AIYIMA A20 Stereo 2.1 Amplifier Review

[whazzup]

Yes.

I have no idea. I'm not a professional pc user. My mainboard is just those generic one bought on the market. I connect my pc to a dac via usb-c, and from dac to amp. Does that have anything to do with whether I should upgrade my amp, and the choice of which amp out of those 2 I mentioned?

I understand.
If you want to tinker with your PC setup, it is possible that you can get away with not buying any new hardware. The cons are that you do need to check your motherboard hardware, for example, what kind of outputs are available, and also download free EQ software to apply the subwoofer / speaker crossover.

With regards to your earlier question, the Wiim is going to be more powerful with proper PEQ and automated Roomfit, but it can require more time to setup if you're unfamiliar with software equalization in general. If you're not a tinkerer, the A20 will probably be a lot more fuss-free with just the HPF knob adjustment. Other amps to consider are the Ampapa D1 or the O-noorus D4 pro.

 

[staticV3]

Yes.

I have no idea. I'm not a professional pc user. My mainboard is just those generic one bought on the market. I connect my pc to a dac via usb-c, and from dac to amp. Does that have anything to do with whether I should upgrade my amp, and the choice of which amp out of those 2 I mentioned?

Yeah it does.

If you were using a 2.0 setup, then I'd keep the A07 as it's a fine Amp and all I'd do to improve sound quality is:

A - Install Equalizer APO and enable it for the DAC
B - Load the loudspeaker correction for the Monitor Audio into Equalizer APO:

(dashed: Stock, solid: Corrected)

C - Use a measurement microphone like the miniDSP UMIK-1 or Micbooster EM258 to correct room modes below ~500Hz


A 2.1 setup changes the equation.

Here, I'd either switch the DAC to a miniDSP 2x4HD (again keep the A07), or I'd replace both the DAC and A07 with a WiiM Amp Pro.

Amp Pro instead of the cheaper Amp because it has some 10dB less noise (hiss).

In either case (WiiM or miniDSP), I'd load the same corrections (loudspeaker + room) now into the hardware directly so no need for Equalizer APO, plus do some basic subwoofer integration by setting the SVS to LFE/Bypass and changing the Subwoofer phase, level, delay, crossover in the miniDSP/WiiM so that integrates nicely with the Monitor Audio.

A measurement microphone is again a great help here.

 

[Mark185]

The high pass filter and subwoofer out on the Aiyima A20 are not very good at integrating with a powered sub that has its own crossover for reasons I explained in early parts of this thread. The A20 has slightly better distortion measurements than the A07 and depending on power brick, may have more power. Given the quality of your SVS sub and Spendor speakers, I recommend one of the Wiim amps or the Wiim Ultra preamp and just keep using your A07. The Wiim has parametric equalization and crossover functions that are far superior to the A20 simple filters. It costs significantly more but offers more. I own both Aiyima A07 Max and A20 amplifiers. I also own a Wiim Ultra preamp that I paid $299 for.

 

[Mark185]

Agree with @staticV3 suggestions but if you are not comfortable with the process he describes or do not want to spend that much time doing it, the Wiim Ultra can automatically make EQ and crossover adjustments using your cell phone microphone. It won't be as accurate as what staticV3 suggests but may be good enough depending on how critically you listen. I find the automatic adjustments to be good enough in my TV room where I feed the Wiim Ultra an optical SPDIF signal from my TV and use the subwoofer out and RCA out on the Wiim Ultra for a 2.1 setup. I do own good microphones and know how to use Room EQ Wizard to measure and generate parametric EQ settings and I use them in my home theater setup. I also have a miniDSP C 8 x 12 signal processor that I use in that home theater but that is almost $1000 alone. For nearfield listening, I think that is overkill.

 

[toilagamer852]

Thanks guys. In the end, I decided to buy the A20 because I got a promo code that brought the price down to $110. It however only comes with 48V 5A power supply. I heard a lot of people here said that the best to use is 48V 10A. How does it look like, or officially called, so that I can find a vendor to buy? And do I actually need it at all if I do nearfield listening 90% of the time?

 

[Mark185]

Thanks guys. In the end, I decided to buy the A20 because I got a promo code that brought the price down to $110. It however only comes with 48V 5A power supply. I heard a lot of people here said that the best to use is 48V 10A. How does it look like, or officially called, so that I can find a vendor to buy? And do I actually need it at all if I do nearfield listening 90% of the time?

You do not need the 10A power supply for near field listening. The larger power supply is really only if you need to extract maximum out of the TPA3255 amplifier chip (~200w into 4 ohms). $110 is a great price. I paid a lot more for my A20.

 

[fwwwk]

also might be beneficial not only for power issues but driving lower impedances, 3e audio initially suggested 10A for loads below 4ohm

 

[Mark185]

also might be beneficial not only for power issues but driving lower impedances, 3e audio initially suggested 10A for loads below 4ohm

All I can say is I own both the 10A and 5A power supplies and Aiyima A20, A07 Max, and 3E Audio A7 stereo amplifiers. I also own 2 Fosi V3 Mono amps. The only situation where I can clearly hear a difference with 10A power supply is when drive a pair of NHT tower speakers in my home theater. In nearfield listening at any reasonable volume level, I cannot hear a difference between 10A and 5A. I have also tried this with a variety of speakers with different impedance and sensitivity. No difference in nearfield listening up to very loud levels (>90 dB). > 90 dB is harmful in nearfield for any sustained length of time.

Yes with 2 ohm loads, the higher current power supply should make an audible difference but how many of us have 2 ohm speakers? Reality is 99% of the speakers on the market have complex impedance that varies with frequency and down in the bass region where most of the power is needed, woofer impedance rises. I think 2 ohms in bass region is probably only when you have multiple parallel drivers - common in car audio but not so much in home audio.

 

[whazzup]

All I can say is I own both the 10A and 5A power supplies and Aiyima A20, A07 Max, and 3E Audio A7 stereo amplifiers. I also own 2 Fosi V3 Mono amps. The only situation where I can clearly hear a difference with 10A power supply is when drive a pair of NHT tower speakers in my home theater. In nearfield listening at any reasonable volume level, I cannot hear a difference between 10A and 5A. I have also tried this with a variety of speakers with different impedance and sensitivity. No difference in nearfield listening up to very loud levels (>90 dB). > 90 dB is harmful in nearfield for any sustained length of time.

Yes with 2 ohm loads, the higher current power supply should make an audible difference but how many of us have 2 ohm speakers? Reality is 99% of the speakers on the market have complex impedance that varies with frequency and down in the bass region where most of the power is needed, woofer impedance rises. I think 2 ohms in bass region is probably only when you have multiple parallel drivers - common in car audio but not so much in home audio.

Thanks for sharing the real world differences! How far would you say you are from your NHT towers? And are the differences down to a max output? Like 10A allowed you to go louder? Any distortion differences you can hear?

 

[Mark185]

I am about 15 feet away from the NHT towers. They have dual 6" drivers that are probably running in parallel below 200 Hz with one rolling off higher into the midrange. That means the impedance is lower in the 50-150 Hz region than most speakers. I usually cross them over to a subwoofer at 100 Hz. Running full range, the bass response is clearly better with the 10A power supply. I have not measured it for distortion. The difference I hear is best described as 'thin' meaning the bass notes do not sound as deep and full. I believe that is down to the 10A supply expending all the energy in its capacitors with sustained bass sounds. As a point of reference, when I use a 30 year old Hafler XL280 Class A/B amplifier to drive the NHTs, the bass is noticeably better than even the 10A supply with A20, Fosi V3 Mono, or 3E Audio A7. I believe that is down to a lot more capacitance in the Hafler power supply for reserve power for transients. In a home theater, this is noticeable. Not sure if it will be audible with music in a nearfield setting.

 

[ICIETDIYEUR]

All I can say is I own both the 10A and 5A power supplies and Aiyima A20, A07 Max, and 3E Audio A7 stereo amplifiers. I also own 2 Fosi V3 Mono amps. The only situation where I can clearly hear a difference with 10A power supply is when drive a pair of NHT tower speakers in my home theater. In nearfield listening at any reasonable volume level, I cannot hear a difference between 10A and 5A. I have also tried this with a variety of speakers with different impedance and sensitivity. No difference in nearfield listening up to very loud levels (>90 dB). > 90 dB is harmful in nearfield for any sustained length of time.

Yes with 2 ohm loads, the higher current power supply should make an audible difference but how many of us have 2 ohm speakers? Reality is 99% of the speakers on the market have complex impedance that varies with frequency and down in the bass region where most of the power is needed, woofer impedance rises. I think 2 ohms in bass region is probably only when you have multiple parallel drivers - common in car audio but not so much in home audio.

Hello.

You wrote: "...At low frequencies, where the power is highest, the woofer's impedance increases. ..."

When and where did you observe this?

 

[Mark185]

Hello.

You wrote: "...At low frequencies, where the power is highest, the woofer's impedance increases. ..."

When and where did you observe this?

All woofers have an impedance peak at their resonant frequency. It is frequently 5-10x more than the rated impedance of 4 or 8 ohms. I have been designing and building loudspeakers for 50 years as a hobby. I have tested >> 100 woofers over the years. All behave like this. Look at any speaker impedance plot in Amir's speaker tests and you will see this. Look at the attached data sheet for Dayton audio woofer. This is typical. Also attached ScanSpeak midrange data sheet. Impedance peak is there but at slightly higher frequency. Enclosure design changes the impedance peak but it is always there.

 

[toilagamer852]

So I got the A20 today. Just finished installing.

1st impression: damn this thing is huge when placing side by side with my old A07. Hopefully the heat dissipation is good. The A07 is literally a grilling plate.

Next is the fun part, I'll try to play around to find the best HPF for my system.

Question: there's a RCA +3dB switch at the back, should I turn it on or off?

 

[antcollinet]

So I got the A20 today. Just finished installing.

1st impression: damn this thing is huge when placing side by side with my old A07. Hopefully the heat dissipation is good. The A07 is literally a grilling plate.

Next is the fun part, I'll try to play around to find the best HPF for my system.

Question: there's a RCA +3dB switch at the back, should I turn it on or off?

If it goes loud enough with it off, leave it off. If you need more volume, turn it on. Assuming it doesn't distort when you turn it up.

 

[toilagamer852]

Another issue: although the A20 is bigger and seemingly has more ventilation, it also heats up just as much as my previous A07. Is it safe to place my DAC on top of it?

 

[whazzup]

Another issue: although the A20 is bigger and seemingly has more ventilation, it also heats up just as much as my previous A07. Is it safe to place my DAC on top of it?

On this issue of whether these chip amps are running hot, generally there're 2 camps: the engineers who place their trust in component specs and acceptable thermal tolerances, and the worriers. I belong to the latter.

You can get a usb fan to place underneath the amp to drive some airflow.

https://www.aliexpress.com/item/1005003194280865.html

 

[Mark185]

Another issue: although the A20 is bigger and seemingly has more ventilation, it also heats up just as much as my previous A07. Is it safe to place my DAC on top of it?

Do not place anything on top of it. The case is the heatsink. Using a fan is recommended even though it adds cost. Fosi makes a small amp rack with ventilation holes and mounting holes for fans. There are some very quiet cooling fans you can buy on Amazon. I bought a pair for about $20 that can run on 5 volts or 12 volts and have a switch built in. Using 5 volt usb power supply they are very quiet. Your amp will last a lot longer if you cool it. The TPA3255 runs very hot on 48 volts. I am a EE. When we do life testing of electronics, the method is to bake the boards in an oven with repeated temperature cycles from cold to hot. Temp cycles are what age electronics. Reducing the high temp results in longer predicted life. Fosi rack is $50 on Amazon. Even without fans it will help your A20 run cooler due to better ventilation.

Search for : Fosi Audio Amplifier Rack HIFI headphone amplifier DAC rack desktop Solid Aluminum Column Double-layer Acrylic Audio Equipment.

Here are the fans I bought: https://www.amazon.com/dp/B0CNZY9F93?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_5&th=1

 

[toilagamer852]

Guess I'll find a workshop to craft a minirack, or buy a premade minirack made of metal. Since I place both the dac and the amp at the space right below the pc monitor (around 15cm high), I don't have the luxury to place a full size rack there.

Search for : Fosi Audio Amplifier Rack HIFI headphone amplifier DAC rack desktop Solid Aluminum Column Double-layer Acrylic Audio Equipment.

Isn't this rack really similar to the Aiyima anniversary rack?

Also, I notice this weird phenomenon: if I turn on bypass and adjust volume by the dac, it seems to have more volume overall. Why is that so?

 

[Mark185]

Guess I'll find a workshop to craft a minirack, or buy a premade minirack made of metal. Since I place both the dac and the amp at the space right below the pc monitor (around 15cm high), I don't have the luxury to place a full size rack there.


Isn't this rack really similar to the Aiyima anniversary rack?

Also, I notice this weird phenomenon: if I turn on bypass and adjust volume by the dac, it seems to have more volume overall. Why is that so?

Bypass eliminates the high pass filter circuit and volume control circuit. The DAC probably has more gain than the amplifier input circuits. This especially true if using the XLR balanced inputs. I run my A20 in bypass mode and feed it from a Fosi ZH3 DAC with a miniDSP in between them for active filtering between speakers and sub.

 

[toilagamer852]

Bypass eliminates the high pass filter circuit and volume control circuit. The DAC probably has more gain than the amplifier input circuits. This especially true if using the XLR balanced inputs. I run my A20 in bypass mode and feed it from a Fosi ZH3 DAC with a miniDSP in between them for active filtering between speakers and sub.

I see. However, my main reason to buy the A20 is the HPF, so I won't be able to use the bypass then.

Finding a rack for my dac and amp will be difficult, as I only have 15cm of space right below my monitor. Placing them away to a more open space is also not ideal because I want the volume adjustment to be within arm's reach. May have to go with office tray for compact size.