Cameron Marshall problem ****FIXED!!!****

[projectx102]

I have an '83 Marshall JCM800 2204 modded by Mark Cameron with his Aldrich mod and when I first fire it up and start to play,the amp cuts down to a very low volume intermittently and I have to wiggle a certain preamp tube to bring the full volume back.Now when the amp warms up for about 4-5 minutes or so the problem goes away and it stays good for the rest of the night.I have also found that the problem stays with the socket as I have swapped out preamp tubes in this socket with the same result from a cold start.I have also tried cleaning,retensioning and reflowing the solder joints on this socket with no change.

 

[RACKSYSTEMS]

If Marks to busy to fix it I would do it sounds like a bad solder joint or socket.

 

[projectx102]

Hey Dave thanks for the offer but this is my only amp at this time and I need to get it back quick as I have a big session coming up.I might have to go at this myself or take it to someone locally.I just hope the problem isn't under the epoxy or I'm up the creek.I'm also assuming that I would have to drill the rivets out of the socket to remove it as that's how it is now.

 

[projectx102]

You could always open the amp up, turn it upside down, turn it on and using a chopstick (or pencil with any metal cut off), move some of the wires around on the tube that is giving you trouble. If any wire makes noise, it could be the source of your problems. DO NOT move wires all over the place, just move them slightly back and fourth. DO NOT touch anything else since the amp will be on and one wrong move and ZAP!!!! Good luck.

Sounds good and all but why once the amp is warmed up for a while it stops cutting out? I can wiggle the tube at that point and it's fine with no dropouts.

 

[dawnofdreamx97]

hey just thought of this... you wouldnt happen to be using a sovtek 12ax7lps in that gain stage would you ?

if so i believe thats the cathode follower and can cause some wacky stuff to happen ... just a thought!

 

[projectx102]

hey just thought of this... you wouldnt happen to be using a sovtek 12ax7lps in that gain stage would you ?

if so i believe thats the cathode follower and can cause some wacky stuff to happen ... just a thought!

I think I got it now.I retensioned the sockets again and made sure that all of the pin holders were moving on the underside when I wiggled the tubes.That tells me that all the pins are making contact.I also cleaned the pins on the tubes themselves with a scotchbrite because they looked a little dirty from cleaning the sockets.I then tested for about 15 minutes and it never cut down once even when wiggling the tubes.Hopefully that cured it.Thanks for the help guys and please excuse me for being a wet blanket today.

 

[projectx102]

Update is the problem is still happening.It was cutting down throughout half of my band's rehearsal last night and they were pissed! This obviously has to be gone over by Mark himself so I'm selling it(make a reasonable offer i paid $1950 for it a few months back) or trading for something Marshally in the same vein and the buyer can send it to be fixed.It sounds incredible when it works right but I can't afford to send it out right now and be without an amp.I'm about to get fired from this band as it is.

 

[projectx102]

Update is the problem is still happening.It was cutting down throughout half of my band's rehearsal last night and they were pissed! This obviously has to be gone over by Mark himself so I'm selling it(make a reasonable offer i paid $1950 for it a few months back) or trading for something Marshally in the same vein and the buyer can send it to be fixed.It sounds incredible when it works right but I can't afford to send it out right now and be without an amp.I'm about to get fired from this band as it is.

Why not send it to RACKSYSTEMS? They are willing to work on it for you.

Otherwise, I wouldnt pay more than a $1,000 for it since it has an undetermined problem.

If you read what I wrote I stated that I can't afford to send it California and back plus the cost of the repair.My wife just had a miscarriage and was hemmoraging and in the hospital so any money that I did have is gone to medical bills.I don't have another amp either and these guys in the band are not going to wait for me on a long repair.And it definitely will not leave this house for $1000 dollars.I can't take that kind of beating and be able to sleep at night.So I guess it will sit here and rot.

 

[J.B.]

Update is the problem is still happening.It was cutting down throughout half of my band's rehearsal last night and they were pissed! This obviously has to be gone over by Mark himself so I'm selling it(make a reasonable offer i paid $1950 for it a few months back) or trading for something Marshally in the same vein and the buyer can send it to be fixed.It sounds incredible when it works right but I can't afford to send it out right now and be without an amp.I'm about to get fired from this band as it is.

Why not send it to RACKSYSTEMS? They are willing to work on it for you.

Otherwise, I wouldnt pay more than a $1,000 for it since it has an undetermined problem.

If you read what I wrote I stated that I can't afford to send it California and back plus the cost of the repair.My wife just had a miscarriage and was hemmoraging and in the hospital so any money that I did have is gone to medical bills.I don't have another amp either and these guys in the band are not going to wait for me on a long repair.And it definitely will not leave this house for $1000 dollars.I can't take that kind of beating and be able to sleep at night.So I guess it will sit here and rot.

Where do you live? I ask because there might be a good tech in your area that you might not know about.

 

[dawnofdreamx97]

pm sent...

 

[projectx102]

Update is the problem is still happening.It was cutting down throughout half of my band's rehearsal last night and they were pissed! This obviously has to be gone over by Mark himself so I'm selling it(make a reasonable offer i paid $1950 for it a few months back) or trading for something Marshally in the same vein and the buyer can send it to be fixed.It sounds incredible when it works right but I can't afford to send it out right now and be without an amp.I'm about to get fired from this band as it is.

Why not send it to RACKSYSTEMS? They are willing to work on it for you.

Otherwise, I wouldnt pay more than a $1,000 for it since it has an undetermined problem.

If you read what I wrote I stated that I can't afford to send it California and back plus the cost of the repair.My wife just had a miscarriage and was hemmoraging and in the hospital so any money that I did have is gone to medical bills.I don't have another amp either and these guys in the band are not going to wait for me on a long repair.And it definitely will not leave this house for $1000 dollars.I can't take that kind of beating and be able to sleep at night.So I guess it will sit here and rot.

Sorry for your loss, prayers and mojo sent.

Where do you live? If close enough to me, I will look at it for free and let you use my JCM800 until it is fixed (if needed).

Thanks Dave I'm in Yonkers,New York just north of NYC.

 

[projectx102]

pm sent...

Thanks man.Hit me up when you hear something.

 

[dawnofdreamx97]

replied..

 

[projectx102]

No, I meant when you hear from the tech.

 

[projectx102]

Does anyone know of a decent way to get the goop off? It's the rubbery silicon type not the real hard stuff.I would really like to change both sockets.

 

[Capulin Overdrive]

i'd probably start slowly and carefully cutting the silicon off with an exacto knife.


don't know of any product that would help get the silicon off there?


but yea, just as well jump in and fix it yourself. just not worth taking your lumps on selling the amp as is.

 

[RACKSYSTEMS]

yeah basically you need to pic away at it with a pic and knife. Dave

 

[projectx102]

Wow.Sounds like a very time consuming job.I did order the tube sockets so I will change the first one that seems to be the bad one and see if that clears it up.If not then I'll have to start picking away at the epoxy.

 

[MrDan666]

Just outta curiosity... have you tried calling Mark yet? If not, then do so before going any further, as he could probably help you over the phone!

 

[projectx102]

Just outta curiosity... have you tried calling Mark yet? If not, then do so before going any further, as he could probably help you over the phone!

I haven't but I don't think he can replace a socket over the phone.