Post
by JimmyR » Sat Feb 14, 2015 10:58 pm
Having read this thread, I just did a comparo between my Marstran/Heyboer equipped amp and my MM amp. From memory i THINK the Marstran amp has around 450VDC on the plates and the lower B+ MM has around 380VDC on the plates. So there is a substantial difference there which will obviously affect the result, but perhaps not exactly as you might imagine.
I played each amp through the same speakers. Each amp is almost identical in spec - both have F+T electrolytics, Sozo caps, same era spec, etc. As close as I can make it they are the same except for the transformers.
First the Marstran: fat, powerful, extremely warm tones. Outstandingly vintage. I remember comparing it with an original Marshall and while it wasn't identical exactly you would be hard pressed to pick which was which in blind testing. In fact when I did compare it we were in a store and everyone seemed to prefer the new amp - but only slightly. It is a classic, old school sound.
The MM amp is surprisingly different. You can get close to the tones of the Marstran amp but you have to tweak the knobs differently. Bear in mind that I was not intending to get an identical sound. My goal was to see what a lower B+ version would sound like. I was hoping to make a smaller amp with it for gigs. I was hoping for earlier breakup and a warm tone. Well, the amp is sparkly, bright (but not too bright!), clear, punchy and downright beautiful to listen to. Yes it breaks up earlier. With a 335 it breaks up at around 3 on the linked volumes, where the Marstran was at around 5-6.
The clean sounds on the MM are amazing. Some of the best cleans I have heard from an amp. Thick, chewy cleans with outstanding definition. No shrillness but plenty if sparkle. Massive, clear bass. Complex mids. It is similar to the Marstran but I would have to say I like the MM cleans better. For my intended purpose the MM amp is better than I could ever have hoped. Not as outright warm as the Marstran but more usable clean. with similar breakup. I think the Marstran sounds more authentic, and if I could gig with it at the volumes necessary for it to break up it would make the best classic rock amp ever!
I love both. One day I will build a MM 1987 with the regular voltage and be very interested to hear what it sounded like.
One last thing - the MM holds together so well. The cleans stay tight right up to the point of break up, and even then you have excellent definition. It's not like an old fender where when you get close to break up it all dissolves into a bass-soggy mess.