AIYIMA A07 TPA3255 Review (Amplifier)

[daftcombo]

Mean Well power supplies are often mentioned here but can anyone recommend a 'plug&play' power supply (clean case, no extra wiring required) as an upgrade to the stock 32V 5A?

Some Mean Well PSU are plug and play. I ordered a Globtek though.

 

[Zek]

Even a 32v 5a does the job.

5A are 2,5 times of 2A.

 

[Raindog123]

2A (3A) would not be enough for driving A07 properly.

Not sure where 2A comes from for a 3A PS... But for a current-limiting case the sustained output power is (into an 8-Ohm speaker): W=Z*I^2, or 8*3^2=72W (even 8*2^2=32W). Either of which is at least a few times higher than what you need to light-up a room.

 

[Zek]

Not sure where 2A comes from

From here

 

[cyberzigot]

Not sure where 2A comes from for a 3A PS... But for a current-limiting case the sustained output power is (into an 8-Ohm speaker): W=Z*A^2, or 8*3^2=72W (even 8*2^2=32W). Either of which is at least a few times higher than what you need to light-up a room.

With 32v5a ps, sitting 8 feet away from a pair of 8omh xls encore, 9 o'clock achieves a normal listening level, 10'clock gets uncomfortably loud. Sounds great. Don't know why one would need to go through all the length to achieve max output possible.

 

[Raindog123]

From here

Well, I do not see the spanish version following the link, but it might be Amazon's regional games... But even my rusty Spanish tells me that your highlighted translates as "[also] a replacement for 2.5A and 2A [devices]"

 

[Steamrolly]

@Steamrolly: I’ve ordered this from Amazon in the US. That seems to be the same as $2.50 cheaper this. Good build quality, all possible certification markings, and my 6-Ohm boxes sound great with it.

Raindog123 I may just grab the same one from Amazon.ca . It doesn't have the certification I was looking for but if I have concerns I can address them much more easily that dealing with Ali Express. Very little in the way of 32v from Amazon.ca for some reason.

 

[Bruce Morgen]

With all due respect, it drives it well enough. Even a 32v 5a does the job. Proper.
I don't understand the fetish of running the amp at it's maximum spec and generating unnecessary heat.

Apparently, that's a non-issue. If I understand Class D correctly -- always a consideration -- the heat generated by the chip corresponds to the power actually dissipated regardless of PSU voltage. Figure 11 in the TI data sheet seems to indicate I'm correct -- it shows "case temperature" in relation to output power, not "DC supply voltage" AKA "PVDD_x."

TPA3255 data sheet

 

[pma]

-- the heat generated by the chip corresponds to the power actually dissipated regardless of PSU voltage. Figure 11 in the TI data sheet seems to indicate I'm correct -- it shows "case temperature" in relation to output power, not "DC supply voltage" AKA "PVDD_x."

TPA3255 data sheet

No. The plot is for the defined supply voltage. There is a less heat if you have 50W power with 30V power supply than with 48V. Considerably less.

 

[Bruce Morgen]

No. The plot is for the defined supply voltage. There is a less heat if you have 50W power with 30V power supply than with 48V. Considerably less.

So you're saying a lower voltage -- which would incur more current draw for any given power output, right? -- would result in a lower case temperature than a higher voltage, which would draw less current at the same power output? That doesn't compute here -- but the computer between my ears isn't programmed for electrical engineering, so you could well be correct. At any rate, running my two A07s at 48VDC has resulted in zero problems here -- their cases are barely even warm at idle and still hand-friendly (and much cooler than the power supply vents of my vintage Yamaha DSP-1 processor, which is rated at only 30 watts) at near-deafening volumes. Since one of my SMPSs has variable voltage output, I can informally test your contention by turning it down to 30VDC and seeing if the A07 it powers runs any cooler.

An hour+ at the same medium-high volume later: no discernible difference in the temperature of the top of the A07's case between 30VDC and 48VDC -- and IMO no real world reason to deny myself all that extra headroom.

 

[tifune]

P.S.: THD 1kHz at 1W/4ohm is 0.001% (-100dB) ...

View attachment 104126

So I've read through this entire thread and I'm a bit lost. I know absolutely nothing about power supplies, or even power in general. But, this chart I understand - what PSU would I need to buy to get this result? Could I simply search for "regulated linear 30V"? Thank you in advance

 

[pma]

So I've read through this entire thread and I'm a bit lost. I know absolutely nothing about power supplies, or even power in general. But, this chart I understand - what PSU would I need to buy to get this result? Could I simply search for "regulated linear 30V"? Thank you in advance

I apologize if it is confusing, I am only trying to collect valid info with (to me) well defined power supplies. A linear regulated power supply of 30-35Vdc voltage and 4-5A output current should be adequate. Same would apply to a good SMPS. However, you probably know that I hate general suggestions and I want to have a possibility to make a measurement before giving any suggestions. I found that Mean Well RS-110-24 SMPS, set to 27V, is good but has to be built in an appropriate case for safety reason.

https://www.audiosciencereview.com/...-100-24-smps-power-supply-measurements.19507/

 

[ironhorse128]

Does a linear power supply really have to be regulated to pair well with tpa3255? A transformer with rectifier and caps are not sufficient?

 

[Toku]

Does a linear power supply really have to be regulated to pair well with tpa3255? A transformer with rectifier and caps are not sufficient?

Class D amplifiers are greatly affected by fluctuations in the power supply voltage due to the operating principle. Therefore, it is necessary to reduce voltage fluctuations by using a transformer and smoothing capacitor with as large a capacity as possible. It is also important to take measures to block noise from the power supply line.

 

[Bruce Morgen]

Class D amplifiers are greatly affected by fluctuations in the power supply voltage due to the operating principle. Therefore, it is necessary to reduce voltage fluctuations by using a transformer and smoothing capacitor with as large a capacity as possible. It is also important to take measures to block noise from the power supply line.

All these issues and several more combine to make linear power supplies a bad choice for Class D amplifiers -- although variations in DC output weren't a problem here when I reduced and increased the DC between 30 and 48VDC while the A07 is running while looking into PMA's contention regarding voltage and heat. That's why all the leading vendors of high performance OEM Class D output modules -- e.g. ICEpower, Hypex, and Purifi -- recommend and/or incorporate switch mode power supplies for their products. My elderly subwoofer has a linear power supply for it's Class D amp -- not only is the transformer immensely heavy, but a fuktonne of unnecessary heat is generated, making me grateful for the ATO (auto turn off) function that shuts the thing down in the absence of signal.

 

[Guddu]

Will something like this not work well for TPA3255 modules?

 

[Guddu]

Or may be something like this:

 

[Bruce Morgen]

Either would work fine AFAICT -- but they'd require some DIY wiring effort plus some sort of enclosure. I think something along the lines of Aiyima's recommended semi-enclosed industrial SMPS would be both cheaper and require a bit less DIY. Here's a example from eBay that's usable if (a) you're confident you can work safely with electricity, including (potentially dangerous!) AC mains voltage and (b) acquire the necessary cables and connectors. If not, it's best to stick with a plug & play "power brick" solution and avoid the DIY completely:

https://www.ebay.com/itm/Mean-Well-...142881&hash=item1a23a408a8:g:e8oAAOSw241YeCQg

 

[Guddu]

Either would work fine AFAICT -- but they'd require some DIY wiring effort plus some sort of enclosure. I think something along the lines of Aiyima's recommended semi-enclosed industrial SMPS would be both cheaper and require a bit less DIY. Here's a example from eBay that's usable if (a) you're confident you can work safely with electricity, including (potentially dangerous!) AC mains voltage and (b) acquire the necessary cables and connectors. If not, it's best to stick with a plug & play "power brick" solution and avoid the DIY completely:

https://www.ebay.com/itm/Mean-Well-...142881&hash=item1a23a408a8:g:e8oAAOSw241YeCQg

I would personally prefer Mean Well or laptop style power brick for sure to avoid any wiring related work, because of my lack of electrical knowledge.
I was looking for something and saw those switching PSU, so though of sharing it here as everyone here is looking for single board PSU solution for a small form factor build.
What is "Aiyima's recommended semi-enclosed industrial SMPS"? I guess I missed it if it was listed somewhere in this thread.

 

[Zoomer]

What is "Aiyima's recommended semi-enclosed industrial SMPS"?

https://www.aiyima.com/products/amp...switching-power-supply?variant=32961903394891