need to be clipped off and individually wrapped so they don't make contact with anything, then bundle those extras up out of the way.

johnnyeggz · Post by **johnnyeggz** » Thu Apr 28, 2005 1:15 pm

thanks man....where do ya think id be able to find out which two i gotta splice together?

Flames1950 · Post by **Flames1950** » Thu Apr 28, 2005 1:18 pm

There were a couple of threads at Plexi Palace recently about a guy who was buying a '74 Super Lead from Guitar Center, had some pretty big pics of that section of the board, and someone had labelled them in marker on the PCB. I'd start there and see if you can make out the colors that are spliced together.
Sorry I can't call you....I'm kinda supposed to be working, and they won't wanna pay for the call either.......I'll check back here when I can though.

Guest · Post by **Guest** » Thu Apr 28, 2005 2:39 pm

Did you take before pics, they will show which two wires were hooked up. Just cut the others off and shrink wrap them out of the way. Someone here can give you the PT Color codes for the right Voltage. On my 100Watter it was Red, it's a 2203 though.

Dax

Guest · Post by **Guest** » Thu Apr 28, 2005 7:46 pm

ok i got it working...wooohooo.....i added the rich mod........wooohooo..............now ...how do i tame the noize..its a lil hummy....and the normall volume....has not alotta clean head room.....thanks fellas

Dax · Post by **Dax** » Thu Apr 28, 2005 11:47 pm

Take a pencil or a wooden stick and move your purple presence wire, tone control wires and the wires on pins 2 of your preamp tubes, lift these wires up if you can. keep your other hand in your pocket! 450 Volts DC can kill! If it doesn't kill you, it might turn you into an amp tweaking madman like Gnugear!!! Ha!!

Dax

Flames1950 · Post by **Flames1950** » Thu Apr 28, 2005 11:50 pm

If you've got noise issues you've probably got one of two common problems: a potentially bad ground in there somewhere, or problems with "lead dress" (which wires run where, and the exact path they take to get there; also which wires don't play nice together.)
If you have the capability to post pics we can try to make suggestions, if wire layout is the issue. If not, get as many pics off this forum, George's CD, or any other source you can of working Marshall chassis, and do all you can to carefully lay your wiring out like the pics.
Resoldering grounds never hurts.

Guest · Post by **Guest** » Fri Apr 29, 2005 1:40 am

I just recently unsoldered twisted the shit out of my Heater wires and man, it is quieter now.

Dax

Guest · Post by **Guest** » Fri Apr 29, 2005 6:50 am

i moved a ground...and lifted some preamp tube wires....much better now.....thanks

Dax · Post by **Dax** » Fri Apr 29, 2005 10:36 am

You're the man, Guest!!!!