Article: Power Amp Comparison | Cambridge Edge W, Benchmark AHB2, Bryston 4B Cubed

[Josh Mound]

13 hours ago, feelingears said:

Out of curiosity, did you ever consider the Raggy 2?

 

4 hours ago, jaynyc said:

echoing the question: @JoshM have you heard / considered the latest Ragnarok 2 from Schiit, in comparison to these other amps?

I actually do have a loaner from Schiit, and will be writing a review. It’s just been that I haven’t gotten around to setting both up, matching the levels, etc. Plus, I want to compare them as headphone amps, too. 

[Josh Mound]

14 hours ago, MikeJazz said:

What a great review.

You called my attention to https://www.philharmonicaudio.com/.

That diy kit must be fun.

I wonder if you could elaborate a bit about the difference between your two speakers. The KEF of course I already know and appreciate.

The "Phil" is not know of this side of the Atlantic, I guess. But it ticks some of my favorite boxes...

I bought the finished BMR Monitors from Dennis (a.k.a. Philharmonic). Mine are the square cabinet Monitors. I think the curved cabinet option was introduced a few months later. At some point, I’ll write my own review comparing it with the KEFs and a few other bookshelf speakers, but I think Erin’s review is pretty much on the money.
 

Do they surpass the KEFs, which are many multiples their price? No. But they hold their own way more than they should for the price. I’ve tried lots of bookshelf speakers in the BMR’s price range (I hate to say it, but it has to be in the dozens by now), and they’re the best I’ve heard by a wide margin.
 

The three-way design is superb. They have a very, very wide sweet spot. Sure, this horizontal dispersion means they don’t have quite the pin-point imaging of some other speakers (they’re similar to the KEFs in that way, actually), but it’s a good trade off for the excellent off-axis performance. Tonally, they’re fantastic, and the FR is very neutral, maybe shading slightly towards warm. They just sound like much larger and more expensive speakers than they are. They’re what I imagined/hoped the Ascend Sierras (which were solid, to be fair) would sound like. 

[Gregory_SD]

Thank you so much for this review, it's really priceless! (unless you are pretty wealthy, are well connected in the hifi biz, and have the time and the ear.

[feelingears]

22 hours ago, JoshM said:

I think the above comments are all related in my mind. When I think about equipment, I don’t necessarily first categorize them by price. What drew me to all of the amps I tried is that they either measured well, got good subjective reviews, or both. So, for example, even though I don’t tend to like Class D amps, the NAD M22 got great reviews, measured well, and I found one used at a good price. I tried it, didn’t like it, and resold it. 

 

This has been my process as well, although I have tended to group amps/designs together into certain categories based on the semantics of the reviews. Over time and reviews/-ers, there are some commonalities and that is what I was after with my question; price is very much secondary. I am curious if you had sonic qualities in mind but maybe the measurements are your common denominator.

Anyway, thanks for the comparative review. I'll have to check out Bryston sometime.


 

[Geoff13]

Hello,

 

Yes i also feel like the Bryston is in another category but a lovely review nonetheless

[MikeJazz]

On 10/2/2021 at 7:32 AM, JoshM said:

I bought the finished BMR Monitors from Dennis (a.k.a. Philharmonic). Mine are the square cabinet Monitors. I think the curved cabinet option was introduced a few months later. At some point, I’ll write my own review comparing it with the KEFs and a few other bookshelf speakers, but I think Erin’s review is pretty much on the money.
 

Do they surpass the KEFs, which are many multiples their price? No. But they hold their own way more than they should for the price. I’ve tried lots of bookshelf speakers in the BMR’s price range (I hate to say it, but it has to be in the dozens by now), and they’re the best I’ve heard by a wide margin.
 

The three-way design is superb. They have a very, very wide sweet spot. Sure, this horizontal dispersion means they don’t have quite the pin-point imaging of some other speakers (they’re similar to the KEFs in that way, actually), but it’s a good trade off for the excellent off-axis performance. Tonally, they’re fantastic, and the FR is very neutral, maybe shading slightly towards warm. They just sound like much larger and more expensive speakers than they are. They’re what I imagined/hoped the Ascend Sierras (which were solid, to be fair) would sound like. 

Thanks for the very useful response. Erin's review is also useful.

[Josh Mound]

On 10/3/2021 at 12:50 AM, feelingears said:

 

This has been my process as well, although I have tended to group amps/designs together into certain categories based on the semantics of the reviews. Over time and reviews/-ers, there are some commonalities and that is what I was after with my question; price is very much secondary. I am curious if you had sonic qualities in mind but maybe the measurements are your common denominator.

Anyway, thanks for the comparative review. I'll have to check out Bryston sometime.


 

 

There's a baseline of measurements that I look for, but it's definitely a lower baseline than the ASR folks, for example, want. However, if I can't find any measurements, that won't necessarily stop me from buying something. My preferences are definitely neutral/detailed. But I also want some smoothness (which isn't to say warmth) from my gear. I can't say for sure, but I think smoothness has something to do with harmonic structure and IMD (perhaps square wave reproduction, too).

[fas42]

1 hour ago, JoshM said:

 

There's a baseline of measurements that I look for, but it's definitely a lower baseline than the ASR folks, for example, want. However, if I can't find any measurements, that won't necessarily stop me from buying something. My preferences are definitely neutral/detailed. But I also want some smoothness (which isn't to say warmth) from my gear. I can't say for sure, but I think smoothness has something to do with harmonic structure and IMD (perhaps square wave reproduction, too).

 

"Smoothness" is the absence of distortion anomalies that are disturbing to the listening mind. It's as simple as that - and those who have achieved this from their playback understand the value of reaching this point. Recordings don't have "lack of smoothness", which somehow the rig is magically meant to compensate for; it doesn't, and can't work that way - if some recordings are "smoothed over" by the signature of the replay chain, then other recordings will sound worse; there will always be some recordings whose intrinsic distortion conflicts badly with the distortion of the replay chain - and they will sound, 'orrible, 😁.

 

Best solution is no distortion. Of the playback parts. There will always be some audible characteristics from this, but they should be as benign as possible. If you do this well enough, then the presentation becomes, well, smooooth ... automatically, 😉.

 

The side benefit of this is that the presentation becomes convincing, and, can be turned up as loud as your system can go before starting to manifest misbehaviour, with no discomfort ... 🙂

[pga]

Great review Josh.
 

I haven’t had a Bryston in my system since the 1990s, so I surely cannot say much about the current 4Bs.  

 

That said, I’m quite happy with my ABH2s, that replaced a pair of Centaur mono amps.  I found the ABH2s to be more transparent and yet more musical.  That was with two ABH2s in mono.  In my set up with TAD R1s the Benchmarks had plenty of bass slam and dynamics, every bit the equal of the 8x cost Centaur mono.  
 

Since then my system evolved to 4 ABH2s in a hybrid biamp using a Pass XVR1 to divide the signal between the woofers and the coax in the TADs. The low pass in the TAD for the woofers is bypassed as this LPF is now handled by the XVR1.  The high pass for the coax in the TADs in still in use but an additional active high pass pole is also employed using the XVR1.  
 

As a one time Electrical Engineer, biamping the TADs had been a long time ambition.  I was very fortunate to get some invaluable input to set up to the crossover from Andrew Jones, if not the most talented then perhaps the nicest speakers designer in the business. 
 

Also layered on top of all this is a Mitch Barnett designed 60,000 tap convolution filter. With Andrew’s help, the “hot rod” TADs have an amazingly smooth response from below 20hz on up even without DSP, but then EQing the room properly takes the system to another level of performance in every respect. 
 

So how do 4 ABH2s all in mono, in a biamp system with the woofers directly connected to the amps sound? Well it’s easily the best system I’ve had at home. 
 

Four Constellation amps just made no sense from a cost, power or heat perspective. So that prompted me to look at the ABH2s.  Interestingly Andrew Jones’s twin brother who is an Electrical Engineer, was involved in the design of the ABHs.  I’m sure two Brystons would also sound great, and have a similar price tag and power rating to 4 ABH2s. But I felt perhaps out of subconscious loyalty to the Jones’s twins that I should give the 4 ABH2s a try.  In the end that was a good bet. 

[feelingears]

Shucks, I'm just thinking about branching out from my Naim loyalty for fun. Maybe an esoteric preamp with a Bryston 2B^3 or heck, a Schiit Aegir...

 

Maybe someday an AirBnb experience will be hopping around a city to some local audiophile homes for auditions of insane setups like @pga's. Actually I could see a kind of documentary/slight mock-umentary film about audiophiles and the search for the perfect amp going along these lines...

[pga]

One slightly off topic point worth mentioning is how much of an engineering company Bryston and Benchmark truly are, and how important this is.  I’m less familiar with Schiit and Cambridge, but I suspect that is also true there.  There is no substitute for great engineering.  
 

The guy that bought my Centaur monos took a listen on my system when it was just two ABH2s in mono.  He was surprised at how good they sounded.  I’m just glad he didn’t change his mind on purchasing the Constellation amps.  But what surprised him the most is that I had taken out all the audiophile cables and at the time had all Bryston interconnect and speaker cables.  
 

Guess what, Bryston makes great cables, sound great and are built amazingly well.  I needed a bunch of new cables for the biamp system, so I switched to Benchmark cables.  These are also excellent.  Both companies simply use great parts and quality manufacturing to put these together.  

 

One lesson I learned is don’t try to fix a room response problem with cables or subtle differences between electronics,  the only real way to fix this is either with a new room or EQ.  The other lesson I learned is to avoid audio equipment made by companies that emphasize marketing over engineering.  At best you will end up gorgeous, expensive equipment that sounds as good as it looks (like Constellation), at worst you end up with stuff that’s just overpriced.  

[kennyb123]

Thanks for the excellent review @JoshM.  Really well done!

[feelingears]

18 hours ago, pga said:

One slightly off topic point worth mentioning is how much of an engineering company Bryston and Benchmark truly are, and how important this is.  I’m less familiar with Schiit and Cambridge, but I suspect that is also true there.  There is no substitute for great engineering.  
...

One lesson I learned is don’t try to fix a room response problem with cables or subtle differences between electronics,  the only real way to fix this is either with a new room or EQ. 

 

Largely agree, although I think engineering is important but not the be-all, end-all. Even Schiit, which has a few distinctive in-house technologies behind their designs in both digital and analog, does not design simply by engineering. I don't know if you're trying to say this so I'm not trying to put words in your mouth. In Schiit's case, they are quite open about listening tests and even the differences in impressions between the founders (Stoddard and Moffat). Case in point is the latest DAC upgrade which you can read about elsewhere. I wish/think other companies should follow Schiit's openness as it builds community/brand and fosters better products.

 

Not to go totally off-topic, but preferences are huge and as it happens, I read about a Bryston owner's preference for Sugden. Having heard the latter recently, I can only imagine because I think Sugden doesn't get enough credit for the extremely high quality of their sound. And, I think their slogan is along the lines of "getting technology out of the way of music."

And to your point, our rooms and room-treatment are definitely an under-discussed topic. Drapes are a huge part of mine and when they were out for a week for cleaning, OMG I never imagined my system could sound so. incredibly. terrible. And, I almost couldn't believe I heard that bass traps "work" when I put one in.

 

Back on topic: I'll be sure to have my drapes and traps in place when I audition a Bryston!
  

[pga]

Not to belabor the point, of course engineers (or anyone else that is designing an audio product) should listen to what they produce as this is perhaps the most important test to verify that the product is performing as expected.  Schiit seems like an engineering driven company that listens.  That's the ideal combination.  

 

Specs can be very misleading.  In the 1960s and 1970s there was a race to lower THD and increase watts.  So much so that the FTC had to step in to dictate how power would be measured.  We learned that some products with very low THD and high watts sounded pretty bad.  It took a while to realize that stability with reactive impedance loads, IMD, robustness of the power supply all mattered as much as simply THD and watts.  Maybe this was discovered by the public by listening, but if I had to guess, the engineers at McIntosh, Levinson and Krell had it figured out.  The problem was that the marketing guys at other manufactures didn't care and they were happy to play the spec game.  

 

What do you think measures better, a Marantz tube product before the company was sold or a Japanese Marantz?  I'm pretty sure the old stuff sounded better and it still sells for premium prices.  Behind those tube amps was an incredible designer that was science based, Saul Marantz.  You can find many others like him at AR, Pass, Levinson, Quad ... It's a long list.  

 

It also seems like when a new technology comes out the marketing priority is to out-spec the technology that preceded it. That clearly happened when transistors first came out.  Another great example of this is when RedBook CD challenged the LP.  What were the problems with LPs?  Noise, frequency response and channel separation are three big ones.  But with a CD it's easy to have great specs for all these.  Yet early RedBook CD sounded really bad compared to a great turntable.  Why? Because in the new technology things like jitter and digital artifacts were more important.  Meridian was one of the first companies to develop consumer products that addressed this.  Did the engineers at Sony and Phillips that developed CDs understand jitter and digital artifacts?  I'm guessing they did, but the marketing guys were fighting another battle which was how do we quickly show that a CD is better than a cassette or LP.

[Josh Mound]

On 10/6/2021 at 12:09 PM, feelingears said:

Not to go totally off-topic, but preferences are huge and as it happens, I read about a Bryston owner's preference for Sugden. Having heard the latter recently, I can only imagine because I think Sugden doesn't get enough credit for the extremely high quality of their sound. And, I think their slogan is along the lines of "getting technology out of the way of music."
  

 

Not to go even further off topic, but I've been buying/trying/collecting some vintage DACs for fun (and for a future "Reconsidering Redbook" article), and the Sugden SDA-1 is one of the final three out of about 10 or 12 that I've bought/sold.

[pga]

Suggestions on your off topic, other than the original Sony, some DACs that I would consider historically important are of course the early Meridian, the Wadia 2000 (perhaps first DAC with custom digital filters, sounded good, measured poorly), any of the DACs using the Ultra Analogue chips (Levinson, Spectral made two outstanding DACs) and the pro DAC Apogee made (this was a bargain, better than almost anything at the time, they made a version for Cello).

[Josh Mound]

1 hour ago, pga said:

Suggestions on your off topic, other than the original Sony, some DACs that I would consider historically important are of course the early Meridian, the Wadia 2000 (perhaps first DAC with custom digital filters, sounded good, measured poorly), any of the DACs using the Ultra Analogue chips (Levinson, Spectral made two outstanding DACs) and the pro DAC Apogee made (this was a bargain, better than almost anything at the time, they made a version for Cello).

 

The only Ultra Analog-based DAC that I've had thus far was the Parasound DA-2000. I'd like to get a Spectral SDR-2000.

 

I *just barely* missed out on buying the Apogee DA-2000, but someone responded to the ad ~20 minutes before me.

[89reksal]

I'm surprised in all the above comments, not one mention was made of Bryston's unheard of 20 year warranty. Shows what a manufacturer thinks of their products when they're prepared to stand behind them like that. They also pay return shipping for any warranty repairs.

 

Resale market on Bryston is probably one of the best out there as well.

 

I just picked up a brand new 4B3 today using my 25 year old 4BST as trade in towards it (that I was still using daily, powered on 24/7) so you could say I may be biased.

 

[M_audio]

On 3/2/2023 at 3:22 AM, 89reksal said:

I'm surprised in all the above comments, not one mention was made of Bryston's unheard of 20 year warranty. Shows what a manufacturer thinks of their products when they're prepared to stand behind them like that. They also pay return shipping for any warranty repairs.

 

Resale market on Bryston is probably one of the best out there as well.

 

I just picked up a brand new 4B3 today using my 25 year old 4BST as trade in towards it (that I was still using daily, powered on 24/7) so you could say I may be biased.

 

Any diffs comparing 4B ST with the Cubed one?

[John Siau]

There are a couple of important reasons why the bass response of the Benchmark AHB2 is different than that of the other amplifiers. 

 

First, the bass response of the AHB2 extends down to 0.1 Hz. The reason for designing in this extended response is that it keeps the phase response flat to below 20 Hz. This flat phase response means that the bass will be delivered in the proper time relationship to the rest of the music. In contrast, most audio devices deliver the bass late. This is especially true of power amplifiers. Late bass will often sound louder because the bass decays too late and this obscures reverberant details in the music. Detail is lost when bass is late. The bass will sound louder, but the kick drum will have less impact. In contrast, the AHB2 accurately reproduces the bass with the proper timing and this tends to reveal details in the music that are often obscured when the bass is delivered several milliseconds too late.

 

Second, the AHB2 does not produce any audible distortion when reproducing low-frequency tones. Most amplifiers add audible harmonic distortion, especially when encountering difficult phase angles in the speaker load. In contrast, the AHB2 is not adversely affected by the load angle and it stays clean under severe loads. If an amplifier produces audible 2nd harmonic distortion this will give the impression that the bass is deeper and louder. The low-power 1-watt THD performance can have an impact on these effects. The feed-forward error correction in the AHB2 keeps it exceptionally clean at all power levels, including the first few watts.

 

Whenever bass is emphasized through one of these two mechanisms, details will be obscured. The AHB2 is designed to reveal details captured in the recording. It is not designed to modify the sound in any way. The other amplifiers in this group are also designed to be transparent, but there seem to be some audible differences which may be due to the effects I have described above. These effects do not show up in a simple full-power THD+N measurement, or a simple frequency response measurement. They do show up when you dig deeper into the measurements.