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

 

[Eevil]

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.

This

Sometimes squeaky clean is nice and sometimes crackly clean works wonders..

 

[Tal C.]

Guys excuse my poor playing i made a lil jam yesterday night nothing serious really just to check out how it compare a bit before the real comparison starts with more serious setup when the first batch of RI's arrives to players...

I copied the same settings and played the same riff shown at the 00:49 mark on MESA's video using my '83 IIC+ DRG + dirty fingers pup equipped explorer type guitar.

Recorded on my phone directly to a 1x12

Just a heads up really

What do you guys think?

 

[spawnofthesith2]

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.

Interesting! I've never played any type of II so don't have a frame of reference there. I forgot to add that I always have my keeley compressor plus on too. Been too long since I had the red stripe so I don't remember my settings there, but I wonder if maybe this is part of the "more mellow" nature of the purple stripe

 

[Fiveband]

Guys excuse my poor playing i made a lil jam yesterday night nothing serious really just to check out how it compare a bit before the real comparison starts with more serious setup when the first batch of RI's arrives to players...

I copied the same settings and played the same riff shown at the 00:49 mark on MESA's video using my '83 IIC+ DRG + dirty fingers pup equipped explorer type guitar.

Recorded on my phone directly to a 1x12

Just a heads up really

What do you guys think?

It does sound really close.

 

[rarebitusa]

It does sound really close.

Yea it does... cool

 

[Theresa]

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.

So, if we refer back to the first mention of mixing the EL34/6L6 tube compliment, I defer to the Mesa Boogie Mk III manual paragraph Tube Switch...

"This is the "Class A/Simul-Class" switch or the "60/100" watt switch, depending on amplifier type. In the Simul-Class amplifiers the power (before clip) is much less in the Class A position - mere 15 watts. But the unique way the system is wired allows you to achieve a much greater degree of power tube distortion than with most other amplifiers ... and it is still very loud! In Class A, only the outside (outer left & outer right) pair of tubes - the EL-34's will be on. The inner pair - which are 6L6's - will also be turned on when the switch is in the Simul-Class position. In addition to this obvious difference, the biasing and control circuitry of the socket pairs are radically different ... and this is the heart of the now famous (and patented) Simul-Class circuitry. It is worth noting that almost all of the major players who have gone over to Boogie have chosen the Simul-Class power design!

NOTE: In the past, MESA/Boogie advertised the "interchangeable power tubes" feature of the Mark III Simul-Class. We told players that they could use either EL-34's or 6L6's in the outer (Class A) power sockets. However, in recent years we've observed a much greater reliability factor with the use of EL-34's in these outer sockets, with much fewer incidents of tube failure. Therefore, today we strongly recommend using EL-34's in the outer sockets and 6L6's in the inner sockets of your Simul-Class Boogie."

If I read this correctly, the IIC+ EL34/6L6 complement was not a "thing" until the MK III happened on the scene. I have always used EL34's in the outer position and the 6L6 in the inner positions for all my Mark series amps with the exception of the VII. This kind of explains a good many things as to whether the reissue will accommodate the Tube Mixing/Tube Switch or not. Further exploration also discusses transformer impedances (Soldano discussions on mixing EL34 vs. 6L6's and compatibilities).

Further reference of Tube Mixing is outlined in the MK IV manual as follows:

"This procedure is in keeping with Mesa/Boogie’s quest for ultimate versatility. As you know, different tubes offer different sounds and playing characteristics and your new MARK IV offers four choices:

FIRST: the standard four 6L6’s which produce by far the best all-around performance. They deliver the most powerful clean sounds along with the richest distortion.

SECOND: Type 5881 is similar to the 6L6, but these tubes are just slightly less powerful. Although they will produce a somewhat rounder, more “vintage” tone.

THIRD: For those seeking the traditional British edge to their overdrive sounds, EL-34’s can replace the 6L6’s in the end two sockets (outer-left and outer-right). When running the amp in class A, only the two EL-34’s will be operating. In Simul-Class, a combination of two 6L6’s plus the EL-34’s produce a louder, fatter sound while retaining the British edge. (Expect the clean sound to suffer a bit whenever EL-34’s are used.) All combinations of Triode, Pentode, Tweed and Normal power can be used with this EL-34/6L6 combination.

FOURTH: Those of you who recall the great sounds of old Fender Deluxes will be delighted to know that four 6V6’s can also be used in the MARK IV...but, ONLY when TWEED and SIMUL-CLASS are selected. Also, to reduce tube wear when using 6V6’s, the 8 ohm speaker should be plugged into the 4 ohm jack. However, please note that Mesa/Boogie cannot accept responsibility for any blown 6V6’s incurred during such usage! Proper operation depends totally on the correct setting of the aforementioned switches and this will be impossible to verify for warranty tube coverage. So please exercise caution when using 6V6’s! Incorrect setting of the switches won’t usually cause immediate tube failure, but the strain caused is far in excess of recommended ratings."

Regards....