AIYIMA A07 TPA3255 Review (Amplifier)

[trungdtmc]

Hi all, i has measured my modded A07 with cosmos ADC, load is 4ohm resistor, Meanwell LRS-350 48V

 

[antcollinet]

Hi all, i has measured my modded A07 with cosmos ADC, load is 4ohm resistor, Meanwell LRS-350 48VView attachment 328950View attachment 328951View attachment 328952

Nice work - Just a suggestion : Your first chart shows SPL which obviously for an electrical measurement it is not - would be good if you could show that as dB.

What was the mod?

Do you have measurements from before the mod?

 

[MCH]

Hi all, i has measured my modded A07 with cosmos ADC, load is 4ohm resistor, Meanwell LRS-350 48VView attachment 328950View attachment 328951View attachment 328952

Hi @trungdtmc thanks for sharing. How is your experience with the LRS-350-48, does the fan start very often? Isn't it very noisy? (the fan, I mean) Thanks!

 

[Sokel]

Do you have measurements from before the mod?

I think they are already there,41V vs 48V (?)

 

[antcollinet]

I think they are already there,41V vs 48V (?)

OK - if that is the mod. I assumed that was just testing with two differnt PSUs.

 

[trungdtmc]

Nice work - Just a suggestion : Your first chart shows SPL which obviously for an electrical measurement it is not - would be good if you could show that as dB.

What was the mod?

Do you have measurements from before the mod?

Ok, i also will remeasure with wider bandwidth later.
I had add PFFB (with small negative feedback), replace components in LC filter, input coupling cap. I changed voltage on LRS then you see 2 level in thd+n vs power

Unfortunately I bought Cosmos Adc after modding so I don't have previous results

 

[trungdtmc]

Hi @trungdtmc thanks for sharing. How is your experience with the LRS-350-48, does the fan start very often? Isn't it very noisy? (the fan, I mean) Thanks!

I has no problem with lrs-350 daily listening

 

[SmokedBurger]

Hello! I just bought these from the official aiyima store in my country for $40 usd and i would really like to know, does it create a "pop" sound or a loud noise when turning on or off? especially when the volume is not set to zero. I am afraid that it might break my speakers or active subwoofer if i turn it on or off and it pops. thanks!

 

[Ykar]

Hello! I just bought these from the official aiyima store in my country for $40 usd and i would really like to know, does it create a "pop" sound or a loud noise when turning on or off? especially when the volume is not set to zero. I am afraid that it might break my speakers or active subwoofer if i turn it on or off and it pops. thanks!

It doesn't. I used it as power amp (max vol) and never had pop noise while turning on or off. I think there is internal relay/circuitry to avoid such pop noise issue.

 

[staticV3]

Nice work - Just a suggestion : Your first chart shows SPL which obviously for an electrical measurement it is not - would be good if you could show that as dB.

You need to use SPL in REW if you want to align graphs to some value.
In this case, trung aligned the FR to 0dB, which then requires that you set the unit to SPL.

 

[antcollinet]

You need to use SPL in REW if you want to align graphs to some value.
In this case, trung aligned the FR to 0dB, which then requires that you set the unit to SPL.

OK - makes sense.

Thanks.

 

[trungdtmc]

You need to use SPL in REW if you want to align graphs to some value.
In this case, trung aligned the FR to 0dB, which then requires that you set the unit to SPL.

Thank you, that is correct!

 

[earworm]

Non-scientific question - my speakers (Paradigm Micros) connected to my A07 sound fatiguing and distant - not pleasant the way I want my office system to sound when I need a work accompaniment or distraction.

Picked it up at the reco of this thread and just dawning on me that I don't enjoy the sound of my system (non-scientifically speaking of course).

I'm wondering how to troubleshoot if the problem is the amp, amp psu, speakers, source or something random like failed cables without spending a lot of time or money. I'm hoping the experts here can start me down a path.

Current office setup that I'm diagnosing is:

• Amp: A07: ~2 years old from Amazon US
• Amp PSU: Whatever it came with - I'll edit when I go check, but I have this buried for cable management
• Source: RPi 3b running Moode Audio --> USB output --> USB Dac (older DAC based on PCM 2704 LSI)
• Speakers: Older Paradigm Micros - not sure if v1 or v2

Basically I don't like the sound and not sure why

I don't get audible hiss from the system when on without sound, but there is some kind of audible background noise - faintly resembles what you'd hear from noise canceling headphones while turned off. While not wholly audible I feel relief when I turn off the amp.

Any suggestions on where to start? I don't trust my ears or experience to know if the speakers need a refresh, caps are blown, etc.

Happy to start a new thread as well if my question strays into non-A07 territory.

 

[Joe Smith]

Non-scientific question - my speakers (Paradigm Micros) connected to my A07 sound fatiguing and distant - not pleasant the way I want my office system to sound when I need a work accompaniment or distraction.

Picked it up at the reco of this thread and just dawning on me that I don't enjoy the sound of my system (non-scientifically speaking of course).

I'm wondering how to troubleshoot if the problem is the amp, amp psu, speakers, source or something random like failed cables without spending a lot of time or money. I'm hoping the experts here can start me down a path.

Current office setup that I'm diagnosing is:

• Amp: A07: ~2 years old from Amazon US
• Amp PSU: Whatever it came with - I'll edit when I go check, but I have this buried for cable management
• Source: RPi 3b running Moode Audio --> USB output --> USB Dac (older DAC based on PCM 2704 LSI)
• Speakers: Older Paradigm Micros - not sure if v1 or v2

Basically I don't like the sound and not sure why

I don't get audible hiss from the system when on without sound, but there is some kind of audible background noise - faintly resembles what you'd hear from noise canceling headphones while turned off. While not wholly audible I feel relief when I turn off the amp.

Any suggestions on where to start? I don't trust my ears or experience to know if the speakers need a refresh, caps are blown, etc.

Happy to start a new thread as well if my question strays into non-A07 territory.

Your best bet is to change one item and see what that does to your perception of the sound. Is there an alternate amp that you can borrow from a friend? Or a different source you can connect in place of the digital streaming?

 

[earworm]

Your best bet is to change one item and see what that does to your perception of the sound. Is there an alternate amp that you can borrow from a friend? Or a different source you can connect in place of the digital streaming?

Thanks and yes, I need to be thorough about this. I can take the speakers elsewhere but in my office it's hard to maneuver. I can swap in different speakers. Will start a spreadsheet for myself with notes.

The one I don't think I can test easily is the PSU for the A07 - if it needs replacement for what it shipped with (holding edit to paste in the model name) then that's a $ bet to make. Almost as cheap to replace the whole amp then.

The hard part is that I don't trust my ears for the diagnosis. I know what I like and don't like, but at this point it's hard for me to figure out what the issue is to get it back to "like". I have a sneaking suspicion it may also be that I don't like the answer that the speakers are no longer to my taste or need to be refoamed and/or recapped, both of which I don't know how to diagnose and likely exceed my patience/skill to fix.

Part of why I like this forum is that there are some graphs to take my ears out of the equation

 

[saberger0357]

Thanks and yes, I need to be thorough about this. I can take the speakers elsewhere but in my office it's hard to maneuver. I can swap in different speakers. Will start a spreadsheet for myself with notes.

The one I don't think I can test easily is the PSU for the A07 - if it needs replacement for what it shipped with (holding edit to paste in the model name) then that's a $ bet to make. Almost as cheap to replace the whole amp then.

The hard part is that I don't trust my ears for the diagnosis. I know what I like and don't like, but at this point it's hard for me to figure out what the issue is to get it back to "like". I have a sneaking suspicion it may also be that I don't like the answer that the speakers are no longer to my taste or need to be refoamed and/or recapped, both of which I don't know how to diagnose and likely exceed my patience/skill to fix.

Part of why I like this forum is that there are some graphs to take my ears out of the equation

I would suggest trusting your ears. If it's a technical issue pointing at something that needs updating or repair, that might get done, and you still might not the way the piece sounds to your ears. As valuable as the tests/reviews are that are on his forum, listening to music, and the gear we listen on and prefer is still highly subjective.

I happen to really like the 07, but ultimately perhaps that's because it's a small, very inexpensive piece and my expectations were much different then what they were when I bought my McIntosh amps that cost me several thousand and came with years and years of glowing endorsements.

Use the reviews and analysis as a valuable resource, but don't force yourself to enjoy something that's supposed to be enjoyable. Especially at these prices.

 

[Joe Smith]

You probably have the 32v 5a power supply, that's what they were shipping out with the original A07 in most cases. And for nearfield or small room use, that should be fine for power supply. There's a lot of different feelings about the power supplies for these, but my general feeling is that pushing these small class D amps to the top of their limits with the 48v power supplies is less than ideal. With the 32v supply, my original A07 can get very loud with the volume knob only at 12 o'clock.

Great that you can try some different speakers with the A07, that will give you additional information. Would be good to swap in a direct source such as CD to see how that sound compares to your digital source. Ideally, listen to the same song or piece of music CD versus streaming.

Right now, I am using the new A07 MAX with a 36v 5a power supply with my first generation (c. 1990) Paradigm Titans (refoamed) and the combination sounds very, very good. If your speakers are older and have not been refoamed, that could of course be affecting your sound. Refoaming is not that hard, but it takes patience, or you can hire it done. Or, it may be time for new speakers to fine tune your nearfield setting. I have speakers as old as 1986 that have not been recapped, and they still sound fine; caps do age out and it can affect the sound, but usually not as dramatically as degraded foam or other speaker driver issues.

 

[Deleted member 48726]

you've been here more than 3 1/2 years. Have you not been paying any attention at all?

That explains a lot about a lot of things in the world, doesn't it?

 

[trungdtmc]

i added more negative feedback

 

[audio_tony]

I'm curious to know how one of these would compare to the various class AB power amps* I have.

*NAD 2200, HK 870 + other DIY amps.

My earlier experiences with Class D (TPA3116D) left me unimpressed. Good bass but top end was grainy.