Bryston 4B3 or Ps Audio M700 monoblock?


I'd like to replace my 20 year old Bryston 4B SST with a new amplifier, solid state or hybrid. I have been considering the 4B3 and the PS Audio BHK 250. Both got great reviews but I am a bit concerned about the midrange withe the 4B3 and I do not like the amount of heat that the BHK 250 is  reported to produce. I am thinking now of the PS Audio M700. These are efficient class D and do not produce much heat. The M700 has also been reviewed favorably. It's a stereophyle class A.
I appreciate any thoughts on this, an din particular if you have experience with these amps.
benjosef1
beeswax, thanks for the comments.  It's a deal killer though to not read CDRs as that's what I already have a lot of and will be recording more of on the old Harmon Kardon CDR20. 

I'm actually falling deeply in love with the Rega Planet 2000 that I bought on here including a killer remote (the Solar) for all of 195 including shipping.  I think it sounds great to my ears.  I've never had CDs sound so "analog".  The top end is killer without that harshness, the soundstage is to eat off of, the bass is top notch, and zero listening fatigue. 
gammonit_2000:
"noble 100 I haven’t, I need power and low impedance capability. I went from 300 watts to 600 watts a channel. These Infinity Kappa 8s need lots of juice down to literally under an ohm. Am I missing something in the Class D department?"


Hello gammonit,

     Are you missing something in the class D department? As a matter of fact, I believe there are a pair of mono-block class D amps that may perform extremely well with your notoriously difficult to drive Kappa 8s.
     They're the original D-Sonic M2-1500-M2 class D monos that were reviewed very favorably on this 6 Moons review back in 2012. In the review these amps were auditioned on the Apogee Duetta planar-magnetic speakers, which I believe also present speaker loads to the amps of down to literally under an ohm, with very good results. D-Sonic claims stability into below 2 ohm loads but apparently they're stiil stable even lower.
These amps are rated at 1,500 watts into an 8 ohm load, 2,400 into 4, deliver 160V and 30A and were priced new at $1,075 each at the time. Here’s a link to that review:

https://6moons.com/audioreviews/dsonic/4.html

     Yes, this is from 7 years ago but I was thinking you could probably purchase a used pair currently for a reduced price if any owners are selling.
     Or, you could try out a new pair of their current version, the M3a-1500M that uses the latest Pascal class D power modules for $1,375 each, $2,750/pair. These have the same power output and the very low speaker impedance load capacity as the M2 series but now have a bit more neutral overall sound quality and several added internal monitoring safety features. Here’s a link to the new D-Sonic monoblock amps:

https://www.d-sonic.com/products/m3a-1500m-mono-amplifier-per-channel.html

     I’m not sure which amp or amps you’re currently using on your Kappa 8s. However, I’d venture to guess they’re good quality but large, heavy, expensive, hot running requiring large heatsinks, inefficient class AB amps that currently perform and sound sufficiently good to you that you’re not actively searching for replacement amps right now.
     I’m fairly certain that, if you paid less than $50,000 for your current amp(s), either a used or new pair of the top of the line mono D-Sonic amps will outperform them by a significant margin in sound quality while also being much smaller, lighter, more affordable, cooler running and consuming a fraction of the electricity. I believe that’s what you’re missing in the class D department.


Tim
Running big inefficient Bryston 7BSST2.  Paid 4300 for two of them 10 years old.  Smaller and lighter doesn't do much until I need to move them.  Also just curious about shielding reqts for Class D?  Seems I was reading something about that aspect.  Obviously this is new to me on the Class D thing.  Anyway thanks for your comments and I will try to check out one of these units next time in the "big city"...
Hello gammonit_2000,

     I know your Brystons are nice amps but I know a good class D pair of monoblocks will also at a minimum match them on sound quality and pay for itself fairly quickly just on all the electricity you'd save, even if you left them on 24/7.
     Yes, rf interference can be an issue if the power modules aren't properly shielded internally.  But virtually all the good quality class D amps are properly shielded and you shouldn't have any issues. I have three, a Class D Audio SDA-440-CS and Emerald Physics EA-100.2SE stereo amps and a pair of D-Sonic M3-600-M mono-blocks, and I've never had any interference issues.  There's no special shielding requirements you need to take except buying a good quality amp from a good company.
     The problem is finding an audio shop to audition one.  Most class D amp companies sell internet direct to keep prices low.  But you can usually purchase the amp and get about 30 days to try it out at home in your system.  If you like it, you just keep it.  If you don't, you just send it back and get a full refund, no questions asked.
     Just an fyi, these amps are very neutral and revealing, like the audio ideal of 'a straight wire with gain'.  If upstream components and recordings are not high quality, it'll be easily noticed since there's no flavoring or coloring going on, nothing's added or subtracted from the inputted signals.  On the plus side you'll easily notice the effects of system changes, even power cord and cabling changes.
     I sincerely believe you'd be pleasantry surprised by the hi-end performance level of the numerous good class D amps currently available at relative bargain prices.


Tim
  
   
Thanks Tim,
I appreciate your input (so to speak).  I do like the "straight wire with gain" ala a CJ PV10B design for example.  I won't bash Class D again unless I actually hear one.
Karl