B2 vs MX2000
I couple of posts ago there has been some discussion of the best sounding Yamaha amp. I’m not going to go there and proclaim something ‘best’, however, I made some changes in my system recently and have a perspective to share. First the system; tri-amped - cdx2020, cx2000, modified Marchand XM9 4th order xover (263hz, 63hz), B2’s and MX2000 feeding Altec 311-90’x/902A, Altec 416A’s in 835 cabinet, and 2 JBL SUB1500’s in an Altec 820 cabinet. (other components –PX3, KX1200, TX100, RT-707, 5kva balanced power + .5kva balanced power for cdx). I just added FRED’s to my three B2’s and wanted to listen to them awhile. Normally I use 2 B2’s for the highs and lower mids and the MX2000 for the JBL sub1500 subwoofers, but in order to listen to all three B2’s, I hooked the 3rd one up as the subwoofer amp. As the sub1500’s are not terribly efficient and the B2 only puts out 140 RMS WPC versus the MX2000’s 180 RMS WPC, I thought the B2 would be a little wimpy. To my surprise it was actually very powerful and much more musical than the MX2000, instead of a ‘thump’ I got a ‘thumm’ --- a warmer, rounder, fuller, controlled, musical bass that was reminiscent of the JBL 2226J’s I had used previously as subwoofers (I know they aren’t subs but tuned properly they produce deep musical bass although they don’t go really as low as the sub1500’s). In fact purchased the sub1500’s on hype, specs and reviews without ever listening to them. Once I did I was disappointed and it was too late as the 2226’s were sold. Now I’m quite happy with the sub1500’s and in fact I believe they are as musical as the 2226’s and certainly go lower. (the 2226’s don’t make Captain Kirk’s Enterprise sound as good as the sub1500’s either). Why do the sub1500’s now sound better? I keep getting back to what I’ve stated in earlier posts…power supply. The MX2000 has only 1 power transformer and 20,000mfd/channel of storage while the B2 has 2 power supply transformers and 36,000mfd/channel of storage. Of course the B2’s have the FRED’s and the PS caps are bypassed with polycarbonate caps and the MX2000 is untouched stock Yamaha. I think the power supply is the biggest difference in determining ‘warm’ sounding amps has been the power supply …. Generally the bigger the better it sounded. Another difference is the damping factor … the MX2000 has a damping factor of 1000 while the B2 has a measly 70. I’m not sure how this comes into play perhaps someone has an idea. Meanwhile the B2 is going to be the subwoofer amp.
It sounds pretty good, and is a nice visual match for the amp and tuner. I finally got my TC-1000 repaired recently, which is the TOTL cassette deck for this same vinatage as the TC-520.
