5.0 out of 5 stars Best Value mono block on the market in my opinion.

2025-12-23    -James McLellan

This mono block amplifier is such a great value, best currently on the market in my opinion in regards to bang for the buck. Currently using it for my center channel (kef r2 meta) in my system and the sound quality is excellent with noticeable improvement in clarity over the onboard amplifiers built into my AV processor. The auto on function works perfectly and the amp stays remarkably cool and the build quality is impressive considering the price. Highly recommend trying it, I am considering adding two more to replace the emotiva amp I am using for my front left and right speakers.

5.0 out of 5 stars Best price performance.

2026-02-11    -Music Mike

Bargin of the century. The saying that good things come in small packages is true. Don't let the size or price fool you into thinking you won't get much. These mono blocks offer excellent sound quality. Great imaging. Excellent instrument detailing. Close your eyes and you would swear your listening to amps selling in the thousands. Just buy them.

5.0 out of 5 stars Best Value mono block on the market in my opinion.

2026-01-03    -James McLellan

This mono block amplifier is such a great value, best currently on the market in my opinion in regards to bang for the buck. Currently using it for my center channel (kef r2 meta) in my system and the sound quality is excellent with noticeable improvement in clarity over the onboard amplifiers built into my AV processor. The auto on function works perfectly and the amp stays remarkably cool and the build quality is impressive considering the price. Highly recommend trying it, I am considering adding two more to replace the emotiva amp I am using for my front left and right speakers.

5.0 out of 5 stars Everything done right. DGM

2026-02-09    -Dave Michalak

This ChiFi amplifier is a well designed and highly performing device that will challenge even the Best class A/AB stereo amplifiers. It will benefit from 48v 10a GaN smps. They run very cool with a very high damping factor. High frequency performance is superb. High quality speakers are appreciated by this amp. Imaging is very good. Excellent Bang for your buck!

5.0 out of 5 stars A great class D amplifier with the class A/B performance that costs in the thousands

2026-01-30    -scsi_boy

A great class D amplifier with the class A/B performance that costs in the thousandsTL;DR: You do not need to spend thousands of dollars for an amplifier to reproduce clean sounds from the preamp or processor (DAC or AVR) and commanded by your speakers. I know because I have a much more expensive amp (class A/B), and the 3e-audio A7 mono produces the equal sonic qualities, if not better, especially in the low frequency range. It might not have over 200W into 8ohm or 400 into 4ohm, so it does not have the head room, but i never listen at a loudness level where the extra head room is needed. A7 mono has 150W into 8ohm or 260 into 4ohm is more than sufficient. Understand that these ratings are clean wattage, and you'd probably go deaf permanently, if exposing yourself at these volume levels for too long.This is a class-D topology so the amp is highly efficent >85% efficient. This means that less than ~15% is lost to heat, which is EXCELLENT. Class AB will get you between ~45% - ~65% efficient, assuming the amp is highly well designed and likely will cost you in the thousands if not well into tens of thousands of dollars to achieve somewhere near 65% efficiency.---The Design: A7 mono is based on Texas Instruments TPA3255 chip. 3e Audio enhanced the PFFB filter implementation to remove unwanted noise; hence the amp produces SNR above 100Db. High end components onboard is used to reap the best amplification from 3255 and deliver them to the speakers. 3e Audio has done great engineering R&D on the implementation of the A7 series (stereo or mono). The implemenation is not just about the selection of high end components but also the routing of circuitry design, so KUDOS to 3e Audio.---Hissing Noise: Dead silent with zero hissing noise from my Elacs DB63.----My Thoughts & Suggestion: Skip the Fosi V3 mono and get this amplifier. This is a special amplifier in that it should be used in your main system for both watching movies and listening to music for the critical listeners. The power delivered to my speakers (Elac DB63) is very clean at high or low volume. The amp is neutral, which means that if the speakers sound warm, then they will sound warm. If the speakers sound neutral or bright, then they will sound as such. In other words, there's no coloration of the amp amplifying the signals from the preamp or pre-pro AV. Coloration caused by an amplifier is distortion that some folks actually want in the reproduction of sounds to make them sound "warm". An amplifier's sole purpose is to amplify an incoming audio signal from the pre-amp or pre-pro or DAC source.----IMPORTANT (must read): Initially the amp fresh out of the box and dead cold straight from the manufacturer, it may sound flat and un-engaging; try to be PATIENT. Play it for a few hours of different music genres to break-in the amp. After a couple of hours the caps should start to form. Remember to play the amp easy and step up the volume and back to easy and any volume in between. A few more hours on the 2nd day, and you will hear the sonic qualities from the A7 mono as intended by the designers.----Input sensitivity for RCA (or single-ended connection):- rated @29db, the minimum input voltage required is ~1.2 Vrms (i had to compute this value because it was not advertised)- rated @26db, the minimum input voltage is ~1.75 Vrms (3e Audio advertised)- NOTE: @29db gain, the minimum input voltage to reap the maximum power from the amp is ~1.2 Vrms. This is very close to THX Certified requirement of 1 Vrms. Most good AVR (like the Denon 3700H or higher) has 1.1 Vrms output sensitivity, if you configure every channel to pre-outs and not use the internal amplifier. You can see that the Denon 3700H has 1.1 Vrms is very close to the 1.2 Vrms for 29db gain on the 3e audio A7 mono block. This is a good match between source and amplifier.----Soundstage Impression: The soundstage is limited by the speakers you are playing. If the speakers play a wide soundstage, then the amp will play the equally wide soundstage. The amp does not reduce sound stage or widens sound stage. A lot of this is due to the performance of the speakers you are playing. For example with my Elac DB63, if i toe them in by a few degrees, the sound stage is so wide that the sounds would literally wrap around my head.----Clarity Impression: The amp delivers clean power to the speakers and clarity is determined by your speakers and the source signal integrity (e.g. DAC or preamp, etc). I had these mono blocks at high volume and the sounds that were amplified were superb and clean, but again it depends on the quality of your speakers and the signal source.----Sonic Qualities in a nutshell: Great transients, excellent sound stage, tight fast bass and precise imaging. The best of all, since these are mono blocks, stereo separation is superior to any stereo amp, regardless of price. Nothing beats mono blocks when it comes to stereo separation - NOTHING.----Form factor - small but very sturdy built. When you pick it up, it feels quality and heavy for its size. Seems like it is built like a tiny tank.----48v/5A or 48v/10A: This decision is based on your speakers' impedance. If you are driving 4ohm speakers, then I probably would get the 48V/10A power supply to be sure. Understand there is efficiency at play here. Class-D is generally greater than 85% efficiency.So assume that the efficiency is 90%, then the usable output wattage is ~191.5 watts into 6ohms speakers.- The calculation- the power supply is 48V rated at 5A == 240 watts (P = V x I) - this is theorectical value if the amp is 100% efficient, which it is not.- assume the amp is 90% efficient, then power drawn from the outlet is 212.7 watts (191.5 / 0.90) (. 10% of power goes off to heat or 21 watts dissipate as heat.- Vrms = Vpeak / sqrt(2) = 48/ sqrt(2) = 33.94 Vrms (so 48V is peak power and 33.94V is continuous power)- P = V^2 / R = (33.94) ^ 2 / 6ohm = 191.5 watts continuous into 6ohm.- if you have 4ohm speaker, then P = ~287.98 watts continuous. This is why you would want a bigger power supply rated at 48V with 10 amp. when driving speakers rated at 4ohm nominal and likely dip into 3 ohm depending on frequencies.----My Setup:- Denon 3700H; movies watching is very engaging with this amp- Speakers are Elac DB63; perfect for watching movies due to the design of the speakers' intentions for spatial sound stage. Music listening will have sounds that kind of wrap around your head depending how you toe in your speakers for the Elacs.- Amp - 3 x 3e Audio A7 mono blocks to drive left, center, front speakers.Other reviews: search for ASR review, ARchio for 3e audio A7 (mono or stereo)

5.0 out of 5 stars Top Notch

2025-12-30    -Slip

After enjoying a 3e A5 in a smaller system I decided to pick up a pair of these and try them in my main system. I’m glad I did. These really are excellent mono block amps and will drive just about any speaker with ease. It’s all there, great clarity, bass, and the overall sound is superb. Their small size is a bonus too.

5.0 out of 5 stars Amazing value, high end sound with 2x mono

2026-01-21    -Cynthia Freund

Excellent, you can spend way more and get worse sound. Get 2 of the mono, worth it!

5.0 out of 5 stars A great class D amplifier with the class A/B performance that costs in the thousands

2026-01-15    -scsi_boy

A great class D amplifier with the class A/B performance that costs in the thousandsTL;DR: You do not need to spend thousands of dollars for an amplifier to reproduce clean sounds from the preamp or processor (DAC or AVR) and commanded by your speakers. I know because I have a much more expensive amp (class A/B), and the 3e-audio A7 mono produces the equal sonic qualities, if not better, especially in the low frequency range. It might not have over 200W into 8ohm or 400 into 4ohm, so it does not have the head room, but i never listen at a loudness level where the extra head room is needed. A7 mono has 150W into 8ohm or 260 into 4ohm is more than sufficient. Understand that these ratings are clean wattage, and you'd probably go deaf permanently, if exposing yourself at these volume levels for too long.This is a class-D topology so the amp is highly efficent >85% efficient. This means that less than ~15% is lost to heat, which is EXCELLENT. Class AB will get you between ~45% - ~65% efficient, assuming the amp is highly well designed and likely will cost you in the thousands if not well into tens of thousands of dollars to achieve somewhere near 65% efficiency.---The Design: A7 mono is based on Texas Instruments TPA3255 chip. 3e Audio enhanced the PFFB filter implementation to remove unwanted noise; hence the amp produces SNR above 100Db. High end components onboard is used to reap the best amplification from 3255 and deliver them to the speakers. 3e Audio has done great engineering R&D on the implementation of the A7 series (stereo or mono). The implemenation is not just about the selection of high end components but also the routing of circuitry design, so KUDOS to 3e Audio.---Hissing Noise: Dead silent with zero hissing noise from my Elacs DB63.----My Thoughts & Suggestion: Skip the Fosi V3 mono and get this amplifier. This is a special amplifier in that it should be used in your main system for both watching movies and listening to music for the critical listeners. The power delivered to my speakers (Elac DB63) is very clean at high or low volume. The amp is neutral, which means that if the speakers sound warm, then they will sound warm. If the speakers sound neutral or bright, then they will sound as such. In other words, there's no coloration of the amp amplifying the signals from the preamp or pre-pro AV. Coloration caused by an amplifier is distortion that some folks actually want in the reproduction of sounds to make them sound "warm". An amplifier's sole purpose is to amplify an incoming audio signal from the pre-amp or pre-pro or DAC source.----IMPORTANT (must read): Initially the amp fresh out of the box and dead cold straight from the manufacturer, it may sound flat and un-engaging; try to be PATIENT. Play it for a few hours of different music genres to break-in the amp. After a couple of hours the caps should start to form. Remember to play the amp easy and step up the volume and back to easy and any volume in between. A few more hours on the 2nd day, and you will hear the sonic qualities from the A7 mono as intended by the designers.----Input sensitivity for RCA (or single-ended connection):- rated @29db, the minimum input voltage required is ~1.2 Vrms (i had to compute this value because it was not advertised)- rated @26db, the minimum input voltage is ~1.75 Vrms (3e Audio advertised)- NOTE: @29db gain, the minimum input voltage to reap the maximum power from the amp is ~1.2 Vrms. This is very close to THX Certified requirement of 1 Vrms. Most good AVR (like the Denon 3700H or higher) has 1.1 Vrms output sensitivity, if you configure every channel to pre-outs and not use the internal amplifier. You can see that the Denon 3700H has 1.1 Vrms is very close to the 1.2 Vrms for 29db gain on the 3e audio A7 mono block. This is a good match between source and amplifier.----Soundstage Impression: The soundstage is limited by the speakers you are playing. If the speakers play a wide soundstage, then the amp will play the equally wide soundstage. The amp does not reduce sound stage or widens sound stage. A lot of this is due to the performance of the speakers you are playing. For example with my Elac DB63, if i toe them in by a few degrees, the sound stage is so wide that the sounds would literally wrap around my head.----Clarity Impression: The amp delivers clean power to the speakers and clarity is determined by your speakers and the source signal integrity (e.g. DAC or preamp, etc). I had these mono blocks at high volume and the sounds that were amplified were superb and clean, but again it depends on the quality of your speakers and the signal source.----Sonic Qualities in a nutshell: Great transients, excellent sound stage, tight fast bass and precise imaging. The best of all, since these are mono blocks, stereo separation is superior to any stereo amp, regardless of price. Nothing beats mono blocks when it comes to stereo separation - NOTHING.----Form factor - small but very sturdy built. When you pick it up, it feels quality and heavy for its size. Seems like it is built like a tiny tank.----48v/5A or 48v/10A: This decision is based on your speakers' impedance. If you are driving 4ohm speakers, then I probably would get the 48V/10A power supply to be sure. Understand there is efficiency at play here. Class-D is generally greater than 85% efficiency.So assume that the efficiency is 90%, then the usable output wattage is ~191.5 watts into 6ohms speakers.- The calculation- the power supply is 48V rated at 5A == 240 watts (P = V x I) - this is theorectical value if the amp is 100% efficient, which it is not.- assume the amp is 90% efficient, then power drawn from the outlet is 212.7 watts (191.5 / 0.90) (. 10% of power goes off to heat or 21 watts dissipate as heat.- Vrms = Vpeak / sqrt(2) = 48/ sqrt(2) = 33.94 Vrms (so 48V is peak power and 33.94V is continuous power)- P = V^2 / R = (33.94) ^ 2 / 6ohm = 191.5 watts continuous into 6ohm.- if you have 4ohm speaker, then P = ~287.98 watts continuous. This is why you would want a bigger power supply rated at 48V with 10 amp. when driving speakers rated at 4ohm nominal and likely dip into 3 ohm depending on frequencies.----My Setup:- Denon 3700H; movies watching is very engaging with this amp- Speakers are Elac DB63; perfect for watching movies due to the design of the speakers' intentions for spatial sound stage. Music listening will have sounds that kind of wrap around your head depending how you toe in your speakers for the Elacs.- Amp - 3 x 3e Audio A7 mono blocks to drive left, center, front speakers.Other reviews: search for ASR review, ARchio for 3e audio A7 (mono or stereo)

5.0 out of 5 stars Amazing value, high end sound with 2x mono

2026-01-17    -Cynthia Freund

Excellent, you can spend way more and get worse sound. Get 2 of the mono, worth it!

5.0 out of 5 stars Best price performance.

2026-01-21    -Music Mike

Bargin of the century. The saying that good things come in small packages is true. Don't let the size or price fool you into thinking you won't get much. These mono blocks offer excellent sound quality. Great imaging. Excellent instrument detailing. Close your eyes and you would swear your listening to amps selling in the thousands. Just buy them.