Posted by Al Sekela on November 14, 2003 at 12:16:59:
In Reply to: Has anyone considered an OTL design? posted by Bill Lamb on November 13, 2003 at 21:39:53:
The Beveridge Models 2 and 2-SW include OTL amplifiers. These amplifiers are built in to the speaker cabinets, so the safety issue with cables carrying high voltages does not arise.
High voltage circuits are not to be taken lightly! Please read Mark's comments carefully. He is being perhaps too polite in answering your inquiry. I would not attempt such a project myself. If I were serious about an OTL amp for Sound Labs, I would hire someone with radio amateur experience, like Mark, but with the time to work out the details. As you know, Mark is very busy with his speaker and Atma-Sphere duties. I can't speak directly for Ralph, but I imagine he has similar burdens on his time.
Roger Modjeski in Santa Barbara is familiar with the design and drawbacks of the Beveridge amplifier. You may want to contact him, to see if he could use the design as a starting-point for a Sound Lab-compatible amp. Since there are many Beveridge speakers still around, there might be a sizeable market for an up-to-date amp that could serve both the Beveridge and Sound Lab applications. This is just an idle thought, and does not represent the opinions of Rick Beveridge, Roger Modjeski, Dr. West, or anyone else with a business interest in these speakers. I apologize in advance if expressing this thought offends any of the principals, including others with expertise whom I do not know of.
Here is Roger's bio taken from a websearch:
"Roger Modjeski is a "quality oriented" audio engineer located in
Santa Barbara. Roger constructs his own tube amplifiers and is
currently developing a series of hand-made electrostatic speakers.
He also works with Water Lily records - an audiophile recording
company that makes all-analog, no-post-production recordings of very
high standards. He owns the company Music Reference. Roger has been
instructing interns and students on the construction of high end
audio equipment including speakers. Roger's aims are to make high
quality equipment available at much less than top-end audiophile
prices - affordable for the normal music-lover."
He does not mention his connection with RAM tube labs, which tests tubes individually with equipment built by Roger. This may be included in his Music Reference business, as suggested by the URL below.