Yes I remember he would say let’s work it out! It annoyed him that people would come out with a statement and say it’s true, and only have erroneous evidence for it.
- 112 posts total
- 112 posts total
I bought an RM-5 Mk.II and RM-9 Mk.I in 1991. In 1995 I sold the RM-9 and bought 2 RM-9 Mk. II's ( hard-wired Mono ). I had ONE tube fail in 24 years. After 20 years I switched all the tubes out on both amps ( Svetlana El-34 & NOS Amperex 6922's.) , tube-rolling as Art told me Roger coined the term.
Early in 2018 Roger wanted to know if I would be interested in a pair of new amps to DIRECTLY drive my Soundlab Majestic 945's, I said HELL YES. Sadly that will not materialize. After 24 years, I have changed EVERY piece of gear in my system, and STILL not needing to upgrade the RM-9 Mk. II's. Clearaudio Stradivari V2, Kuzma 11" 4-Point, SOTA Millennium, Audible Illusions M3B, Soundlab 945's, Tara Lab cabling. I will play these amps 'till the day I retire from earth.
Never met him in person. My sincere condolences to the family. Roger was a delight....... in every aspect..........
Mmm, sounds like he was working on the direct drive amp for the Majestic last year. So a circuit for it probably exists somewhere in his stuff. I imagine it would be a refinement of his 80s-90s one. I wonder if this was going to be a statement circuit for him, an early hint that he was becoming ill?
It was late 2018 when Roger suffered symptoms and was diagnosed so in early 2018 he had no idea he was ill. Roger's first foray into direct drive amps was to modify the Acoustat model by designing a tube input stage for it. Following that he designed his version of the direct drive amp (his personal one sits in my living room as I write this) which was initially done for some Acoustat speaker owners. As those familiar know the amp puts 5000 volts on the panels. Following that Roger used the same design for his ESL speakers, which in some ways are modeled after the Acoustat but with a number of improvements especially with dispersion. Roger always said that Jim Strickland himself was on the same path to improving dispersion in Acoustat designs, but never got to finish the process.
If I recall correctly my conversations with Roger about using the direct drive amp for my Quad ESL had more to do with adjusting the voltage the amp put out than anything else. I could be wrong but I believe he said the Quad ESL needed 1800 volts on the panels. So for the Sound Lab speakers the process might be similar. We do have the circuit and it is not inconceivable @gallassero might see an amp for his Sound Labs in the future.
The Quad 57s run 6kV on the two bass panels and specified for 1.5kV on the treble panel. I remember Roger musing that he wanted, I thought at the time somewhat ambitiously, to run 1.8kV on his Quads. I always thought that would be pushing them a bit too far as the classic design is already quite prone to arcing over at higher volume. It was to do with lowering the distortion IIRC.
I’m not that familiar with the Acoustats but have heard them. How did he improve dispersion? Are there multiple tweeter panels on an Acoustat so you can use different phase to each, like on the Quad 63?
It would be brilliant to get Majestics going with direct drive, if you can make it, do! I’m sure Roger would have loved that. (Be very careful with instantly lethal voltage on the tube voltage power supply!!!) You’ll need to have a good working knowledge of their characteristics first, and liasing with Soundlabs would be the way to go I suspect.