I bought a used Aesthetix Io mk2 for about $3800 years ago, and later upgraded. To my ears it sounds better than e g the Steelhead, ARC PH6 and others I've heard. Especially after I upgraded to dual power supplies and partial eclipse status. You have to accept some tube noise, but with the latest quiet stock tubes recommended by Aesthetix it runs more quiet than before and it is not much of a problem with a cartridge giving 0.3 or more mV output. The main issue is to get ultra-quiet tubes in the very demanding first gain stage. Maybe, it can tackle 0.2 SL types of carts also. A step-up transformer is not recommended. It only has MC inputs (one XLR, one RCA). It is not fully balanced, but the balanced output is clearly better than the single ended output. So to get the best of it, you need a balanced preamp (and - ideally - amp). Regarding the input, from the cartridge, Aesthetix tells me opinions vary, but often, customers prefer single-ended (RCA) input. I use a DIN-RCA Kimber KCAG cable, and have never had hum problems. If you go the Io route, eventually starting with a Rhea, I don't think you'll regret it. But be prepared, this is a "purist" solution.