When is it time to consider adding a SUT?


I have an ARC reference phono 2 and am about to take possession of a Benz LPS with a low output. I have heard that installing a SUT such as one from Bobs devices can help the phono pre and provide better end to end performance. Would this help a quality phono pre like the ref 2?
thanks 

gtaphile

Showing 1 response by andrei_nz

gtaphile

As a bit of a simplification a MC phono stage does two things.  First there is some gain, and secondly there is equalisation  - usually RIAA.  That first step can be done
  1. On the cartridge (High Output Moving Coil);
  2. Electrically - MC Phono Stage
  3. Externally via a Head Amp
  4. Externally via a Step Up Transformer.

This latter option is not adding a component.  Yes you see another box but the Transformer is a passive device (the actual key to why they are so effective, by the way).  If anything it is subtracting a component as you bypass electronic circuitry.  Other things being equal and the Transformer is well done it is the perfect solution.  

Other things are not equal and the downsides to an SUT are that they are susceptible to noise if placed too close to other components such as power supplies.  They are expensive, the good ones anyway.  Also there is the issue of impedance matching.  If the quality of your Phono Stage is good, and I guess that includes ARC, then I would not bother.  On the other hand I have read in other forums of of good results with Step Ups into other high quality phono stages.  One of the best resources out there is by Andrew Rothwell

http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html