@bdp24 thanks for posting. this. Not sure how I missed it but nice to know John DeVore liked the RM-10 with his speakers. There were two keys to enabling that amp to get 35 watts out of a pair of EL-84s. One was using a voltage doubler to put 700V on the plates. Roger always liked to write his own applications for tubes and not solely rely on the applications presented in the tube manuals. Also prior to his death Roger redesigned the RM-10 to more closely match the original circuit. As of today, the first RM-10 MkIII is built and being tested in my system. One new twist is that bias can now be safely set to 350mV, so just slightly more power than the original without stressing the tubes. We hope to have new production going soon. Roger also wanted this to be offered in kit form as well so we are working on those details as well.
Loudspeaker designer/manufacturer John DeVore shows reviewer Ken Micallef his system.
And quite a system in it is!
At one point John tells Ken that he searched for the best amplifier of each "type" he could find, to use in the development of his various model loudspeakers. John explains in great detail how his speakers interact with different types of amplifiers.
Amongst the rare, unique, rather expensive, and/or otherwise unusual amps he chose, two more common and affordable models stick out: The Parasound A21, and for medium-power push/pull tube amps the Music Reference RM-10. John didn’t call it out by model number, but as he described it as a push/pull design using EL84 tubes it can only be the RM-10 (the only amp matching that description that Roger Modjeski ever marketed).
Modjeski marketed three push/pull amps: the first was the general purpose RM-9 (four EL34’s for 125w/ch)---a favorite of former Stereophile reviewer Dick Olsher, the second the RM-200 (a single pair of KT88’s for 125w/ch), designed to work unusually well with low impedance loudspeakers---Michael Fremer’s reference "affordable" tube amp for many years, and lastly the cute little RM-10 (a pair of EL84’s for 35w/ch). Modjeski said the sound of the RM-10 was his favorite of the three.
https://youtu.be/i9WYbi7afGQ?si=qkf8AiUCF_9_z2cl
Showing 5 responses by clio09
@prof The Super Low Noise RAM 6922 are expensive but if you like the 5751 you will love the 6922. Also, no tariffs, we have hundreds in stock as Roger would buy thousands of tubes at a time. Contact us via our website and let's chat. I wish more people would appreciate the 5751s which are NOS GE solid plates. An exceptional tube. |
@bdp24 I wish more people used 5751s. Roger originally stocked them for Conrad Johnson preamps. The GE gray plates we have don't seem to be of much interest to folks for some reason. Maybe I need to put them on sale for a bit so more people realize what a nice tube it is. Sadly, people prefer the ribbed plates, but Roger's research determined the solid plates were superior in electrical and reliability testing. |
@prof Unfortunately we do not have any 6FQ7s. When you are ready let us know. We don't ship worldwide any longer but we do ship to Canada. To help offset the tariffs we are thinking of providing an equivalent discount on goods for Canadian customers. |