The Benchmark is as smooth or smoother than any class A amp I’ve heard...IF it’s paired with a good class A preamp. There is no point in owning a low distortion amplifier if the preamp is a weak link.
In my mind there are absolutely no reasons to own any other amp unless you either want a very colored sound or your speakers require more than 100/200 WPC, 8/4 ohm. You get an AHB2 then tailor the sound with your choice of preamp. Class A tube preamp paired with an AHB2 is that cliche “match made in heaven.”
Agree with the Benchmark stack being smooth, It is a smoothness that also has the most clarity that I ever heard.
I recently added a Gustard X26 Pro to my Benchmark HPA4 | AHB2 mono. It replaced the Benchmark DAC3B (still keeping it). The sound of my system was transformed to that of the Gustard. The HPA4 and AHB2 do not seem to add any flavor.
Comparing company X’s class A amp with company B’s class AB amp may not mean much. I bet even there are many class D amps that sound better than class A amps at the same price point. I cannot think of apple to apple comparison, but how about these?
Between a class A amp with another class AB amp at the same price point: if you find a class AB amp sounds better than or equal to any class A amp at the same price, why would you go for class A?
Between class A setting and class AB setting from the same amp: if class A setting does not sound any better than class AB setting, what’s the point for the extra cost of class A setting?
For my Plinius SA102, I cannot hear any difference between class A and AB settings in most music. Only when the music is very demanding (more bass and dynamics) I can tell some difference, but still the difference is not day and night difference.
New Class Ds (e.g.NAD etc)..it's the future, like it or not. Have a listen, go on.I've had a range of A, A/B and early Ds over the last 50 years. Not going back away from D now - sound, size, heat, weight, WAF - all ticked.
The only thing that matters to me is the interaction with the speaker I'm connecting it to. Over the years I always seem to gravitate back to class A. It's a finer more complete presentation to my ears. The whole notion of everything on audio being black and white across the board is what makes the used market ripe with choices.
Class A amplifiers don’t always sound better. It depends on the headphones or speakers you’re using. Headphones and speakers with superior transient response (able to keep up with and resolve complex music) tend to sound better with Class A. But not all are made equal. This means you could have a Class A amp that performs worse than a Class AB - although, if designed well and without compromises, Class A is the gold standard.
I recently added a Gustard X26 Pro to my Benchmark HPA4 | AHB2 mono. It replaced the Benchmark DAC3B (still keeping it). The sound of my system was transformed to that of the Gustard. The HPA4 and AHB2 do not seem to add any flavor.
It’s the ultimate chameleon. What the source puts in is exactly what the AHB2 dishes out.
You're not going to operate Class A on solar panels and it is the opposite of going green. What it can be when properly designed is a fabulous sound that's very involving, Hey folks all Class A aren't created equal, just like Class D or Class AB for that matter.
No, this is not going green at all. I would personally compensate with other things, and others could too. So, with less than capable speakers and headphones class AB can sound better ? Even if we are talking about excellent class A amp ?
So, with less than capable speakers and headphones class AB can sound better ? Even if we are talking about excellent class A amp ?
Who’s saying this rubbish, you get rid of transistor Class-B xover distortion when you bias higher into Class-A so long as everything else is unstressed. Unless xover distortion is liked🤦♂️🤦♂️🤦♂️🤦♂️
So, with less than capable speakers and headphones class AB can sound better ?
It can sound better even with great speakers! The sound of any amplifier is always about what distortion it makes, and what distortion it doesn't. You can prevent crossover distortion in any AB circuit, since its a function of push-pull rather than whether its class A or not. The only exception is if the amp is operating class B but I don't know of a single example of a class B amp in high end audio.
The sound of any amplifier is always about what distortion it makes
The sound of ANY amplifier is better without ANY distortions whatsoever. (Sure some distortions are not AS bad as others.) So long as very little distortion is NOT attained by using means that create other problems areas EG: like masses of feedback global or local, global especially! And there no such thing as "good" sounding class-B xover distortion!
The sound of ANY amplifier is better without ANY distortions whatsoever. (Sure some distortions are not AS bad as others.) So
long as very little distortion is NOT attained by using means that
create other problems areas EG: like masses of feedback global or local,
global especially!
Of course, this being planet Earth, there are no amplifiers with no distortion.
Feedback is problematic in insufficient amounts- it can cause brightness and harshness as it introduces distortions of its own (mostly higher ordered harmonics). But if you are able to apply enough feedback then this phenomena does not occur. That amount seems to be north of 35dB. This also has to be consistent at all frequencies. Most amps have sufficient feedback at 100Hz (which is why they are usually measured at only 100Hz and not higher), but at 1KHz and 10KHz is where amps get into trouble. As a result most of the amps using feedback made in the last 60 years have increasing distortion as frequency goes up, because the amount of feedback is falling off, due to insufficient Gain Bandwidth Product.
This is why solid state in particular has gotten a reputation for being bright and harsh (and it does not matter what class of operation is being used) because the ear is very sensitive to those harmonics! This is literally why tube amps are still around since they can mask the higher ordered harmonics they make.
"There no such thing as a "good sounding" class-B xover distortion!" Because Class-B xover distortion it’s NOT a "nice/colored" sounding distortion like many tubes give, and to eliminate if possible (without sterilizing the sound it with large amounts of feedback) is ALWAYS better than having it.
And those that continue to profess that a Class-B amps xover distortion can sound as good if not better than no xover distortion in Class-A amp are seriously kidding themselves, and worse are charlatans.
Hmm, I don’t get it. When I owned a Plinius SA100 mkiii amp the difference from class A listening to A/B was like night and day. The amp of course does both Class A and Class A/B. It’s as if the lights were turned on. I’ve owned lots of Class A from Threshold T400, T200, Coda, Pass Labs, Plinius, and it wasn’t until I switched to tubes did I begin to here something different.
But SS Class A is as good as it gets to my ears. To those that can’t hear a difference I feel a bit sorry for you for you don’t know what you’re missing. Class A is where it’s at. Whomever suggested Class D was better than Class A suggests they’re in Audio training and haven’t had their training wheels removed.
"I might be off here, but class A amps don’t drive lower impedance speakers very well either. Most class A amps aren’t stable into 2 ohm loads. Krell being one Of the exceptions."
Yes, you're way off. Ever hear of a well known audio company called Plinius?
As no one in their right mind would prefer the sound of class-B xover distortion no matter how little. To the same amp in Class-A (unstressed) with no xover distortion.
The doubters, should do themselves and those here a favor and listen to a Gryphon Antillion that can be switched from 10w Class-A to 50w Class-A to 100w Class-A on the run while listening. And there are others like the Parasound JC1’s etc etc
Then the persistent doubters can hang their head in shame for even suggesting Class-B can sound better than Class-A if all is equal.
Wrong info to those reading this. When listening at normal to loud levels "or" on hard to drive speakers, Class-B xover distortion is just as prevalent in low bias Class-AB amps when pushed past the low Class-A bias point. And thats fact.
And I'll say it again. For the same given amp that is comfortable within all it's design aspects either at 100w Class-A bias or at 5w Class-A, the 100w Class-A bias will ALWAYS!! sound better. unless you are listening to 110db horns You can prove this for your self by listening to an amp with user switchable bias while listening. EG Parasound JC1 Gryphon Antillion etc etc.
For the same given amp that is comfortable within all it’s design aspects either at 100w Class-A bias or at 5w Class-A, the 100w Class-A bias will ALWAYS!! sound better. Unless you are listening to 110db horns
Just to add to the end of that. "Unless you are listening to >110db horns, then they will sound the same" because it only take 5w to get >110db horns going.
You are false, and have no idea about the BS you spread sometimes, eg Zeroformers, OTL’s drive capabilities etc etc
Do your homework before posting this **** you spread.
I’ve built many Class-A’s from 20watters to 150watters, including massive 2 man lift self contained water cooled ones
Get off your horse, stop the BS and concentrate on your own "so called patented Class-D" I can link to on another forum, because it will be left behind and over taken with cheaper ones coming out the rate your going.
You can prove this for your self by listening to an amp with user switchable bias while listening. EG Parasound JC1(low/high bias), Gryphon Antillion (low/high/higher bias) etc etc.
The difference you hear with more/higher Class-A bias, is an easier, smoother, richer presentation to the sound, that’s no less dynamic and yet makes the speakers disappear, even as the music goes louder. And as a result the sound washes over you rather than being fired at you from the drivers, and that is the result of the lessening of the class-B xover distortion when you engage more and more Class-A bias.
Ralph - Let me know if you need a Beta tester, I can pay the freight both ways. My systems are visible in the virtual systems page. I appreciate your balance of the theory and practical application ( the hard work of design ) I also appreciate that you understand the ear / brain sensitivity to and preference for certain types / orders of distortion. A deep understanding of that can greatly inform the design objectives for any amplifier. jim
Class A runs very hot and very inefficient , big watts in pure class A is big bucks
~~~~~~~~~ And when one's listening room is located in say Here in New Orleans, or Phoenix, or South Florida, , the heat factor of a class A amplifier is a important consideration. The Defy7 is like, I think Richard Gray says more like class B, throws off less that I had anticipated/with 12 tubes. , Richard also prefers Class A. But as you mention, Big Bucks. Did you say very inefficient? Oh I see , requires plenty of power current = heat. Glad the Defy is not class A. the heat radiation would be too much to deal with in my 10x12 listening room.
Im not sure what I'm missing, as in, who cares how efficient an amp is. Are any of us concerned with how much power we consume while listening to music.?? We spend zillions to achieve the best sound on components speaker etc, power is pennies compared to what i spent on speakers. Same with heat . So What. Ive got 4 tons of ac so bust out the marshmellows. ive never understood why people bring those up when what we are going for is sound.
"The difference you hear with more/higher Class-A bias, is an easier, smoother, richer presentation to the sound, that’s no less dynamic and yet makes the speakers disappear, even as the music goes louder. And as a result the sound washes over you rather than being fired at you from the drivers, and that is the result of the lessening of the class-B xover distortion when you engage more and more Class-A bias."
That has been my experience as well. I experimented with various bias currents in my Integrated Amp and the sound quality improved considerably with higher values. The music had more body with a richer midrange, which was quite noticeable at low (SPL) listening levels. Nelson Pass talks about this in his "Leaving Class A" article.
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