Can this tiny amp really produce 600 watts? - Fosi Audio V3
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Sunday October 29, 2023
David Mellor
David Mellor is CEO and Course Director of Audio Masterclass. David has designed courses in audio education and training since 1986 and is the publisher and principal writer of Adventures In Audio.
Here's the important bit: If you configure that amp as a bridge-tied load (BTL) you will get around 310W. That's RMS. From a single-ended 50v DC rail.
Besides using DC voltage steppers, that's how you can get many hundreds of real RMS watts out of a car audio system.
So obviously the Fosi amplifier is running four Class-D amplifiers. Therefore, a pair of 2 amplifiers per single output channel are connected internally as BTL's and which generate around 300W RMS into 4 ohms.
Yes, I agree that the power supply needs to be beefed up a bit, a 4-ohm load will draw about 12A at 300W. So you'd need a minimum of 24A at 48v or so to drive 600WRMS.
Two amps and four power supplies like this will deliver 1,200WRMS... I could use these for a live band!
@AudioMasterclass replies to @andrevdsandt8017: Readers may speculate where science ends in this comment and fantasy begins.
@andrevdsandt8017 replies to @andrevdsandt8017: @AudioMasterclass OK. Here's a bit of (real) science:
One needs to consider the peak voltage because that is what the amp should properly and indefinitely be able to deliver into its load. Therefore, in an amplifier, peak voltage swing is always used. This is different to loudspeakers which will have peak, and maximum and RMS power handling figures. And they're all different numbers depending how long it takes you to cook the voice coil.
Amplifiers... Consider the peak voltage because the amp can (should!) deliver peak voltage into the load 'til the cows come home.
For a single-ended amp:
Vpk=50V. (assuming a single 50v rail)
Load = 4r
Vrms = Vpk/(Sqrt(2) = 17.68V
Power = Vrms^2/4r=312.5/4=78.125Wrms.
No problem.
There are two ways of getting the BTL RMS power. One is by multiplying the single-ended RMS powerby 4 (because that's just how it happens to work) and that gives you 312.5Wrms
or
Work on DOUBLE the voltage swing... (https://www.aia-cinema.com/glossary/btl-bridge-tied-load.)
In this case Vpk would be 100V. Then you do the same equations using 100V and 4r load, and you get 312.5WRMS.
There's no fantasy here. It's basic, straight-forward, 1st year Electronics: Double the swing = 4 x the power. And that's the Law.
Loudspeakers, of course, are an entirely different basket of fish altogether, because that's an electro-mechanical system and a time element must be added.
@alferro3149: IMHO, it sounds great for the money ( got the 48v for £80)
I use it for my TV set with Q acoustics 3010i, Modi3 dac and a tiny 1kw Velodyne Microvee II sub. All minuscule components and the sound is BIG
@AudioMasterclass replies to @alferro3149: I’ve used the V3 every day since my review in my music production system. I doubt if any more costly amp could improve the quality of my work.
@alferro3149: You forgot class G (not Mercedes).
My Creek evolution 100A uses class G
@AudioMasterclass replies to @alferro3149: I think the letter system got a bit messed up after D. But it might be an interesting topic for a future video. As for G, if there is ever to be a Wagen in my village, mine won’t be the first.
@tensevo: not bad when the biggest drawbacks are, it seems like it should be bigger and more expensive,
@AudioMasterclass replies to @tensevo: I've been using mine daily since I first received it. It works well with my Yamaha NS-10M Studios.
@stefaanbraet5305: 600 watt, and the answer is ??
@alferro3149 replies to @stefaanbraet5305: It sounds good enough.
@pcno2832: 19:18 Those who rely on YT subtitles will be happy to know that the "fuzzy" amplifier can power the "BMWs", despite its small size and unimpressive appearance. Great explanation, no matter how YT interprets it.
@luto2000: Thanks for the great review! one question: as the Fosi V3 Stereo does not have 12v trigger power control input, would it possible to leave the amp On all the time, an cut the power to it via an external relay? thanks!
@AudioMasterclass replies to @luto2000: This is a good question. However I use the V3 every day and shut all my system off at the mains every night. I might consider this issue for a future video.
@Chris.Davies: I hope not, because I sold the (useless, heavy, and inefficient Class-AB) amp that previously drove my ProAc Response 2.5s, and the V3 is now fulfilling that role. And it rocks! But the ProAcs are only rated 25 to 200. Somehow, I don't think the V3 is going to challenge them at full volume. In the week I've had the V3, I've never had it over 70% volume, and the performances are giving me goosebumps, and in one case I actually cried, listening to Oscar Peterson Trio's We Get Requests. I could see the smiles on the faces of the band.
When I consider the V3 output through the ProAcs, I think the V3 power rating is "More than adequate for my purposes" - and leave it at that.
I am pairing it with the ZD3 DAC, and a cheap-but-effective AliExpress USB Isolator to avoid the PC ground issues plagued by so many PC-based audio systems. I got the biggest PSU I could for it. I'm excited for audio again - after 25 years of audio boredom.
Edit: and now I went and ordered a tiny T20 for our bedroom, a BT30D Pro for my workshop, and got a free BT Volume knob to boot. And I have placed ALL my very expensive old amps on TradeMe at $1 reserve each, as I am completely over them. They cost a fortune to run and they do NOT match the musicality or pure sound of the tiny Fosi units. Especially when they are plugged into the sets of world class speakers and subs I got many many years ago.
These little Class-D amps are the most honest of all the amps I have listened to since the 1990s, and to me, they make old speakers, and old music sound brand new again. I'm easily hearing things in my (best quality) music that I could once only hear using NZD $100,000 worth of NAIM gear in the mid-90s. My mind is truly boggled, and I am happy to confirm that we are now officially living in the future.
But most people don't realise it, because the future looks a lot like the past on the surface.
@codycody1955: I donnt care if it has 600 watts or not ,it has a nice sound for the price ,i pair mine with book shelf psb3 speakers and the sound is amazing and i also useit with a preamp
@alferro3149 replies to @codycody1955: Same here. Qacoustics 3010i and Modi dac. Sweet
@motleypixel: 19:00 thank you for the great talk, you handle the stage like a pro. So what if you tried the V3 Mono's with the 25/33db gain switch on the back? I'm interested now, so volume and gain are different?
@AudioMasterclass replies to @motleypixel: I'm not the best electronics expert in the world so consider that, but I do know a bit. Suppose you have 4 ohm speakers and you need the volume on your preamp maxed out to get a good volume (and there is no distortion). If you change to 8 ohm speakers, you'll get less volume. The gain switch will fix that. I'd set the gain low unless you need more volume. I'm using the XLR input on mine for which the gain switch is inactive. Volume is more than adequate through my Yamaha NS-10M Studios.
@TheFlutecart: Transistors.. ah, the good old days. I still play and design with them, building guitar pedals and preamps. But I finally got one of these V3's on the way because, why not? I might even swap out the 5532 OA's, I got some quality doubles handy. Make sure of the the voltage rating, some duals won't take higher voltages, you let the smoke out of them.
The number soup on the spec sheets from these guys! - LMAO! . reads like a car stereo booster from 1989 ..we tried to get RMS ratings to stick- they are determined to pretend like were too stoopid. They should be accurate and detailed with specs as if they are proud of it. Proud of that TI chip though. It's got a data sheet I guess.
@MarkRehorst: As always, "the large print giveth, and the small print taketh away".
@molesad: What a lucid account, thank you. I've just ordered a B30D Pro and look forward to testing them on my old Sonys.
@Wised1000: Its an utter B<SH>T rating! if rated correctly its a 150W per channel at 8 ohm amp. Worse yet if driven at any significant output at anything below 4 ohms, the response abo500 hz becomes non linear and sounds horrible, if it doesn't turn your tweeters into magma in the process. Pure unadulterad audio crap.
@W3bcr4wl3r: fosi is cheap china shit. overhyped on yt and reddit, but pure shit!
@DariusKuzmickas: You are smart and very funny. AI girls at the end is the proof,
@t_allen2000: I’m 56 and stopped fiddling with Stereo around 1990. But I can no longer stomach politics in the US and I needed listening material for my radiation treatments and endless MR and CT scanning. Seriously, I needed something worth listening to. I happened to buy this amp after selling my 70’s-80’s components. All of them. Glad you gave me the “approval” that others couldn’t. Orange is my color after all. Grateful for the Avatar twins making me laugh. And the plain language that only someone quite smart is capable of. The material on this channel is worthy of broadcast, if that still meaningfully existed. And it has helped me get through life a bit more easily. And it’s not so easy this year. Thank you, sir.
@001yohan4: What kind of review is this? All talks and no demo of the sound from the product. Very disappointed.
@ArielBacchus: No I’m not involved in a fuckin car crash🤬
@fernandoxavier5688: Excellent review!
@jgbelmont: The RMS is far lower.
@johnb6723 replies to @jgbelmont: Yes, for he is quoting peak to peak. To get from peak to peak watts to root mean square watts one divides by eight.
@adrianmillard6598: I watched for 17 minutes before I realized you were superimposed on the background.
@AudioMasterclass replies to @adrianmillard6598: As to why, conspiracy theories abound. The real reason - It saves me cleaning, tidying and setting up. I just pull down the screen and get to work.
@adrianmillard6598 replies to @adrianmillard6598: @AudioMasterclass I just wanted to say sorry if I came across as criticizing you. I absolutely don't have a problem with it - my comment was to say how silly I felt for not noticing for so long! :)
@adrianmillard6598 replies to @adrianmillard6598: @AudioMasterclass Since I know you're going to see this, I also want to say that this video was great. I loved your presentation style, manner and explanations - perfect.
@FiveFiveZeroTwo: 1:49 Netflix looks a lot like Spotify nowadays..
@EnjoyingLife-sm7cg: Paul Mcartneys brother. ;)
@cherudge: I’m sorry I was trying to concentrate on the video, which is fascinating. But the way you are sat, every time you say let me know what you think down below, it looks like you are pointing to your pecker. Kept making me chuckle!
@Iowa599: Did you test it with the black knob?
Maybe the orange knob improves performance.
@Iowa599: How's it perform on 2 ohms?
@Shamshiadadd: Haha gold thankyou
@nicktan4530: Why do we even need 600 watts ?
@AudioMasterclass replies to @nicktan4530: A good question in very few words. I might consider it for a future video.
@nicktan4530 replies to @nicktan4530: @AudioMasterclass And as you know, all amps sounds the same with few exceptions to the rule. Do people even need 6W per channel ? Unless its pre amp or power amp.
@ABADDJ: If everything after 175 watts is pure distortion and we only care about listen to clear music why would we mention the wattage that is pure distortion it only has 175 watts of clear music per channel it is not a 300 watt per channel amplifier wherever the clear music ends that's the amount of wattage it puts out let's learn how to talk properly now please
@simonnoble2345: And chinese watts are between x10 to x100 as much for the same hardware
@7302ab: Ok.but how does.it. sound
@AudioMasterclass replies to @7302ab: If you can hear any distortion, noise, lack of flatness of frequency response, or any other measurable artefacts then you have better ears than me. On the other hand you could watch some subjective review videos and wonder whether they're making it all up.
@arthurriaf8052: Did you mention the signal needs a pre amp to boost the line level signal before the V3?
Without a preamp, the V3 is useless. 😢😮
@wallstreetcrash1: Here’s a story…
Before setting off on my hi-fi purchasing journey (and being a complete novice) after becoming tired of listening to my Makita Bluetooth radio and streaming from YouTube on my iPad, I decided the time had come for a dedicated hi-fi system for my living room.
I decided to educate myself via YouTube in the hi-fi world …. So..
After a month or was it six weeks of nightly viewing And considering budget constraints.
I pushed the boat out and purchased a pair of speakers ..Klipich RP 600 mk2
This left me short of cash to buy an amp ..(I was desperate to hear the speakers)
So much so that I thought I would buy a temporary cheap one with the idea of that will do for the time being ..
I purchased a Yamaha RS-2020… which offered Bluetooth connectivity and therefore a listening opportunity.
Again after sometime I realised Bluetooth is not quite the full ticket .
So again on a budget, I decided to buy a streamer, which was the Wiim Ultra.. along with a subscription to Tidal.
( At last no adverts! )
Finally, I also decided to buy a DAC ..SMSL-SU1.. to hook up with the Wiim ultra… along with a power conditioner and some inexpensive ferrite cable cores for my speaker cables..
My speakers are singing to me … despite the fact that the speakers were almost 3 times as much in cost as my Yamaha amp.
I just like to say thank you, Yamaha ..! a fantastic little amp.
@TheJessefuji: I just bought from the Fosi Ebay store for $86.50 AUD, with the 48V supply!
@AudioMasterclass replies to @TheJessefuji: It's a nice little amp. I use the review sample every day.
@thomaswomack3888: Concerning your comment about driving speakers that cost 7k with a $100 amp....While an interesting test and appropriate for the purposes of entertaining video content, there is one consideration here that comes to mind...You have exposed Fosi as gilding the lily a bit too much on the real power available to drive your speakers and that calls into question their integrity as a company. Why would you trust your expensive speakers by hooking them up to an amplifier of questionable quality? I get that its a practical thing, but is it advisable? IF the amp takes a dump while connected to your pricey speakers, Fosi isn't going to fix them for you. I don't know about you, but connecting an amplifier that I can feel confident WON'T kill the speakers connected to it is pretty much a necessity and not up for debate. That said, I have several small class D amps from Dayton Audio scattered around my house driving small inexpensive speakers. And I haven't fried any speakers....yet. But my level of trust for class D is not fully established yet. Especially at these low price points. Just saying....
@matthew_mayton: There’s a few ways to calculate it.
RMS Voltage= Peak V/2
However RMS Power is calculated differently.
RMS POWER= Peak Power/ the square root of 2
It is also
RMS W^2= (Peak W^2)/2
So let’s say we want 600 peak whats. 600/(square root of 2) =424.26w RMS
Now we use the power supply voltage to get the current.
424.26/48=8.84 amps
So the larger power supply would be enough, assuming you only do a sign wave. The concept of RMS power of a square wave is very different. It would be more like 600/48= 12.5 amps
Now let’s calculate the idea resistance of the speaker.
A single channel would have half the power, so 600/2= 300w
V^2/P=R
So (48^2)/300=7.68 ohms calculate if the current yields
V/R=A
48/7.68= 6.25A
But that’s the peak current. It only reach it for a fraction of the time, so capacitors can be used in the power supply to raise the peak current.
@michaelkaercher: Bought one of those. Sound is very good.
@vincentw9610: Any OPA recommendations? I just found BURSON AUDIO V7 VIVID PRO Dual OPA.. but idk if it's worth the investment..
I use Fosi Audio ZA3 with monitor audio bronze 50 (wanna upgrade later to 100/200 or silver 100)
@stefan_lus: Dear Sir, Mister great audio master & best in class ! (... and all other persons who read me ! )
I have seen several vids and ... congrats !!
I'm just a simple great lover of wonderful music in top quality sound !
But ... I've no 20k-40k-60k euros/pound/dollars to spend on that.
So what? ... After having seen a vid from "jmc" about a flat loud speaker panel (6000 euros), I had been investigating on "flat panel speakers" (forget all what you can see/hear on youtube) and putting hands on it by myself.
The result after months of hard work (hand work/ ear work/ internet work/ money) , compared to my wonderful Denon hifi system, is just deeply amazing !
FACTS :
Best set-up found so far : 1 flat sound panel (made of raw guitar wood with a 20W exciter) + 1 acoustic guitar (with same exciter) + 1 active standard/commercial subwoofer (denon, sony, yamaha)
RESULT : from my point of "ear", this is the very best combination !
All that powered with a 100 bucks Fosi Audio T3 amplifier and fed with FLAC, mp3@320 or m4A ....
CONCLUSION : a wonderful & delight sound ! --- > what else & more do want / need for so less money ?
DETAILS : flat speakers gives you a amazing surround sound, being the flat guitar wood speaker providing incredible & clear highs & mids, while the guitar produces wonderful & resonant mids/highs and of course, the subwoofer to provide that delicious point of lows which makes you feel your entire body !
_____________
What else you want / desire / can aford for only ... let's say 600 euros ? (ps : picked up here in Barcelona, Spain)
-------
Please let me know & if interested, contact me personally : "stefan.slu/AT/gmail.com"
Cheers to all !
@667hodge: Not capable of that many watts
@WillSapp_0: Guy doesn't know what BTL is
@AudioMasterclass replies to @WillSapp_0: Oh that bridge-tied load thing. I know nothing about that.
@taransingh5083: Which one i should get now 2.1 im looking
@thesilverfish: Oh what a great review. Glad to see you mention Yamaha NS-10s. I have this idea to use one of these D-class mini amps to drive my guitar cabinet. Recently got a guitar modeling pre-amp and looking for a small amp to drive to 12" speakers which can be wired at 4 or 16 ohms. Wonder if you have and advice? There are multiple modeling amps that use d-class power and mark up the price to "guitar players do not understand" prices.
@AudioMasterclass replies to @thesilverfish: Free advice comes without guarantee but I can't see why this wouldn't work, and work well. If you go for it, I'd be interested to know how it works out.
@thesilverfish replies to @thesilverfish: @AudioMasterclass Thanks for your reply. Looking at Fosi ZA3, AIYIMA A07 Max 2. Love the high power and bridge-able. Also looking at the amps with bass/treble amps.
@joanherman9118: parfait
@joanherman9118: hahhahahahahha
@asdf072xxp: It would be great if you could use an oscilloscope to show the clipping point of this amp
@paulyoung4817: Thank you for the review, really honest i thought, and the hilarious ending, I laughed a lot!
@turbomustang84: Not one of these Type D manufacturers give a real world power rating.
Aiyima does list the actual power in the ad which is good but 600 wats is an unreachable mark and they should just drop the practice of over boasting
My Aiyima A08 Pro puts out close to 200wpc driving my 4 ohm speakers and rarely will I ever drive it that hard .
@lonewolfmtnz: BS on steroids
@AudioMasterclass replies to @lonewolfmtnz: Haha Which of my facts do you dispute? Which of my opinions do you disagree with? Got anything useful to say?
@greenbeginner3353: What’s the difference between “a power output issue” and “a gain issue”? Aren’t they the same concept?
@AudioMasterclass replies to @greenbeginner3353: No. Suppose the gain was 0 dB. No matter how many volts or amps the amplifier is capable of, there will be hardly any volume from the speakers.
@greenbeginner3353 replies to @greenbeginner3353: @AudioMasterclass But you said you had to turn the volume to 100%, … what an I not understanding?
@AudioMasterclass replies to @greenbeginner3353: @greenbeginner3353 Then I would get the full gain that the amp is capable of. The most volts, and therefore the most watts, up to the amount of current the amp can deliver.
@greenbeginner3353 replies to @greenbeginner3353: @AudioMasterclass Hmmm. I wonder if we’re speaking about the same thing. I’m talking about your comment starting at about 19 minutes where you talk about “a non-issue“ with your 801 B&Ws. After your kind responses to my questions, I’m starting to wonder if I’m understanding your statement at all. Were you simply saying that you’re 801s require that you turn up the volume on any amplifier at all? Or was there something specific about this amplifier that required some special action unnecessary with any other speaker than the 801s?
@AudioMasterclass replies to @greenbeginner3353: @greenbeginner3353 The V3 only has just enough gain to drive my 801s to an adequate volume in my home cinema system. I’d find it difficult to express this in any other way.
@dvdport89: "Quod erat demonstrandum" may be the only bit I did understand!
@HaraldBergTechTv: Yes it can drive a pair of speakers, my main gripe is it´s tonality as well as how it is handling speakers when reaching higher volumes
@ThomasTVP: What's more important: NOBODY needs actual 600 watts, unless you have very badly constructed speakers. ALL the companies lie about wattage. Who cares? This tiny amp will easily drive any decently constructed (i.e. 88db and up) speaker, with no effort at all. I got the Fosi BT20 Pro, another tiny amp that can drive my Q Acoustics 3030i's to ear-splitting levels without distortion. THAT'S what matters.
@BurnsRubber: As you referenced, Audio Science Review Amir measured this Amp with the 48V power supply where output is much higher. I run a pair of these to biamp my speakers. Ordered direct from Fosi to get the bigger PSU. It works out to about 400W channel of clean power for $200. Amazing value. Plays very loud and clean.
@multicyclist: I would be willing to test one, but I am not willing to purchase one along with the proper power supply to do 600 watts. From just seeing online glimpses of the construction inside, it does not appear the supporting circuity is robust enough. But that all can be verified by proper testing and a closer look at the construction. I would imagine that someone, or perhaps many, would have already done this but just have not seen it yet? A year or so ago, I purchase a Fosi "Box X3 tube phone preamp" with blue tooth for a 3rd system. Well, the Fosi X3 has a couple of NE5532 Op Amp chips in it for the tone controls, and they are counterfeit fake chips. The caps are a known junk brand. From my experience with Fosi and products like it from other manufactures nearly identical products, they are built to have an appearance but in reality are cheap junk, in an aluminum case, made with fake parts whenever they can get away with it to fool customers. Most of the YouTube reviewers get free products and apparently value getting free stuff over integrity. Or they are technologically inept and just read off the unverified manufacture's lofty specs without performing any actual testing of any kind except a listening test by themselves, of course. Which in their view is end all be of testing and always seem to recommend whatever free product they are reviewing.
@Billfish57: This guy is my favorite for audio info.
@huytonbaddy: Why did you say American units ?
@AudioMasterclass replies to @huytonbaddy: I can't remember saying that but it is thought to be true that British watts are louder than American watts https://www.google.com/search?q=british+watts+louder+than+american+watts
@scottlarson281: I carefully positioned my speakers in a mid-size room so that they were "kind of near field" and angled them strategically towards my ears. This "pulled back the veil and opened up the sound stage" and "made instruments seem as if they were actually coming from different points in space". I was careful to put masking tape on the floor to mark optimal positioning so the setup could be duplicated whenever I wanted to listen to a couple tracks. (I also sit bolt-upright in a chair and don't move my head at all while listening....lest I risk spoiling my relaxation.)
The speakers are then moved back into a more "this room needs to be practical as well" arrangement when I'm not listening to music so the space doesn't resemble an obstacle course on American Ninja Warrior.
My vehicle is another situation altogether. My desire to have true audiophile credibility means I have to sit in the middle of the seat while driving. Still working out some kinks there....
@petesjk: Class D amplifiers are something I’m not familiar with, so thanks for your review of this. I’m also a fan of Audioscience’s reviews, so it’s a nice cross reference. I’m certainly curious about Class D amps, and the price point of this Fosi is nicely accessible. 50-60 wpc amps are also a sweet spot for me, since my listening rooms are usually relatively small, and my ears seem to prefer efficient speakers, so larger rooms still get plenty loud. However, it turns out my ears have also already led me to good amp choices, since my amps have tested well at Audioscience. What I would be more interested in is higher quality lower power amps, maybe in the 30 wpc range, more or less. There are some rooms where 50-60 wpc are just too loud, and one of my setups is so efficient it just doesn’t need 60 wpc to fill any size room. One day I may splurge on some nice B&W speakers like those shown in this video, and I may have to look for more wpc.
@hintoninstruments2369: There is no such unit as Watts rms. Volts rms x Amps rms = Watts average (x Power factor if not in phase).
@toonertik: Hahahaha.." I never want to hear them again".... "Me neither".. well played mate LOL ;-)))
@AdamsOlympia: Last year I returned a $2500 stereo setup w/ KEF 350s, a Cambridge CXA81 + SVS sub, due to buyers remorse. I just couldn’t shake the feeling that I overspent and could achieve just as good sound for a fraction of the price. Though I’ve really missed that sound ever since I let it go! NGL, that setup was the best I had ever heard — But I think I can get damn close with the V3, an entry level SVS sub and KEF 150s for under $600. Just need an HDMI to RCA converter and I’ll be set. (Mostly listening to Apple TV/iTunes content)
@zorst99: Seeing that you have the same 801s that I did I would highly recommend that you upgrade your internal capacitors if you haven't done it already. I used the Solen BP400 series. The clarity and imaging improved dramatically. Bass actually showed up. Then ended up having better bass than I ever remember them having. I had taken them apart a couple of times thinking the woofers might be out of phase. I purchased these as used speakers a year and a half old. I used them for a long time then bought my 802Ds, then I had the balls to work on the 801s I wish I had done it sooner I would have never bought the 802Ds. They ended up sounding as good as the 802s the midrange wasn't as good but I would have to say the bass was a little better. Oh, and I am using tonight a very small class D amp, which can be had for less than 30 dollars and I like the sound of it better than my other expensive amps.
@zorst99: Seeing that you have the same 801s that I did I would highly recommend that you upgrade your internal capacitors if you haven't done it already. I used the Solen BP400 series. The clarity and imaging improved dramatically. Bass actually showed up. Then ended up having better bass than I ever remember them having. I had taken them apart a couple of times thinking the woofers might be out of phase. I had purchased these as used speakers a year and a half old. I used them for a long time then bought my 802Ds, then I had the balls to work on the 801s I wish I had don it sooner I would have never bought the 802Ds. They ended up sound as good as the 802s the midrange wasn't as good but I would have to say the bass was a little better. Oh and I using tonight a very small class D amp, can be had for less than 30 dollars and I like the sound of it better than my other expensive amps.
@grandadgamer8390: I've been flying the RMS flag for years, been in decline for years as an honest measure. M
Nice little amp though 😊
@bigcassssino: OMG Your girls at the end!!!! Priceless!!!! I got a good laugh!! Keep up the good work! Cheers!
@NeverTakeNoCut-offs: Au contraire , I installed the orange knob, and I got a much more open, velvety sound. You are clearly stupid
@izaakgray1718: Your physics teacher was right - but you need to extend that analogy. If the amplifier was supposed to deliver a continuous and true 600 watt into a speaker, pretty much any home speaker would set on fire wit the heat produced. The ratings are all based around crest factors, dynamic non sinusoidal waveforms, and burst power ratings. And that actually makes sense because we're trying to put a number on any inherently dynamic signal, and we're concerned with whether it can do that momentarily without distortion, when for instance reproducing a bass drum. At this point, the power supplies burst capability delivered by its cap bank, and not its input power, actually matter a lot more. Please re test for burst capability. If it can deliver that, it's a fair cop, if it can't, it's a lie.
@hs7921: I’ve got one of these. Bluetooth from my Mac, connected to my Yamaha NS 5X speakers. Unbelievable.
@mikaelAedo: Have owned at least four pair of Sonab OA5 and from now I'm gonna be a lot more questioning about what you state.
That one of the worst speaker I've heard, ok mid but hars treble that bounced all around and totaly absent base. I turn down a pair of version 2 for €70 some day ago. I buy and sell vintage hifi as a hobby and have had a lot of stuff. OA5 is better as a waist basket than a speaker.
Did see Stig in the early 70's, he was a friend of our naighbour, Martin Persson.
@AudioMasterclass replies to @mikaelAedo: Don't worry! I'm going to trade them in for a pair of Bose 901 soon.
@samaradaf6640: its a kid amp
@Bastelcontainer: The Sonab OA5 MK2 are really great. I grew up with the sound of these unusual speakers
@gregbailer8701: Engineering, Science, Math, Physics, ...all in one video. Well done David. I'm not a $100 Class D fan currently. My 20-year-old Pro Level A/B stage gear is: Loud, clean, and reliable. The amp gain level is set @ 50% with superb headroom for clarity. Pre-amp level 20%. Easy 80 DB SPL. No flowery adjectives are needed. Seat belt suggested.
@robertwestinghouse4098: Love your no BS delivery and content. I have the V3 and the binding posts are a joke. The power is also a little ambiguous. When I swap my circa 1980 Aiwa SA-P22 Power Amp (30 watts stereo into 4 Ohms) within the Aiwa Mini 22, the 44-year-old Power amp was was much louder and drove the speakers with more authority than using the Fosi V3. But using my PC the volume was OK.
@chelfyn: I used to run a super cheap ($15 ish) class D amp that ran off a wall wart, or 4 AA batteries, into some mid range wharfdales and it sounded fantastic. I couldn't believe the quality for the price. it was about 15W per channel iirc, but loud enough for my tiny apartment.
@R3dlined: Wait so are we saying this will drive a pair of ELAC Uni-Fi 2.0 UB52 just fine?!?!?
@totembarada6900: 32v 5a 95 wat x2 4 Om | 8 Om 53 wat x2
@georgecorey1320: I use two similar inexpensive (TPA 3116 D2) digital amps regularly, at home and work. I think that they sound very nice for near field, listening running at up to 4 W per channel. I think that they actually sound excellent in driving speakers that are easy to drive, at a volume suited for conversation. The real discrepancy between their useful output, wattage, and their advertise output wattage comes from two factors, I think. If you test with a dummy load and a sine wave input, for instance, one of my amps will put out 40 W per channel. With music programming, it drops to 4 W. I think that the variable pulse duration mechanism that these amplifiers use does much better with a sine wave because this wave form has a minimum of slew rate for a given amplitude. reproducing, actual music is more challenging. The second major limitation is the limit in increasing current sourcing for demanding speakers and demanding passages of music. And you can demonstrate this easily by diminishing dummy, load, and seeing if the output wattage actually drops fairly sharply. Used with these limitations in mind, I like these amps.
@LenovoLenovo-g2f: Why this Fosi looks so ugly? I prefer Mitsubishi M -A04.
@royrogers7644: It`s 600 mW for headphones......
@dj-kq4fz: This is my first time watching your videos. I thoroughly enjoyed the review and your sense of humour. The end caught me by surprise. Well done, sir!
@danielduesentriebjunior: Already 20 years ago Bang&Olufsen introduced 1000 Watt class D amps in the Beolab 5 about the size of a cigarette package.
@edwardasmannjr.2438: Damn you with you your facts, knowledge, experience, and, and, and, sense of humor! (Crap! Now he knows I’m a Yank.)
Thank you, I thoroughly enjoy these videos, and learn useful things too. : )
@TheEulerID: The peak to peak measure is only valid if the amplifier you are using has differential output. That is one terminal is producing a mirror image output to the other. In effect, the signal across two amplifier outputs with one inverted relative to the other, a configuration known as "bridged mode". The majority of power amplifiers have one fixed voltage reference terminal, often to ground, and only one terminal is actually outputting a varying voltage, then the peak output is the peak voltage to fixed voltage terminal. However, the TPA3255 does have bridge mode output, which means the theoretical maximum voltage range across the load is, effectively, doubled.
@BrianHall-Oklahoma: I just got one of these to power the monitor speakers in my home recording studio. I'm impressed with it.
@9th_note: they shouldn't even measure amplifiers in wattage at all it's a stupid way to measure power. current is what drives the speakers not wattage.
@peteleoni9665: A note on your B&W 801s. I too owned a pair. 2 in fact. I bought them to master with. Here is a sad fact about those much vaunted speakers. They do not sound that good, nor and more importantly are they that damn accurate. Here, I am curious as to why you have kept them. It's plain to see you are no one's fool. Please clue me in because I have no doubt that you heard what I did? Did you perhaps modify the crossovers? P.s. I am no audiophile I am a mastering guy, we laugh at audiophiles because we actually know what makes the difference. I am curious?
@AudioMasterclass replies to @peteleoni9665: Sometimes you just like what you like.
@peteleoni9665 replies to @peteleoni9665: @AudioMasterclass
This is true! There were several versions of the 801s as well both mine were variations of the vented ones and that may be the deal. I thought btw, that the 802's were a lot better and that's what I kept. As far as listening, I just rolled my own with some tad drivers and never looked back after venturing into high efficiency horn land. But you really can't Mix on them because they uncompress things due to the very low excursion and you can't really ref with that.
@peteleoni9665: The older I get, the less bullshit I can tolerate. Thank you for no bullshit! Subscribed!!!!
@richh650: I have watched V3 reviews all over YT and I must say, your reviews are by far better and more enjoyable than any others. Very well done!
@Andrii_DrD: I keep my Sonab's in a toilet, useful to cover up old fart farts 🥲
@carlsitler9071: Aesthetics is a factor as well. I prefer an amp that looks a stereo amp rather than a power brick.
@carlsitler9071: I bought the original little powerhouse, the Aiyima A07. The new one (Max) is just like the V3 but can be bridged. My second system has omni-directional speakers as well, the Mirage OM-9s. Not audiophile but good enough.
@smithy_uk: I could listen to you all day
@bubbleone6526: I just love this not an audiophile guy as he claims but the orange volume knob gives him away! But really no joking aside, he’s probably the strangest shooting reviewer on uTube. As far as class D is concerned I’ll stick to my class A and AB amps. Oh 19.38 minutes to say you love the class D amp was a little it much. 😂😂😂
@KG-zh2cg: this is to good review for that amp
@c.s.herman860: How much power does it use at idle? I wish it had auto-on
@Douglas_Blake_579 replies to @c.s.herman860: A few milliwatts. idle current is about 30ma.
@c.s.herman860 replies to @c.s.herman860: @Douglas_Blake_579Is it the same for most class D amps? If I just left it always on, connected to a wifi streamer, it wouldn't be so bad eh?
@Douglas_Blake_579 replies to @c.s.herman860: @c.s.herman860
The overall idle current will vary from design to design, depending what else is also running (op-amps, tone controls, sub out, wifi, bluetooth, etc) but most class D amplifiers are very efficient.
With the power switch on the volume control, you have to reset your volume every time you turn it on. So I imagine quite a few of these amps will be left idling when not in use. Time will tell us if this particular implementation stands up or not.
@andrejgregoric1324: Right! It allways amazes me, when I read incredible pwr output numbers, but checking device pwr consumption is mostly up to max 200W. So, how do we get those incredible output numbers... simply adding foot size, house numbers, po numbers 😂
@Douglas_Blake_579 replies to @andrejgregoric1324: The 300 w/ch spec is the Absolute Maximum output of the chip. It's generally taken as a one time pulse at about 10% distortion. So, you might get 300w/ch from the V3 ... once.
The actual low distortion power is spelled out in the "TPA3255 data sheet" (do a search) and tops off at about 50w/ch on 8 ohms, and 90w/ch on 4 ohms with the 32 volt supply. The 48 volt supply bumps that up to about 100 and 200.
@ericbain507: Omg, absolutely brilliant vid. I laughed, I cried, I learned a thing or two. Finally a review with context.
@owenjbrady: Class D in the 2020's is nothing like it was years ago