Music Reference RM-10mkiii Kit

The challenge one faces is manufacturing to scale. There is no shortage of interest in the MkIII, just not enough resources to make it work. When Roger conceived of this his goal was to find a way to make the RM-10 more affordable without sacrificing quality. He was dismayed that we had to start selling MkII versions for nearly $4,000. We showed Roger that based on the original MSRP nearly 35 years ago at the time, with standard COLA applied the amp would MSRP for nearly the same price in 2019. Still he was adamant he could get the price down to a sub $2,000 level. Again, he put his foot down and went to work. One way to make it happen he surmised was to use a PCB. Back when the initial RM-10s were made Roger wasn't happy with the quality of the PCBs, but he found the manufacturing had improved quite a bit so he decided to use a PCB for this project. He also felt it would lend itself better to DIY classes. Outside of that it was just the transformers and he found a source that would wind them to his specs with a high level of quality. So there you have it in a nutshell. Then he passed.

So a couple of us were left to figure out how to bring this to market. Then COVID struck. Fast forward a couple years and while we made a lot of progress on design and other aspects of the build, we still needed to come in at Roger's preferred price point. Well no matter how much we sharpened the pencil and we got it down to the nub, it wasn't going to work unless we made it a straight DIY offering. So there you have it. If someone wants a build I can do it, but there will be an add on fee and you are on your own with tubes as we won't supply them with the complete build. Recently we spoke to a couple heavy hitters in the industry to see about helping us with manufacturing and marketing. Both loved Roger's work and loved what we did with the MkIII, but neither felt they could help. The market has changed so much. I suppose if we showed up with a really nice Class D amp the story might end differently.

The OTL -1 is also a  phenomenal amplifier, the best I have had driving my AG Trios.  It is unfortunate so few of these were built, as they are giant killers with high efficiency speakers.

In the introduction to his instruction sheet for biasing the  amplifier, Roger states that he felt this was his best design.

The last 5 years have been tough for manufacturing and businesses all around. Even this last year with tariffs, it's one thing after another, that small business have to deal with. Manufacturing to scale is a crazy up front investment, so I completely understand. 

I really think the RM-10 is the perfect amp for most people; it's space friendly, as well as cost and energy efficient. At least on the west coast, we love our JBL's and the RM-10 is great with them (almost all of them). I think the RM-10 would appeal to tube amp lovers who have SET's because the RM-10 offers a little more grunt for the low end without sacrificing tone. I wish I had studied electrical engineering.

I read a review of the OTL-1 awhile back and it seems amazing. I am not sure what the typical characteristics of OTL's are? Similar to SET's? How is the damping, because I assume they are low powered and could be mated to high efficiency speakers with large woofers. 

Depending on the design demping will vary with OTLs. I have owned both Atma-Sphere and Roger’s OTLs. Ralph Karsten uses very little to no feedback in his circuits and as such the damping is low. Atma-Sphere OTLs are also based on the Circlotron architecture. Roger’s OTL is based on Futterman’s totem pole design and not only uses feedback but has an impedance matching inductor that allows the amp to see a 32-ohm load whether you use the 2, 4, 8, or 16 ohm taps. There is also a direct 32 ohm tap if you want to bypass the inductor. The damping, which is on the high side, and conversely gain can be adjusted based on how you use the feedback wire which can be attached to any of the taps regardless of which one you are using for the speaker cables. If you want to learn more here is the manual:

 https://static1.squarespace.com/static/61d0e00ac8fd8f2d31e7f907/t/65409de3490f124354d9f737/1698733543099/OTL-1+Manual.pdf

I expect your efforts with the RM-10 will be worthwhile.  Many years ago I bought a RM-100 to match with Vandersteen speakers.  It was one of the favorite amps among the many I owned.  At one point I was curious about the RM-10 but felt my speakers at the time would not have been a good match.  I had/have high regard for all of Roger's work.