#1
Hey,

TL;DR: Hum in preamp, not tubes/guitar, what is it? & Help with a mod I might do.

I've got a new rig atm but having a little trouble with my Studio Pre.

It has a tiny bit of hum on the clean channel, and quite alot of hum on the lead channel, I've got my ISP decimator set to around 2 o'clock to kill it which is alot, I'd like to find out what the problem could be (ofcourse alot of gain, but how could I reduce/remove it?)

I've tried fresh tubes in it, different guitars, different leads, different power amp, I'm 99% sure its from the preamp, and from looking it up it seems to be a common issue with them with high gain.

The amp is from '91 and looks completely stock, I believe is it that caps can wear out over time? I'm wondering if this is it.. if not could it be an issue with the transformer? Are there any shielding tips or tricks I could use to help minimise this?

I'm also looking at modding the amp if I have to replace any components.. there are a bunch of schematics for the amp and there is the IIC+ mod I'd like to do
http://www.associatedcontent.com/article/1969488/converting_the_mesa_boogie_mark_iic.html?cat=33

I've not got much experience with a soldering iron; any idea how much this would cost for parts and having it done? or where I could get the components and any tips for doing it myself?

Also I don't use the reverb circuit at all and have removed the 12AT7 for it, hasn't made a difference but have left it out anyway.

Any help is appreciated!
Thanks alot,
Max
Mesa/Boogie Studio Pre | Marshall EL34 50/50 Power | Harley Benton 2x12 V30's

How do you like, your mids in the morning?
#2
Anybody? I could really use the help!
Mesa/Boogie Studio Pre | Marshall EL34 50/50 Power | Harley Benton 2x12 V30's

How do you like, your mids in the morning?