Step Up Transformers….Are they Worth the Trouble?

The problem with current drive is that to have true current drive, the input impedance of the phono stage has to be zero, and that's not possible (because the signal would go to ground; in effect a mute switch).  Atma-sphere made the interesting point that ICs (often used at the input of current drive phono stages) can present a "virtual ground" at the input.  In other words, a virtual zero input impedance.  But the real world impedance always must be a few ohms above zero.  I think (I guess) that is where the unpredictability in SQ, when matched with various LOMC cartridges, of these devices arises.  The BMC MCCI that I owned in fact uses discrete transistors, not an IC, at its input.  It definitely worked with even my Ortofon MC2000 at .05mV to produce plenty of gain, but I didn't "feel" it.

Update: Lot of listening yesterday with my new TT, cart and phono. I end up preferring Allnic H-6500 (tube) phono over Konus MC3000 (trans impedance) phono in my system. Allnic was more synergistic with rest of my system. For a tube phono (12 tubes), H-6500 is one hell of a phono pre; I am pleasantly surprised by it’s perfect balance being a tube phono (in direct contrast with Konus), it’s dead quiet, harmonics that are synonymous with valves but not overly tubey or syrupy yet incredibly detailed. Not to mention thoughtful features, exquisite build quality and tube rectification in external power supply.

Similarly, Etsuro Bordeaux bettered Fuuga in terms overall detail and depth. Bordeaux is a beautiful sounding cart, just like a fine vino; the passion and attention to detail of artisans at Excel Sound was evident from very first note. Bordeaux aptly renders clarity, balance, and the immersive quality of any well recorded album.

My modest but carefully chosen collection of recordings shined through the foursome of 301, 3P, Bordeaux and H-6500. They allowed music to simply breathe, quiet passages were intimate and louder sections just as impactful without any distortion. The tonal balance was also impeccable, ensuring that no frequency range dominates or feels lacking, bass was tight and controlled, revealing subtle details and nuances that enhances our emotional connection to the music.

I plan on getting Etsuro SUT once I cross the initial break-in threshold.

My next priority is to get a better TT isolation. Thinking about SRA Ohio Class platform and Scuttle 2 level extra-wide custom rack.

Back to cleaning records and more listening. Thank you all for your thoughtful input and advice.

If it were I, I would want to have a concrete reason for why an outboard Etsuro SUT would outperform the SUTs built into the Allnic, before spending the bucks for the Etsuro. There are more readily conceivable reasons why that might be a downgrade rather than an upgrade (extra connectors, extra wiring, added capacitance, etc) than there are good reasons to expect an improvement.

@lewm

Thank you for your input. I hear you on extra connections but this is something I would like to explore down the road. I wouldn’t know if Allnic is doing full justice to Bordeaux unless I pair it with an external SUT. SUT is not a priority right now but more or less a wish list item that needs to be checked off :-)

@lalitk : I’m with @lewm : the Etsuro Urushi SUT might be different but not necessarily better and quite possibly worse. It is 1:20, which your Allnic offers (along 1:26, which you might even prefer with a .25 mV cartridge at 3 ohms DCR). And your Allnic silver-wound transformers are far from broken in at this point. I’d say listen for a few months before considering the expense and electronic complication of any outboard SUT.