JCM 800 2205 Split Reverb problem

[IbanezObsession]

I don't know if this is a serious issue or not, nor do I know how to describe it. I was refered to this site from a friend that reads it religiously, but couldn't find a similar problem. Just changed all tubes Power and Pre, the only thing I can think of is the Power or Pre amp tube sockets being worn. Everytime I hit a lower note on my guitar clean channel only, it gives me the raspberry sound, and kind of sounds like it is cutting out. Could this be the sockets, or something else that I have no idea about.

Thank you for your help in advance!!

Rich

[jcollins]

I don't know if this is a serious issue or not, nor do I know how to describe it. I was refered to this site from a friend that reads it religiously, but couldn't find a similar problem. Just changed all tubes Power and Pre, the only thing I can think of is the Power or Pre amp tube sockets being worn. Everytime I hit a lower note on my guitar clean channel only, it gives me the raspberry sound, and kind of sounds like it is cutting out. Could this be the sockets, or something else that I have no idea about.

Thank you for your help in advance!!

Rich

It could very well be one of your new tubes. Try subbing the old ones back in.

If you retubed with JJEl34's, you might need to retension the tube sockets.

[IbanezObsession]

JCM 800 2205 Split Reverb problem

My old tubes were doing it too, I put in Groove Tube GT-EL34R's matched pair, which was the same power tubes that were in there previous. I'm going to test to see if it's a vibration problem or a wireing problem via direct out to an audio interface. That way there is no speaker in the way to vibrate anything in the head. You may laugh, but when I hit the head with my hand, the noise goes away breifly and returns as I continue to play. I'm just posting to see if it's something else I may have to spend $$$ on besides just some new sockets.

Thanks for the imediate response. Hopefully I'll be of assistance to someone else because I am Captain DIY, and if I can help someone where I have broken something ha ha I will.

Rich

[drewl]

Try cleaning the FX send and return jacks, and run a jumper between them and see if the problem is still there.
Another cause could be a bad solder connection between one of the pots and the pc board.

[IbanezObsession]

Update

No cutting on clean channel only on low volumes, meaning vibration is the culprit. Fun part of this is what's shaking. Tube sockets, wires, this is an OLD amp, probably the whole thing is rattleing. I just don't want to change transformers or caps, have to bring a technician bleh. Thanks for the info, I'm going to check out all the wires... suck city, but the thing sounds phenominal when it works.

Thanks again

Rich

[Alex R]

Speaking as a technician bleh, I think you might need one. The problem may be physical vibration, but could be blocking distortion, or a lack of ground reference on a preamp grid, or a leaky coupling cap, all of which a technician bleh could be expected to find with his special equipment. Bleh.

[IbanezObsession]

HA HA nice, yeah, would like to learn it by myself, but knowing the risk negatory. The worst part of this is it takes 3 weeks for my local tech to even look at it. It could cost a pretty penny to get it looked at, but thanks for your much needed info. You guys have been great.

Rich

[Mars Amp Repair]

Rich,
Try hitting a note on the guitar & then tap the tubes. This should either get you to the tube/socket that is causing the issue.
Unless you're familiar with the dangerous voltages in the amp & how to keep from electricuting yourself, I'd steer away from doing the same with the board or components under the chassis....a few bucks with the (blech) technician could save you your life....glen