boland audio

[hispls 5,000+ posts]

one of the things that Bernie stressed with me on the phone was the noise floor. Yes, cars are the furthest thing from ideal as far as noise goes, but to eliminate as much as possible before adding the noise of the car into the equation would be a good step to take.

If you can find the man who can hear the difference between 1% and .001% distortion just have him reach out to Richard Clarke to make an easy 10 grand.

 

[youdoofus]

If you can find the man who can hear the difference between 1% and .001% distortion just have him reach out to Richard Clarke to make an easy 10 grand.

im not talking about distortion, im talking about noise floor

 

[wew lad 5,000+ posts]

Considering modern class D amps are already in the 90% efficient and up range, how much is left to gain?  At what cost?  Why aren't the companies who actually do R&D implementing this?  Surely JL, Rockford, Alpine, etc. have the budget and the brain power on tap to utilize this and already have a customer base ready to  pay premium for their brands.

Do some research and take a look at the improvements. Class D is not 90% efficient on average. The switching times are 2-4x faster, the power dissipation and output is higher, the size is smaller, the cost is lower. Not only do GaN fets have potentially better sound quality, they'll allow new designs that do actually focus on improving quality because of the improvements. They're going to be an important part of full bridge amplifiers

I get you're playing devils advocate here, but you don't work with circuit design, and neither do I. But when experts put this factual data out there it's hard to ignore. 

 

[PPI_GUY 10+ year member]

The fact is GaN FET amplifiers are coming. They'll become more common in home audio first and then make their way to car audio.
90% efficient car amplifiers do not exist AFAIK. You may get the occasional well thought out amp that is 80% efficient @ 4 ohm loads. But, with GaN FET's we're talking about 90-95% efficient with sound quality that rivals class A. You don't think that is significant? It's at least as important as the move from class a/b to class D that is the underlying subject of this thread.
And ALL of car audio will benefit, including the SPL crowd where every last 1/10th of a watt is coveted and solid/stable electrical is vital.
I can see a day in the not so distant future when aftermarket amplifiers the size of a cell phone will be capable of producing 1000 watts or maybe more.
Which brings us back to the question of viability regarding class a/b amps like Bernie's.  

 

 

[ciaonzo 5,000+ posts]

The fact is GaN FET amplifiers are coming. They'll become more common in home audio first and then make their way to car audio.
90% efficient car amplifiers do not exist AFAIK. You may get the occasional well thought out amp that is 80% efficient @ 4 ohm loads. But, with GaN FET's we're talking about 90-95% efficient with sound quality that rivals class A. You don't think that is significant? It's at least as important as the move from class a/b to class D that is the underlying subject of this thread.
And ALL of car audio will benefit, including the SPL crowd where every last 1/10th of a watt is coveted and solid/stable electrical is vital.
I can see a day in the not so distant future when aftermarket amplifiers the size of a cell phone will be capable of producing 1000 watts or maybe more.
Which brings us back to the question of viability regarding class a/b amps like Bernie's.  

 

I never valued efficiency, I always went with amplifiers that ran hot because they always sounded better. Early on I didn't even understand why that was so, just that it was. With reading I began to understand that it was the bias in the circuit usually responsible for this. The ability of these amps to pass seemingly endless amounts of current was also a factor in both the heat and good sound. But that's all class D amps are, if you think about it. They are simply current steering devices. Why not keep refining these designs until they are as good or better than class A or a high bias class A/B? That's a no-brainer and I'm glad we're headed there.

I think the problem, understandably, is that most don't understand why true class A is a sonic benchmark or why it is so incredibly wasteful and inefficient. True class A runs the highest bias and is basically always running full tilt creating the most heat possible. It also involves zero crossover distortion between different banks of output devices. And most don't run negative feedback circuits. The benefits of this are easily heard, even if it's a marvelous class A/B that has carefully gotten rid of crossover distortion and is running high bias. Even better if is has a low amount of negative feedback, or none at all.

*For the visuals below and folks who are unfamiliar - Having zero crossover distortion just means that the banks of transistors are very carefully combined or that a single transistor is handling the entire waveform without chopping it up and handing half of it off to another transistor. But there is always an amount of compromise between crossover distortion and efficiency.

To have a class D that can offer a phenomenal slew rate and sound as good as class A, that can also offer an incredibly significant amount of efficiency is a real breakthrough. Even if some of them only end up sounding the same as any old class A/B that was once heralded as a great.

 

[youdoofus]

The fact is GaN FET amplifiers are coming. They'll become more common in home audio first and then make their way to car audio.
90% efficient car amplifiers do not exist AFAIK. You may get the occasional well thought out amp that is 80% efficient @ 4 ohm loads. But, with GaN FET's we're talking about 90-95% efficient with sound quality that rivals class A. You don't think that is significant? It's at least as important as the move from class a/b to class D that is the underlying subject of this thread.
And ALL of car audio will benefit, including the SPL crowd where every last 1/10th of a watt is coveted and solid/stable electrical is vital.
I can see a day in the not so distant future when aftermarket amplifiers the size of a cell phone will be capable of producing 1000 watts or maybe more.
Which brings us back to the question of viability regarding class a/b amps like Bernie's.  

 

i looked into it a bit and what i think i understand about GaN amplifiers is that they are audiophile class d amps, is that a fair assessment?

 

[hispls 5,000+ posts]

I always went with amplifiers that ran hot because they always sounded better.

And yet Richard Clarke is still in possession of his 10 grand.

 

[youdoofus]

And yet Richard Clarke is still in possession of his 10 grand.

i also looked into the richard clarke thing, and didnt find much. whats the deal there?

 

[ciaonzo 5,000+ posts]

And yet Richard Clarke is still in possession of his 10 grand.

I've heard differences in amps. I can even tell you why but it's irrelevant. I'm not going to get into it. There is enough content on the web for each us to simply grab copy/pasta rebuttal and we will be no better off, regardless of our respective viewpoint. 

I will simply state that his criteria is flawed and he will literally never need to worry about having to pay out the 10 grand. It will never happen. The fact that someone had previously nailed all twelve choices, and he went back to adjust things further until the person couldn't do it again, suggests the same. He has even changed the rules on the fly in some instances, lol.

This thread contains some of the better rebuttal I've seen on the topic, FWIW, to anyone who isn't familiar.

https://forum.audiogon.com/discussions/the-richard-clark-quot-all-amps-sounds-the-same-quot-test

 

[hispls 5,000+ posts]

i also looked into the richard clarke thing, and didnt find much. whats the deal there?

http://tom-morrow-land.com/tests/ampchall/index.htm

https://forum.audiogon.com/discussions/the-richard-clark-quot-all-amps-sounds-the-same-quot-test

I read about 3/4 of that thread, a bunch of assclowns trying to justify their horribly overpriced snobophile brand purchases to each other.  And none of them went 12 for 12 and took the 10 grand either, did they?   Even after claiming it's all trickery.

Whatever.  If the fact that you paid thousands of dollars for some boutique brand home receiver makes it sound better to you, I guess it's money well spent, but it's commonly accepted science that the threshold of the sensitivity of the human ear is nowhere near precise enough to notice the difference, and that's assuming the difference is something you couldn't just simulate with EQ or even a simple passive filter.

 

[ciaonzo 5,000+ posts]

Assclowns. That's not like you at all, and please don't take any tone with this because I'm not intending any. But insulting a bunch of people you don't know and discounting their collective experiences all in one go, for the sake of conveniently propping up and perpetuating the notion that all amps do indeed sound the same? I mean, there are countless threads on this, not just one or two guys that say they can appreciate or perceive some type of difference in the presentation of amplifiers paired with speakers that haven't changed. In reading many of those threads over the years, that wasn't my takeaway at all but that's okay, you are entitled to your viewpoint the same as I am. All like-wattage amps do not perform and sound the same and it's an awfully short-sighted perspective to have in a world full of so many different designs. Even from a statistical standpoint, it just shouldn't be possible for that to be the case. RC simply "paints" competing amplifiers very close shades of white (if you will) that are so similar, telling the differences in shade would be all but impossible. Why not simply impose a single criteria to limit the power output of each like-wattage amplifier to a percentage well under clipping, and allow the amps to perform as they would otherwise? In a subjective fashion, since that's what is really being debated to begin with. Not the science of thd or other distortion measurements. Meaning, allow the character of the amp shine through. No, he white washes every and all amplifiers until they do sound essentially identical. Well, congrats on making two different amps sound the same as possible and ask people if they can tell the difference. No wonder people don't hear a difference. Any differences that would have been appreciated would have been subtle and difficult enough.

And there was indeed a fellow who nailed all twelve. Because of that, RC had to go back and adjust levels to within 1/10 of a dB and run the gamut once more. Of course, the gentleman did not repeat his success and no monies were paid out. How convenient. I would imagine listening fatigue might have had a little to do with those results but I wasn't there so it's purely speculation.

Like I said, I don't want to go back and forth with you on this because; 1) I respect you and allow for your viewpoint, and 2) it's a complete waste of our time because you will never convince me and thousands of others there are no differences to be heard in amplifiers. Likewise, I will never convince you that you need to spend two pennies more than is necessary to achieve a sound that is acceptable to the ears on your head. I would simply posit that our ears have different requirements. My question then, is, if all amps sound the same why don't you run the lowest grade garbage that offers the best reliability possible for the shortest money?

 

[ciaonzo 5,000+ posts]

The only direction one needs to look in to know why there could possibly be a reason for amps to sound different and have it be correlated with the science behind it, is to read up on impedance matching and current source versus voltage source. Followed by negative feedback loops, slew rate, and crossover distortion. This information, of course, should be considered with and weighed against the speakers those different amplifiers might be paired with, correctly or incorrectly. You can see where a few years of experience with widely varying equipment may be of some value for these comparisons.  

 

[PPI_GUY 10+ year member]

i looked into it a bit and what i think i understand about GaN amplifiers is that they are audiophile class d amps, is that a fair assessment?

They are indeed class D amps. However, the problems that have long been associated with class D topology are greatly diminished with Gallium Nitride FET's. Efficiency increases, distortion is reduced and the signal is purer. The application for this new technology won't stop with audiophile components. You'll eventually see manufacturers incorporating them into stock head units in upscale luxury autos to begin with. 
Class a/b has been around for a very long time. Then came class D. It's only reasonable to expect improvements with new technology and better production methods/materials as we move forward.
The article I linked is a great read and not terribly long.