Marshall Backplate Corrosion

[Mentalo]

Hi all,

I‘m interested in buying a used Marshall Head, but it got some strange corrosion going on that I‘can't get my head around. Do you have an idea what might caused this?

Best Regards
Mentalo

 

[LCW]

Looks like someone opened up a can of pop while standing behind the amp. Not saying it’s that, but it’s a theory.

 

[anitoli]

Those panels are anodized aluminum. It appears to have gotten some agent that reacts with aluminum sprayed on it if it won't clean off. It won't affect the amps operation just not pretty to look at but then again how much time does one spend looking at the back of an amp?

 

[dtier]

Kinda looks like white mold. Possibly was backed up against a basement concrete wall. It may not come off.

 

[V-man]

Kinda looks like white mold. Possibly was backed up against a basement concrete wall. It may not come off.

The screen print lettering of the backplate would probably wipe off long before that crud came off

 

[Matthews Guitars]

Using the wrong spray cleaner can cause that.

 

[ReWind James]

Probably needs a new output transformer.


Someone probably cleaned a guitar, sprayed a jack or pot, or cleaned another amp or cabinet nearby. Or dropped a drink.

 

[JSJ900]

It’s relic’d - hopefully they don’t charge extra!

 

[Mentalo]

Hi all, thanks for your input, much appreciated . I‘m also guessing that some kind of acid caused it.

 

[Mentalo]

Probably needs a new output transformer.


Someone probably cleaned a guitar, sprayed a jack or pot, or cleaned another amp or cabinet nearby. Or dropped a drink.

Why do you think that it might need a new OT?

 

[ReWind James]

Why do you think that it might need a new OT?

Purple text indicates sarcasm.

Amp forums are like webMD for diagnosing problems. You'll go in having stubbed your toe and walk out thinking you have radiation poisoning. It's always the OT, online. Always. It's an internet rule!

 

[Mentalo]

Oooops okay , thanks again!

 

[ribo1989]

Hi all,

I‘m interested in buying a used Marshall Head, but it got some strange corrosion going on that I‘can't get my head around. Do you have an idea what might caused this?

Best Regards
Mentalo


View attachment 144653

It may be the air bubbles under the adhesive film on the backplate.

 

[Kutt]

COVAMP-19

 

[paul-e-mann]

Spit on it and see if it wipes off

 

[Mentalo]

Okay thank you all for your feedback. I think I‘m pulling the trigger on it.

My first tube amp 20 years ago was a DSL 100 but I was just to young and inexperienced to use it correctly and sold it after just 2 years. Just recently I came back to the DSL family by buying a used DSL1H. That amp with a Boss SD-1 as a boost in front is just sonic glory. But for my band it just can’t score against our drummer. So I guess it’s time to get the big toys again. Anyhow my just GAS‘ing for a made in UK Marshall again and want to keep it a a collectible. The ruined back plate is a bit of a downer in that regard but like someone mentioned before, I won’t end up looking to often at the backside…

Good old times:

 

[Plexitim]

Well. Not for nothin' there is a whole market out there in the guitar field for "relic" instruments. These are pre-worn to suggest honest player wear. Color me old fashioned but to me, the ultimate Marshall test is about tone. Does the amp have "that" tone, the presence and the raw balls to project your musical message.

Can it keep up with an aggressive drummer?

Can the amp articulate the sounds that are in your head and heart?

If so, the spots on that back panel may simply just be taken as part of the head's history. Sure its good to keep a Marshall in good condition as best you can. But part of the amp (any used amp honestly) is about some honest "relic" wear that happens through time and history.

Respectful opinion: if the amp has "that" sound, what are ya waitin' for?

 

[gkelm]

If it’s a fair price and the amp is solid, that back plate is very tiny issue, IMO. Oh, that kind of thing is not uncommon to see… Even plexi panels get discolored.

 

[Mentalo]

Little Update on my journey. This specific amp got out of reach for me because the seller decided not to offer shipping (contrary to his first offer) maybe I‘m better of this way. Now I took a complete different turn and bought a 6100LM, which I never heard of before a week a go. Now I‘m really excited and can’t await to receive it.

Seems to be an real odd ball. But 3 channels controllable via midi are just perfect for me. And I‘m really impressed by the features that were available 30 years ago (power reduction, pentode/triode mode, XLR out)

 

[nevermind]

Does it still have that protective plastic film on it? If yes, peel it off!!!!!!!!