Jmc800 4210 combo head sooty chassis around power tubes?

[Amarutuf1]

Dear community,

I am new to the forum and the amps. I recently obtained a head of jcm800 4210 taken from the combo cabinet. It is from 1985 if I am not mistaken.

I found the sooty spots around the power tubes on the chassis surface. To me, it looks alarming. I plugged the amp in and it worked through Captor to radar mooer to the interface.

The first time I played through the head. It sounded amazing to my ear. Less so the next time. However, it is about the time to swap the filter caps for this veteran. Yes, they are stock.

Apart from changing the caps, could anyone hint me towards why there are those spots on the chassis metal. Should I be looking at other problematic compartments. Should I change the power tubes? They seem to be SovTek stock tubes.

Cheers in advance!

Kind regards. Stan

 

[Tatzmann]

I dont see any soot.

What i see is a somehow bare metal looking chassis and a laydown powertransformer.

Is this an amp built for the canadian market?

The filtercaps dont have to be changed necessarily if there isnt any hum present that can be traced back to compromised filtercapacitors.

 

[Tatzmann]

Looking at the pic again i see now what you mean, maybe take a better picture from it closer up and sideways.

Since this is a combo (canada or scandinavian version?), could it be that it is just patina on the metal coming from the heat of the powertubes?

I know the "sounds good one day, not as good the next" very well from 2205 amps that i played extensively, which came from different factors,
the amps were technically sound.

One thing with those is that all the controls
interact with each other quite a bit, so you could
try to write down your settings on a good day
and use those as a starting point next time you play.

 

[Amarutuf1]

I dont see any soot.

What i see is a somehow bare metal looking chassis and a laydown powertransformer.

Is this an amp built for the canadian market?

The filtercaps dont have to be changed necessarily if there isnt any hum present that can be traced back to compromised filtercapacitors.

Thanks for your reply! When I inspect the caps, i see no leakage similar to what they amp doctors show in youtube videos. In fact, the caps look intact to me. This soot is the only thing that confuses me at the moment..