SUT - electrical theory and practical experience

rubandscrub - the cost effectivity is certainly an important aspect, like you write. I also have an ASR Mini Basis, now used mainly as a backup in case my main phono stage has problems. If your Denon carts have 0.2 - 0.3 mV output, I am not surprised that things improved with a SUT. More 'muscle', I imagine. Although I think the sound of the Mini Basis is quite good for the price, it is a bit 'polite', even with my 0.56 mV cartridge. The noise you heard may be due to stretching it, with the gain at or near max (I did not have this problem, using a medium setting).

Hi, I am looking for some real world advice. I recently purchased a new LOMC (Etsuro Urushi Cobalt Blue) that has an output of 0.25mv and 3 ohm internal impedance. I use an Allnic H-3000 phono preamp. An audio friend has the next step up (pun intended) of my cartridge with similar specs. Not sure what phono pre he uses. He swears by the SUT he’s using with it (Luna Cables Rouge):

My question is:

With the Allnic’s design, is it likely that I would achieve a significant improvement in sound quality if I were to add the right SUT (the Rouge may or may not be “right” for my cartridge specs)? I must say, the cartridge sounds great with the Allnic but only compared to the last cartridge I was using, a Kiseki Purple Heart, but maybe there’s a chance I’ve left something on the table?

The H 3000 already uses built in step up transformers for moving coil cartridge levels of gain. If you want to use an external step up transformer, you would need to use moving magnet cartridge inputs on the H 3000. I don’t know whether the H 3000 even has MM inputs. If it does, that’s where you could go. You cannot hook up an external step up transformer to an internal step up transformer. Personally, I think you may be chasing your tail if you are even able to try this experiment with your H 3000, because the internal step up transformers on the H 3000 are already excellent.

Thanks Lew. Yes, there is a MM input. I wasn’t sure if the transformers in the Allnic were being used in the same role as a SUT plays. And yes, it is my understanding that Allnic hand builds the transformers and uses permalloy cores, which seem preferable to those with SUT experience/expertise.

I guess there is no harm in borrowing one to try but given that good SUTs are quite pricey (for a passive device), there would need to be a decent audible improvement for me to keep one in my system.

Adding the SUT that is most attractive to one's unique preference is more the discovery to be made than the adding the right SUT.

Matching the SUT to the Cart' is only one sector to be a consideration.

SUT's add a Coloration to a presentation, it is a case of how 'Rich in Tone' is ones threshold able to entertain before it becomes a repellant and how much of a compromise to the overall performance is the presence of Richness to have.

Lovely Deep Rich Tones are easily able to suppress Upper Mid' and High Frequencies and completely paste over the details in a recording. 

My preferred SUT's only add a hint of a Rich Tone and are not too far from the effects a Head Amp can have.

The Link has a Thread which is produced by an individual I trust, and have direct dialogue with via email on the subject of SUT's quite a few years past.

Not too long ago, I learnt that this individual favours the Ikeda Ist-201 as their 'go to' SUT, (this may have changed in recent times).

The Ikeda is able to be acquired for a similar price as the Luna, the Ikeda is also seen as a used item occasionally, so a few ££££'s can be saved. 

SUT's are a voyage of discovery, I wish you a safe journey.