Is Class D actually killing the "soul" of high-end audio?

But shouldn't it be the music itself that creates the ambience of the sound in your room, rather than the kit reproducing it? Some composers write music that could be described as warm, or cool, or strident, or bright, or whatever, and that's how it is intended to be heard - as near as possible to the concert hall performance when sat in the best seat! Best perhaps not to add warmth or coolness, etc to music that isn't intended to have its emotions messed with? :cry:
 
Mechnutt said:
The Ruby with its vintage warm and textured midrange contributes to evoking emotion, what is so hard about that. KEN Ishiwata voiced it to sound romantic and emotional. Neutral or bright sound does not for me:)
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It is quite simple Music is the soul HEA is just gear period... so you need coloration and artifacts injected into your music. You do you, Cheers.

Also never cared for the Marantz sound well okay in 1978 maybe for a week. Had a college roommate with some of his gear. It was relegated to the basement after my HK Citation came into that frat house... Enjoy your colorations, artifacts and affects.
 
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Soul or PRAT whatever you want to call it some gear has a way with timing that better conveys the rhythm or melody of the music. To go there again, this is what is missing from the Class D I've heard. I haven't heard the Ruby or Mola Mola if they can do that, then great.

And again, some are more intent or discerning listeners than others.

If anyone has heard a Conrad Johnson system and not understand gear can breathe soul into music you'll never get it.

The performance is recorded onto whatever medium but it's up to the gear to reproduce that performance. So if the performance has "soul" then it would be up to the gear to convey that. It could be some gear strips any soul from the music. I'm not convinced distortion is what is responsible for PRAT, if so, then distortion is good.

Even before Class D there is gear that is considered analytical. We can assume some prefer that and that's their thing.
 
Mechnutt said:
I have heard warmer Class D amps before. Nuprime makes warm amps and they have a chart comparing the warmth of all their amps. People seem to love their gear.

I had a Marantz PM-KI Ruby integrated that was warm with a very liquid, warm mid range that was just fabulous. It imparted emotion to the music and it had a romantic sound. It was just lacking a little detail, otherwise I would still own it. Its sound reminds me of the 70's Pioneer receivers (own a Pioneer SX-780 that sounds fabulous). The Ruby has a vintage sound to it. Unlike my Levinson integrated which has a modern sound.

nuprimeaudio.com

Amp Comparison & Sonic Characteristic - NuPrime Audio

Read this article about NuPrime's hybrid Class D amp designs that put them on par with the best Class A and Tube amps.
nuprimeaudio.com nuprimeaudio.com
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I've heard good things about NuPrime trying to tune their modules for a more tube like warmth, but it still feels like a workaround to fix what's fundamentally missing in the tech. Interesting to hear about the PM-KI Ruby Marantz definitely knows how to tune for that liquid, romantic midrange, even if it trades off some ultimate resolution. But transitioning from that vintage-leaning Ruby sound straight to a modern Mark Levinson must have been a massive jump in presentation. Do you find the Levinson strikes a better balance of detail without crossing into that dry, clinical territory I'm struggling with?
 
Mr Peabody said:
Soul or PRAT whatever you want to call it some gear has a way with timing that better conveys the rhythm or melody of the music. To go there again, this is what is missing from the Class D I've heard. I haven't heard the Ruby or Mola Mola if they can do that, then great.

And again, some are more intent or discerning listeners than others.

If anyone has heard a Conrad Johnson system and not understand gear can breathe soul into music you'll never get it.

The performance is recorded onto whatever medium but it's up to the gear to reproduce that performance. So if the performance has "soul" then it would be up to the gear to convey that. It could be some gear strips any soul from the music. I'm not convinced distortion is what is responsible for PRAT, if so, then distortion is good.

Even before Class D there is gear that is considered analytical. We can assume some prefer that and that's their thing.
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Conrad Johnson is the perfect example. That liquid, lifelike presentation they pull off is exactly what defines 'soul' in a playback system. It’s definitely not just simple harmonic distortion it's about how the gear reconstructs the transient response and flow of the music without making it sound mechanical. If a design strips that PRAT and timing away just to hit ultra low THD numbers on a graph, it defeats the whole purpose of listening to music.
 
Randy Myers said:
I got to disagree. There are many pieces that produce a certain type of sound, of warmth, of soul no matter what music is played. Certainly, it varies with the music, but I would definitely say some gear, especially some older gear have a soul.
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Older gear was often voiced by ear rather than just being built to satisfy an analyzer. That human element in the design process is exactly why classic setups carry a distinct warmth and character across different tracks, whereas a lot of modern, ultra low distortion gear ends up sounding completely sterile because they only optimized it for the test bench.
 
luizamarns said:
I've heard good things about NuPrime trying to tune their modules for a more tube like warmth, but it still feels like a workaround to fix what's fundamentally missing in the tech. Interesting to hear about the PM-KI Ruby Marantz definitely knows how to tune for that liquid, romantic midrange, even if it trades off some ultimate resolution. But transitioning from that vintage-leaning Ruby sound straight to a modern Mark Levinson must have been a massive jump in presentation. Do you find the Levinson strikes a better balance of detail without crossing into that dry, clinical territory I'm struggling with?
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Well, I actually transitioned down from a Pass X250 amp and a BAT VK51se tube preamp as I am almost 68 and have a bad back. I didn't need to be moving around 105lb amp and a 50 pound preamp. The Ruby was excellent but the loss of detail was not what I wanted. I realized that there would be some trade offs in transitioning but I would have liked a little more.
The Levinson gives me actually a bit more detail and wider sound stage but with the loss of some musicality.
After the Ruby, I got the Marantz PM-10. It had some issues with an indistinct sweet spot and it was actually the opposite tune of the Ruby. It was neutral to bright. The ML was just right.
 
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luizamarns said:
Older gear was often voiced by ear rather than just being built to satisfy an analyzer.
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That would have been pretty long ago! If you are setting up feedback in an audio circuit, you'll need a squarewave generator and an oscilloscope at a minimum to do it. That stuff has been around since the 1950s... from all the 'scope traces you see in the vintage magazines, its pretty obvious that testing was really important.

In tube equipment it is very difficult to run the feedback needed to really make the amplifier neutral. This is because usually the output transformer introduces so many variables- extra poles and zeros, as they say. So too much feedback and you exceed the phase margin of the amplifier and it goes into oscillation.

So its not because of a 'human element' tuning the older amps for a certain sound. They were trying to get the best measurable performance they could at the time. The lucky bit is that the 2nd and 3rd harmonics are musical to the human ear, and innocuous as well, so even though the distortion could not be eliminated, what remained was musical.
 
atmasphere said:
That would have been pretty long ago! If you are setting up feedback in an audio circuit, you'll need a squarewave generator and an oscilloscope at a minimum to do it. That stuff has been around since the 1950s... from all the 'scope traces you see in the vintage magazines, its pretty obvious that testing was really important.

In tube equipment it is very difficult to run the feedback needed to really make the amplifier neutral. This is because usually the output transformer introduces so many variables- extra poles and zeros, as they say. So too much feedback and you exceed the phase margin of the amplifier and it goes into oscillation.

So its not because of a 'human element' tuning the older amps for a certain sound. They were trying to get the best measurable performance they could at the time. The lucky bit is that the 2nd and 3rd harmonics are musical to the human ear, and innocuous as well, so even though the distortion could not be eliminated, what remained was musical.
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The Manely 300B mono blocks I reviewed had a 10 position user adjustable negative feedback dial.

I spent time going through every one. I preferred no negative feedback. It sounded the most natural and organic to me.
 
Michaels HiFi said:
The Manely 300B mono blocks I reviewed had a 10 position user adjustable negative feedback dial.

I spent time going through every one. I preferred no negative feedback. It sounded the most natural and organic to me.
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Is Manley still in business? I haven't heard much from or about them since the company was sold.
 
Michaels HiFi said:
The Manely 300B mono blocks I reviewed had a 10 position user adjustable negative feedback dial.

I spent time going through every one. I preferred no negative feedback. It sounded the most natural and organic to me.
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Here's some peculiar things about feedback.

In a tube amp, its usually applied to the cathode of the input tube. The audio is coming in the grid of the tube, so the two are mixed in the tube, which is not linear.

IMO this is a poor practice but everyone does it that way, mostly out of tradition. IIRC, Norman Crowhurst wrote about this about 60 years ago but didn't propose a solution.

So the tube distorts both the feedback signal and the input signal. Higher ordered harmonics are generated, along with some intermodulations (which can be generated any time a non-linearity is present).

There is a way around that. If you were to invert the phase of the feedback (which can be done at the output transformer), you can then mix the audio with the feedback using a simple resistive divider network at the input of the grid. Resistors are a lot more linear than tubes are, so the feedback signal can be mixed in a far more linear environment.

The result is the feedback is then more accurately able to do its job, with less distortion introduced by its application.

There are tube products that do it this way although its rare in amplifiers. The Leak Point One preamp is a good example.

This happens to also be the way opamps have feedback applied to them. You can do it that way in a class D amplifier as well.

Here's another pesky issue: if the gain and bandwidth of the amplifier circuit is insufficient and feedback is used, what will happen is the distortion vs frequency will show a rise at some frequency were the feedback is no longer supported by the gain and bandwidth. This can cause the distortion at higher frequencies to be unmasked and so the amp can have a brighter and harsher presentation. This was a common problem with solid state amps well into the 1990s.

Class D allows for a lot of gain and bandwidth (known as Gain Bandwidth Product). For example in our class D the GBP is about 20MHz, and since we 'only' have about 37dB of feedback, the distortion does not rise anywhere in the audio band. That is a big reason why the amp isn't bright. Most self oscillating class D amps have this property.
 
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