AIYIMA A07 TPA3255 Review (Amplifier)

[remlemasi]

Ha. We lived in Placentia (by Brea and Yorba Linda) only two years ago... now across the country. And I’ve already got mine!

(And not to be a broken record... But unless one really plans to draw all that power into a matching speaker load - and it’s a lot of acoustic power, even as a peak! - the 3255 chip does run hotter (ie less efficient and potentially with shorter life) on 48V compared to lower supply voltages. I did not realize it at first, even though was told by wise ones here... So, if you truly are after the max power out of a 3255 into 8+Ohm speaker, the 48V is the way to go; otherwise - a 36V [5A] power supply is da-bes.)

Nice! You're part of the exodus from California....

Yeah, I might be a little too ambitious here... I'll reconsider just doing the 36V 5A. Any huge difference between that an then 36V 4A? Does the amp really pulling all that current, maxing out the 4A? What's the optimal efficiency/performance for these AC-DC converters, 80%, 90%?

 

[Raindog123]

Any huge difference between that an then 36V 4A? Does the amp really pulling all that current, maxing out the 4A? What's the optimal efficiency/performance for these AC-DC converters, 80%, 90%?

It really depends on how loud you like to have your music and how far from the speakers. Someone posted this nice >calculator< earlier in the thread... Depending on your listening mode/mood, the RMS volume at the listener can easily vary between 80 and 100dB. Typical speakers‘ sensitivity is, what, 85 to 90dB... While the RMS/continuous amp power would most probably be modest regardless (<10W), to assure undistorted peaks - that’s where you might want some substantial extra juice (so pay attention to the “Required amplifier power (peak/burst)”).

For my - “borderline background“ listening (through 96dB speakers at 10ft) - my 36V 4A PS [$23 at amazon] is more than adequate - the volume dial is only at 9 o’clock and the sound is fantastic... For someone initially hunting for a 48V 5A one, a [$31] 36V 5A might be just right, though I doubt there is a “huge“ difference.

And, as the switched PS is hardly even warm, does not glow or such, I would say it’s efficiency is very high - at least 90%.

 

[Bruce Morgen]

But with those $17 bricks you never totally know what‘s under the hood...

Actually, the seller does show its innards, which look pretty typical for a power brick.

 

[boselover61]

It really depends on how loud you like to have your music and how far away from the speakers. Someone posted this nice >calculator< earlier in the thread... Depending on your listening mode/mood, the RMS volume at listener can easily vary between 80 and 100dB. Typical speakers‘ sensitivity is, what, 85 to 90dB... While the RMS/continuous amp power would most probably be modest regardless (<10W), to assure undistorted peaks - that’s where you might want some substantial extra juice (so pay attention to “Required amplifier power (peak/burst)”).

For my - “borderline background“ listening (through 96dB speakers at 10ft) - my 36V 4A PS [$23 at amazon] is more than adequate - the volume dial is only at 9 o’clock and the sound is fantastic... For someone initially hunting for a 48V 5A one, a [$31] 36V 5A might be just right, though I doubt there is a “huge“ difference.

And, as the switched PS is hardly even warm, does not glow or such, I would say it’s efficiency is very high - at least 90%.

I bought the 48v 5A and this one 24v 8a for my loxjie a30

https://www.ebay.com/itm/24V-8A-192...rger-For-LED-Strip-5-5mm-x-2-1mm/313134771074

Seems like a reputable seller. We'll see how it goes.

 

[Toku]

Actually, the seller does show its innards, which look pretty typical for a power brick.View attachment 117890

Is this a 24V/8A Tear Down photo?

 

[Raindog123]

Is this a 24V/8A Tear Down photo?

This is one of the pics by the seller on the eBay page for 48V 5A.

The caveat is, it depicts a unit with detachable power cord, while what is currently sold is non-detachable. When I was buying mine (in Jan), the seller informed me that “he’s out of detachable stock, and whether I still wanted the ones he now has... and that he had changed the description photos accordingly (apparently all but this ‘innards’ one)”. I went with the order... But the point is, this pic might or might not truly represent the currently sold device. (And I am not quite ready yet to crack mine open ) Just FYI, should not stop anyone.

 

[pma]

Repeated nonsense. It is useless to explain anything here.

 

[Lambda]

A Class D amp acts like a step down DCDC converter so the input voltage is not important.
Voltage must be higher then output voltage + some margin of cause.
Speaker current is not equal power supply current with class D!

So chose a power supply with enough power and enough voltage

look pretty typical

typical Crap and not like it can do 144W

Take a look in typical Lenovo/HP/Aplle power supply. completely different game!
https://www.myfixguide.com/lenovo-thinkpad-65w-pd-adapter-review-teardown/
So sure the Cheap thing is about the same size build like crap and makes twice the power

 

[Bruce Morgen]

A Class D amp acts like a step down DCDC converter so the input voltage is not important.
Voltage must be higher then output voltage + some margin of cause.
Speaker current is not equal power supply current with class D!

So chose a power supply with enough power and enough voltage


typical Crap and not like it can do 144W

Take a look in typical Lenovo/HP/Aplle power supply. completely different game!
https://www.myfixguide.com/lenovo-thinkpad-65w-pd-adapter-review-teardown/
So sure the Cheap thing is about the same size build like crap and makes twice the power

Whatever -- it sells for $9 (if you buy four at a time) and its innards are commensurate with that sort of price, so you're getting the build quality you pay for. As for how much power it actually "makes" -- well, that's to be determined by measurements, not dueling tear-down photos. Powering an 80-90 percent efficient little "chip amp" is nowhere near as demanding in terms of steady current demand as powering/charging a modern laptop with a battery, a multi-core CPU, and a complete graphics subsystem, so it's probable that all those admirable thermal measures in the "Lenovo/HP/Apple" brick are unnecessary in the former application. I have a generic 24V 10A power brick powering a 2.1 chip amp with two TPA3116s -- it's rated for the same overall wattage as the $9 wonder under consideration here and it works just fine despite being plugged in 24/7.

 

[Lambda]

As for how much power it actually "makes" -- well, that's to be determined by measurements, not dueling tear-down photos.

Yeah, sure looking foreword to your test of the load regulation and EMC, till then let me tell you this is crap.
There is reasons brads that are legally liable for there products and make them meat emissions, efficiency and safety specifications don't sell power supplies like this.

 

[Bruce Morgen]

Yeah, sure looking foreword to your test of the load regulation and EMC, till then let me tell you this is crap.
There is reasons brads that are legally liable for there products and make them meat emissions, efficiency and safety specifications don't sell power supplies like this.

The thing is labeled with all sorts of safety-related symbols -- are you saying the manufacturer is flat-out lying? The seller apparently specializes in surveillance systems and this particular item is sold to power video cameras -- a 24/7 task with specific voltage and (steady, unlike Class D audio) current requirements. Offhand, I'd say the thing is entirely adequate to power a $50 chip amp -- not as good as the industrial SMPS I use, but most likely more than good enough for most users of that sort of product. Is it good enough to be bundled with a modern laptop that carries a hefty four-figure price tag? Probably not, especially considering the liability issue you mentioned. Is it good enough to run a $50 amplifier at normal home stereo listening levels? IMO it's a pretty good bet that it's up to that relatively undemanding job.

 

[imagidominc]

Hey everyone,
Just bought this amp but unfortunately my 12 awg parts express speaker wire is too thick to fit through the speaker posts on the back of the amp. I’m looking at some banana plugs and spade plugs on parts express to solve this problem. I’m not sure which plug to go with so I’d like to hear someone’s input who has more experience with this than I do. I’m worried about buying a banana plug that doesn’t fit the posts.

 

[Lambda]

The thing is labeled with all sorts of safety-related symbols -- are you saying the manufacturer is flat-out lying?

In short. Yes.
Thy can print on it what ever they want. what ever you order.
you want extra safety labels. Pick the ones you want:

I worked in Shenzhen doping quality control for this kind of consumer products.
Even if you are there its hard getting trustworthy power supplies but also most all of them have a CE logo. it’s not like it costs extra to put it there so why not... means nothing.

Maybe an ancestor of this power supplies was once tested. but i assure you there is nothing independently tested about this power supply in the shipped configuration.
very likely its not meting Europeen safety and emission standards!

Is it good enough to run a $50 amplifier at normal home stereo listening levels?

Sure.
Are you getting the full potential from the amp in terms of power ,distortion,SIAND. No
Is it emitting lots of Noise. Probably.
Is it burning down your House. maybe. good luck explaining it to your insurance company and good luck.

The same thing is sold wit an FCC logo so ask the seller for the FCCID and look it up at https://www.fcc.gov/oet/ea/fccid

 

[Steamrolly]

Hey everyone,
Just bought this amp but unfortunately my 12 awg parts express speaker wire is too thick to fit through the speaker posts on the back of the amp. I’m looking at some banana plugs and spade plugs on parts express to solve this problem. I’m not sure which plug to go with so I’d like to hear someone’s input who has more experience with this than I do. I’m worried about buying a banana plug that doesn’t fit the posts.

I am using these and I am happy with the quality but they are on Amazon.
GearIT Banana Plug Connectors, Closed Screw, 24K Gold Plated, 6 Pairs, 12 Pieces: Amazon.ca: Electronics

 

[boselover61]

Repeated nonsense. It is useless to explain anything here.

In short. Yes.
Thy can print on it what ever they want. what ever you order.
you want extra safety labels. Pick the ones you want:
View attachment 118048

I worked in Shenzhen doping quality control for this kind of consumer products.
Even if you are there its hard getting trustworthy power supplies but also most all of them have a CE logo. it’s not like it costs extra to put it there so why not... means nothing.

Maybe an ancestor of this power supplies was once tested. but i assure you there is nothing independently tested about this power supply in the shipped configuration.
very likely its not meting Europeen safety and emission standards!


Sure.
Are you getting the full potential from the amp in terms of power ,distortion,SIAND. No
Is it emitting lots of Noise. Probably.
Is it burning down your House. maybe. good luck explaining it to your insurance company and good luck.

Proof you worked there? Anyone can say anything on the internet.
Edit: Also that seller has close to 7000 sales on ebay. If they eventually "burn down the house" like you said I don't think the seller would still be in business, would most likely get sued to death.

 

[Bruce Morgen]

Hey everyone,
Just bought this amp but unfortunately my 12 awg parts express speaker wire is too thick to fit through the speaker posts on the back of the amp. I’m looking at some banana plugs and spade plugs on parts express to solve this problem. I’m not sure which plug to go with so I’d like to hear someone’s input who has more experience with this than I do. I’m worried about buying a banana plug that doesn’t fit the posts.

The binding posts are the same as the ones on the Dayton Audio chip amps, so any pretty much any banana plug Parts Express sells is going to fit just fine. You can contact their tech support to make sure.

In short. Yes.
Thy can print on it what ever they want. what ever you order.
you want extra safety labels. Pick the ones you want:
View attachment 118048

I worked in Shenzhen doping quality control for this kind of consumer products.
Even if you are there its hard getting trustworthy power supplies but also most all of them have a CE logo. it’s not like it costs extra to put it there so why not... means nothing.

Maybe an ancestor of this power supplies was once tested. but i assure you there is nothing independently tested about this power supply in the shipped configuration.
very likely its not meting Europeen safety and emission standards!


Sure.
Are you getting the full potential from the amp in terms of power ,distortion,SIAND. No
Is it emitting lots of Noise. Probably.
Is it burning down your House. maybe. good luck explaining it to your insurance company and good luck.

As has been explained in other threads, worrying about "your insurance company" is basically a non-issue in the real world -- most of us leave all manner of uncertified devices (e.g. cellphone chargers, power strips) plugged in and I doubt there's been even a single instance of an insurance claim being denied on that basis. As for SINAD, the amp measured just dandy with two different cheap/generic power bricks -- and there's no hope of getting the full potential power out of the amp with anything short of a 7-8 amp PSU and this thing is a couple of amps short of that, so that's not a reasonable expectation. Someone like me who's intent on the getting the very most out of an A07 is going to choose something else -- but for the average home stereo user on a tight budget, this thing will probably do very nicely.

 

[Lambda]

@boselover61 @Bruce Morgen

Edit: Also that seller has close to 7000 sales on ebay. If they eventually "burn down the house" like you said I don't think the seller would still be in business, would most likely get sued to death.

Good luck with suing them
Whats the worth of an eBay shop wit 7000 sells... not to mush

Look it has a FCC logo so just ask the seller for the FCC ID and look it up
https://www.fcc.gov/oet/ea/fccid

Proof you worked there? Anyone can say anything on the internet.

 

[boselover61]

@boselover61 @Bruce Morgen


Good luck with suing them
Whats the worth of an eBay shop wit 7000 sells... not to mush

Look it has a FCC logo so just ask the seller for the FCC ID and look it up
https://www.fcc.gov/oet/ea/fccid


View attachment 118058View attachment 118059View attachment 118060View attachment 118061View attachment 118065

Ok thanks for the picture. You still couldn't explained to me why I would be the 7001 customer that would get his house burnt down while the others 7000 didn't. If these items from the sellers are so dangerous then there would be reviews showing damages already.

 

[Raindog123]

Sometimes drunk buys are the best. Current price $23 on Amazon, free slow ship from China.

The price just jumped to $80!

 

[Raindog123]

A Class D amp acts like a step down DCDC converter so the input voltage is not important

Apparently it is important from the efficiency point of view. Ie, the output/input power ratio (thus how much heat is dissipated by the amp chip) does depend on input voltage (It’s in the chip spec). While both the output voltage and current into a certain load are only defined by the loudness (power).