Mark IV A and B

[spaivxx]

I have what, from what I have read, is a Mark IV A. It has not satalite send, and instead of the loop jacks being in the triangular configuration I have 2 switchable loops. It is a combo, I am told a 93. Has a really nice EV.

I noticed right away that the amp seemed to have a bit less gain than I am used to Mark IVs having. Especially Rhy 2. I used to love the Rhy2 channel on past Mark Ivs I have owned. I could get some really tight, hard hitting metal tones out of Rhy 2 on those amps. But on this one, Rhy 2 does not dial in a lot of crunch at all.

Having used clues gathered here to ID my Mark IV as an A (earlier, pre Satilite Send model) and then having read somewhere that the Rhy 2 on later Mark Ivs was signifigantly stronger, with more gain I am curious to know the truth.

What are the sigifigant, real differences between an A or B?

I have owned quite a few Mark IVs (and a whole crap load of other Boogie stuff....) and never even knew there were A and B type Marks IVs until a couple weeks ago.

 

[ytse_jam]

i suggest you to search the forum, you can find two or three topics about this with great and clear explanations! however, mkIV A preamp should be exactly the same of the MKIIC+... MkIV B is considered to be darker in the lead channel and more modern sounding. Despite of that "vintage obsession", many people prefer the B over the A but in the end is only a matter of taste.

 

[Russ]

Though I do not play much on R2 I can say that I do get a reasonable amount of crunch there with my A. I think that you just might be needing a retube. I know that my amp changed completely when I changed my tubes. It went from acceptable to :shock: OMFG!!!!!!! It is either that or you may not be dialing in your amp in the same manner as you had in the past to get the tones that you had previously achieved. Were there any other changes that you may have made since having played your other IVs? ie. pickups or guitars?

The main difference in the A v. B falls on the preamp design. There were changes made that strayed form the classic IIC+ preamp that became the B. The A preamp was pretty much the same as a IIC+ however due to the fact that the old tranny wasn't available the power section does not follow with the IIC+ thus leaving you with a IIC+ preamp on a newer power circuit. When the B was introduced there were changes made to the preamp to make it sound more like it's own amp though it still retained the basic feel of the amp. This is about where the progress stopped as far as changing the sound. The loops changed and a satellite send was added but that really didn't change the sound of the amp if used without them. As ytse_jam noted more people find that the B is darker. Depending upon your preference you will find one or the other more appealing though to most there really isn't a significant enough of a difference to notice because the differences are subtle. I can tell you from having played mine enough that when I play a B I can tell that something is different though it may just be because I am the one playing. I think that due to the fact that people sound a little different as they play individually that it would be difficult for the people that are not actually playing through the amp at that moment to discern which is which. As you have even said yourself, "I have owned quite a few Mark IVs (and a whole crap load of other Boogie stuff....) and never even knew there were A and B type Marks IVs until a couple weeks ago." , this clearly shows that there wasn't necessarily that big of a difference betweent the two. I am assuming that you have a relatively developed ear for your own tone. It has been my observation also that due to the nature of tube amps that even the same amp will sound differently at times due to forces out of our control.

Another thing to consider is that if you haven't had the EV in the Mark IV and now you do then of course the amp will sound a little different. Celestions like the MC90 have a tendency to have that slight British flair to them that has a little bit of breakup to it while the EV will remain clear till the cows come home. I would suggest maybe trying different settings and maybe a hotter pickup or just a different speaker.

I personally prefer the sounds I dial in on Lead to the sounds I dial in on R2 for the purposes of hard hitting metal tones. I like to make the amp really crunch up to play what I would normally supposed to be playing out of R2. It kind of limits the amp in that sense for me when I am playing more aggressive harsher metal but I just boost pedal to get the little more to step out even further. If I do not have to spend time playing rhythm I seriously lvoe the Lead tone I get out of the amp all by itself. I was actually fence sitting originally before trying to decide if I should be in the Mark or Rec camp. I love the tightness and clarity of the Mark amps but also dig the pummeling delivered by the Recs. I ended up getting the Mark IV because it handles more of the tones that I need. I guess the versatility is what kept me playing a Mark. I am not sure though if it is the tubes or the guitars or both or maybe even the B too but I am usually not very happy having to play on a different Mark IV than my own when I am out and about without my own gear.

FWIW my Mark IVA is a 91 model that was built in the 560's so it is definitely of the older design. I wish that there was a + mod for this amp. Maybe they could reissue the old trannies and install them with anything else necessary to recreate a faithful IIC+ sound. As it is, I can get pretty much as close as there is without being a III+ from a newer amp. There may be some vintage obsession but it is warranted. I would not spend my daughter's tuition fund on a IIC+ but I sure wouldn't mind picking one up. :wink:

 

[spaivxx]

Thanx for the replies guys. Russ thanx for the info. I a thinking retube as well. I may throw a compressor in front to, cause I am using a strat. But, the thine sound I am getting on Rhy 2 is not the same thin quality of the strat, it is different.

On my old Mark IV rigs, I always used Boogie 4x12 (between 2 to 4 of them) cabs with 2 EV, 2 Celestion Black Shadows. I just bought a 2x12 cab, will arrive next week, I am certain it will bring some improvement.

Ive just always like these amps and am trying to settle into a "one amp, one guitar" kind of groove, with the other amps and guitars I have serving as backups. Maybe in my current situation the Mark IV was not the best choice, but I am sure once I continue tweaking, I will get what I need from it.

 

[Scary Guy IRL]

Is there a way, from looking at a Mark IV. To tell if it's A or B?

 

[ytse_jam]

Is there a way, from looking at a Mark IV. To tell if it's A or B?

a satellite send was added [for B version]

 

[Scary Guy IRL]

Okay Thanks.

Also, i dunno if i missed it. But when were the B's brought in?

Thanks

 

[Shep]

look at the mk iv thread..