So, let’s get into some meaningful spec-manship. Let’s compare the frequency response, and output impedance (8 / output impedance = damping factor) of ICEPower and nCore to see about what could matter with different speakers. Here are the source docs I start with: Ncore docs: https://www.diyclassd.com/documenten/download/860ICEPower : http://www.icepower.bang-olufsen.com/files/solutions/icepower250aspdata.pdfI’ll use a couple of examples. My own custom built speakers which have around 9 Ohms of impedance at the top octave, and ESL’s which are basically giant capacitors, and murderously low impedance at the top octave often near 0.3 Ohms.
I should point out most SS amps have coils at the output to protect
from hyper-sonic oscillation. This coil acts as a low pass filter and will cause the frequency response to droop at the top octave. This is not by
itself unusual or ONLY about Class D amplifiers.
Using a "normal" speaker like mine let's examine how the output impedance changes response at the 20kHz mark: nCore: -0.003 dB ICEPower: - 0.3 dB 0.3 dB isn’t inaudible.... but VERY subtle. Below this, in the bass where many speakers get difficult to drive, there’s only tiny differences in response. Certainly better than most tube and zero feedback SS amps. This is a small difference which fits well within the idea of "system matching" an amp to personal preferences, speakers and room tuning. But let’s take an extreme case of an ESL which has around 0.3 Ohms in the top octave: nCore: -0.08 dB ICEPower: -6 dB This is a case where the nCore could make a very significant, audible difference when playing the same speakers. My point to this is, based on specs, both modules will perform very well with normal loads. Any differences in the top octave may be inaudible, or useful. This is one example of where I think specs and technology can help us understand how to match an amplifier with our system better. Best, E |
I wanted to describe an additional benefit of good class D amps that I quickly discovered after switching from my former class A/B Aragon 4004 MKII amp to my first class D amp, a ClassD Audio SDS-440-CS stereo unit and is a quality of all 3 class D amps I’ve owned thus far: the latest 2 are an Emerald Physics EP-100.2 and a pair of D-Sonic M3-600-M mono-blocks.
It’s a benefit I never read about in my prior research on class D, still don’t read much about and that I believe is common to all good class D amps and not unique just to my 3 amps but I’m not currently certain.
As many of you already are aware, humans generally perceive bass and treble frequencies to be attenuated relative to mid-range frequencies when listening at lower volume levels. This means as volume is reduced, the less we perceive the bass and treble frequency extremes and the more the mid-range frequencies predominate; which flattens out the perceived sound since the mid-range frequencies are accurately perceived but the bass and treble frequencies are perceived as under emphasized. Some of you are old enough to remember ’loudness buttons’ on receivers from the 1970-1980s. These controls were used to boost the bass and treble frequencies when listening at lower volumes to compensate for this known deficiency in human hearing.
Okay, enough preamble. I’ll describe the class D benefit now even though I haven’t yet thought of a better short description of it than ’a consistent and continual loudness contour’. I began carefully listening to my first class D amp at a lower volume and immediately noticed the sound was much different than I was accustomed to with my class A/B amp at lower volume. There was no flattening of the frequency range, I perceived the entire frequency range of the music with seemingly no under emphasis of the bass and treble. This struck me as amazing since it was the best I had ever heard my system sound when listening at a low volume.
After a few days of listening I decided it was safe to experiment with higher volume listening levels closer to the levels I formerly listened to music at with my class A/B Aragon amp (probably in the 70 db and up range). As I began slowly increasing the volume, I was pleasantly surprised to notice the frequency range balance or perspective of the music remained constant while everything within this perspective just gradually increased in volume. The music sounded well balanced and enjoyable from low volume to high and all points in between.
This well balanced frequency perspective was also consistently maintained even at volumes well above my normal listening level.
Some of you with higher quality systems are probably thinking ’what’s the big deal’ about turning the volume up and the music just gets louder without the fidelity or overall frequency perspective within the sound stage changing but this was revelatory amp quality behavior in my experience. My former Aragon didn’t sound near as good at low volume levels and required volume levels in the 70 db plus range to sound its best in my opinion. Music at low volumes seemed to flatten out with attenuation in the frequency extremes.
I’m a bit embarrassed. As I’ve written this post, I’m thinking the quality of my former Aragon class A/B amp may have been lower than I thought or it was gradually aging and sounding worse just prior to the power supply caps leaking and it going belly up. Perhaps I was just hearing the difference between an older amp on its last legs and a brand new class D amp of good quality.
Well, at least I consider the good sound quality at any listening volume a class D benefit and hopefully others who may enjoy listening at lower or very high volumes will find this attribute useful as well.
Thanks,
Tim
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Hi Erik, the big old ICEpower 1000ASP also had an output
impedance of 1000… Perhaps that is one of the reasons why it outperformed the
authority of the Boulder 2000 series in authority on Die Muzik…. Not sure of the
damping factor of less powerful modules though.
The audible difference between an old ICEpower 1000ASP and
an NCore NC1200 is that simple amps based on the old ASP1000 with little design
around them did not sound terribly good, no matter how much they were broken in….
ASP 1000 gave the high current, the raw resolution, the compatibility with
difficult speakers, but could sound quite harsh unless the designer created a
solid input stage to raise input impedance and attenuate common noise….. The
native power supply was somewhat weak in regulation…. The better amps used
regulated custom SMPS, and at least in the case of M312 and M301 also an
integrated power factor corrected rectifier to avoid any grundge contaminating
the signal….. So much so that rowland created an external rectifier called PC-1
which could be used with some of his lower end ICEpower amps like M501, M201,
and M102.
Here then comes NCore NC1200 with its companion NC1200/700 unregulated
supply…. Turns out that a simple implementation of this module inan amp, even
without the amp designer doing too much in custom active circuits, usually
outperforms any sophisticated class D amps created round the older ICEpower
1000ASP modules. Then, if the designer does apply his more sophisticated input
stages, power regulation, power supplies, and rectification to NCore…. Things
sore.
Having said the above, I have not
tried the latest generation of ICEpower 1000ASP, but I have heard that they are
much more musical than the older ones.
Guido
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I'm just saying that I am open to the possibility that different Class D amps, like their linear counterparts, may sound different on different speakers.
But if this IS true, I won't attribute it to Class D vs. linear.
I believe nCore's do have exceptionally low output impedance across the frequency spectrum compared to ICEPower so I'm not surprised. :)
It also depends where your speaker is difficult to drive. With my speakers, there's unlikely to be much difference since they are easy to drive. ESL's however have the hardest trouble at the top end. I would not be surprised if the difference between an nCore and ICEpower module was more measurable/audible with them.
Other speakers, like say Focal's with double woofers, are hardest to drive in the bass, a place where both nCore and ICEPower excel.
Best,
E
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Hi Erik, the inability of class D amps to handle difficult loads is one more urban legend.... Most non-trickle down modules that I know have damping factors of 1000 or better, and deliver 30A or better..... NCore NC1200 for one thing drive my difficult to handle Vienna DIe Muzik, with their wild impedance curve, without batting an eye... Even the little Merril Teranis could do it without a sweat, once we raised its gain to 029dB.
In olden days, I heard a ROwland M312 (ICEpower 1000ASP) totally trashing the authority and harmonic resolution of a big Boulder 2000 series monoblock pair driving Die Muzik... Not only my opinion either... there were about 15 people in the room.
Guido |
Hi @guidocorona
The general principles that a higher switching frequency with better transistors yields lower distortion and higher efficiency is not really in question.
I question the audibility of anything measurably better than the current state of the art from ICEPower, nCore or Pascal. I question the importance of 0.03% distortion vs. 0.003% vs. 0.00000001%. Having a baking scale that measures in femto-grams does not help you bake a better cookie.
If there are audible benefits, I think the answer will be somewhere else. Such as linearity (lack of compression), noise shape or handling difficult to drive speakers (complex impedance curves), etc.
I won’t get excited at all right now over an amp with a high switching frequency, or lower distortion. Especially not at high end prices.
There may be audible differences between the major Class-D technologies, but harping on things I think were solved a decade ago I don’t think will help me find a "better" sounding amp. Maybe a "different" sounding amp though.
Best,
E
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@noble100 Tim, I love your quote from the upcoming issue of Acta Philosophica Refutata (Vol XXVIII, Feb 29th, 2017.... I have not yet received this issue *Grins!*
Jokes aside, it is my understanding that this conjecture -- it is not a theory in the scientific sense of the word -- asserts that switching frequencies of at least 1Mhz are expected to reduce harmonic distortion to 0.005% or better.
It happens that 0.003% has already been achieved for the entire audible frequency band: Mola Mola Kaluga which uses enhanced versions of NCore NC1200 and its matching power supply. ROwland M925 and M825 are also below 0.005% while using stock NC1200 modules.
But let us come down to Earth from the audiophrenic stratosphere above.... The reasonably priced $2500 Merrill Teranis, based on the lower cost NC500 NCore module, declares a THD of 0.005%, thus achieving the preported distortion goal, using a trickled-down version of NCore, with is mainstream switching frequency of about 450 Khz.
G.
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Also, the meters on the Technics SE-R1 are super cool. Wish I could buy the casework alone.
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At $17k a pair? No. No thank you.
I’ve heard current linear amps that were about that expensive and I wouldn’t switch to them either. To me the idea that we need super technology to finally fix the Class D problem just wont’ fly.
Blame my tin ears if you must, but this was solved a decade ago.
Best,
E
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"randy-11
higher switching frequency moves it further from the range of human hearing and enables "kinder, gentler" filtering
georgehifi+1 many times over Randy, seems like your one of the few that get it here!"
randy and george, I believe I understand george's often stated theory that the current typical class D switching frequency is too low at about 500kHz and results in sonic anomalies within the audible human hearing range of 20 Hz to 20 Khz. This theory further claims that raising the switching frequency to the 3-5 kHz range will cause these sonic anomalies from affecting any frequencies within the audible range of human hearing capacity. My issues surrounding this class D switching frequency theory, that apparently both of you now support, are twofold: 1. Whether to believe 2 people on an audio forum named randy and george, of uncertain class D technical knowledge and credentials,claiming this switching frequency theory is valid but offering no supporting evidence OR whether to believe the actual inventor of class D amplifier technology named Bruno Putzeys who seems to assign no validity to this theory and has stated that "500 kHz is a completely reasonable class D switching frequency". Written down like this, it seems like an especially silly and obvious choice to me concerning whose advice I should rely upon in evaluating this theory. Are you two really suggesting I simply ignore the inventor of Ice and NCore class D power modules and just trust your viewpoint instead? If it was empirically proven that these sonic anomalies exist and are audible to a significant number of humans, I admit I would be curious to determine if it improved the sound of my system once the price was much more affordable As it currently stands, however, I'm not convinced I should care since I've never even heard a hint of any sonic anomalies from any of the class D amps I've used in my system or any I've ever listened to in any system. As Aristotle so famously asked Plato so astutely long ago: "If your class D amp had a switching frequency proven too low and it caused audible sonic anomalies, but you could not hear these anomalies, would they even exist to you?" That hipster Plato then replied to his teacher in the following lesser known and less famous manner: "Mr. Astute, if I cannot hear them pollute then it does not compute and I know the point is thus moot so I properly cease to give a hoot." True story.
I'm with Erik and Plato on this one; I've been living with dreamy sounding amps for a while now, too. I don't need my switching frequency increased to have what I consider the best, either. Later, Tim |
You know what I like about my Class D (Primare I32)?
It sounds really, really good. I have no idea if it has ICEpower or NCore, or Hypex in it, and I'm really not sure I want to learn enough to know if it matters. Every time I get more educated on the technology of HiFi it causes gear-lust costs me money. I'm much better off listening in blissful ignorance.
Seeya, fellas. |
It’s because a simple low order output filter can take the amps full power, but it’s effects reach down into the audio band and still leave some switching noise left overs, hence the need to take it up much higher as Technics did with far higher switching frequencies, so they can be effectively removed, without effecting the audio band. These days when Stereophile tests a Class-d amp, they put on an external output filter, the Audio Precision’s AP0025 filter, which has a -50db rolloff after the audio band so the 1khz square waves look half decent without the switching noise embedded right across it, (good for sales) 10khz square wave still looks a mangled mess though, trouble is this AP filter can only take very low power, would be real nice to leave it in to listen to, but it would blow up in a micro second. http://www.stereophile.com/content/class%C3%A9-sigma-2200i-integrated-amplifier-measurements#31YFAPfYVDGeowzZ.97 And yes steeper filters as you said do have their own set of problems re sound, as ML found out with their No.53 monoblocks. Cheers George |
I always thought the gentle filter slope was b/c steep "brick wall" filtering caused audible distortions...
I do agree that the amplifier is the closest component most of us have that is near perfection. Speakers, room tmts, DACs, source material... all are in more need of improvement on a relative basis. |
I'll lay money on it Eric your the one of the first to change to the higher switching speeds when they come available/affordable, hopefully soon, judging by Technics lead in this area of higher switching speeds.
I know I will sell my inefficient, hot, heavy, boat anchors just before it happens, before they become worthless, as will today's Class-D amps.
Cheers George |
Always fun to talk tech.... but I've been living with dreamy sounding amps for a while now. I don't need my switching frequency increased to have the best.
E
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randy-11
higher switching frequency moves it further from the range of human hearing and enables "kinder, gentler" filtering +1 many times over Randy, seems like your one of the few that get it here! Just to add to that, the "gentle" filter is on the output speaker terminals, and has to take the full grunt (wattage) of what the amps gives out, it has to be "gentle" (low order), if complex it would soon fry up. Or as Mark Levinson tried with $$$$ the No. 53 monoblocks, a higher order filter and massive to take the grunt, (as you can see by the 4 x chokes on each monoblock), but that has problems also as well as expensive, it wasn’t received very well. http://www.stereophile.com/images/1212levin.side.jpg Cheers George |
higher switching frequency moves it further from the range of human hearing and enables "kinder, gentler" filtering |
miner42,
Nice story except for the part about your brother in law dying!
It just illustrates another less discussed benefit of good class D amps; reliability.
Most understand that heat is generally the enemy of electronics and excess heat can cause premature circuit or part failure. Class D amps generally run so cool they don't even use heat sinks unless an analog power supply is substituted for the cool running switch-mode power supplies (smps) typically utilized with, and even now built into, the
class D power modules.
This lack of heat buildup, I believe, can only benefit class D amps and increase their reliability and extend their lifespans as a result.
I also believe the opposite is true of class A and A/B amps specifically because they run much hotter..
Great sounding, very quiet, very neutral, relatively inexpensive,very detailed and powerful amps with low distortion, wide dynamics and very detailed from top to bottom. What else would you want to consider an amp type ideal? Oh yeah, have it consume electricity like a virgin consumes birth control pills, keep its cool like Clint Eastwood and, while you're at it, make it as reliable as Old Faithfull.
'Mr, Old Faithfull', Georgehifi, predictably would add that increasing the switching frequency to 3-5 mHz would make class D perfect My opinion is that this may be making perfect the enemy of the extremely good.
What the Heck, though, if it'll nudge class D firmly into the 'Ideal Amp Technology' consensus, the brains behind class D are likely pondering this as we speak.
If Bostrom at Anaview/Abletec, Putzeys at Hypex or Hansen at Pascal determine that a higher switching frequency would actually benefit the performance of their class D modules, I would not wager against them incorporating this improvement into their products.
Unfortunately, I'm not technically knowledgeable enough to determine whether a large increase in the switching frequency would actually improve class D amp performance. As I've mentioned before, I detect no sonic detriments to the current switching frequency operating in the mid 500kHz range. Obviously, though, I've also never been able to compare a class D amp with a switching frequency in the 500kHz range to an amp with a switching frequency in the 3-5 mHz range.
I'm also a bit perplexed on whether and how this switching frequency issue affects the Bostrom/Anaview-Abletech and Hansen/Pascal class D modules' performance since they both now operate utilizing Phase Modulation rather than the Pulse Width Modulation still being utilized in the Putzeys/Hypex, along with being utilized in most previous, class D modules.
Sorry to get so Geeky about this, but I've read and paid attention long enough about class D technology to be dangerous without completely grasping the subject. I think it would help me if someone had the time, expertise and ability to explain this further in layman terms.
Thanks,
Tim |
Back in 2008 I bought a Rotel RB1092; a Class D 500 watt/ch amp. At the time it was the most expensive piece of equipment I had ever owned. It served me very well until 2010. I sold it to my B-I-L and was working 100% until I packed up after his death. His daughter now has it and is awaiting me to come to Vermont to set the system up for her - I will wait until the fall for that trip. |
Boneman73, I think the word magical does apply because I was stunned how good my turntable sounded with my Class D amp, it never sounded that way before with a conventional designed amp. It just raised the bar on an enjoyable listening experience.
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I would also like to hear someone chime in and give thier thoughts on the differences between the ICEpower ASP modules (like what is in my JRDG 501's) and the current crop of NCore modules. I'm really not looking to upgrade, but would like to hear from owners who have had both. Uhm - this may be directed at Guido :) |
Not many Jeff Rowland owners have chimed in (Guido, aside). I have the (older, yet updated) 501 Mono's. The ICEpower modules inside have been taken from and early revision to the (presumably) latest (Rev J) as I bought them from Jeff in January (really not sure if its an upgrade - I had a bad power day in December and both blew).
I'm very much thrilled with the sound of the amps - yes, they are detailed, and very natural in the midrange. But what I've noticed (compared with my prior 'very nice' Audire class A/B dual mono) was the noise floor and, beyond my logic, the black backgrounds with LP's. It's like noise supression system on my turntable. I've gone back and forth - and something really magical happens in the treble. I hate that word "magical". I really do. But damn it. I can't explain it.
My next 'upgrade' will be the PC-1 modules. They are sitting in my music room, but I haven't installed them yet. I'm laboring through they very well documented, and necessary, breakin period. For those wondering, it's a bit like 7 stages of grief, with maybe 4 stages. Stage 1 - power on and a euphoric midrange, but not right. Kinda boomy but airy. Stage 2 - lack of midrange but bass rises. Stage 3 - bass is getting inline, and so it midrange. Stage 4 - OK...these are nice.... |
+ 1 on the Class D Audio company-- Great amp!!! Driving 1.7i Mags |
The NC1200/700 is an excellent foundation on which to design a seriously good NCore NC500 or NC1200 based amp. The fabulous Merrill Veritas mono is proof positive.
However, NC1200/700 was designed by Putseys as a solid starting point, not as the ultimate power supply for NCore modules.
Putseys himself enhanced NC1200/700 for his own Mola Mola Kaluga amp, and Rowland uses custom multi-regulated SMPS in M825 and M925. Theta decided to implement their own toroidal supply for Prometheus.... I have not heard Prometheus, but knowing Theta, it is probably an extremely good NC1200-based amp as well.
Guido
Some manufacturers have achieved even |
As I read more and more about Class D amps, one thing stood out to me is the power supply. There are quite a few Class D amps out there that are being put together with DIY kits from Hypex. No doubt that these amps with DIY kits does a good 'job' on most systems and afford us the opportunity to stretch our hard earned dollars on rest of the components in the system.
But if you want the very best in Class D, consider auditioning the amps with NC-500 or NC-1200 module and SMPS1200A700 power supply. I think you will be pleasantly surprised!
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Georgehifi, price don't always dictate performance and you sir do not have my speakers. Mark Levinson builds conventional amps very well but maybe he should leave the design of Class D amps to manufacturers that have had a good track record of building excellent sounding Class D amps. Class D does require experimentation, careful matching with the right speakers, interconnects, power cords and preamps to get the most out of them.
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@georgehifi
Guess I didn't pay enough for them to find the problems Fremer had.
Best,
E
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phd
A well designed Class D amp will bring you in and draw you closer to your music. You also will hear deeper into your music and the details you never knew existed before suddenly appear as if previously you’ve been listening in a fog bank. My analogy/ the difference would be like looking through a dirty pane of glass as opposed to a sparkling clean one. I own two Class D amps and love them! Odd the opposite of what was heard from the $50K Mark Levinson No.53 Class-D monoblocks Stereophile's Michael Fremer listens to the ML No 53’s. "Through the No.53s Cassidy’s voice was pinpoint sharp but the reverb, instead of being airy and ethereal, sounded like a hard haze that obscured detail at low levels and became fatiguing at higher ones. As seems to be the case with switching amps, no matter how carefully designed, the higher in frequency the music goes, the more problems there are. That also holds true the more you turn up the volume. Generally speaking, the louder I played the No.53s, the more pronounced the haze. The more high-frequency content in the music—women’s voices, cymbals, reverberant backdrops—the more the haze intruded on and obscured the images, forcing me to turn down the volume." Cheers George |
A well designed Class D amp will bring you in and draw you closer to your music. You also will hear deeper into your music and the details you never knew existed before suddenly appear as if previously you've been listening in a fog bank. My analogy/ the difference would be like looking through a dirty pane of glass as opposed to a sparkling clean one. I own two Class D amps and love them!
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erik_squires
That has been my experience as well... The "Class D Audio" SDS-470C is... very, very close to the Parasound Halo amps. The area in which the Halo amps might be a wee bit better (maybe) is in the clarity, and crispness of the bass (maybe). |
Blang 11
I think you are going to be very pleased with the Bel Canto Ref 600M monos. I just got my new pair installed a couple days ago, also replacing an ARC Class D stereo amp, model 150.2. The Bel Cantos already sound great, though I expect they will provide even more improvement with more break in.
My own theory is that ARC discontinued it’s Class D amps (and thereby all SS amps) to reduce and clarify product lines now that it is under common ownership with MacIntosh--ARC to concentrate on tube gear and Mac to do the big line of SS amps. |
I've come to a Class D amp not through any intentional act, but purely though preference for the sound quality. I had tube gear for years, then moved to Naim for about 10 years. I was going to upgrade along the Naim chain until I heard Devialet. I bought a D120 about two years ago, then upgraded to a D220 Pro in December. I've never had better sound in life. Musical and accurate and emotional.
There aren't that many absolutes in the audio world. You can do SS or Tubes well or badly, and there are a lot of approaches to class D amps as well. But I would not go back to Naim or McIntosh for anything. And nobody who hears my system comments that it sounds metallic or artificial. Source quality matters, cables matter, power quality matters, and of course, we all have our own preferences in musical reproduction, But those who dismiss class D out of hand probably haven't heard a good system. Or else they just like the sound of tubes and their particular sonic signature. |
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I wish we weren’t ragging on Pass.... but yeah, my own experience (but in 2 different systems) was that ICEPower ASP was their equal.
Which also, by extension and if I have any integrity, means the Parasound Halo amps I've heard are also very very close.
Best,
E
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Hifidream :
Interesting, very similar to the Yamaha EEEngine I wrote about a little while ago, and therefore similar to the Carver amps too.
Best,
E
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I took the Class D plunge just a month ago for my home-office system as alternative to the Triode TRV-A300SE Integrated. I purchased the "Waring" Integrated from FLEAWATT (25 wpc into 4), the owner, Derek makes them himself. This little guy (the amp) uses a TPA3116D2 chip and it's built w/ Dueland cotton/copper wire. My Dell computer (JRIVER server) is connected via USB to a Chord Electronics QX (British version) DAC, then downstream of the integrated, Antero bookshelf speakers w/ a 92 dB sensitivity. Does the music lack, euphonics? I'm not hearing it .... and the sound is impressively detailed and transparent, quite musical while bass extension is excellent and tight. I like it so much, I've got him making me another model~! |
Owned 4 pcs mono Spectron Musician III MKII for the past 8 years driving large planars.
Never powered down and the music out of the planars is puresex. |
@noble100 @neil_squiresNiel @neil_squires@neil_squiresand Tim, harmonic distortions lower than 0.005% have already been achieved in class D for a few years. One example is the Mola Mola Kaluga designed by Bruno Putseys using an enhanced NC1200 Ncore modules. THe amp is rated at less than 0.003% across the audible frequency band. The big Rowlands M825 and M925 amps also exceed the 0.005% target, but their price tag makes them somewhat more exotic.
The interesting thing in Gallium Nitride transistors is not so much whether they can in principle enable a high priced class D amp like the panasonic to achieve distortions lower than 0.005%, but if the technology could bring such performance in designs that serve the sub_$10K market, and perhaps one fine day, even below the $5K market.
On the other hand, the audible performance of an amplifier is not created by one particular measurement, nor by a slew of measurements, but by the effect -- iuntellectual and emotional alike -- that the device is capable of having on a listener... Plenty of amps of any class can mesmerize a listener, with a somewhat weaker link to their total declared distortion.
G.
9 @neil_squires@neil_squires |
@hgeifman I'm in a similar situation. I just purchased the Bel Canto Ref600m monos and will be driving them directly with the PS Audio DirectStream Junior. The DSJ isn't quite the M1 DAC, but I hear they are both similar in the way they present more of an analog sense of ease and lack of digital glare. I'm excited to get my new setup running.
This setup is an upgrade to my previous pair of Cambridge Azur 851N DAC driving an Audio Research DSi200 which is a class D integrated using a linear analogue power supply. I was actually very happy with the ARC, but it had a passive pre section that couldn't be bypassed to use just the power section. I need a power amp that will allow me to control volume digitally elsewhere in the chain (and perhaps do some DSP/crossover stuff with a DEQX in the future). The ARC amp had awesome drive and really wide soundstage. Everything I read about it online was very positive from 6 Moons, Absolute Sound, etc., but ARC stopped making their class D line. I always wondered why. I can only speculate. It certainly wasn't from poor reviews.
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I have 2 PS Audio D amps,they are good enough for me and I have no problems with better or newer technologies...after all it is the sound that counts... |
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I think we'll all live long enough to see the day when Class D is the only amp used in subwoofs. The little 350-watt plate amps in my Tylers allow for a higher-frequency roll-off that spares the tubes some real heavy-lifting and allows them to concentrate on critical mid-bass, mids and highs where (don't want to start a flame-throwing contest here) tubes still reign supreme. I also have one of those little cigarette-pack-sized 20 WPC Class D Lepais (which always seem to be on close-out for $20 from Parts Express ) that is on 24/7 hooked up to a pair of small $60 Dayton speaks for the TV: net result being an $80 "sound bar" that sounds pretty good and beats anything from Wal-Mart for $<200. (I mean, who wants to waste tubes listening to Judy Woodruff or some ancient B&W movie with a crappy sound-track anyway?)
Subject for another thread, perhaps, but why do the makers of of $2,000 flat-screen TVs include sound that is worst than a 1950s transistor radio?
Class D amps seem to be very much more speaker impedance sensitive than traditional A/B types. Knowing that an 8-ohm (nominal) speaker can wander down to 2 ohms depending on the music, I wonder about the effect on Class Ds at high levels with fussy electrostats, for example.
So much in future will depend on execution just as it does now: pwr supplies, the outputs' electrical behaviours, good ol' quality control, the quirkiness of the specific technology and the like. I can just see a snobbery develop amongst transistor types towards Class D amps the way some of my tube-loving brethren hold against s/s/ amps. The ultimate arbiter will be the ear, and we each have a different pair ...
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Hi Everyone, I owned a Rogue Pharaoh for over a year. I can attest to how good it sounds...it was a vast improvement in every way over the Cronus Magnum it replaced. It drove my Magnepan 1.7s very nicely. What I really enjoyed was how responsive it was when tube rolling the two 12au7s in the preamp section. You could really taylor the sound to you music & speakers.
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I'm using a little HiFiBerry AMP+ that's mounted on top of a Raspberry Pi 3 Model B in our family room to drive some old JBL 4311B studio monitors. The RPi is running Roon Bridge, so it serves as a Roon output. This combination sounds surprisingly good. I have not tried this little gizmo in the big rig, but it's clear that there's fun to be had at all price points in Class D these days. https://www.dsnyder.ws-e.com/photos/potn/HiFiBerry_AMP+.jpg |
My Primare I32 arrived yesterday. I am a convert and it's not even fully burned in yet. Female vocals are simply indescribable! |
@erik_squires
Thanks for starting this. I had just ordered a NuPrime IDA-16 class-D amp when this popped up.
It is a great amp. Many have already described how good class-D can be so I won't go into that. I'll just say I concur.
Anyone looking for an amp owe it to themselves to at least check out some class-D offerings.
It's new and I'm only a week in with about 70 hours on it but my NuPrime is the most satisfying amp I've listened to since giving up my octal tube pre/845 SET amp. No, it doesn't sound like tubes but it so musical and easy to listen to.
Here's to class-D!
Cheers,
Scott |
@jt25741
Thanks for the heads-up. I was not familiar with the new Pioneer Class-D AVRs. They look great.
Cheers,
Scott
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Nu-Force mono's and they bested his high-end Pass Labs amp by a fair margin.
Which Pass labs amps was this, as I've worked on and listened to mainly the NF 9se v3 mono's, and am very curious to know which Pass Labs they bettered, none I've heard so far. Cheers George |
