Maintaining old jcm800 2210 from 1986.

[jcm_rock]

I have this legendary amp. I dont play anymore on it, just use my small home amp to jam with youtube from time to time. My marshall is stored in a dry room at my parents house since I live in a Small condo in a building and dont have a room for it and the tenants would go crazy how that amp is LOUD. I did not played on it for 10 years. Today I mentioned this to my work colleague and he told me that the amp could be damaged for not playing for that long period of time. Is that true? I cannot test the amp since my parents are not close by. He told me to sell it, but I cant, I just love this amp and I know it is a good solid build that is hard to find these days. It’s just a classic, and it has sentimental value for me when I did gigs with it when I was younger.
Thanks for the responses.
Cheers.

 

[Tatzmann]

I bought plenty of old amps, Marshalls and others, that lay dormant sometimes for a quarter of a century. Had not had much problems at all.

The capacitors pre-year2000era are oftentimes, but not all the times, of higher quality then newer equivalents.

There are some people who change out the electrolytic capacitors right away, others just plug in the amp or bring the voltage up slowly over a certain timeperiod. If the amp doesn't misbehave, they keep the old capacitors.

The potentiometers certainly will be scratchy and need a bit of cleaning. I had a couple cases of Marshalls from the late 1980's to 2000 models where the pots seized up because of hardened grease, but this too can be loosened up again.

The valves need checking too, in some cases they loose the vacuum, but thats more frequently the case when the amp is stored away in non climated areas, like basements or attics.

As said, it'll surely need a little bit of cleaning (general, pots, jacks, valvesockets), but there is a high chance that its working fine still.

 

[Pete Farrington]

the amp could be damaged for not playing for that long period of time. Is that true?

Yes, the electrochemistry of the electrolytic caps is such that if left uncharged for an extended period of time (eg >1 year), the insulating oxide layer between their plates will tend to degrade, aka deform, and the caps will appear as a short.
To reform them, a current limited supply of their rated voltage can be used. That will allow the electrochemical process to rebuild the oxide layer without excessive heat.
If just powered up, yes the caps may reform very wuickly without apparent damage. But the risk is they’ll overheat and at the very least become damaged, eg by their electrolyte boiling off.
The worst case is that may happen explosively.

My view is that basic good practice would be for initial power up to be via a current limited supply, eg remove valves and use a light bulb limiter, starting with a low wattage bulb eg 20W, and working up in wattage to at least 100W, say 30 mins with each bulb.
Then refit the valves and a load, and power up, again via the light bulb limiter.
If ok, remove limiter, check bias, and check for correct operation.
Yes pots and jacks will need a clean to remove oxides etc.

 

[flyingvmach3]

Keep your JCM 800 2210 in dry storage like you are (at your parent's house) and you'll probably be in good shape. If you are worried, you can inspect the circuit board and internal works for corrosion by pulling the works out of the chassis.

My JCM 800 2210 has been kept in a dry room for most it's life and still has the original LCR blue capacitors that came with it in the 80's. Haven't failed me yet. However, if they are bloated, leaking or discolored you might need to worry - I've been keeping an eye on mine all these years without replacing them.

If any of the pots have become scratchy from lack of use or lack of lube - spray Deoxit in the slot in the back of the pot to limber them up again while the amp is not plugged in. Turn the knobs on the pots back and forth while you do so. Sometimes you have to do it twice to get them all smooth and quiet. Getting the pots so they are smooth and don't crackle will make it like new - and easier to sell.

10 years isn't too long in the grand scheme of things. I've also had tube amps sit for much longer than that - without fail.

If you need the bread and don't plan on using it anymore (they are too loud for neighbors - agreed), you'll find the selling price of these is always going up - and they are still in high demand.

Oddly, the 2210 didn't come with one of the original Marshall channel switching / reverb switch pedals - you had to pay extra for it. If you can find the channel switching pedal to go with it, your head will probably fetch a higher price - 2 maybe 3 large - if it's in reasonable shape.