Fosi Audio ZA3 Balanced Stereo Amplifier Home Audio Component Mini 2 Channel Mono Amp TPA3255 for Subwoofer Desktop Home Theater Bookshelf Tower Floorstanding Passive Speakers with 48V Power Supply

After already using the device on stereo with Fosi's Bluetooth DAC and P3 preamp, I am now using two ZA3s on my Klipsch RP600 biamplified (separate whoofer and tweeter), and a powered 100W subwoofer and the sound that was already great became magnific! The HiDef sound from my computer goes through the DAC to receive the warmth of the P3 tubes, then gets amplified with tons of headroom into my RP600 delivering a highly impressive soundstage and crispy clarity and depth to the sounds. I am hearing details that were only noise before. Even on extremely low volumes at night, the level of detail is very impressive. Highly recommend to any one who wants to enter into HiDef and wants to buy quality, easy to install, and use devices while not breaking the bank! I just wish it came with the 10a power supply

I was replacing an older NAD integrated amp that I really liked. Decided to go class D amp for a replacement. WAY smaller. MUCH less expensive, and this unit has all the functionalities I was looking for at an incredible price (I bought mine for about $130 each on Amazon. Will be using two in mono mode. At first I thought they were defective. PAY ATTENTION TO THE MANUAL THAT WARNS YOU TO CONNECT ALL CABLING BEFORE YOU INSERT THE POWER CONNECTION. If you power the device first, then attach cables, it won't work at all until you detach the power cable and reinsert it. This is no fluke. It happened several times. Attach ALL cabling first, then insert the power connection. Secondly, if you're running it in mono mode the inputs for both units are inserted into the RIGHT side on the rear of the unit. The left channel is disabled in mono mode. This is all spelled out in the manual but it's counter-intuitive at first. As for sound, I'm pleased. I'm sending Tidal or Spotify digital signals to a Fosi ZD3 via bluetooth (works perfectly). The ZD3 is the DAC and connects to the paired Za3s. My speakers are very modest, a HSU powered sub that I've connected to the ZD3 (not the ZA3). Main speakers are HSU HB1 mk2. The ease of use with my iPhone is just fantastic. Essentially any song I want is at my fingertips. Sound quality is very good to my untrained ears. I'm very happy with this purchase. These amps have more than enough power to drive these smaller speakers even at higher volumes than I'd ever naturally want. The fit and finish of the amps is very good. No noise in the volume knob at all but I leave them in a fixed position adjusting volume either at the ZD3 "preamp" or even more commonly with my iPhone volume controls. I've been buying / building stereo equipment for about 55 years. I'm a huge music fan, but I can't hear all the mumbo-jumbo the experts can. I just know these are great little amps for an incredible price, and even one would work nicely in stereo mode. Very happy. Will see how they stand up to time and use.

I dove headfirst into the hi-fi realm at the beginning of the year and not knowing what to expect. I come from a studio set up with active monitors (Adam A7) hooked up to an Audient ID44 audio interface. For my small but amazing bachelor pad, I was actually using an Echo Dot hooked up to a small pair of Presonus Eris 3.5 speakers (Don’t Laugh). Obviously knowing what good sound sounds like, I wasn’t satisfied with that set up. I started looking up amplifiers, Dacs, and bookshelf speakers. Of course people swear by AB amplifiers as better sounding, but I wanted a minimal set up that sounded good without using up too much space. Not that I don’t mind spending more cash, but I also know that you reach a point of diminishing returns. Do I really want to spend an extra thousand dollars for a 5% increase in sound quality? Not me, at least not now. So I began my research. At the beginning of the year I purchased the Aiyima A07 Pro with of course the infamous Sony SSCS5 that everybody seems to have; thank the Cheap Audioman for that. I wasn’t using a DAC, I was streaming straight from my iPhone paired up with Bluetooth. I thought OK this is cool, I can live with this. But then I started binging on more YouTube videos and soon realized that I wanted more. Sound was cool but not great. I would say that the turning point came when I found out about the WiiM Pro streamer. You wanna talk about a life-changing product, that’s it! It literally changed the game for me. From streaming from my TV, tablet, phone, everything... Chromecast, Airplay, Spotify connect, Tidal. You name it! They put all of the pieces together for me and made everything seamless. After a bit more research, I came across the SMSL SU-1 DAC everybody was raving about. As for speakers, I purchased a pair of Polk XT15 to go along with my Sony's. I liked the Sony's, but they were lacking a bit in bass and chose the Polk XT15 because they were on sale on Amazon for $135 and were also significantly smaller than my Sony's while still having a 5“ driver and a better frequency response in my opinion. The highs were crystal clear yet non-fatiguing, and the bass punchier and hefty while the Sony's sounded more boomy in comparison. Beautiful speakers all around and definitely recommend them. Of course you know I didn't stop there though! I started late night binging on YouTube and foaming at the mouth thirsting for more and better gear. Upon yet more research, I realized that everybody was swearing about the new Fosi ZA3, so on launch day, I jumped all over it and purchased it. I swapped out my Aiyima A07, turned on the Fosi ZA3 and my first impression was warmth, wideness, punch. Now don’t get me wrong, the Aiyima A07 Pro is no slouch, and it has served me well throughout the year. I’m still keeping it and putting it in the master bedroom. I love the tone controls, the Bluetooth connectivity, but the Fosi definitely had the “IT” factor. Music was immersive, I started bopping my head, tapping my feet on the ground and busting the nickel in the living room (for those that know about break dancing). I felt it was definitely an upgrade. I also like that it has balanced XLR connections which sound better than RCA and louder. Here's my setup: • Polk XT 15 Bookshelf Speakers • Fosi ZA3 Amplifier • WiiM Pro (Not the Plus) • SMSL SU-1 DAC • Audioblast Speaker Cables • Mogami 2964 RCA Cables • Gotham GAC-1 Pro SPIDF Cable Could you get a better set up? Of course! But then again, do you really need it? The diminishing returns factor kicks in really quick. I mean, It’s easy to become addicted to buying gear. FOMO is REAL! I found that out this past year. New gear is always coming out at a feverish pace, on a monthly basis it seems. but seriously, just go with what you need and sit back roll a fat one, break out the wine, crack open a cold brew and just enjoy the music! With my current rig, I dropped $600 and I’m at the point where I’m happy with my set up. It’s more than good. It’s great. Could I drop an extra thousand dollars on a better DAC and amplifier? YES. Would people notice the difference? Absolutely not! With my current set up, I get compliments all the time. The music sounds amazing, and the ladies love it. Good luck on your journey and remember, diminishing returns!

Impressive little class D amplifier out of the box. Lots of power with low distortion and practically no noise. Very efficient due to class D operation. Construction seems nice with excellent components. I first bought one and used it in the stereo mode. I enjoyed it, but was intrigued by the swappable op amps. I bought two Sparkos Labs SS3602 op amps and installed them for the RCA inputs. While the amp is very good out of the box the difference with the Sparkos is amazing. Separation, detail, space depth, imaging and frequency response all improved dramatically. This is a killer combination. Later bought a second one, did the same easy mod and am running them in dual mono block mode making an awesome combination. As I said, these are very nice out of the box, but with the mods and in the mono block mode they make a great system.

Great little Chi-Fi amp. Plenty of power for a desktop system or a system for a small room. I am running this with their ZH3 DAC\headphone amp, The only complaint I have, which is very petty, is it would have cost them a few cents to include a trigger cable, other than that, it works well, I did replace the Opamps with some high end Virtual HiFi Supersonic V2's which makes this amp sound amazing.

First, let me say how impressed I am with the ZA3. It packs a huge punch for its size. I own a pair of PSB Stratus Gold i speakers, which are known to be difficult to drive. I bought a Yamaha A-S701 and the Fosi ZA3 just to compare the best I could get for the price in a Class AB and a Class D amp. I ultimately returned the Fosi just due to the amount of extra cables I needed in my particular setup vs the Yamaha 701. I would 100% recommend the Fosi though as it gave me 85% of the performance of the 701 for a small fraction of the price. The Yamaha and Fosi sound about the same TBH. The Fosi also barely gets warm at higher volumes where the Yamaha definitely gets toastier. The Fosi is clear at all volumes with no distortion that I noticed. About my only complaint with the Fosi is that you have to hold down the volume knob to turn it off and on. I would much rather they move the stereo/mono switch underneath and make that the power switch. Do not hesitate to get the Fosi if you are looking for a reasonably priced amp that performs very well. I think a perfect setup would be to have another brand preamp that has 12v trigger connected to this so it would turn on and off with the preamp, but also have a lot more options for inputs. I do have a lot of sources so that factored into my decision. This is a great amp you won't be disappointed with.

I bought this unit for my desktop audio system. I wanted an amp that wouldn't take up much space on my desk and have enough power to drive my desktop speakers with ease. While the Fosi amp fulfilled these criteria, it has shortcomings: -- the volume knob is flimsy and feels cheap. This is subjective, of course, and doesn't affect the sound. -- related to the above, the on/off switch is integrated with the volume control. I would much prefer a separate, more robust switch. -- the speaker binding posts also are flimsy and cheap. If using bare speaker wire, I suspect they could easily be overtorqued and its threads stripped. -- the two switches on the front panel would be used by most people only once. They would be better placed on the back panel. -- the balanced (XLR) inputs on the back panel strike me as a gimmick. They're most often found on high-end equipment. (Sorry, Fosi: this is not an audiophile piece.) I'm sure the RCA inputs are used by the vast majority of Fosi owners. -- the 'on' light on the front of the unit is small and relatively faint. Yes, this is a nit, but it is easy to overlook it, resulting in leaving the unit on unintentionally. -- as a desktop unit, I wish it had an auto-on/off function, where it would go into sleep mode following a period of non-use and automatically power up when an audio signal is detected. -- I would have liked it to have a headphone input on the front panel. Now, for the positive: -- it lacks a remote. Yes, this a positive-- as a desktop unit, I'd much rather control volume and on/off on the unit itself rather than have to fumble for a remote to control those functions. I am happy to avoid having to pay for a remote control. -- it lacks an onboard DAC, also a positive. I have several outboard DACs so I am happy to avoid paying a higher price for a unit with an onboard DAC. -- the housing of the unit is solid and belies the relative flimsiness of the volume knob and the speaker binding posts. -- the unit appears to be well ventilated, Although I have not driven it hard or for hours on end, it has run cool. -- it drives my desktop speakers to more than adequate volume levels. Final thoughts: At a hundred-fifty bucks, this amp is a good value. I recommend it to anyone seeking an amp for a desktop system and who doesn't want/need a headphone output or a remote. Above all, I want the unit to be reliable. As for this, time will tell.

Works well for my use case. I have a passive dual-driver subwoofer that wasn't getting any use as my home audio receiver doesn't have a powered sub output, just the connections to go to an active sub. This meant I had to use the sub off the front left and front right running as large speakers and had to run 2 satellites off the sub's outputs. It sounded pretty bad. The active crossover ruined the sound on the satellites and there was no point using larger front speakers because the sub stole all the mids and lows. And the sub wasn't getting enough juice to produce much sound without very loud fronts. It was kinda a mess so I had put it in storage, but that sub was just too nice to get rid of. This amp allows me to continue running the fronts directly from the receiver (and use larger nicer full range speakers) and run the bass off the active sub out. The sub has 2 dedicated inputs (one for each driver) so I used a banana connector splitter off this amp in mono mode to maximize how much energy it can put out which turned the woofer from two 8 ohm inputs into a single 4 ohm and it sounds fantastic. I have the amp running pretty hot (volume, not thermally) at around 70% output, but it hasn't introduced any issues with distortion or hum/buzz. And speaking of running hot, this thing does run really cool. Certainly cooler than any amp I've run in a car. Definitely recommend.

I purchased the za3 to power a pair of surround speakers in my HT rig. To test the za3, I connected it to a pair of older Polk RTiA1, Anthem avm70, and Sony SACD player. I chose Rickie Lee Jones Pirates SCAD to demo the Fosi. The sound was very impressive from the start and only got better as the amp continued to play. It barely got warm and the speakers were completely quiet when no source material playing and the Fosi volume set to max. Impressive! I connected the Fosi to surrounds, re-ran the sound calibration, and, again, the Fosi did not disappoint. This little amp proves that spending big dollars isn't always needed. The Fosi has a 12 volt trigger. Sadly, I did not have mono cable on hand with a male 3.5 mm connector on each end. The cable I had was stereo with 3.5 mm male on one end and 2.5 mm male on the other. Through a bit of simple improvisation, I spliced the 3.5 mm connector to a 12 volt DC power adapter, connected both the Fosi and power adapter to the same power bar. Now, turning on the power bar powers on the Fosi.

He comprado 2 unidades del Fosi ZA3 para usarlos en Monoblock (mono) uno a cada una de las cajas que tengo JBL. Espectacular siendo un amplificador bastante económico la potencia que entrega. No altera el sonido y reproduce exactamente la calidad de las 2 fuentes que les he conectado, la interfaz de audio Focusrite por el RCA y una Denon Prime Go+ por su XLR. No se aprecio distorsión alguna y el balance es bueno. Muy contento. La fuente es voluminosa de 48V y con un solo amplificador en estéreo seguro que irá también como un cañón en rendimiento aunque no lo he probado todavía. Me hubiera gustado un interruptor para el ON/OFF fuera del mando de volumen, pero vamos.

48v 5A adaptörü takıp kendi dahili dac.ı rca ile denedim evet ilgi çekiciydi fakat standart bi d -classtı. Daha sonra 3 adet muses02 opamp sipariş verdim ve elime ulaşıncaya kadar amfinin yanmasını bekledim. Nihayet geldi opampları değiştirdim ve sub opampı devre dışı bıraktım(kullanmadığım için) vee Xlr (cardas golden cross) ları bağlayınca vaaay müthiş ses!! Birçok pahalı amfiyi sınıfta bırakır çok net!! Opamp yükseltmesi yapıp güzel bir Xlr ile kullanınız şaşırcaksınız....

These small class D amps are exceptional value for money! I have amps that cost 20 times more than the ZA3 but does not deliver even 5 times the performance. I tried this (just for fun) with my power hungry Sonus Faber Sonnetto I bookshelves and it managed to make them sing beautifully up to the max volumes I listen to (70-80 db). I use two of them in mono mode to power my desktop speakers mainly for nearfield listening. The only thing I miss is a high low pass filter for the sub output. This is honestly exceptionally priced HiFi! The performance makes the price a steal! And I am so inclined to build an entire system of Fosi products just to compare its performance to price against my other ridiculously priced higher mid-range systems, which I 'm sure this will give a run for the money! I heard some premium and expensive high-end amps, and this definitely does not compete with them (I mean, come on if you're expecting this!), but for mid-range and other entry level products, I believe this thing is a certified LGK!

This amp is a replacement for my fried Topping PA3. At first I connected it via minijack to RCA on my laptop and was very disappointed. Sound was flat and I had to put the volume to 40% to have a decent volume. I tried connecting it to different speakers and sources. I was really wondering what the hype was about and almost decided to send it back. I even wrote a bad review. But never posted it. :) After a day or 2 I had the idea to try minijack to XLR. And OMG what a difference. The little amp just opened up. Volume ok. Rich beautifull sound. I was blown away. I don’t know if it’s my unit that is faulty or if it’s just the way it works. So now I’m happily recommending it.