REISSUE Rumor: Mark IIC+ and 2ch Recto

[bandit2013]

The variac note on the EL34 with the Mark V, we can include the same for the MWDR and Roadster (they recommend tube rectification only for EL34).
Mostly due to issues with the EL34 and their variants back in the day. Even Marshalls were having issues with the tube quality so they decided to shift to 6550 tubes instead.

Current production EL34 like the STR447 (EH EL34) or the Gold Lion KT77, EH 6CA7, Tung Sol EL34B They can tolerate the higher plate voltages without sudden death. When dealing with NOS tubes, I would consider them to be of concern. That includes the MESA NOS STR450 Siemens EL34. Tried a set of those and ended up having to ship back the TC50 after the fuse blew out and amp would not function even with the stock tubes and new fuse. (strobe mute circuit took a dive but Mesa claims it was not due to the tubes. Strobe mute will not blow the fuse but the old EL34 will as that amp runs 450V plate voltage.

In other words, the Variac power mode note on the V and the tube rectifier for the Dual Rectos is just a CYA notice. Most of the other manuals indicate if you decide to run with EL34 power tubes, have several sets available due to their shorter life span or unpredictable reliability. However, no mention of such with the TC or Badlander. However, it may explain why you get a volume drop when using 6L6 tube sin those amps.

 

[bandit2013]

As for the IIC+ compatibility with EL34 tubes. depends on the extended class A sockets and their bias points. I did not see any EL34/6L6 bias switch. If they worked out the details with the amp, it may be possible to run EL34 tubes in the extended class A spots. Probably best to get a direct answer from Mesa or wait and see if any details are in the manual regarding power tubes.

I found it made no different in tone or character when I ran the one Mark VII with EL34 and the other with 6L6 tubes. They both sounded the same. The STR445 are voiced like the JJ 6CA7 tube in some ways. So if the amp cannot run a mixed quad, keep the STR445 in the Class A sockets and run a pair of STR448 or STR441 in the class AB sockets. Then again, not sure what 6L6 tubes will sound best in this new amp. Just speculating as I did that with the Mark VII (blend of STR448 and the STR445). I am now running a full set of the STR445 (yellows) in both Mark VII. It did have merit to run the STR448. I did try a pair of the STR415 in the Class AB sockets.

So we will find out what we can use once they publish the manual.

 

[tbonesullivan]

IMHO the "Single Chan Dual Mode" design deal with the II & III is always going to be a bit of a compromise between Ch 1 and the lead chan. If the reissue mimics a real IIC+ in function (as it should) then yea I'd expect it's going to present the same challenge. If I set my IIC+ Ch 1 to a more spanky and sparkly clean then there definitely is less gain to work with on the Lead Chan. Personally I feel the Lead chan has a ton of gain and that makes up for it but I could see why it may be impossible.

I have found that the definition of a "Good clean channel" seems to vary quite a bit from person to person. My definition is pretty much fender blackface. I don't want any break up, no grit, no "super warm" type of sound. I want a jazz clean. For others it seems like "clean" includes a little bit of breakup. Now I've never gotten a chance to play any of the early marks, but I would assume running the input volume on the "clean" mode at 7 would have a decent amount of grit in the sound.

 

[spawnofthesith2]

I have found that the definition of a "Good clean channel" seems to vary quite a bit from person to person. My definition is pretty much fender blackface. I don't want any break up, no grit, no "super warm" type of sound. I want a jazz clean. For others it seems like "clean" includes a little bit of breakup. Now I've never gotten a chance to play any of the early marks, but I would assume running the input volume on the "clean" mode at 7 would have a decent amount of grit in the sound.

I’m also in the pristine cleans camp, with my III and the input volume at 7 I achieve that, but I guess pickup type will have impact on that as well. Sure bridge humbucker full bore has some dirt to it. But I would never use a bridge humbucker for my clean sounds anyway. My go to clean config is a dual humbucker guitar middle position coils tapped. My CE24 semihollow especially sounds amazing for this. No hair or breakup at all

 

[rarebitusa]

I’m also in the pristine cleans camp, with my III and the input volume at 7 I achieve that, but I guess pickup type will have impact on that as well. Sure bridge humbucker full bore has some dirt to it. But I would never use a bridge humbucker for my clean sounds anyway. My go to clean config is a dual humbucker guitar middle position coils tapped. My CE24 semihollow especially sounds amazing for this. No hair or breakup at all

Yea, I'd agree WRT PUs. My IIC+ Ch 1 gets gritty pretty quick. Can't set it near 7 more like 5 and yea you can't slam the input at all. A compressor, which sounds sparkly on the LSS just breaks up on the IIC+ acts almost like a boost pedal.

 

[Joey1970]

Sylvania 6CA7's (STR-616) won't give any problems. https://reverb.com/item/31049775-me...illips-sylvania-6l6-gc-el34-6ca7-mark-iii-iic