I listen to all of my music streaming Tidal hifi (non MQA) with my Notebook with Audinirvana+ and Dirac Room Correction software (very recomendable). From the Notebook, I have the Audioquest Jitterbug (not a big improvement), then the Wyred4sound USB Reclocker with a Linear Power Supply (a very nice improvement), the Gustard U16 USB converter (an incredible improvement, I still cant believe it), then with a HDMI cable to my Audio-gd R8 Ladder DAC (a very nice and extremely detailed DAC), connected via ACSS cables to my Audio-gd Master 1 preamp (another great piece of gear), then with XLR cables to the Nord (no words needed), and then Kimber Cables 8R to my Q Acoustics Concept 500 tower speakers (amazing ones). Everything is connected to a Bada LB-5600 Power Filter with DH Labs AC Power Plus Cable and three PS Audio Noise Harversters. I use in all my connections Sylclear Contact Enhancer. Im about now to try the Synergistic Research HFT (10 Pieces). We’ll see if they are as good as some people say!!
Very good news that a completed class D amp using Hypex's top NC1200 modules and powered by their top Hypex SMPS1200A700 PSUs will be available soon from Nord for 3,995 pounds ($5,214 usd). With class D amps using the new faster GaN FETs availability increasing and entry prices decreasing, I doubt Hypex's decision to now allow Nord the use of their top NC1200 modules is a coincidence. This new amp from Nord raises a few interesting questions:
Why has Nord limited the class A output current of their custom buffer feeding the NC1200 module in this new amp to 250mA?
Is Hypex clearing NC1200 module inventory prior to introduction of a new top module, or even series of modules, utilizing the faster GaN FETs?
What are Hypex designer, Bruno Putzeys, opinions on the new faster GaN FETs and does he plan to incorporate them into his future class D module designs?
Im about now to try the Synergistic Research HFT (10 Pieces).
You had me reading up till then, lucky it was your last sentence and not your first, if it was I would have ignored the rest of your post, I hope directional ac mains fuses aren't next?
Thank you ricevs, Tim, and Jetter... Admittedly, I have been soaked in music since I was a tod... The only reason why I did not become a professional composer is that my retinas failed me in the late 1970s and could no longer use pencil and paper, so I switched major and took a degree in Comp Sci instead.... Good move, as I managed to make a reasonable living with the maddening machines until I retired at the end of '18. Yet, throughout all this time, music has continued to be an integral part of my life in one way or another.
I have no idea if I have expertise beyond anyone else, or if my ears are good or not, but they are the primary tool that I use to perceive the World... What I sometimes post are the stories about the beauty of music and sound that my ears tell to me... It is my joy to continue to share with you Audiogon friends the tonal magic that I hear through my system.
Hello Tim, Bruno Putzeys has left Hypex more than two yers ago, and as far as I know, he is not involved at this time with NCore technology development.
He has since founded a new company, called Purifi:
https://www.purifi-audio.com/
And within Purifi Bruno is developing new class D technology.... No, as far as I know, Putzeys may not be applying GaN transistors in his new design.
Hi Guido. Thanks for the info, my friend. Very interesting about Bruno leaving Hypex to found Purifi. The progress of class D technology continues to be very interesting and promising.
The input stage on an amp is not an output stage. Output stages have to drive a speaker, so you would not want current limiting. The input stage is just an op amp. Most integrated circuit op amps cannot drive over 100ma. They are using a discrete op amp that can drive 250ma. In fact, the circuit will never need much current at all. As all that will come out of it is a few volts and driving maybe 5K load. They are basically bragging about their discrete op amp. The spec has very little to do with sound. You could have a circuit that could only drive 50ma that could sound better.
Thanks for clarifying. I knew it was a class A input buffer stage, which is good, but wondered if its 250mA class A operating limit would negatively affect sound quality performance. I now understand it will not thanks to your very good explanation.
Speaking of directional mains fuses check out the latest and greatest super power cords from the leader in power cords, Audioquest. They’re controlled for directionality. Doesn’t that burn your butt, Georgie Boy?! 🔥
Hello @aolmrd1241 and @KLH007, I will post some observations about the darling Rowland M535 tomorrow... It won't be the complete review, but I'll try address some differences between M535 in stereo mode, and a bridged pair.
AND THERE IT IS!!! and the bait was very old and smelly. Right on cue, mention one word about SR’s directional AC mains fuses, or HFT’s and the snake oilers sniff it out.
I owned a PS Audio Stellar 300 amplifier. Expansive soundstage and very high resolution. Dead quiet and ran cool. I left it on all the time because of a low current draw. If you are fixated on a Class D amp, this one is quality and won't break the bank.
Hello Class D Lovers and Haters I am following class D discussion maybe in last 5 years and though can’t say anything refer to thecnical barriers for achieving like in heaven sound quality but I’ll choose a good class D over any class A/B or A anytime! Main reason is cost and physical design plus sound quality of class D amps! I think other average users have the same idea and the reason market is leaning to develop more advance amps by this technology , is ppl buy it and love it ( except few picky nerds that try by numbers warn us about this fraud ) Best advice for ppl is to test them by themselves , buy a second hand with good reviews ( not those mainly advertised by media but by ppl that have used them) just add a good tube pre amp and you won’t regret it unless you enjoying be the one who always like the old ones ;) p.s) I am not working in audio business so that is my honest opinion ! Cheers /Kevin
yes there are uber expensive class D amps that may or may not be any better than Nord, but here in the USA, PS Audio is leading the way with their Ice Power M700s ($2998 @
350/700w the pair!) and matching Stellar Gain Cell Dac/Pre $1699, plus 2 trusted names, EVS and Atmosphere will soon debut their offerings
I just hooked up the PSA GC dac/pre to compare to my Audio Alchemy DDP-1 + PS 5 power supply ($1995 + $650)
next week I will hook up the M700s to compare to my AA DPA -1 stereo amp
First I hooked up the PSA M700s with my AA DDP-1 and finally a PS 5 power supply. Why these were ever sold separately is a mystery as the PS 5 unleashes the DDP-1s true potential
My big issue in getting the M700s was the small but mighty AA DPA-1 just wasn’t driving my big ass room, so... enter the M700s. I was told by the seller they had maybe 200 hours, and I’ve read that 300 begins to reveal their wonderfulness. They’ve been powering the EP KCIIs since Saturday evening. And yes, my room needed that double the power, but possibly Edge 1200s will be in my future, but as of last night when I spun Diana Krall Impulse: WOW
Texture in spades, expansive and sweet sound reminiscent of Rogue M 150s with cryoed tubes; along wth ample power. I hear zero nasties unless recorded on the cd, and boy I can really hear how poorly mastered some cds are
At 4k the pair, GaN can wait
So AA is for sale, but not because the PSA blows it away, although it does in this room
tweak1: "I hear zero nasties unless recorded on the cd, and boy I can really hear how poorly mastered some cds are."
Hello tweak1,
I'm glad you like the initial sound of your new PSA 700M amps. My class D amps have only improved in sq over time. Some of the main and most obvious characteristics of good class D amps are their neutrality, low distortion and low background noise level. These qualities combined together results in a highly transparent and detailed presentation that is very revealing. As you're aware, good recordings sound amazingly good but bad recordings sound obviously bad, too. However, I don't think anyone would describe the accuracy of good class D amps as a downside. I believe a person can be guilty of being too truthful and honest but not an audio amp. Some may prefer a less revealing amp that doesn't so clearly demonstrate the poor recording quality of some of their musical content. It is frustrating to discover some of your music was not well mastered and recorded. But I still prefer the accurate and honest attributes because the good recordings sound so incredibly good. Unfortunately, good recordings of good music are not as abundant as I'd like but that's a whole related subject that's justifiably been the topic of other separate threads in the past.
I have a few torture dics- Annie Lennox Annie Lennox (solo) Jennifer Nettles Playing With Fire and Wilson Philips. It had been a couple weeks since playing JN and although the poor recordings sucked, they sucked less, as the M700s were able to unravel more; or was it the dac in the Stellar GC... or was it that the amps took better control of my speakers..., or the large space, or some combination? Hard to tell
Last night and this morning the XLO break in disc has been on repeat to expedite that final bit of break in. Probably should have done that from day one.
Hey Guys, Any thoughts on this guy's passive pre's?
I was looking at them, it seems he uses high quality SMD Dact style pots; but I'm a little skeptical because of the price. Is it possible the pots he uses are cheap "knock-offs"? The price-point is really good; but it could be the hint as to what the product really is. Has anyone tried one of these passives?
I was also looking at the Parasound Zpre3; seems really nice. But I wonder how neutral it is being that it's not a passive type preamp.
Understood. I no longer listen to Coldplay discs on my home system due to poor recording quality but I still enjoy these discs on my OEM car system. I've discovered that music files recorded direct to digital are especially good source material that are consistently well recorded and mastered. I have several hi-res 24bit/96KHz FLAC files downloaded from a Dutch site called Sound Liaison: https://www.soundliaison.com/
These are all direct to digital master recordings of live music played at their large studio. Downloads are available in various digital formats from FLAC to DSD. The audio quality is excellent top to bottom with uncompressed dynamics that make them easily sound better than my ripped cds.
I have 2 burn in discs that I use. For some reason I neglected to use them as soon as I inserted the PSA kit. Last night I hit replay all and let one spin for at least 5 hours (muted of course), then again this morning for a couple more. I then played Jennifer Nettles Playing With Fire, which I played the day before the burn in disc.
Far from erased all issues, BUT, nonetheless an amazing transformation. The entire sound stage is more spread out. The location of musicians and backup singer,s as well as tone and clarity is significantly improved
I suggest auditioning the Mola Mola Kulga class D amps for exceptional performance. Hypex 1200 implementation is key, so not all Hypex 1200 amps will sound the same. Also, because an amp uses GaN doesn’t necessarily make it better.
my experience in owning= Lamm ML2.1 M2.1 M1.1 ARC D400Mk2 Music Reference RM9mk2, RM200, Theta Citadel 1.0 &1.5, Rowland 501, ATI mosfet amps, Line Magnetic, Auralic Merak, Classe 400 etc.. I have never cared for latest Mark Levinson, Classe or other bi-polar output amps.
My systems have always required hi-current amplifiers for tough load speakers, Wilson WP7, Maxx1/2/3, Magnepan, Rockports, NHT 3.3. My latest speakers all drop to 1.7-1.8 ohm in bass region but are nominal 4ohm 89 db Sensitivity. CAVEAT - This might be why these other digital amps struggle in my system due to power supply designs.
I think you really have to break up digital amps into classes. If you try a digital amp with less than 200hrs on it, you will be unimpressed they really need break-in time. I found these amps to be hard, with a closed in soundstage and very sterile during break-in.
First off older Digital Class D amps were smooth but sterile ex= Bel Canto, Rowland 201/501, Spectron, etc and really responded to power conditioning.
The Current generation of Digital amps with switching power supplies now are smooth but with faster dynamics but I still find them lacking warmth or emotion. They are attractive to people because they don’t generate heat, use very little power and are cheap. Plus people can put a tube preamp and change cabling to warm it up. It’s amazing what you can buy today compared to 15 years ago.
the 3rd generation uses a combination of amplifier technology and this method I think is a winner. Auralic Merak, Devialet Expert Pro with Roon, PS Audio M700 . These manufactures basically use a variant of Class A driver amp with a Class D Current Output. Best of both worlds in my opinion. Finally, these amps all use high-quality linear power supplies instead of dirty cheap switching power supplies and this is key. To take it up another level I found using a filtering power conditioner like Transparent PIMM dropped the noise floor and solidified imaging even more. My Shunyata Vray makes a larger airy soundstage compared to the solidified Transparent and doesn’t drop the noise floor as much. The latest Devialet with Core Infinity and using Roon over a network eliminated the need for reclockers, usb anti-jitter boxes, and that extra gear. we tried the latest Devialet 140 Expert Pro core Infinity at 4 peoples houses and it wasn’t bright on any system and we were feeding it with a bluesound server and streaming services with Roon. My friend added a Roon server and started streaming that method and everything got cleaned up compared to direct attach. we also found that the 4 sub $300 digital cables all had their own flavors but the Transparent Reference digital cable destroyed them with clarity and no bass bloat. Once again direct attach.
Right now I am waiting on my friend to get 200hrs on his PS Audio M700’s to compare to my Auralic Merak on my Rockports and then compare that to my memory of the Devialet. Also considering the latest Theta’s as my current Theta Cidal 1.5’s are extremely organic but not digital.
I wish this thread talked more about how the amps sounded in their system instead of talking about the chips. The sound is what matters and their synergy with your other gear.
Also, because an amp uses GaN doesn’t necessarily make it better.
But one that does will make it better sounding than the "equal" one that doesn't, if both come from the same manufacture using the same topology, save for the output stage (GaN against Mosfet).
Just like: Plasma v LCD v LED v OLED, Iphone 4 v 5 v 6 ect ect Better technology in the parts = better sound in the end for Class-D.
"Also, because an amp uses GaN doesn’t necessarily make it better."
Hello toetapaudio,
I mostly agree with georgehifi on this one. The critical factor is eliminating or significantly reducing dead time which reduces distortion.
The use of GaN FETs, rather than silicon MOSFETs, is one method of doing this that seems like the method most companies are utilizing. The only exception I'm aware of is Ralph at Atma-Sphere that is developing their own version of a high quality class D amp. Ralph has announced that they developed their own circuitry that eliminates dead time whether utilizing MOSFETs or GaN FETs. They have a patent application pending on this circuitry. However, I believe Ralph stated that using GaN FETs along with his new circuitry would likely just further enhance his amp's sq performance.
Either way, dead time is going to be dead as disco.
Cyloc, as a very happy owner of M700s paired with Stellar GC, 200 hours isn't near enough, unless break in is with a break in disc. Im looking forward to his response
And yes, cables & ICs matter- A LOT.
Last night I spun The Eagles The Very Best Of ( 2 CDs). CD -1 was not well recorded, but dics 2 was, and the best Ive ever heard it sound by a wide margin
I have read through a fair amount of this thread but the back and forth between George and others became pretty tedious. I think the only solution to the "current class D is dandy" and the "current class D is too flawed to compete with A or A/B" war is this: A blind test - perhaps ABX if possible set up for George and or any proponents on the other side of this disagreement. If George can tell the difference between quality class D and class A/B amps in a blind test then his assertion would hold more merit for me. I don't own class D currently, FYI.
I've looked at some of your other posts, and my reply is.
Tedious maybe to those that have no understanding of it's technology. If you don't have the technical ability to see what the new GaN technology is all about, then it's best if you don't even comment on it, as it shows a large degree of incomprehension.
really! water off a ducks back, if anyone believes in snake oil, voodoo ect such as fuses, mains leads ect ect. Instead of what all good equipment was built using, EE laws, measurements, bench tests ec ect. I rather not have them as as you say "my fans" it's detrimental to what I believe.
So, George, notice that I didn't call your posts tedious, just the constant back and forth. So thank you so much for the personal attack. Much appreciated big guy.
Then this, that I noticed you quickly deleted. You’ve deserved everything I"ve said
clarinetmonster2 03-02-2019 8:56pm EST To quote you:The bad being "switching frequency noise".Now put your money where your mouth is and show us that you can hear "switching frequency noise" in a blind test. Pretty cut and dry.
George I deleted it to be nice and to not get involved in the pissing contest anymore, but here we are. But I still would put forth you have absolutely 0 chance of hearing what you claim is a serious downfall of current class D.
I heard the Muraudio room in Florida and it sounded incredibly shrill and thin on anything besides chamber music. On the other hand, one of the most musical rooms I heard at the show was the unassuming MOFI system with Falcon LS3/5's and a Dr. Feickert TT powered by the very fine sounding new Primare I25.
Maybe others who heard it will chime in. I had high hopes as I've been wanting to hear Merrill for awhile now and the speakers seemed intriguing at least. Unfortunately the synergy was not there at all with this system to my ears. I would like to hear the Merrill amps on speakers I'm more familiar.
"merril audio had his christine pre and 116 monos driving Muraudio Stats and that sound was so real it was scary. no embelishments or exaggerations here! items in the sound scape were tangibly and naturally presented. fascinating. really."
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