There have been several other OTL manufacturers that have come and gone- Prodigy (Futterman variant, and IMO the best Futterman execution anyone ever did), Counterpoint (Futterman variant developed by Roger Modjesky if memory serves), Silvaweld (Korean Futterman) and Sans Pariel (Futterman variant developed by Charlie Kittleson for San Pariel).Actually the Sans Pareil was one of several OTL monoblock amplifier models made by Fourier Components in the St. Louis area. Tom Gambill had moved there from California and started the company. I believe John Atwood was involved in the design of one or more of their products. They closed in early 1997.
The Hub: Futterman H3: Seen one lately?
Back in my days as a teen audio geek, an item that popped up in a little classified ad in the back of Audio magazine (in type so small I couldn't even read it now) was "Futterman OTL amp", with comments about its transparency and beauty with Quad electrostatics.
Keep in mind that we're talking 35 years ago. I couldn't email the dealer, as Al Gore had yet to invent the internet. Long-distance phone calls were thought to be prohibitively expensive for such frivolity,so I did what people did back then: I wrote a letter. It's hard to imagine a time when long-distance phone calls were thought to be an extravagance unless used for emergencies, but that's how it was. It was easier and cheaper to steal a couple stamps from the roll on Dad's desk (what were they? Six cents?), and write.
I don't recall what I wrote in my request for info on the amp with the funny name. I probably tried to make myself seem older than I really was, and managed to make myself seem even younger in the process. The few carbon-copies (another lost technology) I've found of such letters make me smile and cringe at the same time.
I've forgotten the name of that kindly dealer in Michigan, long out of business (probably thanks to time-wasters like me), but I received a handwritten response. I was told that "OTL" meant Output-TransformerLess, and the amps were hand-made by the elderly Julius Futterman in New York. Mr. Futterman soldered every joint by hand, and even hand-wound the power-transformers himself. Not surprisingly, there was a lead-time of a few months. I can't recall the price, but I'm sure it would appear miniscule today.
Having more time than money, I wrote to Mr. Futterman. I received a handwritten reply, in which Mr. Futterman told me that tube-life in his amps was excellent, unlike those OTHER amps which had recently become popular (a slight dig at the ARC and CJ amps just coming into vogue then). He also sent me a reprint of an old High Fidelity review of this model. Unfortunately, I never followed up on Mr. Futterman's kind letter, never bought any of his handmade amps. Somewhere along the line, the letter itself vanished. A shame.
A little history is now required. Julius Futterman's article, "An Output Trasformerless Power Amplifier" appeared in the October, 1954 issue of the Journal of the Audio Engineering Society; I still have a plasticky '70's photocopy of the 5-page article. The language is clear and understandable; unlike JAES articles published today, you don't have to have done post-doc work in math at CalTech in order to understand it. There are graphs and scope-photos, but not ONE equation. Try that today, and see if you're published.
Like Sid Smith of Marantz, Futterman was in the Signal Corps in WWII. Postwar, he became involved in developing a power amp that did not require an output transformer, generally required in tube amps due to the huge impedance mismatch between the output stage and dynamic speakers. Some accounts state that Futterman sought only to reduce the costs of building amplifiers by eliminating the output transformer, generally the most expensive single component in an amp. Whether increased sound-quality was the motivation or just a happy side-effect: it happened.
Futterman's 1954 JAES article was followed in 1956 by a piece describing the commercial implementation of his circuit; that was the first iteration of the Harvard Electronics amp featured here. It utilized TV sweep tubes of low cost and long life, and was better-suited to high-impedance loads like the Quad ESL. I seem to recall a 500-ohm speaker sold to accompany it, possibly by Stephens, but I can't find verification of that.
By the early '60's Harvard Electronics was gone, and their commercial version of the Futterman amp disappeared with it. Julius made the amps by hand, refining the design to a level known as the H3AA, which he was building when I wrote him.
The amps maintained a low profile in the audio underground until Harvey "Dr. Gizmo" Rosenberg became involved with Futterman. "Gizmo" was a highly effective marketer who worked for numerous companies, and had a long association with the textile industry. Aside from his "Gay Bob" doll, Giz was best-known for his outrageous promotion of tube amps, often appearing in public in a kilt and wearing a headdress capped with tubes.
Despite his brash public persona, Rosenberg was a dedicated, obsessive music lover and tirelessly pursued improved sound reproduction. His writings in Listener and Positive Feedback showed both aspects of his personality, but his bizarre sense of humor could be offputting to many in the often-humorless world of audio. My few encounters with him showed him to be kind, patient, and relentlessly creative. He loved my idea of a beer sold in 300B-shaped bottles, marketed with the intentionally old-timey slogan, "300B: The Beer With The Wonderful Tone". I expect royalties if you use it.
Rosenberg founded New York Audio Labs to develop and refine the Futterman circuit, working with Ted Hammond, George Kaye, and several others. Rosenberg worked with Futterman until the latter's death, and developed a thorough understanding of the circuit's secrets and its potential pitfalls. NYAL developed several models including one designed for use with Quads, and a massive multi-chassis monster which was the most expensive amp available at the time: $12,000 in 1984. The 2009 equivalent, roughly $25k, will barely buy an amp-stand from some makers today, but I digress....
Given Gizmo's flamboyance, it's not surprising that some elements of the NYAL history are in dispute;
some details are discussed by George Kaye here,
and the various NYAL Futterman amps are shown here.
Whatever. No matter who did what to whom, the legacy of both Futterman and Rosenberg (who sadly died in 2001, following a heart attack in an airport) lives on. German interpretations of the Futterman have come and gone, non-Futterman OTLs continue to be built, most-famously by Ralph Karsten at AtmaSphere. George Kaye builds a refined version of another NYAL amp, the Moscode, with tube inputs and MOSFET outputs. Our Audiogon Museum of Sound Reproduction should include today's piece amd one of Harvey's, as well. Ars longa, vita brevis! (Life is short, art is/lives long)
Keep in mind that we're talking 35 years ago. I couldn't email the dealer, as Al Gore had yet to invent the internet. Long-distance phone calls were thought to be prohibitively expensive for such frivolity,so I did what people did back then: I wrote a letter. It's hard to imagine a time when long-distance phone calls were thought to be an extravagance unless used for emergencies, but that's how it was. It was easier and cheaper to steal a couple stamps from the roll on Dad's desk (what were they? Six cents?), and write.
I don't recall what I wrote in my request for info on the amp with the funny name. I probably tried to make myself seem older than I really was, and managed to make myself seem even younger in the process. The few carbon-copies (another lost technology) I've found of such letters make me smile and cringe at the same time.
I've forgotten the name of that kindly dealer in Michigan, long out of business (probably thanks to time-wasters like me), but I received a handwritten response. I was told that "OTL" meant Output-TransformerLess, and the amps were hand-made by the elderly Julius Futterman in New York. Mr. Futterman soldered every joint by hand, and even hand-wound the power-transformers himself. Not surprisingly, there was a lead-time of a few months. I can't recall the price, but I'm sure it would appear miniscule today.
Having more time than money, I wrote to Mr. Futterman. I received a handwritten reply, in which Mr. Futterman told me that tube-life in his amps was excellent, unlike those OTHER amps which had recently become popular (a slight dig at the ARC and CJ amps just coming into vogue then). He also sent me a reprint of an old High Fidelity review of this model. Unfortunately, I never followed up on Mr. Futterman's kind letter, never bought any of his handmade amps. Somewhere along the line, the letter itself vanished. A shame.
A little history is now required. Julius Futterman's article, "An Output Trasformerless Power Amplifier" appeared in the October, 1954 issue of the Journal of the Audio Engineering Society; I still have a plasticky '70's photocopy of the 5-page article. The language is clear and understandable; unlike JAES articles published today, you don't have to have done post-doc work in math at CalTech in order to understand it. There are graphs and scope-photos, but not ONE equation. Try that today, and see if you're published.
Like Sid Smith of Marantz, Futterman was in the Signal Corps in WWII. Postwar, he became involved in developing a power amp that did not require an output transformer, generally required in tube amps due to the huge impedance mismatch between the output stage and dynamic speakers. Some accounts state that Futterman sought only to reduce the costs of building amplifiers by eliminating the output transformer, generally the most expensive single component in an amp. Whether increased sound-quality was the motivation or just a happy side-effect: it happened.
Futterman's 1954 JAES article was followed in 1956 by a piece describing the commercial implementation of his circuit; that was the first iteration of the Harvard Electronics amp featured here. It utilized TV sweep tubes of low cost and long life, and was better-suited to high-impedance loads like the Quad ESL. I seem to recall a 500-ohm speaker sold to accompany it, possibly by Stephens, but I can't find verification of that.
By the early '60's Harvard Electronics was gone, and their commercial version of the Futterman amp disappeared with it. Julius made the amps by hand, refining the design to a level known as the H3AA, which he was building when I wrote him.
The amps maintained a low profile in the audio underground until Harvey "Dr. Gizmo" Rosenberg became involved with Futterman. "Gizmo" was a highly effective marketer who worked for numerous companies, and had a long association with the textile industry. Aside from his "Gay Bob" doll, Giz was best-known for his outrageous promotion of tube amps, often appearing in public in a kilt and wearing a headdress capped with tubes.
Despite his brash public persona, Rosenberg was a dedicated, obsessive music lover and tirelessly pursued improved sound reproduction. His writings in Listener and Positive Feedback showed both aspects of his personality, but his bizarre sense of humor could be offputting to many in the often-humorless world of audio. My few encounters with him showed him to be kind, patient, and relentlessly creative. He loved my idea of a beer sold in 300B-shaped bottles, marketed with the intentionally old-timey slogan, "300B: The Beer With The Wonderful Tone". I expect royalties if you use it.
Rosenberg founded New York Audio Labs to develop and refine the Futterman circuit, working with Ted Hammond, George Kaye, and several others. Rosenberg worked with Futterman until the latter's death, and developed a thorough understanding of the circuit's secrets and its potential pitfalls. NYAL developed several models including one designed for use with Quads, and a massive multi-chassis monster which was the most expensive amp available at the time: $12,000 in 1984. The 2009 equivalent, roughly $25k, will barely buy an amp-stand from some makers today, but I digress....
Given Gizmo's flamboyance, it's not surprising that some elements of the NYAL history are in dispute;
some details are discussed by George Kaye here,
and the various NYAL Futterman amps are shown here.
Whatever. No matter who did what to whom, the legacy of both Futterman and Rosenberg (who sadly died in 2001, following a heart attack in an airport) lives on. German interpretations of the Futterman have come and gone, non-Futterman OTLs continue to be built, most-famously by Ralph Karsten at AtmaSphere. George Kaye builds a refined version of another NYAL amp, the Moscode, with tube inputs and MOSFET outputs. Our Audiogon Museum of Sound Reproduction should include today's piece amd one of Harvey's, as well. Ars longa, vita brevis! (Life is short, art is/lives long)
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- 29 posts total
- 29 posts total