RFC-MC1 Step-up Transformer

[Marco]

Marco.

[khapahk]

My thoughts on the RFC-1.

Physically I found it remarkably light and the finish is good for a prototype.

To set the scene, my experience of SUTs in my system is quite limited. My phonostage is an Icon Audio PS1.2 MM/MC, which uses it's own internal SUTs rather than active electronics for the MC stage. I presume these operate before the MM stage when MC is selected. The SUTs are not labelled so I'm unable to tell which make they are, or indeed the ratio ! I've also recently acquired a Martha SUT (6:1) which I've been using into the MM stage. My cartridge is a Benz Micro Wood SL – 0.5 mv; impedance 12 ohms; load >100 ohms according to manufacturer's details.

Music – prog rock, jazz/classical piano, chamber music, large orchestral

And the nitty-gritty ?!

I've been trying the Martha for a couple of months now and don't feel the combination of Martha/MM phonostage is as good as the standard MC for the phonostage. The frequency extremes are slightly muted with the Martha in place and some of the detail is lost. Could this be the 6:1 ratio ? By comparing volume level with the RFC-1, I suspect that the unlabelled SUTs in the phonostage are 10:1 as well. Is there a better way of finding this out, for a technical numpty like myself ?

Onto the RFC-1/MM phonostage combination. Firstly, there is no trace of any noise/hum (I followed the grounding instructions closely !). There was no ill-effect on the already wide soundstage from the GyroDec/Wood combination and image location is excellent, more precise than before. The overall sound is very clean, showing a slight improvement to frequency extremes compared with just the phonostage.

Overall, I like this a lot; it gives a noticeable improvement over my current vinyl set-up When funds permit, I’ll go for it.

Good luck with the SUTs, Paul.



k

[Reffc]

Many thanks Bob

level matching by volume can give you an approximation of the SUT value but you'd have to measure it to know what the value is. Many standard ones within MC stages usually consist of a 1:10; 1:12.5 or 1:15 step up.

The RFC-MC1 production units are a little weightier than the prototype and better finished, having some subtle internal changes such as mass loading for reducing any microphonic risks from vibration, the use of a custom board for the electronics and some minor changes (improvements) to the quality of fittings.

[Reffc]

SUT is now en-route to the next person in the trial. I'd like to (tactfully) make a little point at this juncture which is to point out that this is a trial being offered to those interested in the MC1. It is not a "loan" item but is being offered on a trial basis (I've had some enquiries about "borrowing it for a while" but it is not a loaner item to plug a temporary gap in a system! I'm more than happy to add anyone else onto the list as long as it is with this understanding. There are a fair few people waiting to be added to the list who are genuinely interested in the MC1.