RM-4 vs. MCP-33


I have recently purchased the Audio Research MCP-33 phono pre-pre amp, and compared it to my heavily modified Music Reference RM-4 pre-pre(Dynamicaps, Vashay nudes, Blackgate caps, fred diodes, premium power cord, etc) RM-4.
Here is the listening impression so far. My regular phono preamp Counterpoint SA-9 is out to Mike Elliott for upgrads, so I have borrowed my friend's Wright Sound WPP-200C for the audition.

My modified RM-4:
very transparant, lots of details without sounding bright, a little polite sounding, instruments a little thinner than the ARC unit, very smooth and silky, better micro dynamics

MCP-33:
I had to change the tubes to Amprerex Buggle Boy 6DJ8s since the stock Telefunkens sounds too thin and bright to me.
This unit has definitely more macro dynamics than the RM-4, so it is more suited for jazz and pop with rhythm. The RM-4 is more polite and silky smooth sounding, so classical music is good with the RM-4.
So, the MCP-33 has somewhat more apparant (macro) dynamics, a little more foward in the midrange, a little thicker sounding than the RM-4, while the RM-4 is more transparant, smoother and has better resolution and more detail. Occasionally, I felt a little hardness in the high frequency from MCP-33, but I need more listening before I can be sure. Guess the premium parts installed on the RM-4 has paid off (parts alone cost over $1000). The MCP-33 indeed sounds very good, and I am sure stock MCP-33 would outperform unmodified RM-4.

If I had to pick one of them, I would pick the RM-4 because the transparancy of RM-4 is quite addictive. Maybe I would change some parts on the MCP-33 and find out if it gets better.

Any thoughts on the comprasion?

My system is VPI TNT 5/JMW 12.5/Shelter 501 II/Modified Acoustat Servo OTL power amps/Acoustat model 8
Steve
sojs

Showing 4 responses by s23chang

Totally agreed with Steve.

RM-4 is the best head amp I've came across and it is still in my current setup. I only bought it because I had Roger modified one of the tube amp for me and recognized his good work. I then bought the RM-5 preamp and the phono section realized the phono section was really good ( much better than the line stage to match my system.)

I've used both the Counterpoint and Audio Reseach and neither came close to what Music Reference RM-4 offered.
I've tested the stock RM-4 with Arc SP-8, SP-11 MK II, Counterpoint 5000 and H.K. Citation I MM sections to mate with RM-4. They all worked out well with my VDH Black Beauty Cartridge.

Not only it is quieter and smoother sounding, it also has much better dynamic than both ARC and Counterpoint.
The ARC and Counterpoint has too much hiss when compared to RM-4. I've compared to many good step up transformers and I still prefer the RM-4.

You'll be surprised vintage stock HK Citation I phono section for MM is better than ARC SP-8, SP-10, SP-11, counterpoint SA5000, Lehman Black cube and etc.. Compared them in many setups and this preamp really sound better than the most. The line stage needs upgrade to better resistors (Carbon was a little bit soft and lack of focus than metal film type) and power supply caps then it will be as good or better than the most of the modern line stage. I wish Stewart Hegeman had design more of these timeless tube gears other than two amps ( Lafayette KT-550 and HK Citation II ) and this preamp.
The V-cap oil caps were not as preferred as the dynamicap by some reviewer on AA. He gave V-cap TFTFs 2 thumbs up. However, Teflon version doesn't come in 5 uf size from Chris's website. It will probably be surper expensive to make a teflon version that size.
Steve,
I wonder if you loose the warmness after replaced the original caps with Dynamicaps.
Hi Steve, thx for your reply.
Yes. Both the RM-4 and the Counterpoint SA-2 I have are the yellow Rel-Caps. Exactly like what you described.
Rm-4 had additional by-pass cap to enhance or clean up high frequency response.
I guess the SS power supply is quicker and more dynamic than the tube version in SA-2.
I have the SP-11 MK II and I also tried to test the RM-4 for the MC cartridge. The gain is too high that it doesn't work well with SP-11 unless you use super low output cartridge like .2mV. Make sure you have subsonic filter turn on when you use a lot of gain.