Guitar Gear Forum

TLDNR: A batch of 2555x amps from 2017 were built with bad potienometers.
While trying to replace my pots, I fucked up my already fucked up Jube and a new pc board is on the way!!!
Ordered a new potentiometer pc board, Part # M-PCBA-00168 from tubesandmore.com



Now for the Long Story:
Back in 2017, several GGF members purchased a 100watt, Marshall 2555x 50th Anniversary Jube.... they were on sale so, WTF, why not?

It turns out that many of those Jubes had bad pots installed in the Presence, Bass and Mid locations.
These three knobs, on my Jube, were were very tight and not easy to turn. Spraying them with Deoxy helped, but eventually they got so tight that the shafts actually broke off.
This is a common problem with the batch of Jubes from 2017 and there is a thread about it at marshallform.com.
The Marshall Forum mentioned that some people immediately returned their Jubes for a replacement but, I was not one of them!

A few weeks ago, two knob shafts finally broke off and I decided to remove the three bad pots (Presenece, Bass and Mid) and install new ones.
I ordered replacement pots from britishaudio.com in Tennessee. This issue is so common, that they have the three pots listed and available specifically for the 2555x.
https://britishaudio.com/collections/ma ... fier-parts

The failed pots are located on their own, secondary pc board and the board is easy to remove... pull off the knobs, unscrew the pot bolts, pull the chassis, unclip the three blocks of wires and pull the board out.
Easy peasy!!!

The hard part is removing the pots from the board and this is where I fucked up; by mangling the traces under the Bass pot....
My soldering iron doesn't get hot enough to remove the new, silver/tin solder that Marshall used on this amp.
I cleared most of the solder, but one pin, on the Bass pot, wouldn't budge so, I tried drilling it out and in the process, I also drilled out the trace.
Yes, I will be purchasing a Haiko soldering station (that hits 800 degree F) before I try anything like this again!!!

Moving right along, I went ahead and installed the new pots but, the damage was done and the amp crackled like it had an arching tube!!!

Now that I had a totally unusable Jube, I sent an email to Marshall in the UK, asking if they could sell me a replacement potentiometer pc board. A few days later, I got an email from their American distribution company, JAM Industries USA. JAM Industries provided me with the part number (M-PCBA-00168) and recommended that I contact tubesandmore.com (aka Antique Electronic Supply) to place the order.... I did so and now, a new, pre-populated pc board on the way!!! WOOO HOO!!!!

FYI: Britishaudio.com in TN can also order the pc board but, they responded after I had already ordered from tubesandmore.
Interestingly, British Audio said you can't order just the small, potentiometer board, because Marshall only sells both the main board and the pc board as a package. The price is $349 plus shipping.
We will see if tubesandmore sends me both boards, since they didn't mention this and I did pay $349 + shipping.

If any of you 2555x owners want to have a go at replacing the pots, I suggest cutting the pots with a Dremel (see below pic), allowing you to pull the pins out, one-at-a-time. After cutting the pot, you can simply heat the pins from the back and pull the pins out from the front. Then, using a solder-sucker and copper desoldering braid, it will be easy to clean the remaining solder out of each hole in the board.
Of course, I only realized how to safely remove the pots, AFTER I fucked things up!!!

Gut shot...


In the process of fucking up my already fucked up Jube...



The potentiometer board...


Where to cut the pot so you don't do what I done...

FINALLY!!!! After placing my order 7 months ago on March 5th, Marshall wired up my 2555x pc board in September and it arrived last Friday!!! YAY!!!

What they sent, is really three boards in one: the main board with tube sockets, the bias test point board and the perineometer control board.
I only needed the control board but, you have to buy all three.
Each section has to be cut off before installation.
I suppose they made it as an "all-in-one" board to make testing easier.

Hopefully, Crom willing, I will have a fully functioning Jubilee this weekend!!!

The full board...


The Bias Test Point section...


The tube socket side...


The control section...

Sorry you had to deal with this. Hope the repair makes it new again as Jubes are amongst the best Marshalls ever made!

Holy cow, man! Glad you're on the path back to a working Jube, but jesus that's a hell of a lot of work on your end.

Makes me not regret trading my reissue off for the blonde bandmaster rig. Of course my original is badly in need of a recap and retube so...



Unrelated but I wore my Nihilistics shirt the other day and people loved it

I'd suggest taking it to a tech to do the board swap just to be safe this time.

Mike Oxhuge wrote:Sorry you had to deal with this. Hope the repair makes it new again as Jubes are amongst the best Marshalls ever made!

Thanks bro!!!
Luckily, I only paid $1200 for the Jube, the new board was $400 and the resale value is about $1800... if I sell it, that's $200 profit!!!!

Dave wrote:Holy cow, man! Glad you're on the path back to a working Jube, but jesus that's a hell of a lot of work on your end.

Makes me not regret trading my reissue off for the blonde bandmaster rig. Of course my original is badly in need of a recap and retube so...



Unrelated but I wore my Nihilistics shirt the other day and people loved it

When you're working a boring/shit job, rarely go out and you're taking care of your 93 year old mother-in-law (she's really nice), things like this become the only excitement in your life!!!
Seriously, if the one lug, on the presence pot, wasn't stuck in the original board, it would have been a piece-of-cake job.

If that shirt doesn't get you arrested, it should definitely get you some dates!

GuitarBilly wrote:I'd suggest taking it to a tech to do the board swap just to be safe this time.

Nah, It would be more work taking it to a tech.... I'd say, there's <1% chance of fucking up the installation of the new board.
I'm only installing the pot board. It's held in place by the knobs and only has two molex blocks for the connection.... no soldering or de-soldering this time.

The issue was that, one of the pot pins was stuck on the original board - I removed all the solder but, the pin wouldn't come out.
I tried to drill it out but, the 1/16" drill bit flexed and wobbled around, destroying the copper trace in the board.
I should have left the pot pin in and soldered the new pot to the old pin.... ahhh, the things you think of after you fuck shit up!

ajaxlepinski wrote:

Dave wrote:Holy cow, man! Glad you're on the path back to a working Jube, but jesus that's a hell of a lot of work on your end.

Makes me not regret trading my reissue off for the blonde bandmaster rig. Of course my original is badly in need of a recap and retube so...



Unrelated but I wore my Nihilistics shirt the other day and people loved it

When you're working a boring/shit job, rarely go out and you're taking care of your 93 year old mother-in-law (she's really nice), things like this become the only excitement in your life!!!
Seriously, if the one lug, on the presence pot, wasn't stuck in the original board, it would have been a piece-of-cake job.

If that shirt doesn't get you arrested, it should definitely get you some dates!

My wife might not like that but sucks to suck

Alrighty then!!! I had the day off....

Cut the ends of control board, with the Dremel cutting wheel, and snapped it off the main pc board.
The main pc board was dated Sept 27, 2023 meaning, the fuckers at Marshall took seven months to get around to wiring it up!!!


Installed the new control board and fired it up...


The Jube is in the house!!!! WOOO HOOO!!!!
I couldn't get the busted potentiometer shaft ends out of two knobs so, two knobs are on order.

At least it’s back in working order! Always a good thing to have a fully functional Jubilee.

I’ve been looking at the Marshall’s lately I have say this one is a beautiful piece but man what a nightmare you had to endure our all these like this ? I’ve been thinking of getting the re-issue JCM-800 100 watt head I know there is always some kind of jacked up crap when buying the first line before all the quirks out fixed of course you don’t find that out until the warranty has ran out or something else happens along the way but you hope for the best first time around as these amps prices have jumped significantly from 2016 to now the present ..

greatmutah wrote:At least it’s back in working order! Always a good thing to have a fully functional Jubilee.

Thanks GM!!!
The funny thing is, while I'm complaining about how long it took Marshall to send me the pc board, I've been mostly playing my Ceriatone Model Tee and Randall RG80 so, I really have no reason to bellyache! Although, now that the Jube is running, I really dig it... it's almost like a NAD!!!

Blacksabbath1987 wrote:I’ve been looking at the Marshall’s lately I have say this one is a beautiful piece but man what a nightmare you had to endure our all these like this ? I’ve been thinking of getting the re-issue JCM-800 100 watt head I know there is always some kind of jacked up crap when buying the first line before all the quirks out fixed of course you don’t find that out until the warranty has ran out or something else happens along the way but you hope for the best first time around as these amps prices have jumped significantly from 2016 to now the present ..

Marshall actually had all the quirks (in the reissue Jubilee circuit) worked out, my amp just happened to have been built with a bad batch of pots... it could happen to any amp builder, not just Marshall.
I think you can buy that re-issue JCM-100 head with as much confidence as any other amp purchase.

I should mention that, Marshall was recently sold to a Swedish company.
There may have been a production slowdown due to the transition, disgruntled employees, indifference by old management, inexperienced new management, etc.
Hopefully, the new owners will move things in the right direction so others don't have to wait as long as I did.

Great to hear you got this sorted out!

Blacksabbath1987 wrote:I’ve been looking at the Marshall’s lately I have say this one is a beautiful piece but man what a nightmare you had to endure our all these like this ? I’ve been thinking of getting the re-issue JCM-800 100 watt head I know there is always some kind of jacked up crap when buying the first line before all the quirks out fixed of course you don’t find that out until the warranty has ran out or something else happens along the way but you hope for the best first time around as these amps prices have jumped significantly from 2016 to now the present ..

I've had a couple of these Marshall reissues. The 2203x and the 1987x. They were amazing amps. I had no issues recommending them.

VTM wrote:Great to hear you got this sorted out!

right on, Right On, RIGHT ON!!!!

GuitarBilly wrote:

Blacksabbath1987 wrote:I’ve been looking at the Marshall’s lately I have say this one is a beautiful piece but man what a nightmare you had to endure our all these like this ? I’ve been thinking of getting the re-issue JCM-800 100 watt head I know there is always some kind of jacked up crap when buying the first line before all the quirks out fixed of course you don’t find that out until the warranty has ran out or something else happens along the way but you hope for the best first time around as these amps prices have jumped significantly from 2016 to now the present ..

I've had a couple of these Marshall reissues. The 2203x and the 1987x. They were amazing amps. I had no issues recommending them.

Same here. The 2203x and 1987x amps I owned both had traditional chassis mounted pots with flying leads back to the PCB.

tbf I've never heard of any real issues with the 2555x either, and like AJ pointed out above this was simply a bad batch of pots. Certainly nothing to worry about.

If Marshall sent the pc board as fast as they sent the new knobs, I'd be a happy camper!
The knobs arrived 4 days after placing the order with Marshall.


...and the two new knobs are installed. Now, the job is complete!

Nice work! Congrats on the restored Jube day!

Dave wrote:Nice work! Congrats on the restored Jube day!

Thanks homie!
One less thing to lose sleep over! WOOOO HOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

This thread reminds me that i need to have my Jube re-tubed and serviced