Heyboer vs MM.

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Brian Wallace
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Re: Heyboer vs MM.

Post by Brian Wallace » Thu Sep 23, 2010 4:37 pm

marci84 wrote:I need a replica of the C2668 Dagnall to put into my plexi modded to 800 spec. which one do you reccomend? metro and MM only do the C1998 right? i sent an email to heyboer to ask if they do a replica of the C2668 (waiting for the answer)
I have the winding specs for both the C2668 and C2723 transformers I just haven't put them in stock yet.

Patience is a virtue.

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Re: Heyboer vs MM.

Post by swankmotee » Thu Sep 23, 2010 4:45 pm

Brian Wallace wrote:George, Tommy,

Thanks for the street cred on the transformer mojo. :)
Some ole black dude down in Miss told me he sold you a MOJO hand! :mrgreen:

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Re: Heyboer vs MM.

Post by JimmyR » Thu Feb 12, 2015 3:00 am

I have a load of tweed style and Marshall 50W plexi style amps, using MM and Heyboer trannies. I find them equally brilliant - it just depends on what you want out of the amp. When I wanted to build a '68 style 1987 amp I used Marstran Heyboers, and ended up with an amp I would struggle to tell from an old '68 Marshall soundwise. It really sounded the real deal - classic.

But just recently I wanted to build another 50W which gave it up sooner, so used MM transformers, specifically a lower B+ P/T, which I believe only MM do regularly. I am blown away by the sound of this amp. Does it sound exactly like the Marstran amp? No. But it does exactly what I wanted it to, and is better in some ways. In this case the MM sound is a huge benefit to the amp.

I love that MM make so many variations on classic transformers. For example their fatstack power transformers for tweed amps are amazing. I have built many tweeds with fatstack power transformers, and loved the results. They give me the classic tweed tone but with no farting - something the originals can't do. I just built a 5F6-A bassman with a fatstack P/T with lower B+. With Marshall style filtering I have a Bassman which has the toughness and tightness of a Marshall - but still sounds like a Fender. Who else makes transformers like this off the shelf?

I don't see either brand as being better. It all depends on the project you have in mind. We are lucky to have the choice.

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Re: Heyboer vs MM.

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.

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Re: Heyboer vs MM.

Post by crumb » Sat Dec 15, 2018 5:46 pm

I have a 69 super lead clone with one of Georges board kits, mallory 150, brown base teslas, 490v on the plates and a merc mag o100jm output transformer.
No phase inverter filtration, 50 uf 1st stage...50uf screens.
I haven't compared the o100jm to any other transformers in this amp, not through lack of transformers to compare to but rather because this amp is so shit smoking hot I don't want to alter anything...a rare thing around here believe me.
This thing is what I compare everything to, in the jam room it's king. Any stock marshall product from any era, apart from that late sixties era ( I wouldn't hesitate to battle it out with an original 68 or 69 ) is humiliated.
I use it to show marshall amp owners what buzz is. One time a bloke with a '94 1959ri sold his amp straight after hearing mine.
The amp has an extended low end response, but not overpowering...its a smooth bass delivery. the highs are all there but they're not brittle or harsh ( I guess they're not all there are they?)
The amp has an strong upper mids response, not too crazy..just enough...
Whoever designed and built this thing is a genius.
I don't have a marshall amp with a heyboer o/t to compare it too, if the heyboer is as fun as these o100jm, then we are a spoilt lot indeed.

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