JCM2000 good deal?

Kerry Brown said:
This is on the local Craig's List. $600 CAD is $470 US. Seems like a very good deal. I don't know Marshall. What do you think?

vancouver.craigslist.org

Marshall jcm2000 and cab - musical instruments - by owner

Jcm2000 head and fender 4x10 cab for sale. They go together or not at all. Replaced tubes in head...
vancouver.craigslist.org
Click to expand...

There is a possible defect in the circuit board which causes bias failure, blown fuses etc.
This requires replacing the circuit board or modifying the existing board.
However despite the (Voodoo Curse) problems of DSL, many musicians continue to fix them and play them.
Guitar players really like the way the amp sounds and they simply put up with / repair the problems despite the headache.
It's sort of remarkable.
You can buy a new board, or you can buy a modification kit to fix the existing.
You can buy and install new bias adjuster pots (2). Be sure to change the 2 bias pots because they fail pretty often.

And so there is a standard test procedure to verify a DSL circuit board.
This requires a digital multi meter DMM etc.
That is an available test procedure directions if you need it.

More Info:

JCM2000 Stable Bias Mod

drtube.com drtube.com

If anybody owns a DSL I recommend that you do the checkout procedure despite if the amp is working correctly or not.


Attach files
 
Last edited:
Amp Mad Scientist said:
There is a possible defect in the circuit board which causes bias failure, blown fuses etc.
This requires replacing the circuit board or modifying the existing board.
However despite the (Voodoo Curse) problems of DSL, many musicians continue to fix them and play them.
Guitar players really like the way the amp sounds and they simply put up with / repair the problems despite the headache.
It's sort of remarkable.
You can buy a new board, or you can buy a modification kit to fix the existing.
You can buy and install new bias adjuster pots (2). Be sure to change the 2 bias pots because they fail pretty often.

And so there is a standard test procedure to verify a DSL circuit board.
This requires a digital multi meter DMM etc.
That is an available test procedure directions if you need it.

More Info:

JCM2000 Stable Bias Mod

drtube.com drtube.com

Attach files
Click to expand...


Well i know what my decision would be on purchasing this amp, after finding out this info..
 
Amp Mad Scientist said:
There is a possible defect in the circuit board which causes bias failure, blown fuses etc.
This requires replacing the circuit board or modifying the existing board.
However despite the (Voodoo Curse) problems of DSL, many musicians continue to fix them and play them.
Guitar players really like the way the amp sounds and they simply put up with / repair the problems despite the headache.
It's sort of remarkable.
You can buy a new board, or you can buy a modification kit to fix the existing.
You can buy and install new bias adjuster pots (2). Be sure to change the 2 bias pots because they fail pretty often.

And so there is a standard test procedure to verify a DSL circuit board.
This requires a digital multi meter DMM etc.
That is an available test procedure directions if you need it.

More Info:

JCM2000 Stable Bias Mod

drtube.com drtube.com

If anybody owns a DSL I recommend that you do the checkout procedure despite if the amp is working correctly or not.


Attach files
Click to expand...
The JCM2000 bias drift issue is almost exclusively a problem seen in the 100watt models. The 50w for whatever reason, largely avoided that issue, though there are some reported cases of it. The Revision 20 board was supposed to fix that but the problem still occured after replacements on many. The Stabile Bias mod seemed to be the most reliable fix as well as the cheapest. Roughly $80 vs $250 on the Rev20 board
 
It is certainly a great deal for the amp barring as Amp Mad Scientist said: the bias drift issue. But as i mentioned above, that is an issue you find mostly in the 100w, rarely in the 50w. For $80 however, like mentioned above, Dr. tube has a bias stabile kit that will remedy that almost entirely.

That all being said, I have proudly owned a DSL50 since 1998 and the only issue i ever had was the main input jack came loose from the board and a bridge rectifier went out once. Both parts were fixable at home for less than $5 each. I have played the utter hell out of that amp and in most of the videos ive posted, thats what your hearing. It is extremely versatile and can cover a wide array of sounds for its simple 2 channels. Its actually Marshall's best selling amp of all time
 
Clockworkmike said:
The JCM2000 bias drift issue is almost exclusively a problem seen in the 100watt models. The 50w for whatever reason, largely avoided that issue, though there are some reported cases of it. The Revision 20 board was supposed to fix that but the problem still occured after replacements on many. The Stabile Bias mod seemed to be the most reliable fix as well as the cheapest. Roughly $80 vs $250 on the Rev20 board
Click to expand...
Also the problem seems to have been fixed after a certain time. I want to say if it's 2005 or later it's prolly good, but I don't remember for sure.

I know that the rev 20 board didn't fix mine. The Dr. Tube mod worked for a while but the problem area was the bias pots. Or at least that's the weakest link AFTER replacing the main PCB and adding the Dr Tube mod
 
mcblink said:
Also the problem seems to have been fixed after a certain time. I want to say if it's 2005 or later it's prolly good, but I don't remember for sure.

I know that the rev 20 board didn't fix mine. The Dr. Tube mod worked for a while but the problem area was the bias pots. Or at least that's the weakest link AFTER replacing the main PCB and adding the Dr Tube mod
Click to expand...
That sucks chasing a ghost like that. Is yours a DSL100 or 50 and did that ultimately fix it?
 
Clockworkmike said:
That sucks chasing a ghost like that. Is yours a DSL100 or 50 and did that ultimately fix it?
Click to expand...
Actually it's an 03 TSL100
Same issues though. I have yet to replace the pots. AMS showed me that I can get the pcb with the pots already mounted and everything, would be an easy fix. But I'll also need new tubes so not so cheap anymore. I'm stretched about as thin as I can stand at the moment so it's on the to-do list. Meanwhile I jam with my DSL100H and it's never given me the slightest hint of a problem. Bought it new in '13 I believe
 
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