Marshall JCM2000 DSL Popping on powering down

[selloutrr]

Also! Make sure all pressure fit connections are seated snug and all grounds and cards are tight as well as the iron.

Basically when you throw the switch voltage is finding a new path to ground.

On a couple I was able to see a spark with it openned up and the lights off

[mr.tom]

Hi guys, I have build a marshall 1987 clone. It sounds great and I am verry happy with it... but there is one little thing that bothers me a bit. When I swith the amp off, it makes the pop sound too, not extremely loud but loud enough to disturb me. (don't mind my english I am from Belgium;) )
I have build it on a turret board like the good old plexi's

What is the best solution for this problem? Bleeder resistors?

Kind regards
Tom

[selloutrr]

If it's an exact clone you should not have an issue go back and check all your grounds wiring voltage and cable paths as well as tubes.

If u have modified the circuit ?

[mr.tom]

Not an exact clone.
I have build it from scratch with the ceriatone layout from 2008. I build it a while ago (winter 2008-2009) and it didn't work. It squeeld like a pig. After hours of searching I gave up. Last sunday I was cleaning up my attic and I picked the amp back up and I changed the wires on the output transformer. It worked! No hiss or squeeling. There was an error in the documentation supplied with the output trannie.

When I look at the new ceriatone layout I see there is a 100K 2W resistor over the standby swith and an 220K 3W resistor over the filter cap. In the old layout from 2008 (or so) those resistors were not there. Should the pop be the reason for the resistors?

[selloutrr]

Probably it won't hurt anything if you try them.

[selloutrr]

this brings to light.

I've got this piece of shit back on the bench this time the tubes are burning.

http://www.lynx.bc.ca/~jc/TSL122.html

SERIOUSLY NEVER BUY THIS AMP IT'S SHIT and HEARTACHE!!! - Marshall if you are reading this... have some pride and recall them!

[M Fowler]

Man that looks easy compared to the four layers of boards in my Egnator Rebel 20 that blew a resistor on the bottom board.

[selloutrr]

except the PCB is flawed by design so no matter what you do you are chasing a ghost.

I hate the new egnator amps total shit to work on.

[ToneMerc]

When I look at the new ceriatone layout I see there is a 100K 2W resistor over the standby swith and an 220K 3W resistor over the filter cap. In the old layout from 2008 (or so) those resistors were not there. Should the pop be the reason for the resistors?

Resistor and or resistor/cap across the standby is a soft start on power up and the 220K across the first filter is a PS bleed down resistor.

TM

[orrong65]

I have a Marshall TSL2000 602 which had the same popping issue.

Fixed it by correctly connecting the power supply PCB spade connectors to the board, some had become reversed when being taken apart.

In particular, the connections from the power socket to the board (live to fuse W2) then fuse to PT (W1 to W9) were the problem.

Also make sure the HT PT out (W20 red and W21 black) are the correct polarity.

Now fixed, with no noise at all!

[Structo]

Looks like a flight deck on a space ship or somethin'.

[img:720:540]http://www.lynx.bc.ca/~jc/TSL122ratNest-sml.gif[/img]