After a few days with the IIC+...first impressions

[JDH85]

Recently acquired a SimulClass C+ (no GEQ or reverb) from 1985. It has the 105 OT and the head shell is covered in white (cream now) tolex. The head came with a Boogie 5-band Graphic, which I've been running through the loop. I'm running it through a Mills Acoustics Afterburner 4x12 with V30's and K100's in an X pattern. Main guitar is a 1999 LP Studio with EMG 81 + 85.

So far, I can certainly hear some differences between this and my IV. The C+ is bouncier, more lively, and less compressed sounding. It does seem to lack some of the thickness of the IV, but excels in the area of faster single note stuff. Faster palm mutes ala Hetfield are awesome. They have a great depth to them while retaining separation, even at speed. The C+ really shines when I get some volume going, say around 3.5 on the lead master and 3 on the global master.

The clean sound on the amp is, by my standards, fantastic. It would be nice to have independent controls.

The head came with JJ preamp tubes across the board, and Sovtek 5881s in the power section. I have replaced the preamps with a mix of 8th gen Chinese, Tung Sols, and Ruby's. For now, the 5881s are still in there.

When running, there is a smell coming from the amp, which I can best describe as hot electronics. It operates fine, and I have had it turned up to stage volumrs several times with no problems. I took the chassis out and do not see anything leaking from any caps. Does anyone have any feedback regarding what could be causing the odor?

I would also appreciate any suggestions regarding tubes, both pre and power, or anything else you might recommend me to try with this amp.

 

[GJgo]

Just a thought, the hot smell could be cooking power tubes. The 105 transformers run really high plate voltage, mine is around 515v. This is enough to cook a lot of new tubes. Look for a matched set of older Sylvania STR415s, or Sylvania 6CA7s for the Class A sockets, or for new tubes the only ones Mesa has that are up to the task are their STR425s.

 

[Wyzard]

What GJgo said: 5881s run at a lower plate voltage, IIRC, like a 6L6GB rather than what I always use - matched NOS/OS 6L6GC (mostly Sylvanias).

The Mks I have would pretty much all cook a 5881.

 

[JDH85]

Thanks for the input, fellas. Seems like Mesa 415s would cost me more than $500 for a set. Yikes! From my research of the Sovtek 5881WXTs that are in there, it's a very hardy tube and can withstand voltages well above what many other 6L6 types can. Now that I've been playing it for a few more days, I don't notice the odor anymore. I have been pushing the thing pretty hard too.

I've noticed that with this amp, I can really push the lows and low mids on the graphic eq to the extreme without losing note separation. My Mark IV is capable of sound very close, however requires much more fine-tuning to keep it just on the verge of choas like that. The best way I can describe what I like is when I want clarity on single note stuff, the IIC+ delivers all the punch I could dream of. And then when hitting the big chords the notes blend together nicely and have this quality where it seems like they sustain effortlessly, but are not overly-saturated. Yoy can still hear the fundamental characteristic of the instrument. Very nice amp!

 

[xdg999]

When I talked to Mike B. about upgrading my Mark IIc to a +, I told him that when I tried a quad of Green Mesa 440's in my Simul Class c+ it blew the fuse. He told me the only 6l6's I could use in it were Red Mesa 425's. He also told me about a mod that would lower the voltage so you could use other 6l6's besides the 425's.

 

[GJgo]

The high voltage is why they have the attack they do. I have Sylvanias in mine & they sound killer, but rather than get in a high dollar old *** tube habit I'm planning on switching to the 425s. Red in class A, green in class A/B.

 

[JDH85]

After some Google searching, it appears that Mesa STR 425's are relabeled Sovtek 5881WXTs. So I am running the tubes Mike B recommended. The tonal characteristics seem to lean toward a more "brown" sound. Of course, everyone hears things differently so YMMV. I am tempted to throw in the Ruby 6L6's that are currently in my Mark IV hust to hear the difference. First, to research if they can handle the voltage....

 

[xdg999]

I have New Sensor Svetlana 12ax7's, EL34's and 6l6's in my Simul Class. Very happy with the tone but I've been using my upgraded c+ the most since I got it back from Mesa. It has the best clean tone of my c+'s and lead channel is fat with this sag that is really nice. The upgrade has nos chinese military 12ax7's and Ruby 6l6's.

 

[JDH85]

So now you are up to four C+'s?! That's awesome, man. I see yours are all non-GEQ. Have you ever tried the GEQ model?

 

[xdg999]

I haven't tried a c+ with the graphic. The guy I bought my Simul Class from still has 5 c+'s. If I find an original DRG or HRG for a good price I might buy it. I'm also looking for another Mark IIc HR to upgrade. Hopefully I find one before Mike B. retires.

 

[xdg999]

I bought a Mark IIc DRG combo last night. Gonna send it back to Mesa for the c+ upgrade.

 

[BoogieHog]

I bought a Mark IIc DRG combo last night. Gonna send it back to Mesa for the c+ upgrade.

WOW! That's awesome! Pics?

 

[xdg999]

I don't know how to post pics. I got the upgraded DRG back a couple of weeks ago. It got the c+ upgrade, new caps and the bright mod, which makes the preamp the same as an HR c+. It sounds awesome with the new Celestion Redback speaker. I haven't spent much time with it because of work. Lots of overtime and out of town travel. But I did have time to snatch another c+ off ebay on Saturday. It's an original HR wide chassis head. I still can't believe the price I got it for. $1659 including shipping. I just found 2 Mesa Mark Lead/Rhythm footswitches at a Music Go Round for $4.99 each. Now I have to find a vintage 4x12 with the metal grill.

 

[xdg999]

I just talked to Mike B. about the bright mod on the Simul Class c+'s. I thought it made it less bright like the 100 watters. It actually makes it brighter. Oooops! I was wondering why it was still so bright with Mesa/JJ 12ax7's and Sovtek 5881's. Mike said he would talk to my local tech about what parts to change to reduce the brightness.