SUT suggestions for Audio Note System

Zesto makes a variable gain (4, 6, 8, 12x) and adjustable impedance SUT. You can easily fine-tune playing volume with pre/integrated amp volume control and have a bit of tone control with impedance setting on SUT. No need to agonize about details, just listen to what works for you. Works for me.

@pkvintage

I had a look at the Audionote website and the manual for your M6 Phono.

So 126mv for 1v out is 18db - that is the line stage specs.

The phono is quoted as 63db. If the phono is 63db then you should not need an SUT at all, there would probably be an internal SUT and the phono would have enough gain for your Koetsu straight in.

I think it is more likely the 63db quoted includes the 18db in the line stage. If this is the case then the phono alone has 45db gain ( 63 - 18 ). If the phono gain is 45db then you probably need a SUT with a gain ratio somewhere between 1:10 ( 20db ) to 1:15 ( 24db ).

I looked at your power amplifier the Audionote Conquest Silver Signature. There are 2 versions -

first one specs out at 250mv for full power. So given the preamp specs are for 1v out you can see the power amp is very sensitive and you have a bit of spare gain.

For this reason I would suggest you try a SUT with 1:10 gain ( 20db ).

Some folk will go on about loading, but my advice is to forget about that and focus on getting the correct gain. Too much and you’ll be running the volume pot too low which can mean channel imbalance more likely.

If your gain is too low, obvious you’ll have a higher noise floor.

There is a low gain version of the Conquest Silver Signature and this is spec’d out at 3.15V to full power. I doubt you have this version.

I can’t see why Audionote should be able to give you advice on this.

Given the quality of your system you want a decent SUT - Stevens and Billington, Tango, etc. Higher end vintage units can deliver bang for your buck eg Denon AU1000. The Zesto mentioned uses standard Jensen transformers which are very neutral, reasonable quality. Other folk consider the Llundahl transformers quite good. There are obvious other bespoke companies offering solutions - comes back to budget.

Hope this is useful for you.

Thanks very much for taking the time to look into the specs. 3 posts above I mentioned the specs of the m6 phono V4. Mine is a V2 so there could be a difference. Did the specs that you found come from a version 2 manual?  The V4 manual shows the phono at 68db and the line at 16db.  I thought I would mention this as it does change the end db figures.  I’m not sure if those numbers make a difference or not. Again thanks for the effort. 
 

I am starting to Leen the way of getting a quality multi setting SUT to allow for trying other cartridges. Any thoughts on that?

@pkvintage 

I couldn't find a manual for your v2 version on the Audionote website.

I would suggest you try your Koetsu straight into the phono without a step up and you will get a feel for how much extra gain, if any you need. If for example you have enough gain, but the volume pot is high and you are getting a high noise floor, then you would need a low gain step up - say 1:5 to 1:10.

I use to run a Koetsu black goldline straight into my modded Marantz 7 mm input at 47k, and had plenty of gain with low noise floor when I used sensitive tube power amps - eg Quicksilver monos at the time and some power amps.

These days I use a custom built current mode mc step up into the Marantz phono.

I believe Sutherland produces something similar - Sutherland SUTZ. 

I have some pretty exotic SUT's in the cupboard and none of them are as transparent as the current mode step up. I do concede though that some folk like the "sound" of a SUT - they are all different.

You could always go a buy some vintage SUT's such as the Entre ET100 at a modest price to have a play with before you spend up large

I would suggest you contact Audionote with the serial numbers of your unit sop you can confirm exactly what the specs are for your phono.