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Any Members Tried the Audio Interface CST-80 SUT?

My curiosity got the better of me and I just bought this SUT from Japan and wondered if anyone else had any experience with it. The very little I could find seemed to indicate it is a respectable unit and has even been likened to the highly acclaimed Cotter SUT.

It was made in the US around 1982 and came in two varieties. There was a 3 Ohm version with 30dB of gain and a 40 Ohm version with 20dB of gain.

I currently use a Fidelity Research FRT-4 which is excellent and has 4 different taps 100 Ohms, 30 Ohms, 10 Ohms and 3 Ohms + Pass Through for MM.  It will be interesting to see how it compares the FRT-4.

I will use it with my 1.0 mV / 60 Ohms Shinon Boron Red which currently uses the 100 Ohm tap on my FRT-4.

 

ateal
ateal OP
97 posts
 
Hi Dave, this is fantastic information and very informative for me personally as I own both the high and low output versions of this incredible step up transformer. 

It is also great that you are recreating this well regarded SUT in modern form so that many others can easily try it out for themselves. 

If they are anything like the originals they will be very special indeed. I have no intention of selling my Audio Interface SUT’s anytime soon as they seem to impress me more and more each day. 

I will definitely take you up on the offer of the advert and data sheets as they will be great to have. I will email you shortly. 

Thanks again for posting the history of this SUT and the offer to supply the data sheets. 


fleschler
1,922 posts
 
Your SUT is less expensive than the AIs available on ebay.   My friend is anxiously looking for an AI but at under $500 for the L (low output version).  Thanks so much.

P.S. Do you have an opinion concerning the Zesto 10 impedance/4 output level Andros Allasso SUT?  Can it possibly be as good sounding as your Jensen?  Thanks (I need some adjustment for various cartridges but don't want to sacrifice sound quality).  
mirolab
206 posts
 
Adding to this old thread......
I've owned the CST-80 since 1988... got it used for I think $160.  It's the only SUT I've ever owned and always wondered where it ranked in overall quality of SUTs.  Based on what i'm reading here, it's in the 500-1000 category of new SUT's.  
I'm using an Ortofon MC-30 Super-II... and I've often switched between using the MC gain stage of the phono pre and using the SUT.  I do get more raw detail and LF extension without the SUT, but WITH the CST-80, the noise floor is lower, and there is a mid bass fullness that makes the music bloom more.  It simply sounds more punchy & musical..... at the slight expense of HF transparency.   Overall, I find myself preferring the sound using the SUT.   My current phono pre is the Parasound JC3.

Someday I'd like to hear an SUT in my system based on Cinemag or Lundahl transformers, just to see where my CST stands.
Jensen is currently producing a version of the CST-80 for $550, and Hafler's current SUT for $999 uses the same Jensen transformers!   I'd say the new Jensen is a safe buy, as I've been happy with mine for over 30 years.  
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