Good Class D amps ??

[GeneZ]

2 hours ago, esldude said:

Soundlab electrostats.  Not just low impedance in the upper frequencies, but a nasty phase angle approaching that of a capacitor more than a speaker. 

 

 

 

Everybody owns those and drives them with their Sony receivers.  My mom used to have those in the kitchen.

 

Come on folks!    These speakers would give many amplifiers problems, and most people would not own them to begin with. 

 

 

Now.. Interesting point concerning amplifier phase shift:

 

According to the manufacturer, NuPrime amps have no phase shift. Many amps use output filters that create phase shift. When phase shifts, spatial information becomes inaccurate. Most amps present phase shifts of better than 45 degrees at 20 kHz, heading toward 90 degrees as frequency increases. NuPrime amps cancel these distortions owing to a unique closed-loop design producing ZERO phase shift across all frequencies.

https://www.hifi-advice.com/blog/review/analog-reviews/amplifier-reviews/nuprime-st-10-power-amp/

 Note:

 

The reviewer of the ST-10 used Wilson Sabrinas.

[GeneZ]

50 minutes ago, barrows said:

Hypex amps have no such issues with high level sub connection as the "black" speaker output is ground. Additionally, there are simple ways to hook up a sub via high level input to a balanced output amplifier, this is not really an issue At All!  And it is not about Class D, it is about balanced output amplifiers, you just cannot connect the "black" speaker terminal of a balanced output amplifier (could be class D, could be class A, could be class A/B, whatever) to ground without creating issues.

  Good to know....

 

Paul McGowan said that PS Audio amps need the special REL hookup.  That's where I first learned about it.

 

Yet,   REL made a special video for Class D amplifier hook ups in general. 

 https://relsupport.zendesk.com/hc/en-us/articles/115004486607-Class-D-Amp-Connection-Methods

[GeneZ]

Found Nuprime's official word on REL subs.

 

 

 

Can the amplifier’s speaker terminals be used as source inputs (e.g. to REL Subwoofer) ?

In some applications, the speaker outputs from the power amplifier are used as source signals for devices such as REL sub woofer. For such application, usually the receiving devices should have DC offset blocking capability because some amplifier by design has floating ground (DC offset) on the speaker outputs.

The following models have no DC offset on the amplifier speaker outputs and the negative terminal is also the ground:
NuPrime STA-9, MCH-K38, IDA-6, IDA-16

The following models’ speaker outputs can not be connected directly to sub woofer input:
NuPrime Reference 20, ST-10, IDA-8

REL has provided instructions for connecting Class-D amp with floating speaker outputs to their sub woofers, please contact REL.

[GeneZ]

2 hours ago, wgscott said:

I use a class D amp to power my pencil sharpeners:

 

 

That's funny....  Still using lead pencils.

[GeneZ]

1 hour ago, jmpsmash said:

 

The switching power supply in my computer is technically class D. No wonder it tortures me everyday.

 

You may want to try this as a good option other than going the cumbersome linear route. https://www.silverstonetek.com/product.php?pid=481&area=en...

 

Try a solid state drive as well and noise is diminished.  That way you can go fanless,  and even less noise.

[GeneZ]

This page - with video - sheds an interesting light upon Class D when its well implemented. 

 

 

Watch the video to learn something that I did not know. I spoke with an engineer about this and he confirmed its true.

 

This Myth Goes Something Like This: "Switching supplies are noisy." "Linear power supplies are best for audio."

[GeneZ]

18 minutes ago, sandyk said:

 

 

 Not necessarily.

The current demands from the much faster SSDs may result in quite a bit of HF rubbish getting back into the main PSU.

If room permits,  the best way to reduce this is to try and isolate these abrupt current demands by powering SSDs from the +12V supply using an additional voltage regulator set for +5V Output. 

  Interesting to know.  I was thinking of the electrical noise of the constantly spinning hard drive which I assume introduces ripple. Not to mention the audible noise it generates in a quieted environment.

[GeneZ]

On 11/30/2018 at 6:34 PM, sandyk said:

 

 

 Not necessarily.

The current demands from the much faster SSDs may result in quite a bit of HF rubbish getting back into the main PSU.

If room permits,  the best way to reduce this is to try and isolate these abrupt current demands by powering SSDs from the +12V supply using an additional voltage regulator set for +5V Output. 

 

How does one set this up?   Any links to help me see how to do this?    Thanks,   GeneZ

[GeneZ]

6 minutes ago, sandyk said:

 GeneZ

 Do you have a Desktop PC with available internal room, perhaps at the bottom of the case ?

 

Alex

  Understatement ...   The case is huge.   Its a fanless PC with lots of space with ventilation everywhere.

click on picture to enlarge...

[GeneZ]

1 minute ago, sandyk said:

The attached isn't the ultimate, but several members have found that this cheap ebay PSU PCB can make a worthwhile improvement.

It will first need to be adjusted to +5V out before being connected to the SSD  using a cut in half 4 pin Molex to SATA power supply lead.

  I appreciate that.  Thanks.

 

On the other hand...   Looks like what might have been, is possibly no longer the case?

 

https://www.quora.com/Do-SSDs-use-more-or-less-power-than-HDDs-and-by-how-much

[GeneZ]

All I know is that when I switched to a SSD PC the audio quality improved.  There are times when there is a lull in the performance that makes me wonder if my preamp is turned off.  Dead quiet.  Not sure if any tweaks in this area may be necessary.  But I might want to consider upgrading to a newer version SSD because the longevity factor has now been improved.

[GeneZ]

On 3/31/2018 at 5:24 PM, GUTB said:

 

Only you can say if you’re pretending to like the sound or not.

 

I’ll note that no one with high end systems prefers class D.

  No one?   That shows you have no class. 

[GeneZ]

 

 ?

 

I hear you.

[GeneZ]

1 hour ago, jmpsmash said:

 

Lots of trolls in this forum.

 

I will be receiving the Nords today. Gonna give it a few days of burning in.

 

I also listened to the NuPrime ST-10. Quite impressive, great focus and texture, placement and imaging is so precise there is a great sense of presence and realism. It sounds a bit more dark than the NC400 though, the NC400 sounds more open. I wish I have the budget for the Evolution One, I can only imagine how good that sounds.

 

Maybe I will get to do a 3 way comparison.

 

 

  If it sounds dark?   What preamp? What cables?  Speakers?  

 

Mine is effected by anything in front of it. I have made it sound dark with certain speaker cables.  I find its no more darker than what precedes it.  I get a very open 'transparency' with my set up. 

 

Though my speakers are far from what was listened with here.. This review matches my experience.

Amplifier Reviews, Analog Reviews NuPrime ST-10 power amp

[GeneZ]

1 hour ago, jmpsmash said:

 

It sounds darker when A/B comparing with my NC400. Everything else are kept the same. In fact, I think the ST-10 beats the NC400 on all categories except for the sparkle at the upper frequencies. It has clarity and transparency, even at the high frequencies, just that it is not as forward. Mind you that it doesn't have the DTSS mods that yours has. from ppl who reviewed it says DTSS opens up the upper end.  Perhaps the DTSS mod is where it fixes these issues.

 

Its called -  TDSS (no biggy)....   

 

Bob Smith told me can do the same mod to any amplifier.  He first modded my smaller Nuforce STA 100.  When I heard what it did it convinced me later on to have the ST-10 modded when I bought it.  The unmodded ST-10 I guess can sound a bit darker. 

[GeneZ]

1 hour ago, fas42 said:

 

From that review,

 

 

This type of prose always makes me laugh ... as if the amp is doing this 'magic trick' all by itself, because it has some specialness inside it ...

 

Ummm, no. It's the recording, silly , that has these qualities - the "ideal balance" is, that it just gets out of the way, completely, from adultering what's been recorded - sorta what one is after, I reckon.

  If I never heard other amps with my system I might have tended to agree with you.  Yes, a better recording will sound better.  But I listened to better recordings with other amps as well.  Its not all that simple. 

[GeneZ]

1 hour ago, Ralf11 said:

I'd really like to know how the Nords compare against PS Audio's Stellar Gain Cell amps...

   Gain Cell refers to the preamp section of its Stellar DAC.  The Stellar amps are basic amps.  And, very good sounding.

[GeneZ]

1 hour ago, Ralf11 said:

"The S300 combines the slam, linearity, and toe-tapping pacing of a Class D output stage with the warmth, grace, and rich inner detail of Stellar’s Class A Analog Cell. "

 

that's what I thought they used the term Gain Cell for

 

Gain Cell is a means to adjust the volume of a preamp, sans a typical attenuator.  Rather than attenuate the full signal of a signal like a volume control does, the gain cell adjusts the output voltage of the preamp to raise and lower the volume.  Its not a variable resistive device like a volume control.  That's how I understand it.  Paul McGowan explains it in this video.

 

https://www.youtube.com/watch?v=xFdZRLwUI0Y

[GeneZ]

1 hour ago, jmpsmash said:

 

Which really begs the question of why. If the Icepower already has an input stage, adding another fixed gain input stage goes opposite of the less is better philosophy. The only explanation is it colors the sound in a more desirable way that is preferred by the designer.

 

 

 

Why is coloration having to always be bad?   This is an audio system that has glaring deficiencies in the light of what a real live performance sounds like. I have heard too many live performances that I wished I was hearing instead on a good stereo.  Today top bands travel with engineers who know how to better "color" their sound in a given room.  Coloration is the work of an artist. All mastering recording engineers find ways to better color the sound when they can improve what is heard. 

 

There is 'bad' coloration. There is 'good.'  All audio systems color the sound. Every time I recorded my drums what I heard in play back was not what I heard while playing.   Everything gets colored in some way.

 

Now?   Where were we? ?

[GeneZ]

1 hour ago, jmpsmash said:

I was careful to not say that coloring is bad. That's pretty much why we add preamps. Otherwise, everyone will be running attenuated DACs directly into power amp.

 

 

All speakers.. cables... amplifiers... and our rooms add colorations. 

 

DACs?  TT cartridges?   Even TT arms and platters.

 

Probably the gain cell carries with it some sort of coloration most likely.  Yet, it is how something effects the listener's emotions and thoughts that counts.  We are here to enjoy what we hear.  Not to run graphs and measure everything to see if we should be allowed to enjoy.

 

Certain audio rules that everyone tries to abide by may have been originally created out of a necessity for putting the many listeners within a common frame of reference.

 

? .... How does it sound, Bob? 

 

?.... Hi PC Roger.  It measures a higher than usual amount of THD, but everyone who hears it melts in their listening seat!

 

?.... Tell them they are audio hicks if they enjoy it.

[GeneZ]

1 hour ago, crenca said:

 but an older High Fidelity wanted transparency instead or rather as much as you could get given limitations in tech.

 

The irony is?   Transparency only allows for colorations to be presented in a purer way.

 

Chasing wind mills?  Idealistic goal without knowing what can be achieved?  The very room its played back in is a coloration.

 

Though, as a result of the quest for transparency, we have ended up with (potentially better sounding audio systems today.  Greater transparency = sweeter to the ear coloration sound.

 

 

[GeneZ]

52 minutes ago, DancingSea said:

For me, all I care about is that I like the way it sounds.  It’s matters little to me how it got there, colored or transparent.  

  

 

Yup....  Like the jealous husband who thinks all men want his wife, can never truly enjoy his wife, because he is too busy being jealous of imagined rivals.  We need to listen to what we hear and forget about rivals who will tell us what they think we should hear.  Or,  think what we should not hear.

 

??  .. put down that fuse!

[GeneZ]

56 minutes ago, jmpsmash said:

Anyway. Back to topic.

 

The Nords are in the house. Been running them around the clock for the past 2 days. Won't say much before a couple more days of burning in. At the moment they do sound better than my NC400 but not much. They sound completely different than the NuPrime ST-10.

 

Given that, we should stop lumping all class-D into 1 bucket. They each have their own character and sound.

 

 

Every amp... has a taste.

[GeneZ]

1 hour ago, fas42 said:

 

Technically, all systems colour the sound, but there is a plateau of performance where it no longer matters, because subjectively "all you hear is the music".

 

Transient impact is where the problems usually lie is it doesn't sound real - audiophile rigs are notoriously bad at this, because they are trying so hard not to ever sound unpleasant - and lose so much in the prcoess.

 

Drum kits are a good example of this. But it is certainly possible to get a setup to the point where a drummer listening to audio on the other side of a curtain could be fooled by the playback - the main issue would be that the sound had been recorded without significant compression of the stick impacts.

  I find for hearing the 'leading edge' of the music that litz cabling has been the champ for my system.  When I introduced the Nuforce, then Nuprime amps, the leading edge took on even a greater meaning. 

 

Good Class D can be lightning fast.  With AB, it blunted the leading edge heard with real music, even with litz cabling.  Standard cabling made it pleasant, but like someone gave my system nite time cough syrup.

 

Class D, when well-implemented can be like a whip when its found on the audio.  By now I am used to it.  But in the beginning it was an eye opener for me. Drums and bass took on a new life, which was more like what is really heard in a real live performance.

[GeneZ]

1 hour ago, fas42 said:

 

Drum kits are a good example of this. But it is certainly possible to get a setup to the point where a drummer listening to audio on the other side of a curtain could be fooled by the playback - the main issue would be that the sound had been recorded without significant compression of the stick impacts.

 

Drum kits sound startling real on my system.  I am a drummer. Its one of my frame of references when determining a good addition to my audio chain. 

 

Most speakers with typical crossovers will blunt drums because often times the tweeters and mid/woofers are wired in opposite polarity.  For that reason I discovered that first order crossovers will do drums justice.  Even with my (discontinued) inexpensive Cambridge Audio S30's, I found this to be the case. https://www.whathifi.com/cambridge-audio/s30/review

 

I also found that same phenomena to be true with Role Audio Kayaks which have very high quality first order crossover components. https://positive-feedback.com/Issue33/roleaudio.htm

 

If I did not own Audience 1+1 V2's?  These are what I believe I would have gotten for sure.

https://nsmt-loudspeakers.com/Model-15

 

All with first order crossovers if you want realistic cohesive sounding drums. 

 

FYI..  Audience speakers use no crossover.  Desktop nearfield listening makes them my first choice.  Any more bass, and I would be evicted from my apartment. They were the perfect solution for my apartment cave dwelling.