Seeking advice on several specific MC Step Up Transformers


Hello,

I am looking to change my MC Step Up Transformer (SUT) and am hoping some folks may have had some experience with one or more of these combinations...

I currently use a Silvercore 1:10 SUT. It is hooked up to my Garrard 301 turntable, Thomas Schick 12” tonearm and EMT TSD 15 cartridge. The SUT then runs into a Cary Audio PH-302 MkII Phono Preamp>Supratek Chardonnay Line Preamp>a pair of Decware SE84UFO2 monoblock power amps>Altec Flamenco Speakers.

I previously had a Parasound Halo JC3+ phono preamp in this chain, but, found that the Silvercore SUT was overloading it and causing significant noisefloor. Once I upgraded to the Cary phono pre (with a much higher overload capacity), the noisefloor disappeared. And, yes, on both the Parasound and the Cary I have tested just using the MC input but much prefer the overall sound/impact/dynamics that I get by running the SUT into the MM input.

Through several conversations with two differnt SUT manufacturers I have learned that due to the EMT’s output of 1mV and the higher overload capacity of the Cary pre, an SUT of 1:20 is more ideal. 

So, after that long-winded explanation, I am wondering if anyone has used the Decware ZMC1 SUT and/or the Bob’s Device’s Sky 20 SUT. 

The Decware is a 1:20, but, has the added capability of adjustable gain. Which, as I understand, can be nice for adjusting the impedance on the fly as some records may sound a little brighter than others. The Bob’s Devices is switchable between 1:10 and 1:20. The Decware is also about $400 cheaper (which is a major consideration currently).

Hoping someone may be able to shed some light on any of this...

Thanks,
Jared


128x128Ag insider logo xs@2xjvancamp78
@jvancamp where are you located? If possible try and borrow some different SUTs
I'm been using a Cary PH302 for about 7yrs and like you I found external SUT's into the MM stage to work better with the cartridges I used (lower output MC's).
I've tried Bob Sattin's 3440A, Hashimoto HM7 and Lundahl 1941. The first two were 1:15/1:30 (from memory) and latter is pretty similar 1:16/1:32. 
I agree that a healthy input voltage to the Cary MM stage sounds more dynamic.
I never had any overload problems running a 0.4mV ART9 mc into the 1:32 setting which will boost that cartridge to 12.8mV.
However I found the ART9 to work better with 1:16 (6.4mV) and reflected loading of 184ohms.
You're talking about 1:20 which will boost 1mV to 20mV. I would think a 1:10 SUT would be more appropriate - but I don't know what the overload specs are for the Cary.
Assuming no overload issues, 1:20 SUT (26dB) will give 64dB total gain with the Cary MM (38dB) which may be excessive for your setup - but that will very much depend on the rest of the chain.
IMO 1:20 would be more appropriate with lower output mc's, say 0.3 -0.5mV range. But of course much depends on the individual cartridge and system specs.
I have a Bob's Sky10, which works quite well set at 5:1 with either of two cj phono stages.  I recommend that you talk to Bob about your application.  In my experience when it comes to SUTs, less is more.
Cartridges like the EMT TDS 15 are problematic because the output voltage is "in between" most modern MM and MC cartridges.  At 1:20 your SUT gain is way too high for 1mV output.  Something in the 1:3-1:5 range would be more appropriate.

You might consider using a phono preamp with switchable loading so that you can try and adjust for the perfect setting.

Just use a phono stage like Gold Note PH-10 with many gain option, fully adjustable. You don't need a SUT