Help with JCM 800 2203x

[selloutrr]

At least they learned from the mistake of the JCM2000 - but I'm never going to buy another new production marshall, that thing is nothing but a bench whore and they did not stand by the product one bit.


This is the only Marshall Authorized repair center in the USA - WTF?

444 E. COURTLAND STREET
MUNDELEIN
IL 60060

phone 877 459 0170
fax 847 388 4745

marshall.sales@marshallamps.us
marshall.service@marshallamps.us

[lespaulplayer]

Doug Hoffman's EL34 World site lists a tech named Art Jacobson in Rock Rapids. Know nothing about him, but may be worth a call.

I think this Mathes place is my best option so far. I'm just waiting to hear back from them.

[lespaulplayer]

This is the only Marshall Authorized repair center in the USA - WTF?

444 E. COURTLAND STREET
MUNDELEIN
IL 60060

phone 877 459 0170
fax 847 388 4745

marshall.sales@marshallamps.us
marshall.service@marshallamps.us

I sent Marshall an email asking for authorized repair centers in the US close to me. I'll see what they say.

[selloutrr]

with the right packing job shipping is an option.

[lespaulplayer]

Ok, I was playing through it over my lunch hour today, and the buzz was still there at first, then it went away for about 10 minutes, and then it started buzzing again. It is there if I unplug the input cable, but becomes more noticeable with the input cable plugged in. Especially with a boost in front, all you hear is that annoying buzz. So what does this sound like to you guys? Should I not be playing through it, could that cause further damage? It sounds fine until you are not playing and then all you hear is buzzzzzzzzz.

[selloutrr]

have you tried swapping out your V1 preamp tube?
different instrument cable?
single-coil, P=90, or humbucker pickups?
Is the amp on clean power?

The more we can weed out the easier to narrow down.

[lespaulplayer]

have you tried swapping out your V1 preamp tube?
different instrument cable?
single-coil, P=90, or humbucker pickups?
Is the amp on clean power?

The more we can weed out the easier to narrow down.

I've tried swapping out all the tubes, both pre and power one at a time, with tubes I know are good. I've tried different guitars, both with single coils and humbuckers, and the hum is still there. I've tried three different cables, doesn't matter, the hum is still there. The hum is there with a cable plugged in or without, but it is more noticeable with a cable plugged into the input. It's just like a weird hum, that comes and goes, and is sometimes louder than other times. I just don't know what it could be. And what do you mean by clean power?

[Richie]

Might look real good at the socket that had the tube fail. I've seen sometimes a crack or small arc in part of the heater, cause that kind of hum. Could be about anything. But usually if something happens,and their wasn't a problem before,look at the problem sorce or things that might be connected to it. Sometimes the small arc or crack between tube pins is hard to see.

[lespaulplayer]

Might look real good at the socket that had the tube fail. I've seen sometimes a crack or small arc in part of the heater, cause that kind of hum. Could be about anything. But usually if something happens,and their wasn't a problem before,look at the problem sorce or things that might be connected to it. Sometimes the small arc or crack between tube pins is hard to see.

Thanks for your input. I'll look it over real good tomorrow and check for those things. I've got band practice tonight after work, so I wont have time to look at it tonight. I'll let you know if I find anything tomorrow night.

[lespaulplayer]

A little update. I have been emailing back and and forth with that Mathes Amplification, and so far he has been very helpful. With a few trouble shooting tips, we've figured at that the hum is coming from somewhere in the preamp section of the amp. I think I've done all that I can do at this point, now I'm just waiting to hear back from him from the last email I sent him. I think I'm going to end up taking my amp to him to fix it. It sounds like he really knows what he is talking about, and his builds on his website look awesome.