Wonky IIC+ PT

[sbalderrama]

I have a IIC+, serial number 138xx, simul-class, passes the loop test, but the PT is wonky, it's labeled as a Mesa 561136. Is this a Mark IV PT? So maybe the PT was replaced at some point?

 

[gts]

I have a IIC+, serial number 138xx, simul-class, passes the loop test, but the PT is wonky, it's labeled as a Mesa 561136. Is this a Mark IV PT? So maybe the PT was replaced at some point?

Yup it's a MkIV or a Dual Rec PT.
Your PT must have been replaced at some point as they wouldn't have had the 561136 PT when your IIC(+) was built/ made.

From a thread awhile back about BB wrote (bold is mine):

The MK IV PT # 561140 is a direct replacement for the MK III PT. If your PT blew, you would only be able to get a MK IV 561140 PT from Mesa.
The 562003 and 562004 OT's are identical other than the 562004R1. These should have no issues either with Tweed power.
You may have the 561136 PT which is the same as the 561140 and has the tweed function and a 5V rectifier heater as they were
used both used in MK IV's and Dual Rectifiers. The early 561136 in the Dual Rectifier is labeled Bold/Spongy and is the same as Tweed.
It's work a PT # check.

Call Mesa see if they have any info on the PT being swapped out.
Mike B might have info on when it was upgraded to a "+" (maybe the PT was swapped out during the upgrade??).

 

[sbalderrama]

thanks for the info. I sent a message to Mesa on Friday, hopefully they have some information about this amp.