I own a PF-R and both an MF2100 and an MF2300A. I first paired my PF-R with the 2100, and I was very pleased with the sound: warm and liquid (very characteristically C-J) yet very detailed. I was particularly impressed with the sound of cymbals which were extremely realistic (I play the drums) yet not in any way bright. Bass response was deep yet very controlled. The soundstage was very wide and reasonably deep, and the position of the instruments was clearly defined. I thought I had a fantastic combination.
I swapped in three other preamps that I also owned that had impressed me before I purchased the PF-R (including the C-J SC26). None of these preamps came close to the PF-R. My non-audiophile girlfriend politely listened as I compared these preamps, but she was amazed when the PF-R was finally placed back into the system. She could not get over what a difference the PF-R made to the sound presentation. She became a believer that day, and she regularly listens to my system when I am trying out a new component so that she can give me her unbiased impression.
Then I purchased an MF2300A. While I never listen at ear-splitting levels and my speakers do not require a great deal of power to drive them, I could not get over the difference that the bigger amp made when it was swapped into my system. While the overall characteristic of the sound remained very similar, everything that the MF2100 did so well the MF2300A did better. The bass extension was even deeper, the soundstage was even wider, and the microdynamics were even greater. I was truly amazed, and I have kept this combination in my primary system.
You are going to love the PF-R. I believe it is one of the best values in all of high end audio. I have not done comparisons of the newer MF series amps, but I have heard that their sound is not nearly as warm as the older series. The MF2100 is a great amp (I still use it in a second system); but if you can afford $1,000 to $1,200 for a used MF2300 or MF2300A, I think that you will be extremely pleased with the combination.
I didn't answer your question exactly, but I hope that this helps.
Good luck!
I swapped in three other preamps that I also owned that had impressed me before I purchased the PF-R (including the C-J SC26). None of these preamps came close to the PF-R. My non-audiophile girlfriend politely listened as I compared these preamps, but she was amazed when the PF-R was finally placed back into the system. She could not get over what a difference the PF-R made to the sound presentation. She became a believer that day, and she regularly listens to my system when I am trying out a new component so that she can give me her unbiased impression.
Then I purchased an MF2300A. While I never listen at ear-splitting levels and my speakers do not require a great deal of power to drive them, I could not get over the difference that the bigger amp made when it was swapped into my system. While the overall characteristic of the sound remained very similar, everything that the MF2100 did so well the MF2300A did better. The bass extension was even deeper, the soundstage was even wider, and the microdynamics were even greater. I was truly amazed, and I have kept this combination in my primary system.
You are going to love the PF-R. I believe it is one of the best values in all of high end audio. I have not done comparisons of the newer MF series amps, but I have heard that their sound is not nearly as warm as the older series. The MF2100 is a great amp (I still use it in a second system); but if you can afford $1,000 to $1,200 for a used MF2300 or MF2300A, I think that you will be extremely pleased with the combination.
I didn't answer your question exactly, but I hope that this helps.
Good luck!