Studio Preamp Upgrade parts and iic+ mod

[mxr2000]

I want to update My studio preamp with new caps since my Studio Pre is one of the early units from the 80's with all the original parts besides the caps what else might need to be upgraded to improve the sound. Also plan to do the "iic+ mod" on the "SP", what i need to know on the good old "USA" besides Mesa Boogie.. Where all this high quality parts can be found.. any help would be appreciated..

 

[mxr2000]

Can somebody help me with this?

 

[mxr2000]

Anybody could be kind to tell me about any store or supplier with high quality electronics parts for my preamp?
this are the parts needed to upgrade or convert my preamp closer to "iic+"

680k or 2.2 Meg Resistor
120pf Capacitor
170k Resistor
2x 500pf Capacitor
220k resistor
250pf Capacitor

 

[gregr]

I know this is an old thread, but I'm interested in potentially upgrading the lead circuit in the Studio Preamp to a IIC+.

It seems the consensus is that the input resistor to V4A on the commonly available Mark IIC+ schematic is 170k, which is not a standard value. To me it looks like 470k, which is a standard value.

Does anyone know the value of this resistor for certain, either from reading the resistor's value as it exists inside a real Mark IIC+, form a more clear copy of the official schematic, or from the list of materials for the commonly available DIY kit that was reverse engineered?

 

[mxr2000]

I know this is an old thread, but I'm interested in potentially upgrading the lead circuit in the Studio Preamp to a IIC+.

It seems the consensus is that the input resistor to V4A on the commonly available Mark IIC+ schematic is 170k, which is not a standard value. To me it looks like 470k, which is a standard value.

Does anyone know the value of this resistor for certain, either from reading the resistor's value as it exists inside a real Mark IIC+, form a more clear copy of the official schematic, or from the list of materials for the commonly available DIY kit that was reverse engineered?

I would like to reply to you with an answer for that. But to be honest I don't know my mod was done by a qualified amp tech from my area who did a great job with all the info that i provided to him. IF you do a search studio preamp c+ mod you will find a lot of threads with all the info..

 

[gregr]

Thanks for the reply.

All the discussions I've seen online appear to referring to the same schematic I linked.

Does anyone have information about the value of this resistor from a trustworthy source that is independent of this schematic?

 

[crane]

If you take a look at the Quad schematic, lead one (which is supposed to be a MkIIc+) has a 270kohms in that position.

 

[okgb]

I thought some of the voodoo was that it shared 1/2 the tube with the reverb circuit ?