Review: Benchmark AHB2 Amp
Comments
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pearsall001 wrote: ยปI'm finding it amazing how the absence of noise in the system can really open things up to a sonic level that you didn't know existed. You're so used to noise without even knowing it until it's not there.
Where have I heard that before?
Tom
Yes indeed!!! The Snubway that you recommended was a definite step in the right direction of getting rid of as much noise as possible.
Thank you Tom for opening up that rabbit hole. Lol!!! -
The Stereophile review of the AHB2 amp is pretty informative:
https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier
I looked into getting one a few years back but they were out of stock so I moved on to something else. The AHB2 has been on the market for around a decade so knowledge of it is out there. My take on it is that the super low noise floor is an intentional design primarily intended for the professional recording industry like all the Benchmark gear is. The low noise is partly because there's no large transformer inside the box and there is carefully placed shielding inside to block interference from the sensitive components instead. A common nit to pick is the AHB2 has little to no character of its own. As the Stereophile reviewer noted that may present an issue if the amp doesn't pair well with the speakers it's driving. It's good to know these things going in because this isn't an inexpensive product. The price to performance of their original DACs was great. -
It is definitely a space saver. Glad you're enjoying the new amplifier!
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The problem is the word "noise" is all encompassing in audio. It's a very generic descriptor. There's probably more going on than just "lack of noise". S/N specs aren't the singular reason you are hearing differences.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
Here's a bit more info about the "Achromatic Audio Amplifier" technology from THX that Benchmark is using. The word achromatic literally means "without color".
https://benchmarkmedia.com/blogs/news-1/137185991-thx-achromatic-audio-amplifier-technology
https://www.thx.com/aaa/
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The problem is the word "noise" is all encompassing in audio. It's a very generic descriptor. There's probably more going on than just "lack of noise". S/N specs aren't the singular reason you are hearing differences.
H9
I believe that was the intention of my post last night. Also, I am reading now that the A21+ doesn't measure as clean as the original Halo A21 that I had for many years. -
Here's a bit more info about the "Achromatic Audio Amplifier" technology from THX that Benchmark is using. The word achromatic literally means "without color".
https://benchmarkmedia.com/blogs/news-1/137185991-thx-achromatic-audio-amplifier-technology
https://www.thx.com/aaa/
The problem is (or can be) we stray too far from what "real" in person music sounds like. If you make the signal so clean and sterile you take away the fundamentals/harmonics that are intended to be there. In real life those fundamentals are part of the sound we hear in person. Music in real time, is not created in a vacuum.
The above statement is an oversimplification, but you get the point.
I could see Achromatic being beneficial for movies.........but I can't pass judgment on a piece of gear I've never heard.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
The biggest red flag for me is when the manufacturer or reviewer states that "a lot of correction to the signal has taken place to make it sound good".
Everyone knows I'm old school, simple circuits, fewest gain stages possible, excellent parts, minimal to no feedback, etc. But that usually entails large power supplies, lots of heat, heavy components, high cost to name the most obvious tradeoffs.
Remember the 70's and 80' and some 90's gear. In order to publish the best specs (in the spec war) they heavily used both forms of negative feedback. It gave great numbers, but the musical signal left a lot to be desired.
The other side of the coin is we all like different things and have certain expectations of our gear. There's lots of different types of gear to choose from.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
Here's a bit more info about the "Achromatic Audio Amplifier" technology from THX that Benchmark is using. The word achromatic literally means "without color".
https://benchmarkmedia.com/blogs/news-1/137185991-thx-achromatic-audio-amplifier-technology
https://www.thx.com/aaa/
The problem is (or can be) we stray too far from what "real" in person music sounds like. If you make the signal so clean and sterile you take away the fundamentals/harmonics that are intended to be there. In real life those fundamentals are part of the sound we hear in person. Music in real time, is not created in a vacuum.
The above statement is an oversimplification, but you get the point.
I could see Achromatic being beneficial for movies.........but I can't pass judgment on a piece of gear I've never heard.
H9
You're assuming an awful lot without ever hearing the AHB2 especially in your own system. Not even close. -
Class A and A/B amps can easily be outclassed by much cheaper and more efficient class D ..
Any of the amps using the Hypex NcX500 modules readily come to mind - dead quiet and gobs of power.
Gotta admit , Iโm impressed with my S300 - class D , and not even state of the art by todayโs standards.
BkPS Audio S300 , WiiM Ultra , Yamaha wxc-50 , Salk SuperCharged Songtowers , Kimber Kable 4TC, Sony 48โ - BEDROOM
B&K EX-442 ( it will go in my casket when I die ... ) , PS Audio 4.6 preamp ( old school , but it still jams on ... ) , Eversolo DMP-A6 , Boston Acoustic voyager 7โs - POOL
Parasound A21, Eversolo DMP-A8 , Kimber Kable 4vs , Ascend Acoustics ELX Ribbon Towers , Sony XBR-A8F 65โ OLED - DEN , MAIN system
Onkyo TX-nr609 , Polk atrium 7 , Boston acoustic sound ware (4) , Boston acoustic sub , B&W center , Sony 65โ TV - PATIO -
pearsall001 wrote: ยปHere's a bit more info about the "Achromatic Audio Amplifier" technology from THX that Benchmark is using. The word achromatic literally means "without color".
https://benchmarkmedia.com/blogs/news-1/137185991-thx-achromatic-audio-amplifier-technology
https://www.thx.com/aaa/
The problem is (or can be) we stray too far from what "real" in person music sounds like. If you make the signal so clean and sterile you take away the fundamentals/harmonics that are intended to be there. In real life those fundamentals are part of the sound we hear in person. Music in real time, is not created in a vacuum.
The above statement is an oversimplification, but you get the point.
I could see Achromatic being beneficial for movies.........but I can't pass judgment on a piece of gear I've never heard.
H9
You're assuming an awful lot without ever hearing the AHB2 especially in your own system. Not even close.
Read my last sentence. I am talking in generalities."Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
Class A and A/B amps can easily be outclassed by much cheaper and more efficient class D ..
Any of the amps using the Hypex NcX500 modules readily come to mind - dead quiet and gobs of power.
Gotta admit , Iโm impressed with my S300 - class D , and not even state of the art by todayโs standards.
Bk
Yeah, ok.....agree to disagree. Unless by chance you be heard every amp out there. Dead quiet and gobs of power really means nothing.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
I find it funny how a member on this forum was saying how great the Benchmark amplifier sounded, then how great a tube amp sounded. If signal to noise was the end all be all, then the Benchmark amplifier should have sounded way better than the tube amplifier, there is more to this than signal to noise ratio.
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Apples and oranges, and "better" is subjective.
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Most people just listen to music and watch movies. I EXPERIENCE them.
โAnger is an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.โ
--Mark Twain.
โIf at first you don't succeed, then skydiving definitely isn't for you.โ - Steven Wright -
He sure is a crazy funny mo fo for sure. He's very big on headphones & their gear. His reviews are always entertaining but pretty much spot on. This review was no exception. -
I initially expounded on the AHB2 a few years ago here:
https://forum.polkaudio.com/discussion/186705/benchmark-ahb2-power-amplifier?utm_source=community-search&utm_medium=organic-search&utm_term=ahb2 I have a new power conditioning component in my chain now, so might need to revisit things, but I doubt my initial findings would change.
If the original master recording of a track has echo (vocals), tube effects (e.g., via guitar amps), or any other vintage sound effects incorporated into the original master, they will be present (in a raw form) when played back through a Benchmark setup...if the listener is attune enough to hear it. Perhaps the assumption by the original recording engineer is that the end-user consumer will have tube amplification in their chain, with an end result that matches the presupposed outcome. The alternative is that the original recording already incorporates the desired harmonic distortion, and a pure undistorted output is the end game coming through.
Perhaps one pertinent question is: are original recordings meant to include desired 'harmonics', or are the harmonics meant to be added after-the-fact with playback gear?"This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon -
A harmonic is a sound wave that is related to a fundamental frequency or fundamental pitch as an integer multiple. The fundamental frequency is the lowest frequency that can be produced from a sound tube. A harmonic series is the group of notes that are related in whole integers to the fundamental frequency.
Harmonics are both natural and synthetic (artificial), referring to specific pitches created on stringed instruments by lightly touching the string at certain points (nodes) to produce overtones, with "natural" ones occurring on open strings at exact fractions (1/2, 1/3, etc.) and "artificial" ones created by fretting a note and then lightly touching a higher node for different pitches.
Each natural frequency that an object or instrument produces has its own characteristic vibrational mode or standing wave pattern. These patterns are only created within the object or instrument at specific frequencies of vibration; these frequencies are known as harmonic frequencies, or merely harmonics.
2nd (even) and 3rd (odd) order harmonics are frequency multiples of a fundamental tone, but differ sonically and in how they're generated: 2nd harmonics (2x fundamental) add warmth, fullness, and musical octaves (like tubes), sounding rich; 3rd harmonics (3x fundamental) create a sharper, edgier, more aggressive or "covered" tone (like transistors/tape), adding texture but potentially dissonance. They're crucial in audio distortion, with tubes favoring 2nd and transistors favoring 3rd, shaping the perceived character of instruments and effects (this is just in general as there are many transistor amp/circuits that can have tube like harmonics)
Just touching the surface.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
I have a DIY amp as well as pre-amp that can vary the amount of 2nd harmonic to a degree. You can hear a difference in the presentation.
H9"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
I think he is pointing out that many original recordings introduced a certain amount of 2nd order harmonics and distortion from the effects pedals, etc...
However, do we know if the artist expected playback on an amp that introduced more? I guess it boils down to enjoying what we listen to .vs. "knowing" that we are hearing the purest representation of the original recording.
In many cases, I have found that I miss my bass/treble controls, especially for mainstream music mastered in the 80s and through the early 90s. I haven't had tone controls on any of my 2-ch systems since around 2007 when I sold my TA-E80ES preamp. Dang I miss that pre.
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The recording may not sound like the actual live event, some artists have little control over the final product.
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Regardless, congrats on a great amp!
A thing I love about this amp is the amount of power
you can use without distortion. (before clipping)
Speakers: Polk Lsim, ATC SCM19 v2, NHT SuperzeroSpeaker Cables: DH Labs, Transparent, Wireworld, Canare, Monster: Beer budget, Bose ears -
Regardless, congrats on a great amp!
A thing I love about this amp is the amount of power
you can use without distortion. (before clipping)
I really don't know what it's doing differently from my A/B boat anchor but I'm definitely impressed. I know it measures extremely well so I'm assuming that's a major piece of the puzzle & a major factor on how well it sounds. Whatever it is I'll take it!
Merry Christmas everyone!! ๐๐๐๐
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Coming up on the end of the 30 day in home trial period. Things are getting interesting!
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It is amazing what lowering the noise floor can do. I recapped a lowly Parasound C/PT-600 and HCA-800ii with Nichicon caps and was amazed at how dark they became. I still love them in my office rig with the LSi7s.
I got a taste of Benchmark with a little DAC-1 that I found in a thrift store. It is my first experience with an external DAC and I am a ture believer now. It is also in my office rig since that is where I listen most. I am not sure how it stacks up to modern external DACs. I'd love to upgrade with the DAC-3 and would also love to try some of their amp offerings but money is the issue. Besides that, I get my jollies out of finding great deals on good stuff; cheap thrills I guess.Stan
Main 2ch:
Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.
HT:
Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60
Other stuff:
Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601 -
My prediction is that the bass playback is the questionable aspect, but of course I could be wrong.pearsall001 wrote: ยปComing up on the end of the 30 day in home trial period. Things are getting interesting!"This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon -
No not at all. In fact I had to back off the volume by 3 clicks on the REL S812. The XO remained the same. Much deeper, punchier bass from the AHB2 vs the A21+. Cleaner less noise in the signal I'm assuming.
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It's likely partially higher gain settings on the AHB2 in comparison. I understand there's a low-mid-high gain switch on the back.
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Three clicks of +/- gain is A LOT on my measly T/5x RELs.
Brian -
Same here. The trick is to get REL subwoofers to blend with the main speakers rather than drawing attention to them, so it's normal to have to make adjustments when something new is introduced. I've found the adjustments to be pretty easy to make though.
https://youtu.be/Yqde9iAB3Eo
