Class AB or Class D amps?
Paul has long said he prefers the sound of Class AB amplifiers to that of Class D, but recently PS has launched some Class D hybrids. What’s his opinion now? If you want to learn more, grab a copy of Paul’s new book, The Audiophile’s Guide. https://www.amazon.com/Audiophiles-Guide-Stereo-Paul-McGowan/dp/B08STSRW49/
2 x 25W Class D amp who lives in the BC Acoustique speakers SP-102 BT.
This active speakers play in the very uncommon broadband speakers family, with a vertical pair of 3′ on 4 Ohms for each speakers.
It has a very interesting external PSU, u can upgrade. I’d go with a 200VA on 16V Linear PSU. But already stunning with the 60 W switching PSU.
It’s rated 86 db, pretty OK for a small room : u have the level of a Jazz Club live session. It goes down to 40 Hz full power… with like a 3 liters enclosure.
Professor PS Audio, I don’t understand how it does that. I guess some internal equalization ? @ 31.5Hz I don’t hear anything anymore, that said.
Try a current Linear Power car amplifier class AB in a studio or home if you really want to blow your mind 🤯 They are used in some world renowned recording studios today for their pure quality of sound 👌 I would put them against any high end home or studio amp out there.
wow paul , i have a big question if you are planning to buy a subwoofer let say like REL SUBWOOFER some of them used class D but also class AB in this case which one would you buy than?
The Purifi amps are incredible. Just straight transparent gain on a wire.
I have the ac200 iceamp and I notice a rolloff while listening to songs with sustained long base and midrange.
Is it possible it’s because the onboard power supply doesn’t have a big powerful transformer like my class ab, or is it just a class d thing?
I also found I have to drive my line in with a preamp, or it is extremely anemic sounding when using a standard line directly into it out of a cd player or optical to analog dac.
Is that also a class d thing? Because my ab doesn’t even output as much wattage and not only sounds louder, it also sustains low and mid range way better on (most notably older music (pre- punchy short blast beat new age stuff) (I like to think of new stuff as window rattler era, vs the old stuff rattled the entire foundation when it hit that sweet spot in the frequency for a while!)
I am subbed to this channel just because you Paul are so cool. Helps you talk about something I have a vague interest in 😛
Ya but if all I ever knew about was the Lloyds one speaker AM clock radio, I’d probably be happy with that.
I get it, Class D amplifiers are finding their way more in the consumer market than before. However, that doesn’t mean that it is sonically better. In fact, it isn’t better, so that ship doesn’t sail for Audiophiles and also not for recording engineers. Class AB on the backend and class A on the frontend (mic preamps, guitar amps, …) still is the standard setup for recording studios, and class A on the backend for diehard audiophiles.
new Marantz Model 30, Class D
Class a only .. class d is nasty
Concerning analog signal path in general like (pre) amplifiers :
"The conventional analogue audio signal path is highly problematic. It was already problematic with analogue sources. Similar to USB we have all kinds of degrading here that kills resolution, adds distortion and mixes noise spectra together, creating new frequencies that do not belong to the audio spectrum. If one uses one wrong component, volume control, pre-amp, amplifier, speaker, interlink, the music is killed instantly. We had an example with one single capacitor in a speaker crossover (part of an impedance equaliser circuit that one can find in many speakers) when it is installed, the music is gone. So chances are that somewhere in the analogue signal path, some component messes up the music, there are more than enough components to cause this. Semiconductor input can only work in a narrow range (basis of a transistor or FET usually works in the linear region and this translates to a maximum signal swing of approx. 200mV). The signal on the collector can be much higher of course. But strictly speaking, every transistor compresses the signal into 200mV, again and again at every transistor (and there are many in an OP-amp or comparator). What happens is that the lower bits are pushed deep into the (thermal) noise floor, are amplified again, pushed into the noise floor, amplified, pushed into the noise floor. This can happen say 20 times before the signal leaves the Op-amp or amplifier. By that time most of the input resolution is lost (converted to white noise). Semiconductor amps are most destructive for resolution.
Tube amplifiers can have larger voltage swing on the grid and operate with much higher voltages. Usually there are only 3 or 4 tubes in the signal path, so here it is likely that more resolution survives. The biggest degrading in sound happened when sound studios started using mixing desks based on semiconductors (OP-amps). Then most of the resolution was already lost at the studio before the signal was put on record or tape.
Class D (digital) power amps are even worse as resolution is lost in the comparator (that is used for PWM generation), jitter, crosstalk between DAC frequencies and class D switching frequencies and noise spectrum of the SMPS inside the class D amp, ripple voltage on the switched output signal and degrading introduced by the required low-pass filter on the output of the class D amp. In my humble opinion class D amps are totally unsuitable for audio.
The tweaking that has become common practice with audiophiles is basically a result of incorrectly designed circuits and or the given limitations of components."
John BROWN, EC Designs
He created a nice DAC (Fractal DAC) that he plans to launch as a supercharged version (PowerDAC) that will avoid any (pre) amplifier.
Here is more information : https://www.diyaudio.com/forums/digital-line-level/79452-building-ultimate-nos-dac-using-tda1541a-769.html#post6293442
I have an old Technics amp from 75′ and 3 NAD class D amps from a couple years ago. Which I turn on to listen to depends on what kind of mood im in and what I want to listen to. (If it’s a little cold in the room I’ll use the Technics, may as well let the music help heat the house. lol)
I am a technician at a music school, I would say that class D is for Pa sound where quality does not matter, outside systems where wind and background noise disturb the sound, Class D is not so heavy to carry either. Class A and A / B are for headphones / HiFi speakers where you need it to be pure analog.
My main question is if they are distinguishable enough to tell them apart if you playing both class ab and d in the same sound stage? I have a large class ab for midbass and im deciding on running either low power class ab on my midrange horns and tweeters or proper power on the class d amp. I just don’t want It be noticeable. Its car audio, skar audio skv2 1300.2 A/B for my midbass. And for the mids and highs its either the Skar audio skv2-200.4D or the skv2-100.4A/B
Hi Paul! I’m using a class D amp on my Image Dynamics Mid range set, sounds good, but changing to AB would it sound more clear? Of course talking about same watts RMS to be equal
My class d devialet amplifier is sold. Something about class d i can’t live with.
I have ordered the gryphon diablo 120 amplifier. I can’t wait
YES IT’S DESIRED AND SELF POWERED SPEAKERS ARE THE WAY OF THR FUTURE.
class H vs. class D???
Well of course your own amplifiers sound the best 🙄
Class AB is a very mature design. However class D is growing very fast. There is a lot of improvement. A single improvement will affect very far better in class D. For example better mosfet datasheet. implementing better feedback, and so on. You will see always a new born better class D for every soon. Then today Class D can stand at same level clarity with class AB.
Class D amps are getting better and better but their prices are outpacing their quality. Why would I pay $7k for a class D when I can buy a top notch Class AB amp ( read Bryston) for less then that.
I have a class T amp, combines the best of both!
Edit because youtube no longer picks up my spelling errors and I didn’t see that i’d spelled "combines" wrong untill now.
A B all day. Dont like the D sound
he did ask if you could tell the difference though.. Im guessing the answer is yes of course but you didnt really answer that
I like Class D’s (the fake ones) they hit my bench a lot, most of the TDAs got roasted. And Capacitor fatigue by the high frequency switching of the SMPS. About 400Khz or more.
Damn, i do wish sometimes we didn’t "change" for the sake of it. Class A, AB and AA were perfect. And if a transistor failed it was easy to sort, try changing a new PWM chip!!
Class A and B amplifiers are rated on RMS values. Class D amplifiers are rated on Peak values. If you do a comparison of a A or B at 100 Watts RMS, the rated output of a D class would be around 50 Watts output. You will notice a lot of manufactures of D class amplifiers do not have an RMS value.
Putting an audio system together again. It’s been many years. Back in the day had a Threshold class A monster. Put off a lot of heat but the sound was amazing. Had Klipsch corner flagship speakers it powered and mcintosh center channel amp for Klipsch flagship center channel. Definitive speakers for the surround sound and M & K sub with Lexicon processor and Threshold Fet 9 E preamp. Remember Pioneer laser disc where it was a thing?…lol How do your amps compare to say Threshold? I like Klipsch speakers but the horns are just too harsh for me on the high end. I prefer electrostatics. Looking at Martin Logan. The definitive speakers sound great technically but I find speakers that are too technical to be cold and sterile sounding. I like sound with soul and feeling but in a good way. I have heard Marantz amps are warm and musical quality but have not heard in person. I like more A to A/B amps. Have an 8 by 10 foot room in my office building where I envision Martin Logan speakers and placed for sweet spot with my leather chair, pre-amp, separate powered sub, and individual 2 channel amp in stereo mode. Mainly for CD and music listening no movies. Thoughts?
Reality experience is in class A amplifier
Should power amps be left on 24/7 ?
Hey Paul, what about using the M1200 modules, input signal with 12Au7, and 5687 driver tube with a different variant.
Class A is still the best (but not great value). Class AB is useful and practical as more power is required for the bass. Class D is only ready for subwoofers or PA currently. My Two cents. The clear advantage is that Class A will remain high performance for a lot longer life time of the device. AB and D need to be carefully calibrated to deliver the beef!
Get a class A or AB if you live in a cold climate and need a space heater in your home. Get a class D if you live in a warm climate and you don’t want to heat up the room. 😂
I agree, In the end as a Audiophile, I accept the heat, size, and inefficiencies, I am a retired Car Audio system designer, who designed and built IASCA grade mobile audio systems, and I still prefer my old school gigantic, Bar-B-Q grill Pure Class A amplifiers.
Great guy Paul is! I’ve messed with well done Class D and some tubes in the mix. My ears like!
Wait, did I just hear Paul say class D is okay? I never thought I would hear that. Thanks Paul for your honesty. I’ll be looking into those 1200’s!
so, the BHK dual monos are A/B…. how many watts of A till it switches over to B ?
What about the price point? You only seem to review the expensive stuff. There are many Class D amplifiers under 200€ like the Tangent Ampster BT 2. Are they any good? I got the class A/B Yamaha RN 402 instead (is that amp any good?), because it ended up cheaper in a bundle deal with the Klipsch RP 600M. And I feel clueless to be frank.
I propose a fun experiment, it might make a GREAT video as well!
1. you set up two listening rooms in the office – one with the best class AB amp you have and one with the best class D amp you have. Connect them as dummy amps that can be seen – but not touched! Use a pre-amp for volume control, they can touch that when listening! Actual amps PLAYING should be the same as the amps that they see, but "behind the curtains"! Have both amps "not clip" at maximum pre-amp "power" and they must be at the same loudness at max (really important)!
2. have all the people in the office go in and out every day, compare the sound, listen to them and have them fill out the forms with data like: clarity, musicality, distortion, dynamics, timbre, total score, etc. – think of like 10 parameters that can be voted from 1-10 and have someone who will make them fill it up EVERY DAY for 2 weeks! That someone can’t know about the actual experiment – tell them it’s an experiment on psycho-acoustics and no one is allowed to touch ANYTHING but the volume knob of the pre-amp (if even that?)!
3. Come back Tuesday night and switch amps that are "behind the curtains" – no one can see that you were even there and cables must look exactly the same as they were the day before!
4. Switch amps that they can see (but are not playing) over the weekend!
5. Switch "behind the curtains" amps back the next Tuesday night!
6. Compare notes "when you’re back from vacation" and see if anyone noticed the sound change when they should and didn’t when they shouldn’t!
7. Do a reveal and see their reactions.
-> I reckon that there will be a lot of change in answers on Monday and no statistical evidence that they noticed the Tuesday night swap – BUT – most people will claim after the reveal: "I knew something changed every Wednesday, but didn’t wanna say anything because of reason XYZ!" – it’s a classic audiophile excuse! 🙂
… We made a similar experiment on our "audiophile friend" when he bragged about his great new expensive speaker cables – quickly switched them when he went to the bathroom! After he returned and continued bragging about the clarity and musicality of new cables for more than a couple of songs, we revealed that we swapped out his cable and put the cheapest (but still thick) copper cable under the carpet! In the end, he claimed that "he heard something was wrong but didn’t wanna say anything so he wouldn’t look like an idiot"! 😀
-> please make a video and respond to this comment after you made the experiment – It MUST be a "double blind experiment" – no one can see you, no one can talk with you about it because it skews the experiment badly! Water Dowsers DO FIND WATER in a single blind experiment – no one can know what you’re doing!!!
So I’m a southern 35 year old revived bass head but damn I love listening to you speak and describe the sound …great job with voice tone modulation to convey the sense of satisfaction. You just picked up a new subscriber.
Man…i don’t understand one effing bit of all these comments!!!!
I have the +-75 volt power supply,10 amps,thinking of buying an el chepo 500 watt D module…
Question…is a clss D amp,say 200 rms , as good,better or worse than a classical amp ? (ab,or whatever you call it, i have a bridged 200 w Rotel, for 25 years, with added heat sinks, driving 15 inchers, 4 ohms love it, almost like being there).
Class D seems to be getting better. I’ve recently heard of 2 almost "Road to Demascus" level of turn-arounds from two (until very recently) 100% consistent preferer’s of class A/AB amps, the stories & pics came from 2 youtube reviewers who each heard a (different model of) a new class D amp & both guys sounded ultra surprised, more blown-away by the D-amps they had tried, both saying their new D-amp listening sessions lacked all of the sub-A/AB foibles they both independently had heard in all their previous D-amp trials/ reviews. Guttenberg’s D-amp was 13 thousand & something U.S. dollars & (i agreed with the Gut’) looked beautiful. It was rectangular in it’s nodal points yet because of undulating curves it only had 2 parrallel or mirror-imaged curvey wooden/steel/alu'(?) Joined sides to it’s chasis. top, bottom, front & back were all non’ parralel, sounds imposs’ or a mess but far from it.
& the other D-amp that amazed the other consistent A/AB amp preferer was also a Hypex but a 1-off model in a plain box, & supplied to him for testing different input /gain interchangable modules, no price or any mentioned plan to produce in any numbers.
Big But, ive noticed for a long time now that very well-liked B&O Ice-power modules from lowish to "As high as you could need powers" of ?-watts were always very much cheaper by far compared to Hypex’s N-Core OEM module’s prices… (& all of which were priced minus the switch-mode power-supplies they sold you separately) …of similar wattages to the B&O Ice’ modules, plus, those very much cheaper Ice-Power modules had onboard power supplies so wire-up & listen (well, all that i looked at did but maybe all B&O Ice’ modules have?)
Have a Emerald Physics 100.2 SE Amp Class D love it
Word on the street is that Paul sits and listens to his LS50 and Sprout 100 more than anything else …
Class D is getting better
I will save you 5;35 minutes of your life … The ANSWER is AB all the way … Silly Question
Yeah, no. I think I’ll stick with my ME 850 high-current class AB power amp to drive my Duntechs, thanks.
always when I try to look into a video I think it’s mostly "blabla" — the same today…
Do you think class D amplifiers are better than AB for low volume listening? Thank you!
Hi Paul This is Thunder Thumbs Production I need to ask you something about some house speakers I would like to use them for my studio but how do I plug them in a mixer or a interface my contact is 586-320-4142 Thank you.