Class D Purifi Eigentakt / Mark Levinson 333 / Benchmark AHB2 - Listening & Conclusion

I have these 3 amplifiers and am curious how they compare in my environment.

Equipment setup:

CD/SACD player: Oppo BD105
Stereophile’s Test CD2 , Track 15 pink noise, , for level matching the three amplifiers​Volume set 72dBC on track 15 before playing songs B - F​Volume set to 82dBC on track 15 before playing songs G-H​​Standard Music :​
  • B - SACD Norah Jones, Come away with me
  • C -SACD Andrea Bocelli, Melodramma
  • D -SACD Dire Straits, Walk of Life
  • E -SACD Pink Flyod, Time
  • F -CD Ultimate Demonstration Disc: Chesky Records’ Guide to Critical Listening, Track 3 Spanish Harlem
Life Classical Recording Music:​
  • G - SACD Telarc Tchaikovsky 1812 overture, Track 7 Cossack Dance from Mazeppa
  • H -SACD Telarc , Donald Runnicles , ORFF Carmina Burana , track 10 were diu werlt alle min
Blu-Ray Movies:​
  • I -John Williams Live in Vienna, Track 19 Imperial March , watching in 2ch mode
  • J -Patriot, Uncompressed LPCM Audio track, Scene 6
Apple TV 4k:
    1. Streaming Apple music (various pop songs Taylor Swift, Marron 5, etc)
    2. YouTube podcast (for center channel compare)
    3. HBO Max Movies (for center channel compare)

Pre-Pro Anthem AVM50v, XLR audio input from oppo.
802D3 Speakers (Front) , HTM1D3 (Center) , old DM640i (Surround back)
Amplifiers under test:
  1. Mark Levinson No 333
  2. Benchmark AHB2
  3. VTV Purifi Eigentakt EVAL-1

Listening Impression (Stereo 2ch mode):
  • For songs B-F , level match volume based on Track 15 pink noise (A1 above) , resulting in typical music volume swings around 80dB-86dB. They all sound good. The Benchmark and Levinson sounds very similar in tonal balance, my son (blind test) could not tell them apart. The Benchmark AHB2 sounds very clean on E) Time , the ring sounds the clearest. On v vocal on AHB2 sounds a little bit less weight (Andrea Bocelli voice sounds less vibrato) compare to others. Levinson sounds very similar to AHB2 but the vocal is is more full and the bass has more weight. The Class D Purifi Eigentakt tonal balance has stronger mid-bass/low midrange so the vocal sounds more forward and closer but the upper treble is rolled off. The sound of cymbals are not as clear and not as distinct compare to levinson 333 or benchmark. AHB2.
  • For songs G-I, volume knob has to increase by 10dB (A2 above) to compensate for the recording sound level. The Class D Purifi Eigentakt sounds compressed (lack impact), at loud level, the sounds of each instruments are not as delineated, and the high frequency triangle and cymbals are not very clear in comparison to benchmark AHB2 or levinson 333. Both levinson 333 and benchmark AHB2 sounds very similar, but when the dynamic sound peak at 94dB, the 333 sounds more at ease and each individual instruments details are more distinct (more details of cello vibration and triangle resonance) than the AHB2.
  • It is hard to tell apart AHB2 vs 333 but easy to identify the Class D Purifi once we have heard all three on the same or specific songs. The Class D Purifi has rolled off treble and forward midrange that is its strong signature (by comparison, it sounds neutral/normal on its own when there is nothing to compare). This roll off treble reminds me on my previous Krell KSA-200s sonic signature.
  • The life recording song G-H has very wide dynamic (55dB – 94dB swing). Since my son played at the orchestra, I know what orchestra sounds like sitting in front rows. In my observation, to reproduce this life-like sounds of life orchestra is probably the most demanding for high resolution speakers and amplifiers. When playing loud level , songs G-I , the old Levinson still sounds the best.
  • When playing loud dynamic music song G-I, we heard changes in Class D Purifi tonal balance, the peak sounds certain instruments are level off compare to AHB2 or 333. Could the Class D PWM sampling be manipulated so the peak musical waveform dynamic is lost to bias for more midrange clarity ? Or is there soft clip mode where certain peak music waveform is “clipped” so they sound “compressed” . I don’t know but what we heard is a more compressed dynamic relative to AHB2 or 333 on song G-I.

Listening impression (Movie, using it to drive center channel)
  • Playing with K-M, AHB2 (mono bridge mode) and 333 sounds the same.
  • Playing with K-M, even level matching with AVM50v built-in level calibration (per SPL meter), the dialogue still sounds louder with the Class D Purifi. It correlates with our stereo experience where purify midrange is more forward sounding but less treble.
  • This Class D Purifi amp is good match for center channel or a PA system, it accentuates midrange voice (in comparison, sounds "neutral"/normal when listening to it without any comparison). So the dialog is more clear (e.g. comparison on streaming podcast from apple TV).
  • Try watching the Blu-ray Patriot movie Scene 6; It has both uncompressed 5.1 PCM and standard Dolby Digital 5.1. The dialogue on Dolby Digital 5.1 is more clear due to compression (special effects, music, weapons sounds are compressed) . However, if one has dedicated room , speakers and amps, one would want to watch it in uncompressed PCM for more immersive and open sound.

My personal conclusion:
  1. Class D amplifiers have improved a lot of the years but Class D Amps are still no match to good design Class AB term of sound quality and dynamic handling
  2. Benchmark AHB2 is more versatile (good for all music) and more dynamic than the Class D Purifi Eigentakt
  3. Class D Purifi Eigentakt is suitable for center channel, its slight compression and unnatural bias toward midrange makes dialogue more clear It is not an ideal amp for life classical music reproduction.
  4. Mark Levinson 333 is the best despite its old age. It is the most life-like, with more weight on vocal , and more at ease when playing life recording classical orchestra at higher volume level
  5. There needs to additional scientific measurements that can explain why the benchmark AHB2 sounds better than Purifi Eigentakt in my environment and why the Levinson sounds more dynamic and detailed on loud classical music. Traditional SINAD, THD , IMD measurement using sinewave do not have the musical waverform complexity and can not explain the contrast of what we heard among these amplifiers in our environment. What we heard can not be explained with just THD measurement as they all sound good (not distorted) but different. As below certain THD, the delta is not audible.

Ag insider logo xs@2xasin
Great info. I was thinking of getting the VTV and getting it modded by tweakaudio. 

If you used 2 AHB2's in mono the dynamic aspect of the AHB2 would likely be closer to the ML. Your speakers seem perfectly suited for the AHB2 in mono.

Great A/B/C subjective review of the three amps, would have I believe been my choice.
50-150hz that’s where the 802’s nasties lay, low EPDR, (low impedance with high negative phase angle), "should?" have suited the ML333 and ABH2 better as well.

Your speakers seem perfectly suited for the AHB2 in mono.
Not in the bass I believe, as the 802's EPDR impedance is too low for a bridged amp.

Cheers George
Not in the bass I believe, as the 802's EPDR impedance is too low for a bridged amp.
You are correct if that graph indicates a lot of 2 Ohm action. Then the single AHB2 in stereo is better. I speak from experience with Thiel CS3.7 and AHB2's.

Nevertheless the AHB2 is my favorite amp. Just love that clear smooth sound
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Thanks for taking time to both do the comparison and detail it here!
You seem to be drawing a lot of conclusions about the Purifi module from the absolute cheapest implementation.  There are many Purifi implementations that have a much better power supply and much better input buffer that are admittedly more expensive, but then so are the amps you are comparing. 

I have been pretty impressed with the Purifi modules in my own DIY amp. It doesn't quite match my Pass XA60.8s but holds it's own very well with less expensive class A/B amps including the Parasound JC5 that I owned for a while. 

I haven't directly compared my Purifi amps to the other amps you have, but I used to own the ML 333 and I think a good Purifi implementation could easily give it a run for it's money, and would likely surpass it in many areas (IMHO).  Of course, it all depends on system synergy. 
Nice write up. 
I have not heard these exact amps but your thoughts align with mine having owned A/B, class D, and benchmark equipment in the past. I currently am using big power AB and don’t see myself changing for a long time.