Opinions on Mark IV A vs B?

[Gibsonchild]

So I think I have narrowed down my new amp search to a Mesa Mark IV. There‘s a IVa for sale local-ish to me that’s a pretty good deal, and I’m thinking about jumping on it.

Was just curious what the differences are in sound between the IVa and IVb? I’ve watched a couple of YouTube videos, and honestly can’t tell a huge difference between the two. But I also know it’s dumb to try to judge an amp solely by shitty YouTube cell phone clips. Am I going to be missing out on anything major by not holding out for a IVb instead?

 

[Samhain]

Only difference i believe is the B loop is stereo out & the A is mono.
I had the B and loved it but traded it for a Les Paul that i use more than the MK IV.
Also got rid of the MK IV because nobody in town wanted to work on it and i realized the longer i had it the more likelihood it would need work at some point & i didn't want to ship it to Petaluma.

 

[motorboy1]

Supposedly B version is a little darker and compressed. Ask if the amp was serviced due to caps that can leak and cause major issues.

 

[ultimatemetalguitartones]

I've had both. Rev A - more raw / open / in your face lead drive
Rev B - more gain / scooped / compressed
Both are great amps! Get that rev A before it's sold

 

[Gibsonchild]

I've had both. Rev A - more raw / open / in your face lead drive
Rev B - more gain / scooped / compressed
Both are great amps! Get that rev A before it's sold

Based on that description, it sounds like the rev A is the one I want.

It’s going to be a few weeks before I can move on it, gotta sell one of my AK‘s first to free up funds. I’m not terribly worried about it getting away from me. It’s been for sale for quite a while, cause he lives in the middle of absolutely freaking nowhere and refuses to ship.

The only downside is that it’s a combo. I vastly prefer a head, but I’m a cabinetmaker, so I can remedy that problem pretty easily. And there‘s a rev A head for sale about 3 hours away if I miss out on the combo, but it’s not as good of a deal.

 

[anomaly]

I own a B and I've played a A. Honestly, just get what you can get the best deal on cause the differences are very small on the lead channel.

 

[Chris6870]

I've had both at the same time. Very little to no difference. The A may have had a little more gain but could have been the tubes also. I kept the B just because it was newer and cleaner.

 

[blackba]

I always read the major difference was in r2 between the two versions. I have a 1990 rev a, but have heard a rev b bombs, but never could them back to back.

 

[Mark Skid]

Rev B is much better for recording. Better R2 channel as well. Stereo loop.

 

[Samhain]

I own a B and I've played a A. Honestly, just get what you can get the best deal on cause the differences are very small on the lead channel.