Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread - Home Theater Forum and Systems - HomeTheaterShack.com

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post #1 of 250 Old 03-13-15, 04:53 PM Thread Starter
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Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

This thread is a continuation of the High-End Amplifier Evaluation Event Preparations Thread previously under way.

The event has begun. Coming to you from southern Alabama, the Home Theater Shack Evaluation Team has assembled at Sonnie Parker's Cedar Creek Cinema for the 2015 High-End Amplifier Evaluation Event. We have amps, we have speakers, we have tunes, we have great eats, what more could one ask for?

Be reminded of the first law of audio evaluation event execution. They never go exactly as planned. Not everything gets there, not everything works, but you endeavor to persevere and get things done.

We have deal with speakers not able to reach us in time, with cabling issues, with equipment not interfacing properly, a laptop crash, with hums and buzzes and clicks and pops, with procedural questions - - - yet we forge ahead, adapt, evolve, redirect, and forge ahead some more - - - and the task of evaluating amplifiers is underway.

Speakers: We were unable to get the Chane A5rx-c and the Acoustic Zen Crescendo Mk II speaker pairs. We are running the Spatial Hologram M1 Turbo v2 and the Martin Logan ESL. Both are very revealing speakers, baring a lot of inner detail in our recordings. They will serve us well. The A5rx-c will be reviewed for HTS when available.

At the moment, the Holograms are serving as our primary evaluation tool. I will post setup details and interesting discoveries a little later. They are giving us a monstrous soundstage, the kind that eats small animals for breakfast, with extremely sharp imaging and very good depth acuity. They are extremely clear, getting into the realm of rivaling electrostatic transparency. Their in-room response is very good, with some expected peaks and dips, but still very listenable. The high frequency response is extended and smooth. The bass gives you that "Are you sure the subs are not on?" feeling on deeper tracks.

We decided to start with sighted comparisons and open discussion today, and blind tests tomorrow. The Audyssey XT32 / Dirac Live comparison has not been completed yet.

Have we heard differences? Yes, some explainable and some not. One amp pairing yielded differences that several evaluators are convinced they could pick in a blind AB test.

One thing I have learned for sure: The perfect complement to good southern barbeque is a proper peach cobbler. Add great company and you have a perfect get-together.

The Event
  • Date: Thursday evening, March 12th through Saturday evening, March 14th.
  • Place: Cedar Creek Cinema, Alabama, hosted by Sonnie, Angie, and Gracie Parker.
  • Evaluation Panel: Joe Alexander (ALMFamily), Leonard Caillouet (lcaillo), Dennis Young (Tesseract), Sonnie Parker (Sonnie), Wayne Myers (AudiocRaver).

The Amplifiers
  • Behringer EP2500
  • Denon X5200 AVR
  • Emotiva XPA-2
  • Exposure 2010S
  • Krell Duo 175
  • Mark Levinson 532H
  • Parasound HALO A31
  • Pass Labs X250.5
  • Sunfire TGA-7401
  • Van Alstine Fet Valve 400R
  • Wyred 4 Sound ST-500 MK II
The Speakers
  • Spatial Hologram M1 Turbo v2, courtesy Clayton Shaw, Spatial Audio
  • Martin Logan ESL
Other key equipment special for the event:
  • Van Alstine ABX Switch Box, recently updated version (February 2015)
  • miniDSP nanoAVR DL, courtesy Tony Rouget, miniDSP
  • OPPO BDP-105

As mentioned, our deepest appreciation goes to Sonnie, Angie, and Gracie Parker, our hosts, for welcoming us into their home. Look up Southern Hospitality in your dictionary, and they are (or should be) listed as prime role models thereof.

This first posting will be updated with more info and results, so check back from time to time.

Amplifier Observations
These are the observations from our notes regarding what we heard that were supported by being consistent between sighted and blind testing and across reviewers. While we failed to identify the amps in ABX testing, the raw observations from the blind comparisons did correlate in some cases to the sighted observations and with the observations of other reviewers. Take these reports for what they are, very subjective assessments and impressions which may or may not be accurate.

Denon X5200 AVR

Compared to other amps, several observations were consistent. The Denon had somewhat higher sibilance, was a bit brighter, and while it had plenty of bass it was noted several times to lack definition found in other amps. At high levels, it did seem to strain a bit more than the other amps, which is expected for an AVR compared to some of the much larger amps. Several times it was noted by multiple reviewers that it had very good detail and presence, as well as revealing ambiance in the recordings.

We actually listened to the Denon more than any other amp, as it was in four of the blind comparisons. It was not reliably identified in general, so one could argue that it held its own quite well, compared to even the most expensive amps. The observations from the blind comparisons that had some common elements either between blind and sighted comparisons or between observers are below. The extra presence and slight lack of bass definition seem to be consistent observations of the Denon AVR, but everyone agreed that the differences were not a definitive advantage to any one amp that would lead us to not want to own or listen to another, so I think we can conclude that the Denon held its own and was a worthy amp to consider.

Compared to Behringer
- bass on Denon had more impact than Behr, vocals sounded muted on Behr
- vocals sounded muted on ML compared to Denon
- Denon: crisp highs preferred compared to Behringer which is silky.
- Denon is more present, forward in mids and highs than Behringer.

Compared to Mark Levinson
- Denon seemed to lack low end punch compared to ML.
- Denon is smooth, a certain PUSH in the bass notes, cellos & violins sounded distant, hi-hat stood out, distant vocal echo stood out, compared to ML.
- Denon bass seemed muddy compared to ML which is tighter.
- ML more distant strings than Denon.
- Denon is slightly mushy and fat in bass. String bass more defined on ML.
- ML seems recessed compared to Denon.

Compared to Pass
- vocals sounded muffled on Pass compared to Denon
- crisp bass on Denon compared to Pass
- Denon & Pass both even, accurate, transparent, natural, no difference, like both
- Pass seems soft on vocals but very close.
- Denon has a bit more punch on bottom, maybe not as much very deep bass, more mid bass.

Compared to Van Alstine
- bass on Chant track was crisp for VA while Denon was slightly sloppy
- sibilance not as pronounced on VA as it was on Denon
- VA super clarity & precision, detailed, space around strings, around everything compared to Denon which is not as clear, liked VA better.
- sibilanceon Denon, VA has less “air” but more listenable, both very good
- Very deep bass more defined on VA, overall more bass on Denon.

Wyred 4 Sound ST-500 MK II

In the sighted listening we compared the ST-500 MK II to the Van Alstine Fet Valve 400R. The assessments varied but were generally closer to no difference. The Van Alstine got comments of being fatter on the bottom. The Wyred 4 Sound was noted to have slightly better bass definition but apparently less impact there, and slightly less detail in the extreme highs. Most comments about the midrange were not much, if any difference. An interesting observation here was by Wayne, noting that he did not think he would be able to tell the difference in a blind comparison. Considering the ST-500 MK II is an ICE design and the Fet Valve 400R is a hybrid, we expected this to be one of the comparisons that would yield differences if any. As I am always concerned about expectation bias, this was one that I was particularly concerned with. Van Alstine is a personal favorite for a couple of us so I expected a clear preference for it to be present in the sighted comparison. I felt that the Wyred 4 Sound amp help its own with the much more expensive and likely to be favored VA.

In the blind comparisons, we compared the ST-500 MK II to the Emotiva XPA-2 and the Sunfire TGA-7401 in two separate sessions. Of course, in these sessions we had no idea what we were listening to until after all the listening was done. In the comparison to the Emotiva, some notes revealed not much difference and that these were two of the best sounding amps yet. The ST-500 MK II was noted to have the best midrange yet, along with the Emotiva. It was described as having less sibilance than both the Emotiva and Sunfire. Both the Emotiva and the ST-500 MK II were described as unstrained in terms of dynamics. In comparison to the Emotiva it was noted to have solid highs, lively dynamics, rich string tones, and punch in the bass. The overall preference in comparison to the Emo was either no difference to preferring the W4S.

In comparison to the Sunfire, comments ranged from preference for the W4S to not much difference to preference for the Sunfire. The Sunfire was described as having more presence in the midrange, while the Wyred was noted to be shrill, lifeless, and hollow by comparison.

These comments varied a lot, but the points of convergence were generally around the similarities to three amps that would be expected to be most likely to be different, if we found any differences at all. The objective results is that we failed to identify the amp in ABX comparisons to two other much more expensive amplifiers. I would have to conclude that based on the results, the ST-500 MK II represents one of the best values and certainly should satisfy most listeners.

Audyssey XT32 vs. Dirac Live Listening Comparison

Last year HTS published a review of a the miniDSP DDRC-22D, a two-channel Dirac Live Digital Room Correction (DRC) product. The review included a comparison to Audyssey XT. A number of readers requested a comparison of Dirac Live with Audyssey XT32. That comparison was recently completed during the Home Theater Shack High-End Amplifier Evaluation Event at Sonnie Parker's Cedar Creek Cinema in rural Alabama. This report provides the results of that comparison.

Go to the Audyssey XT32 vs. Dirac Live Listening Comparison Report and Discussion Thread.

Spatial Hologram M1 Turbo Speakers

I was very pleased with the Spatial Hologram M1 speakers we used for the amplifier evaluation, and felt that they more than fulfilled our needs. They did not become "gotta have them" items for any of the evaluators, although I had thoughts in that direction once or twice. But they were speakers we could easily ignore through the weekend. I mean this as a high complement. Never did an evaluator complain that the M1 speakers were "in the way" or "holding us back," and we were able to focus on the task at hand unhindered. That alone means a lot, and may say more about them than the rest of the review just completed.

Here is what they did for us:
  • Because of their high efficiency, amplifiers were not straining to deliver the volumes we called for. We could be confident that the amps were operating in their linear ranges and that if we heard a difference it was not due to an amp being overdriven.
  • The stretched-out soundstage opened up a lot of useful detail for us to consider in our evaluations. In discussing the soundstage at one point, there was a consensus that it might be stretched a little too far and might be "coming apart at the seams," showing some gaps, although this did not hinder our progress. My final assessment is that this was not the case, all due respect to the fine ears of the other evaluators. I elaborate on this point in the M1 Review.
  • They served well as a full-range all-passive speaker, able to reach deep and deliver 40 Hz frequencies with lots of clean "oomph," all without the need for DSP boosting and without subwoofer support.
I thoroughly enjoyed spending time with them, and wish to again thank Clayton Shaw of Spatial Audio for loaning them to us. A complete review of the M1 speakers has been posted.

Go to the Spatial Hologram M1 Turbo Version 2 Speaker Review.

A Soundstage Enhancement Experience

Sonnie's MartinLogan ESL hybrid electrostatics were set up very nicely when we arrived, so we avoided moving them through the weekend. There were some improvements made to the soundstage and imaging by way of treatments, and some interesting twists and turns along the way which turned out to be very informative.

I have documented the exercise in a separate post.

Go to the Soundstage Enhancement Experience thread.
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post #2 of 250 Old 03-13-15, 07:26 PM
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Thanks, Wayne, for starting the thread so nicely and for all of your work, both technically and writing.

Another amazing weekend with an awesome group!

This set of reviews is sure to generate lots of questions and debate. Like the first speaker event, everyone needs to understand that we are not attempting to provide the answers to the perpetual great debates nor tell anyone what they should own. We are taking a journey down a path that interests us and asking questions that are meaningful to US in the context of how we enjoy music. Each of us has our preferences, beliefs, biases, and likes. We try to be open about what those are and, while we go to great lengths to set those aside and learn something, we don't apologize for who we and what we believe and like. We have no intention of competing with anyone nor offending anyone and have no agenda but to learn and play.

I try to make it clear where I start in terms of assumptions, expectations, beliefs, and experience. I am at heart an experimenter and look for explanations for everything. I also like to set aside all of the technical stuff and my attempt to understand the why and just experience the joy of people creating and performing great music. So you get two very different pictures if I am successful at communicating my experiences in these sessions. First, the more objective attempt to understand the performance of the equipment. Second, you will hear me speak completely subjectively about what I feel when listening. For me both are essential but I know that the former will never satisfy me, while the latter does. Ironically, I believe that the latter also yields some of my best assessments of the equipment. That will make the objectivists crazy, but as I said above, I don't do for anyone's approval.

I come to this weekend believing that we will likely be able to hear differences between amps, but far fewer than most audiophiles would report. I think we will find more differences in open comparisons than we can validate with blind testing. I believe that blind testing makes it very difficult to confirm differences but at the same time the characteristics of amplifiers that are reported by many reviewers are far exaggerated and unrealistic. I come with assumptions that some of the amps are better sounding by a slight margin but I don't expect that I know which ones they are. I came expecting more out of the Pass and Krell than others, but just based on prior listening to other products from those companies and my appreciation for the designers.

We will see what happens...the first day of listening has been interesting, with some differences noted in sighted listening and no differences in some comparisons. We'll see tomorrow how those observations hold up to blind tests.

Looking for me, just google my username. I have used the same one for most sites for many years.
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post #3 of 250 Old 03-13-15, 09:10 PM Thread Starter
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Re: Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Those steaks we had tonight at Preston's in Luverne, Alabama were epic. My ribeye was one of the best steaks I have ever eaten. Yes, that was a shameless plug.
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post #4 of 250 Old 03-13-15, 09:44 PM
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Re: Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Taste of Texas... Come to Houston and stop there. Just sayin'

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post #5 of 250 Old 03-13-15, 09:50 PM
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Re: Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Home Theater Shack 2015 High-End Steak Evaluation Event Reporting and Discussion Thread

There, I fixed it
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post #6 of 250 Old 03-13-15, 09:51 PM
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Re: Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Talley wrote: View Post
Taste of Texas... Come to Houston and stop there. Just sayin'
Yes - a must if you visit Houston.
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post #7 of 250 Old 03-13-15, 10:11 PM
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Re: Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Peter Loeser wrote: View Post
Home Theater Shack 2015 High-End Steak Evaluation Event Reporting and Discussion Thread

There, I fixed it

Gotta love that!

Home theater:
Onkyo 805, Yamaha YDP2006EQ, Samson Servo 600 amp
3 EV Sentry 500 monitors across the front, 4 Mission 762i's Surrounds, SVS PB13U sub, Panasonic BDT220, Harmony 1100, Nintendo WiiU
Panasonic PT-AE8000 on a 120" 2,35:1 fixed screen

Living room system:
Sherwood/Newcastle R972, Mission 765's, SVS SBS02's, A/D/S MS3u sub, Yamaha YDG2030EQ
Yamaha KX-393 Tape deck, CDC 805 CD changer, Panasonic BD60, Sony turntable PS-T20
Panasonic TC-P50ST60, HD-PVR & WDTV Live, Harmony 900

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post #8 of 250 Old 03-13-15, 10:15 PM
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Peter is on point today!
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post #9 of 250 Old 03-13-15, 10:31 PM Thread Starter
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Re: Home Theater Shack 2015 High-End Amplifier Evaluation Event Reporting and Discussion Thread

Peter Loeser wrote: View Post
Yes - a must if you visit Houston.
Taking notes...
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post #10 of 250 Old 03-13-15, 10:45 PM
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AudiocRaver wrote: View Post
Taking notes...
If you were to come to KC the list is long…
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