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Amplifier Suggestions Wanted

Lbstyling

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I don't know. My guess is both are so good it won't be a difference you'll hear. Both are the handiwork of Bruno Putzeys and designer friends. The Purifi being his latest and presumably greatest work. BTW, March Audio has Purifi as well, but at a higher cost.

Bruno has stated the Purifi amp design (among other changes) removes hysteresis by removing the output coils, and that although this is barely measurable on THD, it is clearly an audible improvement that he himself was surprised is possible.
 
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312elements

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Bruno has stated the Purifi amp design (among other changes) removes hysteresis by removing the output coils, and that although this is barely measurable on THD, it is clearly an audible improvement that he himself was surprised is possible.
I wish I knew a better way to describe it. The c268 reminded me of other class D amps. The c298 did not. Not to say it sounded like class A or anything, just better than any class D amp I’ve ever heard before.
 

Blumlein 88

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Bruno has stated the Purifi amp design (among other changes) removes hysteresis by removing the output coils, and that although this is barely measurable on THD, it is clearly an audible improvement that he himself was surprised is possible.
I'd like dbt results to confirm.
 
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312elements

312elements

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Double blind test results.

I don't doubt the removal of coils might change hysteresis, but I doubt it was an audible amount of hysteresis in the Hypex. So makes me wonder if it is really something you'd hear.

That makes sense. I did not do a double blind test. It was just me and the gentleman that was running the store. According to the review, the 268 has Hypex UcD. There's no doubt in my mind that I could pick out the 298 over and over and over again. I'm not sure if that's the module, or the input buffer or some other aspect of the construction that I'm not educated in, but they did not sound the same. The sales rep kept commenting on the bass. I think that had more to do with the c298 feeding it more power. I felt that it just overall sounded better and that too may have just been the result of feeding the speakers more power. In comparison the c268 sounded thin. I'm not trying to be fluffy here. This isn't a matter of extended high frequencies, soundstage width, air and separation. Maybe the c268 struggled to deal with the impedance dips of the speaker. However, as I mentioned earlier, if I had only heard the c268, I probably would have purchased it.
 

Blumlein 88

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That makes sense. I did not do a double blind test. snip...........There's no doubt in my mind that I could pick out the 298 over and over and over again.

Many a time we've heard the idea there is no doubt I could pick it out over and over again. Only to find when blinded, suddenly differences disappear.
Also sounds like no careful level match. Relatively small level differences sound like a quality difference. 1 db louder and it will sound much better with more bass and more musical enjoyment. If you aren't careful, you likely would never notice the loudness change switching back and forth.
 
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312elements

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Many a time we've heard the idea there is no doubt I could pick it out over and over again. Only to find when blinded, suddenly differences disappear.
Also sounds like no careful level match. Relatively small level differences sound like a quality difference. 1 db louder and it will sound much better with more bass and more musical enjoyment. If you aren't careful, you likely would never notice the loudness change switching back and forth.
Clearly that hadn’t occurred to me. Feel free to go and troll sometime else.
 
D

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The hypex unit in the c298 had a very good review here, as part of the M33. So if science means anything then there might indeed be a different sound perceived as better. I will be saving for this amp too to partner a set of speakers with some naughty impedance dips.
 
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I find this thread very odd,

OK, so some dude claims to hear differences in amplifiers and wants an opinion about what amp "sounds best". Yeah, that makes sense if this was Audiogon, 6moons or absolute sound--right next to the power cord and fuse opinions. Quite bizarre that the OP would call a person a "troll" in a science based/testing based forum but it is a weird world.

Does not know what a double blind test is... figures. Anyhoo, this is how you do it right. First, get three amps and do a proper double blind test and make sure they have their gains within 0.1dB of each other. You can also add a forth amp, get a really crappy one with complete specs and it is a good idea that the top two amps are very close to each other in specs. Do your double blind test, figure out what amps you can tell a difference (if any) and what amps you can't. Then gather those specifications and purchase amps that meet or exceed those specifications and you will have the correct amplifier. If you can, do the amp test in a very, very quiet room as it would be a good idea for the background noise levels to be lower than in your house. Usually a weekend is better with light wind to make it as quiet as possible.

Now comes the easy part! Well, as long as you know what the charts/measurements mean (of course) Look at all those amp tests, know what specs you require and narrow down the amplifiers by cost, reliability, size, efficiency, features, customer service, parts availability and flexibility then choose. You don't need to "hear" the amplifiers once they exceed your ability to tell a difference (why you did the DBT in the first place)

This also helps with sources, be it DVD players, computer sound cards or even record players. If the sources exceed the amplifier specs and the amplifier specs exceed your ability to percieve a difference--you are golden. :D

Say you get caught up in "specmanship" or trying to get the bestestest amp ever made because it will do something. No problem, look at the distortion, frequency response etc. of the speaker testing and compare the two. If your speakers are creating 2% distortion and your amp pushes 0.05% distortion--you won't hear the amp distortion because the speaker will swamp the sound with it's much, much higher distortion levels. This way you won't be stacking up Benchmark amps or becoming a follower of the latest audio messiah.

Now if you refuse to waste your time learning about DBT, measurements, what they mean and how speakers/amps and electricity works--why are you here? I would suggest Audiogon, 6moons and absolute sound as they have an incredible amount of opinions and dogma without those pesky measurements, electrical engineering laws and psychoacoustics sciencey people involved. You can learn about cable lifters, cyrogenically frozen fuses, 5G protection and get the latest stickers that absorb quantum noise. Believe your ears! They sure do so a much better source for opinion than a site that actually tests things.

Freakin' science based trolls...
 

DonH56

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@Kal Rubinson has (had?) an older Bryston 5-ch amp for sale. Recently refurbished, low price, great sound.
 

BDWoody

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Clearly that hadn’t occurred to me. Feel free to go and troll sometime else.

How is pointing out a very common flaw in reported listening impressions trolling? This is a science forum, and there may be some who don't realize the importance of tightly controlling for bias. Of course, that's not what most retailers are interested in setting up for their customers, as the tools (tricks) of the audio sales trade are then effectively nullified.

We get lots of claims here, but very little in terms of controls that would make the claims potentially meaningful.
 

Blumlein 88

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Clearly that hadn’t occurred to me. Feel free to go and troll sometime else.
Was not trying to troll. If you knew all that and matched levels good. If not, I'm giving you some good simple advice. Even in showrooms be careful of level matching. Without that the auditioning process is highly polluted.
 

Jinjuku

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Was not trying to troll. If you knew all that and matched levels good. If not, I'm giving you some good simple advice. Even in showrooms be careful of level matching. Without that the auditioning process is highly polluted.

I knew a bench tech at a chain of audio stores that said if they needed to move a set of speakers they would bump the volume up on it and let the customer hit the speaker selector to their hearts content and more often than not leave with those speakers.
 

threni

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Clearly that hadn’t occurred to me. Feel free to go and troll sometime else.
A troll posts:
inflammatory
off-topic/irrelevant
controversial
deliberately upsetting
content. Which of these definitions do you believe applies here?

Given that this site appears to be the only audio-related site not rammed full of absolutely credulous horsesh*t, he'd actually be trolling if he posted that message just about anywhere else. Here's it's on-topic and welcome; it's the "ooh, don't ask me how, I can just tell" crowd who've nothing to offer except perhaps a little ironic amusement to get us through those cold, dark days.
 

Ron Texas

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What's a TOTL module? How about a NAD C328, in stock in the USA and has Purifi modules? 340x2 into 4 ohms.

@Blumlein 88 is not a troll. He is one of the most helpful members of this forum.
 
D

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There's also a lot of science about what is going on in the mind when one does not test blinded. The placebo effect for instance is measurable. More expensive wines for instance give more activation in the pleasure centre in the brain. This means you will really like them more. However this test was done with the same wine in glasses over and over again, with only a different-made up- price tag. So you should consider just buying the most expensive gear, it will give you more pleasure.
 

Ron Texas

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Id love to see the new purifi technology blind tested vs established hypex modules ( all power requirements respected negating clipping ) .

Not happened , the question of why , I will leave for us to ponder.

I would be really surprised if there was a statistically significant preference even with the nastiest loads out there.
 
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