Roger Modjeski discussing tubes at Burning Amp 2018

One of the many great things about the SF Bay area is that the Burning Amp festival is held here each year. In addition to Nelson Pass, this years guest speakers also included Roger Modjeski from Music Reference/RAM Tubes and Wayne Colburn from Pass Labs. Sadly though, Siegfried Linkwitz's presence was greatly missed (but there were some touching tributes, including one from Nelson Pass), but his room still provided great enjoyment for the attendees. While there were many great projects to be seen, the real pleasure is listening to the lectures. For those interested here is the link to all the videos:

If you would like a primer on tubes Roger's talk discusses various types of tubes in detail. In particular, at one point he even discusses how he designed the RM-10 amplifier to put out twice as much power compared to other circuit designs, old and new. I've known Roger for quite some time and I cannot recall ever hearing him discuss the specifics as he does in this talk.

For those interested in adding 2nd order harmonic distortion to your system, Nelson's talk discusses his new toy, the H2 Harmonic Generator. While this was developed as a kit available on DIY Audio, working boards were distributed at the show. Nelson's analog crossover for the Linkwitz speakers was also part of his talk and again made available as a finished board for attendees. The man's generosity to the audio community knows no boundaries.
Thanks clio. I’ve watched Roger’s 2016 BAF talk on You Tube, which is also great. Tube amp owners (or anyone considering getting one), here’s a chance to learn how a master electronic engineer approaches designing an amp.
As should be obvious to everyone who bothers to watch and listen to this talk by Roger, he knows an awful lot about tubes and how they can be used in amplifiers. He is also a very creative engineer, ignoring old rules and misconceptions about tubes. He is now making a lot of different types of amplifiers, from very low watt single-ended triode to medium power push-pull pentode, as well as direct-drive amps for ESL loudspeakers. He's not big on marketing and game-playing, so you have to search him out. You'll be glad you did!
Nelson’s talk is equally interesting and illuminating. Both he and Roger were speaking to knowledgeable DIY’ers, but what they had to say should be of interest to the rest of us as well. At least half of what each had to say is above my technical understanding, but just listening to them talk made me feel smarter ;-) .
Roger's knowledge of tubes is quite impressive. He has been to the old Sylvania factory and even to Eastern Europe to see the manufacturing process in person. RAM Tubes is also one of only a few resellers world wide for EML tubes, arguably some of the best tubes made right now,. In fact Roger would like to design some kits and complete sets of amps that utilize these tubes.

During Nelson's presentation at the event he and Roger engaged in quite an interesting discussion on active crossover design. It's rare to see two outstanding designers engage in discussions like this. Yes, Burning Amp is for those more technically inclined, but nonetheless I think everyone walked away with an appreciation for people like Nelson, Roger, Wayne, and Siegfried who have made such great contributions to audio. Mario Yrun and his team put on a great event this year. I hope they can expand it to include more participants next year. Burning Amp is a breath of fresh air compared to the traditional audio event.
@ clio09 - Thanks for that. We have some equipment in common and I’ve benefited from your and Paul B’s posts in particular over the years.


August West

PS Audio PWT Memory Player -> PS Audio DirectStream Jr. -> Merlin BAM -> Custom tube preamp -> Custom 120 Watt tube monoblocks -> Merlin VSM speakers c. 2007 with all available upgrades

McCormack UDP-1 Deluxe universal/SACD player -> Thor TA-1000 tube preamp with V-Caps and other upgrades -> Music Reference RM-10 MkII Class A stereo tube amp -> Merlin TSM Black Magic + JL Audio Fathom subwoofer

P.S. - The Fathom is a recent acquisition per Merlin designer Bobby’s recommendation just a couple of weeks before his untimely passing in 2015. The 10" version sings sweetly with the TSM’s, but was almost completely superfluous with the VSM’s IMO. As always your mileage may vary in a different system and a different room.