Thank you for posting the video. I found the discussion of the EMT preamp particularly interesting. I would bet it is a very nice sounding system given the DeVore speakers and a very nice complement of gear. This past weekend I did get to hear the Devore/Komoro 300B amp that was shown as the amp that he is currently using in the video. To me, it sounded decent--open, clear and nicely extended, but a touch lacking in "body" or "weight." I heard them running some fairly high efficiency speakers. This assessment was in comparison with a pushpull 6l6 amp designed as a clone of a Western Electric 124.
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
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And thank YOU @clio09, for both your post and keeping the Music Reference name and products alive.
Though reviews of tube amps in professional hi-fi mags commonly contain little exploration and explanation of amplifier circuit design, reading Modjeski’s writings on the subject (as well as other subjects ) is a free means of gaining a knowledge of what to look for in an amplifier. After Roger moved from Santa Barbara to the San Francisco Bay area, he offered a class in tube amp design at a local adult education facility. Students were not only taught electrical engineering, but also assigned the task of designing and building an amplifier of their own. Positive reviews of tube amps that produce poor performance numbers raise a number of questions, questions to which Modjeski was willing and able to provide answers (in his AudioCircle Forum and at seminars he gave). Audiophiles tend to view the sound an amplifier produces---and the sound of the tubes in amps---being partially determined by factors other than good electrical engineering basics. Parts quality is one such factor. While high end consumers look for boutique parts in their products, Modjeski was concerned first and foremost about parts ratings. He was an advocate of using a part with a voltage rating 10 times what that part would see in a circuit. I learned the wisdom of that approach when I turned on my factory-fresh ARC SP-3 the first time. I heart a "Pop!", then smelled smoke. I took it into my dealer, who found a resistor had blown when faced with the turn-on voltage rush. That resistor was of a voltage rating of only twice what the circuit called for. Roger didn’t make those kinds of mistakes. Not to pick on ARC, but when the SP-3 was replaced with the SP-3a, Frank Van Alstine discovered that what was new and improved in the "a" version" were not the boutique parts claimed for it, but corrections in it’s circuit design, including the inaccurate RIAA response curve that Frank was already offering a correction for in his SP-3 modification. No "magic" parts required, just excellent electrical engineering. That’s what Roger Modjeski was all about. It’s great to learn that @clio09 will soon be offering Music Reference products; for those who can’t wait, know that Roger "approved" of the tube electronics designed and built by Mike Sanders (Quicksilver) and Tim DeParavicini (EAR-Yoshino).
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@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. |
thanks for the information about the tube stock. I am in CANADA so I presume they would still be the 25% tariff slapped on by Canada. Plus, financially, I’m not in a place to order the tubes at the moment. But it’s good to know that You’ve got quite a few of them When that time comes. I bought a whole bunch of different 5751 tubes And really nothing was as transparent as the ones from RAM. out of curiosity, do you have A equivalent low noise 6FQ7 tube available! |
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