I run my Transfiguration Phoenix (original version I think, 4 Ohms internal impedance) through a Spectral DMC 20 with internal phonostage. I used it with 10 Ohm load for a long time, but found it to have too little punch (I guess overly damped). So, I increased it to 100 Ohms load, where it had a lot of punch, but somewhat fatiguing (and highs causing ringing in my ears). So, now I've gone to an intermediate 30 Ohms, which is hopefully Goldilocks...so far, so good, but we shall see. Theoretically at least, I think this is the correct setting, as it is between 5-10X the internal impedance.