C+ came home...

[Stonge]

Did the amp have the hum problem before you sent it to Mesa?Try it and your other amps in a different location to be sure it is related to the outlet.If it is related to the outlet it would indicate a bad ground in that outlet.I would have to open up my IIC+ to see if there is some ground connection that might have been disturbed by removing those screws,nothing comes to mind right now.If I get some time I'll take a look.Dont be so quick to blame yourself,it could very well have been someone at Mesa who left or knocked something loose.Like I said,I doubt Mike B would have changed those sockets himself,I'm sure the days are long gone when Mike B did all/most of the repairs,Mesa has become too big a manufacturer for one guy to do it all.

I can't remember because i usually use a decimater..it just seems noisier than I remember.

Having installed simulclass trannies into MarkIIs with 50w and 100w OTs, I learned that the simulclass OT has a bigger footprint and needs a pair of new holes. If your amp is a stock C+, it may not have been stock simulclass to begin with.

well I know that it is all original except 2 of the large caps and the tube sockets, which I replaced myself. I am thinking it is the outlets.

BTW..I was looking at Tony777s picture of his chassis and it looks like you can see the same holes faintly next to the tranny..they did put the tranny back on wrong.

 

[jvk]

Going by logic, the 2 holes visible next to eachother in your pic means that it was at some point meant for a 50/100W tranny, does it makes sense?

What did you have Mike B do for to amp, was it a general checkup? Didn't know they removed the OT for that, can't think for what they'd do that for. If the OT was mounted in the wrong holes, you can remove the screws and move the tranny around to re-position it and screw it back on.

 

[stokes]

I would have to guess the extra holes are drilled so the chassis could accomodate either tranny,chassis are probably drilled prior to determining simul or not.jvk,if you look closer you will see he has already re-positioned the tranny,seems to be having a hum problem now.If you suspect the outlet,try it elsewhere and see to be sure.

 

[jvk]

I would have to guess the extra holes are drilled so the chassis could accomodate either tranny,chassis are probably drilled prior to determining simul or not.jvk,if you look closer you will see he has already re-positioned the tranny,seems to be having a hum problem now.If you suspect the outlet,try it elsewhere and see to be sure.

Cheers, saw it.

 

[Stonge]

this is the screw I was talking about:

http://img.villagephotos.com/p/2008-1/1293176/screw.jpg

the phillips head one.

 

[jvk]

That's barbarically screwed into the transformer, for what i'm guessing, buzz reduction and/or holding it in place tighter. The trannys have a messy looking hole in the bottom. Not what I would do.

Not all the MarkIIs I've seen have it, here's one I've worked on that does:

 

[Stonge]

thats the thing though. it's not screwed into my tranny. I don't even know if it has any pragmatic purpose.

 

[jvk]

thats the thing though. it's not screwed into my tranny. I don't even know if it has any pragmatic purpose.

Can you see it protruding on the other side, or what?

 

[Stonge]

yeah it's definately touching the tranny, but not screwed into it.