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  »  New  Expressive Technologies SU-1 and cartridge output and i..  MV and Ohms...  Analog Playback Forum     2  33639  07-07-2011
  »  New  The Expressive Technologies SU-1..  “too bright” or “resolution” or “details” with SUT prim...  Analog Playback Forum     33  376260  12-30-2004
06-17-2014 Post does not mapped to Knowledge Tree
Paul Costa
Posts 11
Joined on 04-30-2006
Post #: 1
Post ID: 21002
Reply to: 21002
Expressive Technologies Model 1 preamp
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Romy do you know anything about their preamp. This unit looks massive. Very little info available on it. The one description I found sounds like some of the typical American over done foolishness.
06-17-2014 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,159
Joined on 05-28-2004
Post #: 2
Post ID: 21006
Reply to: 21002
An interesting breed.
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 Paul Costa wrote:
Romy do you know anything about their preamp. This unit looks massive. Very little info available on it. The one description I found sounds like some of the typical American over done foolishness.

Back in 90s there was a now extinct magazine "Ultimate Audio" that I think published a review about it. I had it somewhere and it was kind of strange reviews as I remember where the revere was fighting with some kind of imaginary wind mills and more review the company then the preamp.... I have seen and hear this Expressive Technologies Model 1 preamp in the home of the Expressive Technologies owner, I do not remember his name now, the chemical guy. I do not even remember what I was listening as to hear anything was not my objective then and I was stoking the guy with begging him to make for me his Expressive Technologies SU2 transformer. He has a listening room with that Expressive Technologies preamp that I think used 6 or 8 6SN7. The preamp was huge, super heavy and I need to report in really was not as ugly as it was on the picture. It is not photogenic preamp but seeing it I need to admit that it has own grace.

About looking  massive, it was and I need to admit that pretty much anything that the guy did in his room was super massive. He had I if I remember correctly full range electrostatic that he was driving directly from plates of his amps unit absolutely enormous side transformers. I do not remember if the electrostatic were 6 feet tall of it was the transformers 6 feet tall. It was VERY ambitious.

About the typical American over done foolishness. Unlikely, I did not read the guy as somebody who care too much to build something "over done" and then sell it, he did not live from his audio income  as far as I could tell, good for him. The most important why I would extend some trust to him was of course the absolutely astonishing performance of  Expressive Technologies SU2 transformer that I eventually suck out from him. I am going to tell you: knowing that his SUT goes compare to anything else I have seen out there  would trust to him with ANY transformer project. Well, if it would be a " transformer project" then why shall I presume that his preamp would be " typical American over done foolishness"?

The said story is that Expressive Technologies prams were in play good 15 years back and nowadays it is very hard to correlate what I  fell about preamps today and what I was thinking 15 years back. If you asking then you most likely has it within your reach, and if so then I would defiantly give it a try as I feel that Expressive Technologies were very interesting firm.  
 

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
06-18-2014 Post does not mapped to Knowledge Tree
Paul Costa
Posts 11
Joined on 04-30-2006
Post #: 3
Post ID: 21007
Reply to: 21006
Manual
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I have a PDF file of the manual if it interests you to read it, I can email it to you.
The unit weighs 80lbs, uses 6 6sn7's.
What I found a little odd was the spec for the phono is it says : MM Phono Stage Gain: 64 dB at 1 kHz

I own a Expressive SU-1 and can't imagine it getting much better than that for an SUT. I am very curious about the phono in it but that spec is very unusual for MM.

I read something on line that it uses a 2kva transformer for the power supply. It says it is heavily shielded but wouldn't there be a chance of magnetic fields potentially affecting the sound?
06-18-2014 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,159
Joined on 05-28-2004
Post #: 4
Post ID: 21008
Reply to: 21007
Expressive SU1 + Expressive preamp
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 Paul Costa wrote:
I have a PDF file of the manual if it interests you to read it, I can email it to you.
The unit weighs 80lbs, uses 6 6sn7's.
What I found a little odd was the spec for the phono is it says : MM Phono Stage Gain: 64 dB at 1 kHz

I own a Expressive SU-1 and can't imagine it getting much better than that for an SUT. I am very curious about the phono in it but that spec is very unusual for MM.

I read something on line that it uses a 2kva transformer for the power supply. It says it is heavily shielded but wouldn't there be a chance of magnetic fields potentially affecting the sound?

Thanks, for offering the manual, I really do not need it, if you want I can post it at the site but I do not think that there are a lot of people out there who would be interested, with exception  that it might have a schematics, which I think it does not have.

The 6 6SN7, that is interesting choose. I do not know if they  bridge those dual triode or use them in fully symmetric application, if the unit has phase switch then it might be later. The 3 stages of 6SN7 is kind of interesting chose and they are low gain tubes and usually people put in the first gain stage some kind of high gain triode (let say 12AX7 or 6SL7) and then follow with preamp-type of triodes 12AU7 or 6SN7.  It is perfectly possible to make 3 stage 6SN7  RIAA preamp  and I think RCA did it in past but I wonder how the hell they got 64dB gain. Each 6SN7 stage make 20dB and the RIAA network shall each 20dB, so where they got extra 4dB? I do not have an answer. Anyhow, if they do have  64 dB gain then I do not see why the spec should be odd.  Do not forget that phonostage on the unit does 40dB gain and you have extra 20dB gain by preamp section - sound completely reasonable to me. In fact when I see 40-50dB gain MM phonostage I always feel that it is not enough  - an MM stage shall have at least 60db gain and MC shall have 80-85dB gain - this is how I would like to have.

If you have Expressive SU1 then along with Expressive preamp you have near 90dB gain - so you are all set for any super low MC cartridge. I do not know how the Expressive preamp sound but it might be interesting to hear how Expressive people meant it to be. Expressive SU1 would not work its best with phono-correctors that have  high gain fist stage. I had my 7788 based two stage and I was not impressed how my SU1 worked with them. However, the same SU1 with EAR834PT was throwing the deglitzing, dynamic range and bass that was  absolutely mesmerizing. So, I might presume that when Expressive people did their preamp then knew what they are doing and I think it might be very educational to hear Expressive SU1 + Expressive preamp combination.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
06-18-2014 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006
Post #: 5
Post ID: 21009
Reply to: 21008
Active vs. Passive
fiogf49gjkf0d
44 dB "net" gain seems only a little odd for a MM phono amp, and it may be that "net gain" is even less in this particular circuit. In any case, I'm guessing it still accommodates their own SUT; why not?

2kVA is indeed one hell of a power supply for this application, and it would absolutely require lab-grade shielding and grounding to stay quiet in this circuit. No doubt it lives in the "other" box, but still...

Paul S
06-18-2014 Post does not mapped to Knowledge Tree
Paul Costa
Posts 11
Joined on 04-30-2006
Post #: 6
Post ID: 21010
Reply to: 21008
Total gain
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Romy

So what you are saying for MM gain 64 dB means 48 dB plus the 16 dB (spec in manual) provided by the line section of the preamp are the two gains added together?
48 dB to me is a lot more common for a MM stage. With another 28 dB on top is 76 dB.

There are no schematics in the manual.

A picture of the unit:
06-18-2014 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,159
Joined on 05-28-2004
Post #: 7
Post ID: 21011
Reply to: 21010
This is a full functional pramp.
fiogf49gjkf0d

Nope, if they said that it has 64dB then it has 64dB and I have no reasons to doubt. In reality the gain stages sum 84dB and 20Db is eaten by RIAA. I do not know how they got from 3 stages of 6SN7 84dB but if they claim that they did then they did.



"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
Page 1 of 1 (7 items) Select Pages: 
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Expressive Technologies SU-1 and cartridge output and i..  MV and Ohms...  Analog Playback Forum     2  33639  07-07-2011
  »  New  The Expressive Technologies SU-1..  “too bright” or “resolution” or “details” with SUT prim...  Analog Playback Forum     33  376260  12-30-2004
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