As a preface, l hope this long and wordy post will help address questions of differences between two of PS Audio’s top tier amplifiers.
A recent problem required my BHK250 to be returned to PSA for repair. I had tired of wrestling with the BHK’s weight and bulkiness and was looking at lighter, more energy efficient alternatives. I decided to try the M1200 mono amps while the BHK was being repaired.
A limitation of component reviews is that components don’t function as singular entities, they are evaluated in a system context and system interactions alter the way a component sounds to greater or lesser degrees. As I am not a professional reviewer, my review will be somewhat limited in that I didn’t use the PSA amps with multiple speakers. My system is comprised of Tidal Piano Cera speakers, PS Audio BHK preamp ( I also used a DeHavilland UltraVerve,) PSA Stellar P3 conditioner for the front end, Luxman D-08u sacd player, Acoustic Signature Final Tool turntable with AudioMods tonearm, Transfiguration Axia S cartridge, RCM Sensor phono stage, two REL SHO/3 subwoofers, and a variety of cables and footers (details to follow.)
As Stu McCreary noted in his Positive-Feedback review, I also noted a depressed upper bass/lower midrange during initial listening. This “scooped” tonal character largely disappeared after the initial 150 hours. However, even after that largely resolved, the amps still exaggerated harsh overtones of certain instruments and voices and caused listening fatigue. After around 250 hours, I was about ready to throw in the towel and return the amps when further changes in the amplifier’s sound occurred. The change was so dramatic I questioned my hearing and initially wondered if I was just becoming acclimatized to the different sound. Returning to listen to my second system reestablished a familiar baseline that assured me the changes in the sound of M1200s were real. Recordings I previously couldn’t stand to listen to for more than a few minutes were no longer nearly as grating and harsh. Still, compared to the BHK250, the M1200s were more forward sounding and prone to causing long term listening fatigue with less than perfect recordings. Much experimentation with interconnects, power cords, speaker cables, and footers eventually resolved those issues.
As I listened during the break in period, I listened for the minor deficiencies in upper piano register reproduction that Michael Fremer noted in his Stereophile review. As Fremer’s Wilson Alex speakers cost four times what my Tidal speakers cost, I’m sure there are some differences in resolution. That said, I only heard a hint of the “parasitic halo” he mentioned when the piano’s upper register was played forcefully. The stock Psavane tubes seemed responsible because I never heard that again after replacing them. I generally agree with Fremer’s evaluation with one exception. His “C” grade for micro-dynamic delicacy isn’t the case in my system after all the system tuning I did with cables and footers. After system tuning, I find the M1200s only slightly less resolving of micro-details than the $30,000 or more amplifiers I’ve listened to.
Initially, I felt the M1200s were less resolving than my BHK250. I realized I wasn’t making an apples to apples comparison because I used Stillpoints SS feet under the BHK and I hadn’t done that with the M1200s. Once the Stillpoints were inserted under the M1200s, they increased low level resolution and provided all the other benefits one expects from them. Stillpoints usually shift tonal balance towards the treble along with the other increases in performance parameters. Turning the small rotating ends of the Stillpoints down instead of up corrected that shift with the M1200s. After six weeks of daily use and finding the right ancillaries, I find the M1200s at least as, if not more resolving than the BHK250, albeit with a bit different character.
The M1200 is definitely more revealing of changes in downstream components, tubes, and cabling than the BHK. After trying a number of tubes, 1960’s Raytheon black plate 12au7s are sounding perfectly balanced. Cardas Golden Presence speaker cables sounded too bright and Western Electric 10gauge was too soft, syrupy, and lacked tonal sophistication. Furutech Fa-As22 was a perfect link between the BHK and the M1200s. While they were too smooth and laid back linking the BHK preamp and BHK250, they went a very long way towards taming the over exuberant treble of the M1200.
At that point the M1200s were really closing the gap with the listening pleasure I experienced with the BHK250. They still lacked that last bit of relaxed character that made long term listening to the BHK so pleasurable. Seeing that Furutech speaker cable and interconnects proved to be so compatible, I ordered a pair of used Furutech Piezo Powerflux cables from UsedCable.com. With all Furutech cabling in place, the M1200s shed every bit of the treble exaggeration I and other reviewers heard. While some might question the value and wisdom of pairing power cables that retailed for 90% of the cost of the amplifiers, they definitely elevated the amps to a much higher performance plane. While the previous PS Audio AC12s were excellent providing power to the M1200s, the Furutech cables were on a higher level of tonal sophistication.
One spends similar money for the BHK250 and the M1200s and one might rightly ask which is the better amplification? Each has its strong points.
There is a difference in listening perspective. The BHK has a more distant rendering of a recording’s soundscape. The M1200’s are more immediate with a closer perspective. The usual reviewer’s trope of “moving several rows closer in the auditorium” applies here.
The M1200s have greater macro-dynamic expression and better bass reproduction and authority with my speakers. The M1200s are the first amplification I have heard with my Tidal speakers that produced sufficient bass to even consider forgoing the use of subwoofers.
The M1200s render recording micro-details with greater accuracy of instrumental timbre differentiation than the BHK does. The BHK reproduces those same passages in an equally satisfying but less surgically revealing manner.
The BHK ranks a little higher if one values a relaxed and “musical” presentation as a primary attribute. The M1200s allow more insight into the particulars of how a recording was made. Differences in recording technology and venue are more apparent.
In the end I think it’s debatable as to which is the “better” amp. I suspect the BHK250 is much easier to drop into a greater variety of systems without much tweaking and immediately achieve owner satisfaction. The M1200s strike me as needing much more tweaking and tuning to hit the perfect sonic sweet spot.
In my case, I’m keeping the M1200s and moving on from the BHK250.