Mark IIC+ pics and questions

[JimAnsell]

i scored this 60 watt mark IIC combo that was modded to c+.
I bought the combo and cab from guitar center. they had it tagged as a mark III, which it clearly isn't, so i took the combo and cab home for 1100 out the door.
it pays to be gear smart.
it sounds amazing, but the reverb is practicly nothing.
even on 10. i tried a new tank, new cables, tubes, etc, and nothing will get the verb sounding like it should.
i kinda want to send it to boogie and have them go through the amp anyway cause the filter caps are original i think and should probably be changed considering its from 83.
anyone know how much mesa charges for something like this?
and whats this .001 mod everyone keeps talking about around here?

 

[Boogiebabies]

Try soldering the sleeves of the reverb cables together where they enter the chassis. The output of the circuit uses the sleeve of the tank to ground. Generally, the RCA connector on the chassis is held in by a lock washer that rusts and loses its reference to ground. There is another reverb mod that adds more resistance to the circuit. If you do a search, I think Joey707 had it posted a while back. The .001 mod is a 1000pf 1KV cap in parallel with the 270K V4B plate load resistors. It basically cuts some high end off and makes the amp a bit smoother.

 

[Boogiebabies]

Joey707
Mark II


Joined: 27 Jan 2005
Posts: 69
Location: San Diego, CA,
Posted: Sat Mar 26, 2005 1:28 pm Post subject:
There are 2 mods to boost the reverb on MKIIC+'s and MK III's. The simple one is as follows:
You need a 3.3K, 1/2 watt resistor. Place the resistor in series with the black wire at the EFFECTS RETURN JACK. So, remove the black wire from the effects return jack. Solder the resistor to where the wire was on the jack. Solder the wire to the other end of the resistor. Place heat shrink tubing on the resistor.
This will increase the amount of reverb. How much more you get depends on the tank. You do have to use the correct tank for the amp. The correct tank number is 9AB2A1B.
The second mod is more extensive. It involves changing some parts on the circuit board. You should contact Mike Bendenilli at Mesa for this mod. 707 778 6565. He's done this mod to all my MK III's and they have reverb for days.

 

[Boogiebabies]

That HC thread you have is so full of mis-information it is laughable.

If you want a real answer post the circuit board pics for me.

 

[JimAnsell]

you can see all the pics here
http://www.filecloud.com/files/file.php?user_file_id=103497