Bruno Putzeys ‘Life on the edge’

[mhardy6647]

Esl with high impedance at low frequencies and low impedance at high frequencies paired with the high output impedance of tube amps is one such synergy.

Hmmm... that could explain the pair of ESL-57s that live here.
Yes, exactly so -- and that near short-circuit impedance at high frequencies could be rough on some of the ESL-57's contemporary ss amplifiers. They are an interesting load.

 

[fcracer]

Bruno discusses class-d evolution and much else,

Life on the Edge - A Personal Perspective on the Past, Present, and Future of Class D Audio Amplifiers - HomeTheaterHifi.com

The past quarter century of class D developments look strikingly different when seen through the eyes of the audio consumer and through...

hometheaterhifi.com

Courtesy of hometheatrehifi
Keith

Fantastic read. Love his sense of humour and humility. He’s so right that there’s lots of room for differentiation in hifi beyond amplification. Using my M33 as an example, there’s plenty of space for someone to create a higher end version of this (already amazing) integrated amplifier. Some astute manufacturer can:

1. Improve the case by making it higher quality (better speaker connectors, better volume knob)
2. Increase the refresh rate of the front touch panel and make it OLED
3. Add Dirac ART or bass management
4. Fix the intersample over distortion issue
5. Give it a proper remote control
6. Improve the innards even though I doubt it would make much difference to durability given how cool this amplifier runs, but it would make me feel warm and fuzzy knowing it has higher quality caps
7. Increase the warranty to five years

I’d pay an additional $2-5k for someone that makes this. I’m sure there are others too because the M33 when new was selling above retail where I’m based.

 

[eddantes]

Stereo is dead (when geezers like us leave the world). Long live the era of the soundbar.

Years from now they will gaze upon the IRS Beta, the Magnepans, the 4350a, the M1s, and the Jensen Imperials in wonder. Small tourist business will form around them, selling thotchkes and ice cream as the people come to gawk at the absurdity and the magnificence. They will wonder who were those magnificent bastards that dared with audacity... And we will look down from above and smile, as the wind wispers "We were there. We heard the music."

 

[pjug]

A challenge for you! What pile of "Steampumk" boxes would match the sound quality of the M33 at a lower price? And how can that be if the pile of boxes by definition includes 3 cases (often a very costly item), 3 power supplies, 3 power cables and a bundle of interconnects. It just doesn't make sense, or the innards of that pile of boxes is seriously compromised as so much cost goes into what is shared in an all-in-one.

I suspect you've not had an M33 in your system. I have and chose it after comparing sound quality with numerous other amps. It really is very good.

I think getting off topic so I hope we don't have too much back and forth on this.

Here is my system compared to the $5000 M33. No dirac live(don't want it I just do minor low frequency room correction which I do with Roon but which the Wiim could do just as well). I don't care about balanced. I didn't realize the M33 had so much power, so I have to change what I said to equivalent power at a much lower price. To do more power and still pay a lot less I could upgrade to Buckeye amp or something. My speakers are 85dB and the Outlaws are silent so lower noise of the M33 would be wasted on me. Again, Buckeyes would give the same as the M33. I don't blame anyone who wants something like the M33. I wouldn't buy it because unlike @restorer-john, even with manuals I couldn't repair it if it breaks (I have fixed my own older NAD amps). Again, my system does not give the same feature set as the M33, but it gives exactly what I want, so I hope I was clear that this is the advantage of separates over something like the M33.

System 1	NAD M33	$5,000​
System 2	WiiM Pro	$150​
	Pro-ject Pre-Box Ds2 digital	$700​	(I paid $900 for the one with wood)
	Outlaw M2220 (x2)	$700​
	total	$1,550​

 

[pogo]

Buckeyes would give the same as the M33

No.
I only know Lyngdorf, which plays in the same league with bridged 1ET400A.

 

[Purité Audio]

Stereo is dead (when geezers like us leave the world). Long live the era of the soundbar.

Years from now they will gaze upon the IRS Beta, the Magnepans, the 4350a, the M1s, and the Jensen Imperials in wonder. Small tourist business will form around them, selling thotchkes and ice cream as the people come to gawk at the absirdity and the magnificence. They will wonder who were those magnificent bastards that dared with audacity... And we will look down from above and smile, as the wind wispers "We were there. We heard the music."

Or ‘how could we have been that gullible’.
Keith

 

[pjug]

No.
I only know Lyngdorf, which plays in the same league with bridged 1ET400A.

I really don't know but I bet you can find budget power amps with a lot more power than the M33 and similar noise.

 

[pogo]

The NAD implementation of the 1ET400A design is very special, especially at 2 ohms, as you can see here (headroom, non-bridged): Link

 

[Multicore]

It is a good article but not without flaws. Take this:

"Every time I and afterward my competitors made such strides, class D amplifiers got accepted into ever higher strata of the Hi-Fi market. Not because of how they measured, but because of how they sounded. Barring a few geeks and cranks, nobody buys an amplifier based on measurements alone."

He is completely wrong about this. Class D had and continues to have a terrible reputation for "sound" quality. I constantly see pushback against them. I would say 99% of the high-end subjectivists consider it non-starter. Class D's technical achievements are great, but its marketing stinks.

At the risk of being immodest, it us that came to rescue class D. We created rankings. Showed the good and bad. And designs such as Brunos floated to the top. Folks started to take notice. I have seen this clearly in our local audiophile group.

I dare say outsid of DIY forums, few heard or cared much about Hypex amps 10 years ago. Today it is massively different. Yet the sound has not changed.

And on sound, we all know that it is impossible to show that sound advantage at the top tier of class D. I don't know how a person who is on the objectivist side of thinks believes in drinking our Koolaid that much.

Finally, he seems to be unaware or ignoring the incredible transformation we have seen in class AB designs using active feedback. Has he not seen what Topping has done?

In low power department, when it comes to lowest noise and distortion, Topping rules by a mile.

We have all seen how the TI chip based implementations from likes of Fosi and AIYIMA show that you can bring class D performance to be "hi fi" for so little amount of money. This is another revolution. Again, fueled by the demand we have created for great objective performance.

Purifi came to us on the launch of their amplifier. I assumed they knew how critical it was to show and compare objective performance of their amps and not "the sound."

I see you cleared your throat at the same passage that I did.

I want to agree with both of you. There's more than one way to approach the task of persuading the market. Perhaps Putzeys understands this and believes that the ASR and its ilk have one side well covered and he wants, in this article, to take another approach that involves extravagantly flattering the golden ears of Class D-curious audiophiles, fence-sitters, etc. And I think that the statement about "accepted into ever higher strata" can be understood as saying that venerable brands have been adopting it.

 

[eddantes]

Or ‘how could we have been that gullible’.
Keith

Perhaps. But any labour of love; or a monument to passion, I wouldn't ascribe to gullibility. Innocent love is the purest love.

 

[Mart68]

Or ‘how could we have been that gullible’.
Keith

I think it's the people who reckon a telephone and some ear buds is sufficient who are naïve.

You can't beat a good set of big speakers and a powerful amp. A man should have a proper stereo. I'd make it mandatory.

It's always been a niche interest though and I suspect it always will be.

 

[pjug]

The NAD implementation of the 1ET400A design is very special, especially at 2 ohms, as you can see here (headroom, non-bridged): Link

On noise, it doesn't seem the M33 is anything spectacular. You don't think you could do better (more power, better SNR at max power) with a dedicated power amp, and for a good deal less money?

 

[Multicore]

Or ‘how could we have been that gullible’.

I can only speak for myself. Because I was young and stupid and easily seduced by well-told stories. It's taken a very, very long time to make any inroads in correcting the silly old beliefs and protecting against the hazards of being stupid and an easy mark.

 

[Multicore]

I still have a couple of Tact amps shown in the article. Those and the Tact RCS are what made me leave tube amps.

When did that happen?

 

[pogo]

On noise, it doesn't seem the M33 is anything spectacular.

In the real world, other things matter (one example):
NAD has added a gain stage to increase its headroom so that it works better with the DSP circuits of its room-correction software and tone controls. NAD concedes that this slightly decreases the M33’s signal/noise ratio, but with careful design and premium parts, and because the Eigentakt’s S/N is so low to begin with, the noise is still inaudible.
Source: soundstagehifi.com

And even on speakers that require little power, such as those from Avantgarde Acoustic, the M33 performs flawlessly and without any problems.
Btw., last week I fell in love with the new Colibri system with one sub from AA.

 

[pjug]

In the real world, other things matter (one example):
NAD has added a gain stage to increase its headroom so that it works better with the DSP circuits of its room-correction software and tone controls. NAD concedes that this slightly decreases the M33’s signal/noise ratio, but with careful design and premium parts, and because the Eigentakt’s S/N is so low to begin with, the noise is still inaudible.
Source: soundstagehifi.com

And even on speakers that require little power, such as those from Avantgarde Acoustic, the M33 performs flawlessly and without any problems.
Btw., last week I fell in love with the new Colibri system from AA.

On this I agree. That is why the noise in my Outlaw amps is no problem for me with 85dB speakers.

 

[Multicore]

I'm not sure there is much of a demand for HiFi any more.

Are we too snobbish to consider Sonos HiFi? It doesn't sound good enough?

Do the younger generations really care?

To an extent they do. I'm not sure how much but I think Schiit Audio and its ilk are good for younger people who want to get into the amateur audio systems engineering hobby.

 

[antcollinet]

Unfortunately that's not really possible today without a good acoustical room.

I disagree. I've spent most of my life being totally unaware of room acoustic's importance to hifi, and still had sound I loved.

No-one I know who has audio systems even use DSP, let alone room treatments. It is all icing on the cake, not the cake itself.

 

[Bjorn]

I disagree. I've spent most of my life being totally unaware of room acoustic's importance to hifi, and still had sound I loved.

No-one I know who has audio systems even use DSP, let alone room treatments. It is all icing on the cake, not the cake itself.

If you been unaware of acoustics, how can you know with no references to compare to?

 

[copperblue]

Perception works like that. How can I claim X wine tastes great unless I have tasted, in the opinions of top Sommeliers, the best wine in the world?
If it sounds great to you it sounds great, which takes us back to Bruno and his opinions on soundbars, earbuds, etcetera.
Fascinating article.