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Help With Futterman Mono Amps

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Posted on April 1, 2015 at 09:36:25
Toto
Audiophile

Posts: 19
Location: New York
Joined: December 5, 2007



Greetings,

I recently came into possession of a pair of original Julius Futterman mono amps, serial numbers 56 and 57. So far, I haven't found any photos of identical units and wonder if someone knows exactly which model they are.

One of the big caps was leaking and they clearly need restoration. Can anyone recommend a qualified technician? Any idea of their value "as is" or fully restored. They will eventually be put up for sale.

Thanks,
Joe

 

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RE: Help With Futterman Mono Amps, posted on April 1, 2015 at 10:32:04
6bq5
Audiophile

Posts: 2116
Location: SF Bay
Joined: August 16, 2001
Contributor
  Since:
September 14, 2012
I'd look up George Kaye-
He is on your side of the country - and has a more than passing familiarity with Julius' amps.
Happy Listening

 

We can fix them too. , posted on April 1, 2015 at 10:51:14
Ralph
Manufacturer

Posts: 3152
Location: Minnesota
Joined: April 24, 2002
Contributor
  Since:
April 1, 2002
That Rubycon capacitor is a bit of a trick though. It is an unusual form factor. A part like that should not be used in an audio amplifier like that- even if perfectly good it would be likely to fail in 'short' order...

So my recommendation is to fit a different part in that location (especially since Rubycon hasn't made anything like that since the 1970s).

 

I believe Julius would have called those "H3a", posted on April 1, 2015 at 17:57:27
Lew
Audiophile

Posts: 8652
Location: Bethesda, Maryland
Joined: December 11, 2000
Shortly after making and selling this version to a few folks on a custom basis, Julius discovered the use of photoflash caps as output coupling caps on his amplifiers. Around that time (1972) I commissioned a pair of the later model, which he called "H3aa", with about six or eight photoflash caps per chassis, mounted where that one giant can is sitting on your amplifier. Getting rid of that gigantic capacitor in favor of a gaggle of modern much smaller value, much smaller size Panasonics (for one example) will greatly improve the sonics. The big cap has to go, anyway, because of its age. See if you can get George Kaye to look at the amplifiers. He goes back to Julius directly, but I don't know if he's still active.

As of the early 70s, if you wanted a new "Futterman amplifier" you contacted Julius, sent him a deposit, and waited. Eventually, he would call you and in muted tones of an old man he would tell you your amp was ready. Which meant you made an appearance at his workshop (cannot call it a factory) on West 72nd St in NYC, off Broadway, because there was no shipping. Power transformers that Julius made himself would be hanging on a clothesline so the goop that held the windings could dry. Just smelling that smell probably shortened my lifespan. The PT is very critical and not so easy to replace; don't fire those bad boys up until someone competent has serviced them. I used my H3aa's to run two pair of KLH9s, for a glorious sound.

 

RE: I believe Julius would have called those "H3a", posted on April 2, 2015 at 07:32:28
Toto
Audiophile

Posts: 19
Location: New York
Joined: December 5, 2007



H3a was my guess, too, until I found this image in rhinohifi714's gallery that's identified as an H3a.

Looking at photos of the H3aa, I now think that the ones in my possession are early, hard-wired versions. Later, more finished looking builds replace the single cap with six smaller ones, but otherwise appear to be very similar.

George Kaye is still active. He's in Brattleboro, VT, and has a site called kayeaudiolabs.com. I also found references elsewhere on the OTL Asylum to a retired NYAL engineer named Ted Hammond, in Croton, NY, who also worked on them. However, health issues may have limited his activities.

Joe

 

I don't believe that's an H3a in Rhino's photo…,, posted on April 2, 2015 at 08:52:21
Lew
Audiophile

Posts: 8652
Location: Bethesda, Maryland
Joined: December 11, 2000
but of course I could be wrong. I once owned the model shown by Rhinofi. It is a much earlier amplifier, probably built in the 50s or early 60s that was produced under the "Harvard Electronics" label, when Futterman was more "in business". I think it was rated at 30 or so Watts per channel and was not in the "H3" series. But Rhinofi may be able to prove me wrong by showing a photo with the model number on the chassis. The H3s were all monoblocks, for one thing.

EDIT. The internet is a wonderful thing sometimes. I did a quick search and found two facts to modify my post: (1) I am incorrect, not all H3 series amplifiers were monoblocks, and (2) I was correct, the amp in your photo is not an H3a; it is an H3.

 

RE: I don't believe that's an H3a in Rhino's photo…,, posted on April 2, 2015 at 09:03:17
Toto
Audiophile

Posts: 19
Location: New York
Joined: December 5, 2007
Yes, I think you're right. The previous photo is a mislabeled H3, mine are H3a's, and the later H3aa replaces the single large cap with six smaller ones.

 

RE: I don't believe that's an H3a in Rhino's photo…,, posted on April 2, 2015 at 11:48:20
Lew
Audiophile

Posts: 8652
Location: Bethesda, Maryland
Joined: December 11, 2000
For anyone who is interested in Futterman history, this website is great:
http://www.audioclassica.de/files/Dokumente/Die-Futterman-Story-2.pdf

The photos are surrounded by German text, but in the back there is an English translation of a description of a visit to Julius's shop in NYC. The author nailed it perfectly. That is exactly as I remember it myself. I was there at least twice. Julius was a sweet and humble man in all ways except one; he fervently believed in the superiority of his design for ESLs or for any high impedance speakers. Such speakers were more plentiful in the 50s and early 60s, before the hegemony of solid state amplification. Ralph and Julius have a lot in common.

 

Speaking of photos..., posted on April 2, 2015 at 14:45:44
Toto
Audiophile

Posts: 19
Location: New York
Joined: December 5, 2007



This is the underside of one of the H3a's that I have. The Panasonic caps on the upper right (under the electrical tape) are not original to this build and were added later.

 

RE: Speaking of photos..., posted on April 2, 2015 at 15:04:14
Toto
Audiophile

Posts: 19
Location: New York
Joined: December 5, 2007



I just found a record of a similar pair, fully serviced and incorrectly identified as H3aa's, that sold on eBay in 2013 for $1782.32.

 

RE: Speaking of photos..., posted on April 2, 2015 at 20:25:57
rhinohifi714
Audiophile

Posts: 138
Location: oklahoma
Joined: June 13, 2009
That looks like a zener diode nightmare!!!
Julius used the zeners in a daisy chain to do the alignment procedure on the early versions of that amp, the pair that Ted and I did we brought them up to date using a single zener and an adjustable resistor, much easier, that amp has chains of 10 zeners in a row...WOW That's Beautiful!!!
I'm sure George will suggest a complete rebuild, that will be pricey but money well spent. They are awesome sounding amps.
I'll check the stereo amp for model number when I return home, I'm using it in my bedroom driving a set of Von Schweikert model 4's it has no problem at all driving them.
The stereo amp will put out 60 watts per channel, the mono like yours will put out 90 to 95 watts with a strong set of matched tubes properly aligned.

 

…into 16 ohms, yes?, posted on April 3, 2015 at 07:10:09
Lew
Audiophile

Posts: 8652
Location: Bethesda, Maryland
Joined: December 11, 2000
I doubt you would get that much power into 8 ohms. The downfall of the Futterman comes when the impedance reaches 2 to 4 ohms, which is sadly not uncommon in "modern" multi-way highly inefficient speakers built to be driven by transistors. I never perceived a problem with a true 8-ohm speaker, however.

 

…into LEW, posted on April 3, 2015 at 09:55:43
rhinohifi714
Audiophile

Posts: 138
Location: oklahoma
Joined: June 13, 2009
.

 

for what it's worth., posted on April 3, 2015 at 10:08:11
rhinohifi714
Audiophile

Posts: 138
Location: oklahoma
Joined: June 13, 2009
.

 

RE: Help With Futterman Mono Amps, posted on April 3, 2015 at 10:14:02
Richard P
Audiophile

Posts: 461
Location: Upstate NY
Joined: October 8, 1999
Oh dear. They appear to have suffered from water damage over the years. My one hope is that the output tubes are OK. 6LF6 are really tough to find in good shape, and will be expensive (damn ham radio operators).

 

You didn't stipulate the speaker impedance, and..., posted on April 3, 2015 at 11:34:44
Lew
Audiophile

Posts: 8652
Location: Bethesda, Maryland
Joined: December 11, 2000
in any case, I was just making conversation. I had no idea that my posts were offensive to you or to anyone else. Henceforth, I will be sure not to follow up any of your posts. I never even dreamt that I had a beef with you or you with me.

 

RE: You didn't stipulate the speaker impedance, and..., posted on April 5, 2015 at 04:56:25
rhinohifi714
Audiophile

Posts: 138
Location: oklahoma
Joined: June 13, 2009
.

 

RE: Help With Futterman Mono Amps, posted on June 3, 2015 at 23:31:36
Posts: 34
Location: Northeast
Joined: March 13, 2009
Great Amps but clearly need a complete rebuild and until that is done there not worth much IMHO

 

RE: Help With Futterman Mono Amps, posted on March 3, 2016 at 11:38:13
Posts: 34
Location: Northeast
Joined: March 13, 2009
So lets get started and have some fun. I'm the guy that ended up with these amps from Toto about a year ago. They have been sitting in the original shipping boxes since they arrived at my loft in NYC. Today the rebuild started.

 

RE: Help With Futterman Mono Amps, posted on March 3, 2016 at 11:43:49
Posts: 34
Location: Northeast
Joined: March 13, 2009
No what we have found here after 3 hours of investigation is that the original amps used the 6GF7 as the regulator tube and not the eventual 6LU8. That zener chain that we all commented on above is not original. JF used V83R4 tubes which are still in the amp but likely dead so that is why the zener chain showed up I suspect. The zener chain is made up of old Motorola 2346-108 zeners?? I could not even find the part number on the web.

 

RE: Help With Futterman Mono Amps, posted on March 3, 2016 at 11:48:28
Posts: 34
Location: Northeast
Joined: March 13, 2009
So now the question I am pondering is do I do a complete rebuild??? Or strip away the terrible repair work only and go back as original and as true to JF as possible??

In general I am leaning toward the OTL 3 rebuild with more adjustability. Or a JJ Tesla EL509 rebuild like Rhino has from Ted??

 

Ben Jacoby in Brooklyn, posted on March 3, 2016 at 15:07:09
Bill Way
Audiophile

Posts: 1199
Location: Toms River NJ
Joined: May 28, 2012
Contributor
  Since:
December 14, 2012
Ban Jacoby of High End Audio Repair does outstanding work, and I'm pretty sure he has worked on Futterman amps before. He did a superb job updating and greatly improving an old VTL preamp of mine.

WW
"A man need merely light the filaments of his receiving set and the world's greatest artists will perform for him." Alfred N. Goldsmith, RCA, 1922

 

RE: Ben Jacoby in Brooklyn, posted on March 3, 2016 at 16:05:52
Posts: 34
Location: Northeast
Joined: March 13, 2009
Thx but this is the 7th or 8th time in 25 years of doing this hobby that I have restored these H3 JF OTL/NYAL Amps so no body else is needed, I've got it covered. I just posted to let the crew know the amps are finally getting a face lift. Also I always love to hear the thoughts of others on the way they might restore the pair. I'm thinking JJ EL509's myself but we'll see.

 

RE: Help With Futterman Mono Amps, posted on March 4, 2016 at 05:49:44
Posts: 34
Location: Northeast
Joined: March 13, 2009
As an update they were not water damaged as a previous inmate thought. Just surface patina which is being cleaned up now. Generally I do not like to repaint old amps as I like them to look weathered and in as original a state of appearance as possible. It blows peoples minds when they see an old piece of electronic equipment that makes the sound these amps can make after a rebuild.

I am also think 17KV6A tubes as a replacement to the 6LF6's but again I am in the testing phase so we'll see. 1 amp is stripped already.

 

RE: Help With Futterman Mono Amps, posted on March 8, 2016 at 20:15:26
Lew
Audiophile

Posts: 8652
Location: Bethesda, Maryland
Joined: December 11, 2000
If you still don't know exactly what model this is, I think they are H3a's. As I recall, the H3a had the single huge output coupling capacitor that you have on your units. This was eventually replaced by a gaggle of much physically smaller photoflash caps, 6 of them per chassis, IIRC. That version was re-named by Futterman as "H3aa". That was the end of the line. In consecutive order, I owned H3a's, followed by H3aa's, the latter bought direct from JF. Since you seem to know what you're doing, I am sure you would know to replace all those electrolytics. In my Atma amplifiers, I use a bunch of Panasonic TS-ED electrolytics, 2000uF/200V, for filtering the output supply, but they would also be useful as output coupling caps on your amplifiers. Also, I wonder whether 36KD6 or 40KD6 could replace the 6LF6s. That's just a WAG.

 

RE: Help With Futterman Mono Amps, posted on December 29, 2016 at 00:02:33
lucisfero1
Audiophile

Posts: 7
Location: NYC
Joined: August 17, 2000








I just came across this posting and I can confirm the H-3a use the 4 per channel 6KG6A/EL509 and have the 3 large caps. Julius delivered my amp after he repaired it and we listened to some music ( KLH Model Nines).
Some of the H-3a chassis used the H3 chassis which had on the front left, TECH Instruments Corporation and on the right front, stereo/mono OTL power amplifier. I've had this particular OTL since 1972 and its still powering the Nines. People who say the Futterman is unreliable maybe had bad luck or abused the unit. I also think the Model Nines still stand up to anything made today, the pairing is beautiful and engaging sonically.

 

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