Mark IIB Simul-Class

[BPski]

Can anyone tell me if my 60/100w Mark IIB can be converted to Simul Class? Are the output transformers still available? Any info would be great!
Thanks.

 

[Boogiebabies]

Worst case is that Mesa has the 562004 Simul OT from the MK IV.
It's not much different from the SC-152019B (IIC+) or the 562003 (MK III).
The 562003 is identical to the 152019B, only the part number is different.
Call Mesa and see if they have any 562003's left. I don't think they do, but the 562004 will do the trick.

I have the 562004 in my 90 Green Stripe MK III ( factory stock with 562004) and 1993 MK IV. They sound awesome.

 

[BPski]

Thanks for the info. I have a 60w IIB that sounds great and the 100w is too loud and clean. Even in the 60w position because of the big iron. So I thought that a IIB Simul might be a cool amp. I wonder how much they would charge for the conversion. I don't know if the board has to be changed. I'd actually like to do the work myself instead of paying for the shipping. I do all sorts of amp repairs and some building. Thanks again!! Happy 4th.

 

[Boogiebabies]

The 60 watt power board is totally different and the PI and presence circuit is on it. Ask Mesa if they have any 7C1 power boards left, otherwise most of the upgrade would need to be point to point.

 

[BPski]

I want to do the Simul conversion to my 100w IIB not my 60w IIB. I looked at the schematics and it looks pretty easy after you swap the OT. I will have to call Mesa and speak to Mike Bendinelli about this. He's a good guy. I also changed the PI's on my IIB's to that of a Mark I. It sounds a little more open and has a vintage vibe to it. Cool. Thanks again.

 

[igfraso]

Mike Bendinelli told me that if you run the amp with 100 W and plug the speaker into a 4 ohm jack, the sound will approximate the Simul Class sound.