How many different mark IV versions are there REALLY?

[JimAnsell]

how do we know there are only 2?
Knowing how mesa was with all the mark I, II, and III's, how do we know they only changed it once between 1990, and 2008 or whenever it was discontiuned.
i think its very possible there could have been as many as 4 different versions.
the really early a's, the late a's, early B's, and late B's.
we know early a's existed for about 5000 or so mark IV's maybe more. then they switched the fx loop layout, reverb circuit, and a few other things and it was the B, then there was the later b's that had a detached power cord, but how do we know they didn't mess with anything else in the circuit? seems to me, the newer mark IV's always sounded a bit more compressed than the older ones.
I've probably owned 8 or 9 mark IV's over the years.
the best sounding ones to my ears were always the really old a's, and the really early b's.
what do you guys think?

 

[dodger916]

It's an interesting question. Maybe there were tweaks but didn't want another Mark III on their hands with 5 versions. I guess it also depends on how "version" is defined. It seems Mesa historcally issued new versions when significant changes to the basic operation of the amp was made. The Mark II versions incorporated major changes, whereas the Mark III versions were more tweaks, albeit significant tweaks.

Clearly the change from Mark IVA to B was fairly substantial and calling it version B was appropriate. If they change certain components for whatever reason (availability, cost, etc.) it could influence the sound and feel of the amp without being a new "version". I've heard that they changed from Schumacher transformers in later production. That's a significant change that might result in circuit or component tweaks that would not necessarily result in a new version. (Perhaps they avoided calling attention to the fact that they weren't using Schumachers?) Tubes also evolved. STR 420s were the item in the early 90's, and I've read the Mark IV was originally designed around them (don't know how true that is). The last MIVs came with STR 440s. To speak to your point, perhaps they tweaked the circuits or the components to accommodate them?

 

[igfraso]

I am not so sure about any early As and late As. I am positive about the early Bs (also called "no A/no B") though, and also about the fact that later Bs had some changes in certain components (I guess to make it more cost effective).

 

[fretout]

I have seen one transitional Mark IV that had completely different caps used in the circuitry, but I called Mike Bendinelli for some help and he never returned my call.

I compared it to some of the pics on this forum (in the Mark IV sticky) and I compared it to the Mark IV is have now (latest model) and it is different in so many way (at least to my eyes). If I can find the pics, I'll post them up. Maybe some techs on here will know about them...

Oh, and just to add, the Mark IV in question had an attached power cable, FX Loops in the "pyramid" shape, and had a completely different voice IMO. It was running green-branded Mesa 6L6s (Sylvanias?)...

 

[igfraso]

Mesa told me some time ago that the earky Bs were "the best sounding" ones. Frankly, I don't know if they meant that these are the best sounding Mark IVs or just the best sounding IV Bs.

The "transitional" or "noA/noB" or "early Bs" started with the S/N 6,000 approx and I saw one with S/N #7,100 or 7,800 (I cannot recall).
Regards

 

[Mark Fore]

Having owned three early A's (still have two of them) and an early B (still have it), I think the early A's were more of a transition step between the Mark III lead tone and the B Mark IV's. The early A's have more of a raw quality that the Mark III (red stripe) 's have. My favorite Mark IV is the early A.

 

[CudBucket]

I've only owned Bs. The one I have now is a 2007 and sounds the best to me. The other two were a bit earlier. One was a 2003 and the other around the same.

 

[Glockaxis]

I have a B (last year of production) and it sounds magnificent. Of course I haven't compared it to any other version and don't plan to as I am completely happy with this one.

 

[mule#1]

STR 420s were the item in the early 90's, and I've read the Mark IV was originally designed around them (don't know how true that is). The last MIVs came with STR 440s. To speak to your point, perhaps they tweaked the circuits or the components to accommodate them?

The 440 question is an interesting one! Tubes make a huge difference to me and if the design was around those tubes it could be a big factor. I owned an early A and currently own a B. I have to say the early A was more open and less compressed than the B. However I have found ways to get the B sounding more open with tubes and settings. I think the B's voice is a little more modern, but again can be manipulated. I'd like to try a quad of 420's in there now!

 

[igfraso]

Mark IV-As were designed around STR-420 tubes.

 

[mule#1]

Sorry I meant 420 tubes. I'm not a big fan of the 440's. Does Mesa still sell the 420's?

 

[dodger916]

STR 420s were the item in the early 90's, and I've read the Mark IV was originally designed around them (don't know how true that is). The last MIVs came with STR 440s. To speak to your point, perhaps they tweaked the circuits or the components to accommodate them?

The 440 question is an interesting one! Tubes make a huge difference to me and if the design was around those tubes it could be a big factor. I owned an early A and currently own a B. I have to say the early A was more open and less compressed than the B. However I have found ways to get the B sounding more open with tubes and settings. I think the B's voice is a little more modern, but again can be manipulated. I'd like to try a quad of 420's in there now!

I agree that the Mark IV has a modern voice, especially compared to Mark IIs. I've had very favorable results reducing some of that moden voicing with a pair of STR420s in the inner sockets coupled with a pair of 5881s in the outers. I would also highly recommend trying some vintage preamp tubes, especially Tung Sols, which I run in V1 and V3 (new Mesas in the rest). To me, it makes the amp less compressed and modern without compromising the basic Mark IV voice and legendary liquid lead.

 

[mule#1]

STR 420s were the item in the early 90's, and I've read the Mark IV was originally designed around them (don't know how true that is). The last MIVs came with STR 440s. To speak to your point, perhaps they tweaked the circuits or the components to accommodate them?

The 440 question is an interesting one! Tubes make a huge difference to me and if the design was around those tubes it could be a big factor. I owned an early A and currently own a B. I have to say the early A was more open and less compressed than the B. However I have found ways to get the B sounding more open with tubes and settings. I think the B's voice is a little more modern, but again can be manipulated. I'd like to try a quad of 420's in there now!

I agree that the Mark IV has a modern voice, especially compared to Mark IIs. I've had very favorable results reducing some of that moden voicing with a pair of STR420s in the inner sockets coupled with a pair of 5881s in the outers. I would also highly recommend trying some vintage preamp tubes, especially Tung Sols, which I run in V1 and V3 (new Mesas in the rest). To me, it makes the amp less compressed and modern without compromising the basic Mark IV voice and legendary liquid lead.

That's something I'd like to try. I've been running either a quad of 425's (5881's) or 5881's in the middle and 6L6's outside. What do you think the 420's do for the tone?

 

[JimAnsell]

i like tung sols or tesla (not jj) or rft's in the pre amp.

 

[dodger916]

That's something I'd like to try. I've been running either a quad of 425's (5881's) or 5881's in the middle and 6L6's outside. What do you think the 420's do for the tone?

CAUTION: The manual specifies 5881s in all four sockets or the OUTSIDE (Class A) sockets. You shouldn't be running 5881s in the inner sockets with 6L6 in the outers, at least not according to the manual. The opposite would be fine.

 

[mule#1]

Thanks for the info! I didn't see that. Luckily I just did that once the last time I tried it! Before that it was all four.

 

[kmanick]

Having owned three early A's (still have two of them) and an early B (still have it), I think the early A's were more of a transition step between the Mark III lead tone and the B Mark IV's. The early A's have more of a raw quality that the Mark III (red stripe) 's have. My favorite Mark IV is the early A.

I completely agree with this. I had tried a couple of Mark IV "b"s and was not wowed by them.
I had a Red stripe III that I loved and a friend of mine somehow scored an "A" combo for pretty cheap. it was in almost mint condition. My friend just could not dial it in so he let me take it home to play with. it sounded way closer to my III than any other IV I had ever played.
I bought it and sold my III. I've had it going on almost a year now and everytime I fire her up it puts a giant smile on my face.

 

[igfraso]

I have a B (last year of production) and it sounds magnificent. Of course I haven't compared it to any other version and don't plan to as I am completely happy with this one.

Glockaxis, can you tell us the approximate serial number of your 2008 Mark IV? Something like 148xx would be wonderful.

For info, the transition between A and B versions seems to have happened around the lower s/n 5800's.

In the forum, there is someone with an early B s/n 585X (Dec 92? or Jan 93?) and another one with a full B s/n 689X (Dec 93).
Thank you

 

[hazbin]

I have a quad of 420's in my MkIVB and Satellite currently, perfect IMO. STR420's are always my first choice. Looking for a quad for my Mark V now.

 

[dodger916]

I have a quad of 420's in my MkIVB and Satellite currently, perfect IMO. STR420's are always my first choice. Looking for a quad for my Mark V now.

+1. I also really like 5881s in my Mark IV. Being that the 420 was the current production tube when the IV was developed, I wonder how 420s would work in a Mark V. Please keep us update, hazbin.