Please help me with IIC/IIC+ identification

[Ivan Horvat]

Hello everyone!

I am a new member of this forum and have just acquired a MESA Boogie Mark IIC, but I am unsure what version exactly - sorry if this has been posted before, I searched online but couldn't find the answer.

The amp is the 110V blonde combo version, serial 12084 and there is a 12/83 mark on the chassis where the tubes are. There are markings "MB" under the power cord, and "-" above the power cord (so far I've only heard about IIC and IIC+ but not IIC-). It has the Type MS-12 speaker, serial 005630, and the transformers read "MESA 60-162318 EIA606-325" (this one is hard to discern due to double stamping), "MESA 38-15115 EIA606-330", and "MESA 185225 EIA606-234. For the fourth transformer, I am unable to provide info as of now because it would require me to remove the chassis from the cabinet. Also, it has the "PULL DEEP" knob.

I also did the "loop test", and attached please also find a video I took. I don't understand clearly the results to be able to tell if it is a IIC or IIC+.

Thanks,
Ivan

 

[rarebitusa]

That a fairly late serial number in the IIC run. If you want to get more details look at the Mesa For Dummies Guide, packed with great info.

https://boogieforum.com/threads/mark-iic-guide-for-dummies.18184/post-530089

Congrats on the amp!!!

Oh with the loops test you should manipulate both the lead and gain controls with the note ringing

 

[Fiveband]

You might want to pull the chassis and post clear pics of the part numbers on the circuit boards, and the condition of the boards themselves.

 

[Ivan Horvat]

Thanks for the replies guys! I went through the Mesa For Dummies guide, though still some questions remain open for me.

Like you said, Fiveband, the only way to know is to pull the chassis I guess. In the meantime I had contacted MESA customer support and they also told me the same. (Props to MESA, they responded lightning fast! Kudos.)

Before I do that, I will redo the loop test tomorrow, but from what I've heard today in person, there is some influence on the volume and sound. But I will redo it and record tomorrow to be sure.

The amp sounds great to me either way.

 

[rarebitusa]

The amp sounds great to me either way.

The MS-12 speaker is fairly rare as well, the cab looks to be in beautiful shape. The date written on the chassis Dec/83 would still have seen the production in the IIC timeframe.

The loop test is definite, the squeal heard on your test is a bit questionable as to what it is.

One other thing to note or try. The Fx loop of the IIC was placed before the Lead Drive chan and the IIC+ had it moved to after the lead chan. If you have a pedal with a direct monitor out you could see if that direct out changes with the lead drive engaged, since what one would hear out of the direct out is just from IIC chan 1.

 

[Ivan Horvat]

I tried the loop test (guitar straight to loop return) again and below are the results.

I seem to notice some change in volume/tone when I turn the LEAD DRIVE knob, but it is very very subtle - albeit there is a difference. Hopefully my phone mic picked it up and it can be heard in the video.
Moreover, I turned the other knobs as well, and the only one that made significant difference is MASTER 1, as showcased in the video, while turning both VOLUME 1 and LEAD MASTER made no change to the volume/tone at all.

I am not sure if that indicates that the amp is a regular IIC or not, but hopefully someone can chime in.

Thanks everyone once again!

PS. rarebitusa, currently I do not have access to such a pedal nor the majority of my setup since I am not at home home. But thank you for the suggestion, I appreciate it.

 

[rarebitusa]

PS. rarebitusa, currently I do not have access to such a pedal nor the majority of my setup since I am not at home home. But thank you for the suggestion, I appreciate it.

ok no worries. I haven't done the loop test in a while and will try it later.

I'd suggest one more thing. Take a cable and put it in the Send jack that should decouple all of the circuity before it. Set Vol 1 = 5, Master 1 = 2-3, Treble = 5, bass, mid = 2. Pull Lead pushed in. Hit a note and adjust vol on Master 1 to a moderate level. Set Lead Drive, Lead master = 5. Hit a note and pull the Lead Pull out. Vary the Lead Master volume. Note changes.

The other thing you can try with the same above settings with Lead Pull pushed in, the cable removed from the Send and the guitar now in the input jack. Hit a chord and push/pull the Treble shift. If you hear a change in tone that is IIC.