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Which power supply should I pair with AIYIMA A07 TPA3255 amp?

friarminor

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This is the 48v 7.5A SMPS ordered from Aiyima and the multimeter I got 3 days after. Used power plug from defective laptop computer as the cord that came with the PS was flimsy. Was able to connect and adjust - to 44v. As I had no idea what I was doing, had to watch several YT videos to make sure I don't get to blow this one up.

Compared to the 32v, it was noticeably louder of course with extra oomph on everything driving my KEFLS50s. Wasn't too warm that I couldn't handle but volume was just between 9 and 7 so maybe that's one reason. Other than that i had small rechargeable fan placed near just in case.

BTW, also changed op amp to LM4562 and using an FX audio tube preamp (without the tone controls).


242439186_550292342691765_2231062889379461643_n.jpg
 
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jst

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Is there no box with that kind of PSU ? It looks dangerous with all the cables outside.

I notice from Amazon product page for Aiyima A07 :
  • ❺ Package with a DC 32V 5A Power Adapter for free,But if you want to get the maximum power of 300W, you need to buy a power adapter that uses DC 48V and current is above 7A(Cannot use industrial power supply,and please choose the correct passive speaker power to use ).Any doublt and help, please contact the seller for support: www.amazon.com/hz/help/contact/A3BG62S1F23IH5#
Source : https://www.amazon.com/AIYIMA-A07-TPA3255-Amplifier-Digital/dp/B08CJZGT6H

Why does it say cannot use industrial power supply, the picture above is an industrial psu, right ?
 
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friarminor

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Is there no box with that kind of PSU ? It looks dangerous with all the cables outside.

I notice from Amazon product page for Aiyima A07 :
  • ❺ Package with a DC 32V 5A Power Adapter for free,But if you want to get the maximum power of 300W, you need to buy a power adapter that uses DC 48V and current is above 7A(Cannot use industrial power supply,and please choose the correct passive speaker power to use ).Any doublt and help, please contact the seller for support: www.amazon.com/hz/help/contact/A3BG62S1F23IH5#
Source : https://www.amazon.com/AIYIMA-A07-TPA3255-Amplifier-Digital/dp/B08CJZGT6H

Why does it say cannot use industrial power supply, the picture above is an industrial psu, right ?
Does look dangerous so I tend to place it away from the others as possible. It doesn't heat up though unlike the Aiyima. Wondering also what enclosure I need for this.
 

trl

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jst

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This is the 48v 7.5A SMPS ordered from Aiyima and the multimeter I got 3 days after. Used power plug from defective laptop computer as the cord that came with the PS was flimsy. Was able to connect and adjust - to 44v. As I had no idea what I was doing, had to watch several YT videos to make sure I don't get to blow this one up.

Compared to the 32v, it was noticeably louder of course with extra oomph on everything driving my KEFLS50s. Wasn't too warm that I couldn't handle but volume was just between 9 and 7 so maybe that's one reason. Other than that i had small rechargeable fan placed near just in case.

BTW, also changed op amp to LM4562 and using an FX audio tube preamp (without the tone controls).


View attachment 154884
How long do you usually turn on your amp ? anything worrying yet ? heat ? burning smell ? anything ? How do you change it to 44 if it says 48 ?
How hot is it ? Using infrared thermogun mine is 39.3 °C highest I ever checked using 48v 5a brick adapter, but only 36.8°C using 32v 5a, but that's the black casing , not the heatsink inside.

------

nvm regarding the 44change, I found that it can be adjusted, the tolerance is actually quite low only 1%, and the elco is rated 50v so it should stay under 50 at all times with that tolerance, even at 48v

(This is so tempting, 44*7.5 is 330 watt, amirm measurement is 61watt @8ohm using 48v 3a power supply, which is like losing -18%. so it shld be like 270watt (135w/[email protected]) with this using the same calculation even though it probably wont work like that lol.)

Screenshot_444.jpg




Damn, using 48v5a, 10 oclock volume and the heat went up to 40.0 °C. Guess I'll have to stick to 32v5a
 
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friarminor

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How long do you usually turn on your amp ? anything worrying yet ? heat ? burning smell ? anything ? How do you change it to 44 if it says 48 ?
How hot is it ? Using infrared thermogun mine is 39.3 °C highest I ever checked using 48v 5a brick adapter, but only 36.8°C using 32v 5a, but that's the black casing , not the heatsink inside.

------

nvm regarding the 44change, I found that it can be adjusted, the tolerance is actually quite low only 1%, and the elco is rated 50v so it should stay under 50 at all times with that tolerance, even at 48v

(This is so tempting, 44*7.5 is 330 watt, amirm measurement is 61watt @8ohm using 48v 3a power supply, which is like losing -18%. so it shld be like 270watt (135w/[email protected]) with this using the same calculation even though it probably wont work like that lol.)

View attachment 159854



Damn, using 48v5a, 10 oclock volume and the heat went up to 40.0 °C. Guess I'll have to stick to 32v5a
I'm glad to report that haven't had any issues whatsoever. I'm pretty conscious of anything that doesn't seem right while the amp is on. Usually plays at 1 hour minimum and can play 3 hours straight with volume at 9:30 (10 is loud and rocking already in this small room). It's hot but nothing worrying that I can't rest my hand on top of it. My tube pre amp buffer is way hotter that I can barely touch - ifi itube.
 
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jst

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test
I'm glad to report that haven't had any issues whatsoever. I'm pretty conscious of anything that doesn't seem right while the amp is on. Usually plays at 1 hour minimum and can play 3 hours straight with volume at 9:30. It's hot but nothing worrying that I can rest my hand on top of it. My tube pre amp buffer is way hotter that I can't barely touch - ifi itube.
I see, my tube preamp and my other amp are also way hotter too though, and I leave it on all day if I'm using it for my pc, but dunno why i'm more worried with this lol.
Anyway, thx for the info, shouldn't worry too much.
 

jst

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@friarminor hi friarminor, are you familiar with using multimeter ? or do you have a kwh meter ?

If yes, and if you have the time, could you please test the output of your aiyima a07 with that 48v7.5a industrial psu.

kwhmeter looks like this, it's an awesome tool and cost 7 bucks, my Aiyima A07 with 32v5a only consume 3.8watt and using 48v5a only consume 6.4 watt. I thought it's wrong but then I tested a hairdryer at home showing 196-1000 watt, an airfryer 1490 watt. So it shld be correct.

Here's how it looks like

Screenshot_483.jpg


Here's my measurement (volume at 9-10 o clock)
32v5a 3.8watt / 48v5a 6.4watt.
Screenshot_481.jpgScreenshot_482.jpg
Those are black brick adapters which most likely aren't up to the spec, but I could be wrong.
Just curious how much power an industrial psu with higher spec will feed Aiyima A07.
 
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friarminor

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I do have a multimeter but not really familiar and only used it to set voltage. Where do I place those red and black metal rods to get the wattage output? Use image of SMPS I posted Sept 22 so I don't make stupid mistake. Tnx.
 

jst

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I do have a multimeter but not really familiar and only used it to set voltage. Where do I place those red and black metal rods to get the wattage output? Use image of SMPS I posted Sept 22 so I don't make stupid mistake. Tnx.
You don't actually get the wattage, but the Voltage then use P(watt)=V^2 / Resistance of your speaker, you can use your speaker spec or if you're familiar you can check the ohm yourself using multimeter, but the Voltage alone and your speaker impedance is ok too. Just for estimates.

So you set your multimeter to AC voltage then put the red to positive and the black to negative of your amplifier output while having the speaker connected to it. It will show you the Voltage.

The weird thing is mine and Reddog123 show only small number like 0.7v , so 0.7*0.7/6 ohm = 0.081watt.

Here's a video tutorial , skip the part where he uses clamp multimeter for current, or if you have it too then you can also use it. But just knowing the voltage is ok too.


I'm still shock that Aiyima A07 only plays 0.08 watt to speakers, backed up by the low power consumption using kwh meter, both tools, and 2 people doing the test can't be wrong, now you're the 3rd, but you change the variable using industrial psu hahah.

Oh and please be careful, I don't want any damage to you and your equipment. If you're not familiar or hesitate doing this, then don't. ok.
 
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friarminor

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Let me get back to you on this. I find the back of Aiyima pretty cramped but I think I got a fairly good idea already based on your instruction on how to use the multimeter and where to stick the rods.
 

jst

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Let me get back to you on this. I find the back of Aiyima pretty cramped but I think I got a fairly good idea already based on your instruction on how to use the multimeter and where to stick the rods.
Ok, post the result later if you decide to do it, but it's also ok if you don't. You can just touch the rod to speaker + - or amp without sticking it there, just let them touch (guide each rod/probe with hand and read the lcd).
 

friarminor

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So I connected the rods as advised and played the amp. Pls note that SMPS is set to 44V (not 48) at 7.5A to speakers (Denton 80) spec says nom imp. of 6ohms at 9 and 10 vol. Hope i got it right. Pls let me know what this means?

248956838_4432012653534856_7470191390818838806_n.jpg
248946652_558788231870037_2239027516560819016_n.jpg
 
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jst

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So I connected the rods as advised and played the amp. Pls note that SMPS is set to 44V (not 48) at 7.5A to speakers (Denton 80) spec says nom imp. of 6ohms at 9 and 10 vol. Hope i got it right. Pls let me know what this means?

View attachment 161647View attachment 161648
Were you playing music or test tones ?
That number shows the Voltage going to your speaker.
You can get the watt using a formula : P = V²/R , you can use your speaker impedance or measure it yourself using multimeter because it can be different, but for estimates using impedance is ok too. So it's more or less 0.02666 watt.
or if you have clamp meter and clamp the (+) speaker cable like in the video I posted above, you will get the current (I) and can use P = V * I

I recently joined diyaudio and they had a poll how loud are we listening to our audio, and most people also listen to less than 2 volt, so that's how it is. They use volt because that's before the speakers which will be different depending on what speakers ppl use.
Screenshot_490.jpg

If you have kwh meter you can check how much power is drawn from the wall socket. Someone also mentioned this to me, and my 32v5a adapter uses 0.4watt if the amp is not connected, the other one 48v5a black brick adapter drew 1.7-1.8w with nothing connected.
Screenshot_491.jpg
 
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friarminor

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Normally, volume stays between 8-9. I was playing some Brubeck, Bill Evans & Coltrane. When I increased vol to around 10, saw readings flutter 40 to 53 but will then rest on 40.
 
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bravomail

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Normally, volume stays between 8-9. I was playing some Brubeck, Bill Evans & Coltrane. When I increased vol to around 10, saw readings flutter 40 to 53 but will then rest on 40.
53volt fluctuation? Dangerous for those 50V caps.
My experience with feeding cheap/weak ClassD amps (Alientek D8) was that with higher voltage (36V) I got mildly harsher sound, to the degree it wasn't listenable to me. With lower voltage (24V10A) - no such thing, very nice sound, clean etc, with added bonus of amp being cool.
With AIYIMA A07 I just stick to what works - same 24V10A power supply.
 

friarminor

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53volt fluctuation? Dangerous for those 50V caps.
My experience with feeding cheap/weak ClassD amps (Alientek D8) was that with higher voltage (36V) I got mildly harsher sound, to the degree it wasn't listenable to me. With lower voltage (24V10A) - no such thing, very nice sound, clean etc, with added bonus of amp being cool.
With AIYIMA A07 I just stick to what works - same 24V10A power supply.
Whoa. Thanks for the reminder. Though hadn't been presented with harshness, I'd better not turn those volume knobs any further than 9. Besides, too loud already.
 

trl

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Why do you think I wrote "48V may not be a good choice for this amplifier, given that the PVDD capacitors are rated to 50VDV" on the post above? Pavel said the same thing here: https://www.audiosciencereview.com/...2-and-opa2134-option.19155/page-2#post-639061.

We don't need a sticker post, we just need to look to Amir's pictures and see the voltage these caps are rated for.

L.E.: It's not about volume pot's position, it's about keeping the DC voltage way below 50 V RMS, to not damage the capacitors!
 

KA7NIQ

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According to Amir, dynamic range of TPA3255 amp is limited to 14.5 bits by a bad power supply sold with AIYIMA A07 TPA3255 amp.

Dynamic range can be expanded beyond 16 bits by pairing it with a better power supply.

Does anyone know a good affordable power supply for AIYIMA A07 amp?
I did not get a power supply when I bought this amp, so I am using an old Laptop Power Supply. It is 19.5 volts at 4 amps. My Speakers are giant Horns, well over 100 db efficient. It sounds absolutely wonderful, and will play loud enough to harm your hearing. I have no idea how much power I am getting, but it is what I am using, at the moment. I am very very impressed by this amplifier!
 
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