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What the current Aiyima A07 actually needs.

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Does this make any audible difference?

To be honest ... I don't know. I also had a bad socket under one of the chips, with a poor contact. So I can't honestly say what it was supposed to sound like before. I don't think it would have on just a straight swap, the chips are running at unity gain and are very controlled by the surrounding circuitry. But I can tell you that mine sounds way better now...
 

Ed Midnight

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Extra cooling could be added by inducing convection with a machined slot at the case joints about 2" long and 1/4" tall, on each side and a 1" long slot about 1/4" deep cut on the top centre at front and back... getting rid of the shiny aluminum is a matter for a quick swipe with a magic marker. I've done this on other amps but haven't tested this on the A07 yet... but then I haven't had to.

As others have commented 36 to 38 volts seems to be it's sweet spot for good power and longivity.
I keep my Drok ps set at 36v. Here's a temp I created for drilling vent holes:
Amp_Cut_Temp_4.jpg
Screen Shot 2022-07-29 at 7.09.25 PM.png
 
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Scrufboy

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I would pay for this work. That and shipping both ways.

This is exactly what I was on about...

Excellent!
 

Ed Midnight

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I would pay for this work. That and shipping both ways.

This is exactly what I was on about...

Excellent!
Thanks! I really appreciate it! I've got another A07 that I'm going to drill and vent this weekend and post a how-to video. It's pretty easy, I'm just using a scratch awl to set the marks and using a small hand drill starting with small bits and working up to the 1/4" holes to keep them clean and centered. Works very well!
 
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Scrufboy

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lets see, its currently a $77 device including power supply. very few will care about a beafy heatsink, psu or quality caps. nor will they expect a 20year lifespan. its made to be compact and cheap.
Nobody is talking about a beefy heatsink. Just a better one with more fins. It can be the exact same size. Heatsink effectiveness is about surface area. More, thinner fins equals more surface area and that leads to more efficient cooling.
 
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Scrufboy

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I have 2 also... I'd still pay.

Think about it.

I might be able to do it. I have a clamp on vice... Drill, etc. No scratch awl though.

Looking forward to that video.
Thanks! I really appreciate it! I've got another A07 that I'm going to drill and vent this weekend and post a how-to video. It's pretty easy, I'm just using a scratch awl to set the marks and using a small hand drill starting with small bits and working up to the 1/4" holes to keep them clean and centered. Works very well!
 
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Scrufboy

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It appears the Chinese haven't worked out that extruded fin heatsinks don't work when placed horizontally and particularly, when placed in a sealed box with no airflow. There's no hope for these absolute idiots.

Anyone who buys this garbage deserves exactly what they get.
Hah... Right on! Nail hit squarely!
 

nsfgp

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Saw these video. Anyone understand what he is actually doing here with the 2 A07?? Does it make sense at all??
Followup:
 
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Scrufboy

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Saw these video. Anyone understand what he is actually doing here with the 2 A07?? Does it make sense at all??
Followup:
He actually failed... If you look at the comments... You can see that I interacted with him quite a bit.

What he was trying to do was use them as bridged mono amplifiers. One full A07 for each channel. He didn't bother diving into the data sheet and just basically soldered the inputs together.

His original plans included swapping out the caps, op-amps and making a full vented cover. Some of this he managed to do.

The experiment failed as the amps quickly went into protection mode while under load and shut down. Ultimately a complete waste of his time and resources.

Aiyima already makes an amp for this. The Aiyima A3001. This can be used as a subwoofer amp or in pbtl mode.
 
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Tangband

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To be honest ... I don't know. I also had a bad socket under one of the chips, with a poor contact. So I can't honestly say what it was supposed to sound like before. I don't think it would have on just a straight swap, the chips are running at unity gain and are very controlled by the surrounding circuitry. But I can tell you that mine sounds way better now...
In the Swedish audio forum Faktiskt.io we have investigated one of my Aiyima:s 5532 and it was not a fake one. A switch to lm4562 makes the amplifier sound slightly better though.
 

Tangband

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I’ll start this off. How about:

- a quality 36 (to 46 V power supply - need to pop the top and verify the capacitor rating) and;

- perhaps some vent holes for good measure (though mine never runs hot;

- speaker terminals spaced a bit farther apart.

I‘ll get completely crazy, and suggest an A07 (and/ or) A04 plus with upgraded caps, inductors and caps as suggested in the Mod thread over at DIY Audio. It would probably double the price but with a bit of education / marketing, I think it would sell, particularly to, “the audiophile“ crowd found here.

Overall, I really have no complaints. For the price, the Aiyimas are great little amps.
I agree and I said so in my Amazon Review of the A07...

I had one of mine come back because it kept shutting down... (lord knows how hard my client was pushing it)

Removing the heat sink I discovered they are using two silicon spacers on the bolts between the sink and the board. This is a good thing in that it stabilized the sink but it's also a bad thing because the edge of one of the spacers lands right on top of an SMT part. This may (not necessarily "will") cause the heatsink to sit imperfectly on the top of the chip. What I did was to make a small notch in the spacer to clear the part and hold it in place with a drop of stickum. Then I cleaned away the crappy thermal compound they used and put in some high quality stuff (Loctite 175-125) and re-assembled it using just a bit of extra pressure on the screws (contact +3/4 turn). So far so good.

Extra cooling could be added by inducing convection with a machined slot at the case joints about 2" long and 1/4" tall, on each side and a 1" long slot about 1/4" deep cut on the top centre at front and back... getting rid of the shiny aluminum is a matter for a quick swipe with a magic marker. I've done this on other amps but haven't tested this on the A07 yet... but then I haven't had to.

As others have commented 36 to 38 volts seems to be it's sweet spot for good power and longivity.
Aiyima a08 is an amplifier where they have corrected most of the issues that this thread takes up. Higher voltages ( 36 V and 9,6 A ) and a bigger heatsink. And a higher price.
Aiyima a07 is a good implementation of tpa3255 that have started a cult , and for good reasons. Its sounds very good for what it is, and dont cost a fortune. Just like the Nad 3020 many years ago.
 
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tiramisu

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The Meanwell digital power supplies are commonly used for grow lights. You use Samsung 304 LEDs. The current and voltage have to be dead nuts to deliver the right frequencies of light, when you take a reading with a light meter they deliver clean steady power to Samsungs color spec. No flicker. I have purchased a few of the small ones from Alibaba (not aliexpress) from the companies that sell grow lights and you get a properly certified power supply that way. I'm not saying a better power supply will deliver a better sound. I am saying that this is a pretty effective way of getting a good price on state-of-the-art digital power supplies. 7 Year warranty on the hlg series from the manufacturer. That alone is astounding.

https://led.meanwell.com/productSeries.aspx
Screenshot 2022-07-29 235545.png
 
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Ed Midnight

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Aiyima a08 is an amplifier where they have corrected most of the issues that this thread takes up. Higher voltages ( 36 V and 9,6 A ) and a bigger heatsink. And a higher price.
Aiyima a07 is a good implementation of tpa3255 that have started a cult , and for good reasons. Its sounds very good for what it is, and dont cost a fortune. Just like the Nad 3020 many years ago.
I'd like to see Aiyima make an amp like the A08 but simplified without the bluetooth and DAC, with a bypass switch on the volume control, plus add the extra 3.5 aux out (like the A07) or sub out. My A07 was $60 (w/o ps) + $35 for the Drok ps, + $10 for wires, + $10 for op amps and ext/adapters. About $115 all together vs. $170 for the A08 (but it has no extra aux/sub out).
 

Tangband

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I'd like to see Aiyima make an amp like the A08 but simplified without the bluetooth and DAC, with a bypass switch on the volume control, plus add the extra 3.5 aux out (like the A07) or sub out. My A07 was $60 (w/o ps) + $35 for the Drok ps, + $10 for wires, + $10 for op amps and ext/adapters. About $115 all together vs. $170 for the A08 (but it has no extra aux/sub out).
A power amp version of Aiyima a07 without bluetooth, volume control and dac below 99 dollars would be nice.:)
 
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Scrufboy

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I love options, but I definitely want control of those options. So yes, I whole heartedly agree. A nice power Amp version... Kept simple.

But let's say 1 unit, vented well... 2, A3001's with op-amp sockets- A good PSU, no volume control, no bluetooth or DAC. *Shrug

TLDR -
I run in my chain that Drok in a custom vented
1646934091109681.jpg
enclosure powering the amps via custom canare/oyaide cables to both Aiyima amps. Next version of my power will have a DC to DC isolated buck module to power the DAC. All three components from one power supply.

From the laptop to the Dock, I have Schiit Hel2E DAC - 3.5mm Canare male to male - A07 with SparkosLabs discrete Op-Amps - Canare coax - to A3001.
20220604_171907.jpg

Using DIY Canare 4S11's to LS50 Meta's and a simple Mediabridge coax to my humble SVS SB-1000 pro. (Noted DAC issues necessitates the USB dock)

I was thinking about DAC to A07 as a pre - out to two A3001's when you two mentioned a power amp version of the A07 - But I'm forgetting about the subwoofer bit... So I guess that's a wash.

This is sort of off topic though. But not if we're thinking of what A07 could be.

So while I blathered on a bit... My point is... Yeah, totally a nice single power Amp version... Anywhere from $139 to $169. Maybe that's high... But when you consider the cost of my tiny rig is about $650+/- without the cables and dock...

-Yeah, a company with buying power could make what I'm currently running as amplification for much, much less.

Vented though! Heh.
 
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andrewjohn007

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Thanks! I really appreciate it! I've got another A07 that I'm going to drill and vent this weekend and post a how-to video. It's pretty easy, I'm just using a scratch awl to set the marks and using a small hand drill starting with small bits and working up to the 1/4" holes to keep them clean and centered. Works very well!
Would you be so kind as to let us know when you post your DIY video? I have an A07 and A04 that I would like to ventilate. I've got a Starrett punch that I haven't used enough as well as a DeWalt step drill bit that should do the job. One of these days I'll pick up a drill press... Thank you for being the pioneer on Aiyima DIY ventilation!
 

Bleib

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Nobody is talking about a beefy heatsink. Just a better one with more fins. It can be the exact same size. Heatsink effectiveness is about surface area. More, thinner fins equals more surface area and that leads to more efficient cooling.
Not always. Since it's passive too many fins too close to each other can lead to worse heat dissipation. The closer the fins are the more need there is for active aid with the help of a fan.
 

Roland68

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Not always. Since it's passive too many fins too close to each other can lead to worse heat dissipation. The closer the fins are the more need there is for active aid with the help of a fan.
It is exactly like that.
As long as you do not manage to dissipate the heat from the existing heat sink better (e.g. through better air circulation), more fins with a smaller spacing would lead to poorer heat dissipation and cool the TPA3255 less well.
Only if the air circulation for the existing heat sink was better than just sufficient could you use a heat sink with more fins, but that would then no longer be necessary, since the original heat sink would then be sufficient.
 

Bleib

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It is exactly like that.
As long as you do not manage to dissipate the heat from the existing heat sink better (e.g. through better air circulation), more fins with a smaller spacing would lead to poorer heat dissipation and cool the TPA3255 less well.
Only if the air circulation for the existing heat sink was better than just sufficient could you use a heat sink with more fins, but that would then no longer be necessary, since the original heat sink would then be sufficient.
And the fans need to be high RPM if the fins are close to each other as otherwise the air struggles to get inbetween the fins. If you start hearing the fan all of the sudden the amp's great design with great SNR numbers becomes more irrelevant as the fan would kill how clean the audio is.

I've got quite a lot of experience cooling higher-end PCs almost inaudible and I've always for instance chosen GPU coolers such as Arctic Cooling S1 over something like Morpheus II which would require faster fans.
 
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