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)
"Life isnt short enough"Laurel& Hardy circa 1934 "Art will save us" artist unknown,possibly Art Dudley or Art Carney.....?

Ooo-kay. Thanks for that. Too bad Arts Dudley and Carney never worked together; the team could've been called "Art For Art's Sake".

So...any comments about the piece, or Futtermans, or Gizmo? Anybody??

Sheesh. Must be tryptophan-overload.
I think sometimes your mammoth posts might be an overload for some to get thru.Not sure.Just thinking/stormin here.I like em cause there so loaded with info Im into even though Im not a tech,mainly a audio dinosaur,57-8 or so.Have a large day Mr A
Two decades ago, when I was upgrading my audio system, I traveled to New York to audition varies components at several high-end dealers. Someone suggested I should hear the Futterman OTL. Until then, I never heard of it or of Julius, Harvey, or George. I arrived at what appeared to be a large work room, definitely not a show room. I do not recall anything else about the warehouse-like environment, but I DO recall that I was smitten with the most glorious midrange coming out of the Quads driven by the Futterman amps. Sweet and seductive! But there was a sonic brick wall with very little bass on the other side. For orchestral music, I needed bass....So, I moved on....But I never forgot that moment in sonic heaven.
Thanks for the story. It reminds me a bit of the first time I heard Quads; even with the 33/303 combo, there was magic. Despite Haden Boardman's insistance in his Sound Practices article back in 1994 that "QUADs have bass, and anyone who wants to argue the toss is either a wimp or tone deaf, so there", my reaction has always been, "eh, not so much".

As time went on, Harvey himself went for more dynamic impact, bi-amping heavily-modded Tannoys with 2 SET amps or an SET up top and a P/P on the bottom. Towards the end of his life he talked of addressing the Futterman circuit again, but I don't know how far he got. Sadly, at his death his belongings and projects (Sun Engineering coaxes, anyone?) seem to have been dispersed. Keep records, audio experimenters! SOMEbody out there may want to understand what you did!
Thanks for this thread, and keep up the fantastic work! These spotlights enrich and expand the high-end audio experience more than you might believe.

For too many today, Futterman is a buzz word for an amp that is not only far from being ready for prime time, but one that is both under-engineered and even dangerous. Instead, I believe we should take a step back, and acknowledge the determination and foresight that the man displayed in truly advancing the craft, and allowing us to live in a place more interesting, colorful, and better sounding than we would have had he not shared his creations with us.
Thanks for the kind words. It's hard to judge reader's reactions if they don't (DOH!) react. I appreciate it when someone takes the time to write. Of course, some comments are more appreciated than others. ;->

I agree with your comment regarding Julius Futterman, and suggest that it could and should be applied to Gizmo and his crew at NYAL, as well. Whether you liked him or loathed him, Harvey, along with Joe Roberts, Art Dudley, David Robinson/ Dave Clark and their crews, revived audio in the early '90's. And for that, they deserve our thanks.

So: thanks, guys.
Not exactly an audio comment but one on how business was done prior to Ma Bell being broken up.
Long distance was expensive. The reason being was that local calls were just about free and service was cheap. Phones were given away free by the phone company. It was not till the Princess phone of the 60's(?) that the idea of charging people for the phone in their house came about. So it was the long distance calls that subsidized everyone's local calling. Local calling also meant maybe 5 to 15 miles from where you lived and then it went up in concentric circles, sort of, from there. So that calling coast to coast was as expensive as a telegram, anyone remember them or Western Union, before they became a money order business.
Yup. Connecting it back to audio, when Western Electric did theater sound systems, they did it the same way as their phone biz. The equipment was generally leased, not sold.

Somehow those theaters ended up owning the gear that I pulled out, way back when; but then, how many folks ended up owning those heavy monster phones? Ah, for a REAL home phone....
I keep a corded phone (the older, the better) in my house, as they are the only ones that will work when the power goes out.

In the garage of my shore house, I have one of those "REAL home phones" you mentioned. It's a mechanical, rotary type, in basic black (anyone remember Abe Vigoda's "Fish" spinoff of "Barney Miller"?), of course. If you're in barefeet, which is common when you're at a beach community, you have to remember to either kneel on the chair at the desk there to make sure your feet aren't on the floor or pull your finger out of the dial as its returning to its starting position. Otherwise, you're in for a noticeable zing.

Aside from that, AT&T was a most benign monopoly, in addition to being a powerhouse of creativity and innovation. UNIX and C (and later, its children, C++ and Sun Microsystems' Java), which they began developing in the late 60s, provided both the platform and springboard for a mindboggling number of the "innovations" we enjoy today, not only in telecommunications (even cellular phones, PCs, Macs, defense, etc), and most probably would have come along regardless of the breakup of Ma Bell.
Hi Bill, Just FWIW, our amps, other than being OTLs, are nothing like the Futterman amps. When I went into business making OTLs back in 1977, I rapidly found out that 'OTL' was equated with unreliable. At the time I knew very little about the Futterman. What I have sorted out over the years was that Julias seemed to know what he was doing- his amps seemed to hold up. The later versions sold by NYAL didn't fare so well- that is where the reputation that we have been fighting ever since seemed to come from.

We sidestepped the reliability issue by employing an output circuit called a Circlotron. We did it in a way that had not been done prior and got a patent. The amps proved very reliable, so much so that we even built guitar amps using the circuit, which can be heavily overdriven all day long, something that would cause the prior art to go into oscillation. Apparently we were the first to make class A OTLs as well and for many years the MA-2 was not only the biggest OTL in production, but also the biggest triode amp and the biggest class A amplifier.

Since the amps were fully balanced and differential, we wound up offering the first balanced-line products to the high end audio market (the original MA-1, 1987) and followed with the 2nd balanced line high end audio product, the MP-1 in 1989. The preamps use the same circuit as the amps to bypass the use of an output coupling cap.

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). I am missing a few names here- its funny when you look back on all this stuff and realize how many there were!

Non-Futterman amps include Graaf, Tenor, Naked Truth Audio and Joule Electra. Of those only Joule had staying power. There was a Hungarian OTL manufacturer and I believe another in Italy that is still in business.

There is that whole thing about OTLs being load-sensitive. This is true but I find transistor amps to be just as load-sensitive but there are more speakers for transistors :) This whole conversation lead me to look at how negative feedback can or cannot help an amp to drive a speaker- its possible to make OTLs with very high damping factors and very low output impedances, but running the same amount of feedback as a transistor amp. What I found though is that there is no point. You run that much feedback and the amp can be unstable, and for sure it will never sound right- to make it sound like music you have to run zero feedback (and **that** is where the choice of speaker is important). My philosophy is that if the speaker needs the amp to have feedback, that speaker will never sound like real music, so why bother? There is no question that this has limited sales potential, but in high end sound is what should be paramount IMO.

Thanks for the bit of history.

Thanks, Ralph. I know yours aren't Futtermans, didn't mean to imply they were. If memory serves, the Circlotron OTLs were first marketed by ElectroVoice, of all people.

I appreciate your bit of history, as well.
Fascinating reading!

Here is a link to a site that appears to present good background on the Circlotron topology, on its Electro-Voice incarnations in the mid-50's, and on the several different related patents that were granted and/or applied for around that time:

And here is a link to what I believe is the patent Ralph referred to:

And a link to all issued U. S. Patents that include the word "Circlotron" in their text:

Isn't the Internet amazing?

Best regards,
-- Al

Amazing? Yes, it certainly can be.

I'm reminded of a comedian who said some years ago,"here's the greatest advance in communications in the history of mankind, and it's mostly being relegated to some guy typing 'are you really a girl??' at 3 in the morning."

In all seriousness, if I didn't think it was amazing, worthwhile, and an incredible way to bring a community together, I wouldn't be doing this. Thanks for the comments, Al.
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.
It was Cecil Hall that had the first Circlotron patent, although he did not call it that. BTW the Graaf amplifiers use the Hall approach which incorporates the driver circuit into the output section. The Wiggins amplifier got a patent also, and is the one that actually got the name 'Circlotron'.

I just bought a near-mint H3. ~ ~ I have yet to listen to it on my Q 57's or my Tannoy "reds".

Peter Panaro
Very cool article on this interesting corner of hi-fi history.

OTL amps are definitely the underbelly of our hobby, and having Gizmo proselytizing their beauty (in conjunction with his worship of Futterman as the intellectual Godfather of this amp) only helps to increase their legend.

Thanks again for this write-up!
Hi, thanks for this wonderfully personal historical overview. It took my breath away for a second when You wrote about German copies of the Futterman. By chance, I once saw one, remembering the owner talked about selling it, but without knowing that Futtermans are something special. Did You ever have the chance to listen to one of these? How was their audio quality? I'd love to have a Futterman, and given how rare they are, its quite hard to find one. And it's a little bit hard to believe original amps made by Julius Futterman should be worse or equal as copies or the NYAL models. Well, any information will help. I don't even know the difference between H3 and H3aa models.
And many thanks for the article!
I have a H-3a sitting less than 5 feet away, this is the unit which used 8 6KG6A/EL509 pentode for the outputs. I ran it on my KLH Model Nines.
Haha, Rdiiorio. Nobody likes a show-off. :P

Wonderful reading...thank you Audiogon_bill for the thread's creation, respondents for sustaining it, and AudiogoN for resurrecting it!

Season's Greetings :-)

If you wish to interpret my post as "showing off" your free to do so, i was in fact just stating the truth since I had come across this thread and decided to respond in kind as many had already done previously.
@Rdiiorio - I was just kidding with you, man. Hence my :P emoticon.

Your stating the truth made me a little envious, but in a totally harmless way. Peace.
Just an addon, One day he (Julius) showed up at my NYC residence holding two extra capacitor cans, put them in parallel with the existing cans on the H3a using the octal sockets on the front of the amp. He said it would improve the driving of the KLH Nines. He also told me to change the fuses on the KLH Nine signal inputs to 5amp so it would be more linear than the default fuse values KLH recommended. Just in case anyone else has a pair of Nines being driven by an H3a it's good to know.
I have Quad 57's (two pairs) and KLH Nines in use with a pair of original Julius Futterman H3AA's. No's 56 and 57 recently restored and purchased from Anthony Naso of NYC. Six 6LF6 beam pentodes per amp. Superb "Holy Grail" sound quality! And I also have on hand awaiting restoration a Harvard Music single-chassis stereo Futterman OTL amp for future use! Glorious sound with the right speakers!