Hello group (and hello Roger)
This is my first post here although I frequent this forum often. I have been a big fan of Music Reference and of Roger's for many years now and as many of you have, enjoyed meeting Roger and learning from him, he a is a great teacher, and we are all fortunate for the music his designs bring.
A few years back I found myself enamored once again with the RM9. My father had owned one many years ago and it was my first tube amp. I moved on and bought one of Rogers first RM200's when I was living in Atlanta in 1998. For several years after I owned at one time or another many of the more highly regarded PP designs from all the big names, many considerably more costly. Eventually in 2005 I returned to the RM9 for many of the reasons discussed on this forum.
I really started to play around with the RM9, with Roger's help often. I eventually ran two strapped for mono operation with the feedback pulled in triode. They ran my Harbeth 40 beautifully with only one caveat: they were nosiy due to excessively high gain from the feedback being pulled, you needed phono grade 6922 in the input stage no surprise. For a few years I would intermittently bug Roger to build me a custom pair with a point to point input stage not unlike the SE based on the 6bq7 that would suit my needs. This is really not the best use of Roger's time and I did not persist out of respect for his time. Eventually I found a local guy named Don Allen, many of you on this site know his work. He is a very competent designer and was up to the task beautifully.
We went all out from a design and parts quality standpoint. We started by doubling up the base with an additional RM9 base to give some room and keep the look. Don designed a completey new point to point input stage based on 4 6BQ7. The PS capacitance was increased and all filtration subsequent was film only. Much was spent on parts where appropriate. Don is also a minimalist in agreement with Roger's philosophy. The amps run with a new biasing scheme that is cathode biased. They run fixed in triode with no NFB and the gain is more appropriate, more like a stock RM9 on the medium gain setting.
I got what I wanted but what I was not prepared for was the overall sound quality.Don felt they were the best PP amps he had heard. As you all know the RM9 has some of the best OT's ever wound for a PP amp. One of the things that happens fortuitously when you strap two of them together is you halve the output impedance. Running in triode drops this further as the plate impedance drops. This creates a very reasonable dampening factor that is double what you might find in an amp designed from the ground up as a monoblock with only one big OT (harder to drive the OT in many cases as well). Anyway the amps Don help me create are fantastic and have been my refernce now for over two years. There is lots more I could share about them, PM if you would like. With consederable regret and reluctance I have them listed for sale in the for sale section. I am turning a big page in my life with a new wife and two new daughters, 5 and 3 in June and I can't keep these really, as much as I want to. I fugured this forum would have the handful of individuals that would apprecitate them, including Roger.
