A while back, I listed my Marshall TSL for sale online. At the time, I was enjoying the 6100LM more and figured it made sense to sell it off if I wasn’t using it. Thanks to a number of interested and chatty folks I met on Reverb, I learned some new settings and grew to love the amp again, so I took the sale down. However, one person was interested in a trade for a Mark IV combo amp - which didn’t go through as he was able to sell it for cash first. While researching the trade, I started to really like the Mark IV tones and thought it would be great to have especially since it would be so different from my mostly Marshall-like collection so far.
Fast forward a few months and I found a Mark IV Medium head for a really great deal and picked it up. I specifically wanted the Medium head so that the “lead voicing” switch was on the front panel. I’m really a tweaker at heart and though I would use that switch with enough frequency plus the medium head is a better platform in case I had to place another head on top.
This is a killer amp - the high gain tones are super tight and articulate, and even sounds great boosted. Throwing a light chorus and reverb in the loop can get tones very close to Whitesnake’s 1987 album tones (even though they used a Mark III), and of course it can nail those modern metal tones such as Lamb of God.
Dialing this amp is a steep learning curve, and I understand now why players come back with such conflicting reviews on the Mark series amps. Their EQ is situated much earlier in the circuit, right after the input gain stage. This is very different to the usual Marshall style post-EQ that most high gain amps employ. On the Mark, you really need to bring up the treble control to maximum, keep the bass low to avoid flubbiness, and use the graphic EQ to shape the sound you want in the room. The idea of maxing out the treble control on a Marshall style amp is totally alien, but it sounds fantastic with this style of circuit.
Caps in this unit date to 1997, and it came equipped with 2x 6L6GC and 2x EL34’s, which sound great to me.