Recommandation for 1:6 1:8 SUT under $5K?


I’m looking for some advice on a step-up transformer that pairs well with my Audio Research LS28SE, PH9, and Hana Umami Blue cartridge. I currently have both the Denon AU-S1 and AU-340. The AU-S1 sounds absolutely beautiful—very transparent and open—but at 1:13 the gain is too high, and I’m getting some clipping, especially on dynamic peaks. Even with the AU-340 at 1:10, I can still hear a bit of overload. I’ve tried playing with loading and parallel resistors, but the issue really comes down to gain. I think something in the 1:6 to 1:8 range would be perfect, enough to keep the clarity and tone I’m getting from the AU-S1 but with better headroom. My budget is around $5k, and I’m open to any recommendations for a high-quality SUT?

arazmj

Dover, do you therefore think that the turns ratio of their 27.5 ohm SUT is likely to be ~1:40?

Looks like it based on their published data.

 

It suddenly occurred to me that all they have to do is install a resistor in parallel with the primary to get whatever load they want for a given turns ratio. For example, for a 1:10 SUT, an 18 ohm resistor on the primary will result in about a 27 ohm load seen by the cartridge. Makes more sense.

Many of the Japanese SUTs (Luxman / AN:Kondo) use severe loading on the transformer to reflect back a small multiple of the internal impedance.  This is typically applied to the SUT secondary and could explain this situation.   

I think the key point here is much of the mystery and speculation around SUTs in general stems from the limited published data by the manufacturer.

The assumption of a 47kΩ terminating resistor falls out of the picture if there is a 5KΩ resistor internally soldered across the transformer secondary.  This also mucks with all of the other assumptions/calculations.

dave

Dunno if this would be a good fit. I have one and quality and sound is excellent using my Declare tube amp/pre-amp. Support from UK is also excellent.

 

https://www.zinamp.co.uk/products/Headmeister.html