JCM redirected from the dead

[DennyMarshall]

(Resurrected)

Hello,
New to the forums here. I recently picked up a 1981 JCM 800. The board was in shambles, years of guys and wannabe amp techs poking around and soldering (poorly) resisters on top of resisters.

Long story short, I took the amp to a local repair tech who put the amp as close to original as possible and he spent some quality time cleaning up the board and replacing caps, and resistors that were either shot or the wrong values.

I love the sound of 800’s and I’ve owned at least 50 over the years.

The only issue I have right now is it’s lacking just a little distortion and I mean a little.

What values and where could I change a resistor that might open that up just a little.

Here is a fat old guy clip of myself farting around with the amp and the distortion on 10.

Thanks in advance for any info.



Here are some of the issues as posted by Curran the amp guy

 

[ampmadscientist]

(Resurrected)

Hello,
New to the forums here. I recently picked up a 1981 JCM 800. The board was in shambles, years of guys and wannabe amp techs poking around and soldering (poorly) resisters on top of resisters.

Long story short, I took the amp to a local repair tech who put the amp as close to original as possible and he spent some quality time cleaning up the board and replacing caps, and resistors that were either shot or the wrong values.

I love the sound of 800’s and I’ve owned at least 50 over the years.

The only issue I have right now is it’s lacking just a little distortion and I mean a little.

What values and where could I change a resistor that might open that up just a little.

Here is a fat old guy clip of myself farting around with the amp and the distortion on 10.

Thanks in advance for any info.



Here are some of the issues as posted by Curran the amp guy

Well, if you post clear pictures of the whole insides that will probably help.
I can't tell from the video.
But there are certain preamp tubes that do have a lot better sensitivity than average. And so preamp tubes can make quite a difference.

There are some circuit tweaks but that goes back to modifying the circuit....
(we're not really certain what's in there now)

 

[AlvisX]

Sounds fine on my computer.......Just play Montrose on it ,you'll be OK

 

[neikeel]

Hmm two threads on same thing - need merging Mr Moderator?