AIYIMA A07 TPA3255 Review (Amplifier)

[Jdunk54nl]

I have the a07 paired with a pair of elac dfr52. it gets loud, my volume knob is at 12 more or less.
but im not certain if the power is enough. i dont have another system to do a comparison with so i can't tell if there are distortions. opinions?
i'm probably getting an all in one solution like the yamaha streamer reviewed here. we'll see how it sounds then. im just using an nx4 in the meantime.

Is it loud enough for you? If it is and you can’t hear any distortion, then it is enough. You will be able to hear something wrong if there isn’t enough power. Listen to a distortion test, then you’ll know what it sounds like.

 

[Steamrolly]

Does anyone know if there is any notable difference between using the 3.5mm input verses the RCA inputs on the A07? Application would be connecting a RPi using an Apple USB-C Dongle. The simplest would be to us a 3.5 cable but I could use a 3.5mm to RCA cable if warranted. My suspicion is that for this application there wouldn't be any benefit to the RCA inputs but thought I would double check.

 

[Jdunk54nl]

Does anyone know if there is any notable difference between using the 3.5mm input verses the RCA inputs on the A07? Application would be connecting a RPi using an Apple USB-C Dongle. The simplest would be to us a 3.5 cable but I could use a 3.5mm to RCA cable if warranted. My suspicion is that for this application there wouldn't be any benefit to the RCA inputs but thought I would double check.

99% sure they are just tied together internally, so one could be used as a passthrough.

 

[Steamrolly]

99% sure they are just tied together internally, so one could be used as a passthrough.

Yes, make that 100%. I ran a signal to the RCA input and then a 3.5mm cable to powered speakers from the 3.5mm input. The audio to the powered speakers worked with the amp turned off and both the powered speakers and passive speakers (connected to amp) worked together when the amp was turned on.

 

[Synergy4]

I have a Aiyima 04 (TPA3251) amplifier, 32V 5A supply & Pioneer SP-BS22-LR 6 ohm speakers, which works fine with my desktop computer. It is connected using a 3.5mm stereo plug to RCA cable. I still need to do some "Dennis Murphy" updates the Pioneer SP-BS22-LR speakers

 

[Dotcha]

In my region, 48V 3A PS with ground is available at $28, which is quite close to the price of 32V 5A PS from AIYIMA. If you were given the choice, which would you select? I'm thinking these for polk S20, 8ohm/88dB...

 

[somebodyelse]

Back of envelope calc using the power vs voltage graph from the ti datasheet:
32V gives ~75W per channel into 8R, which needs (75/32)A per channel for a total of 4.7A, a pretty good fit to the 32V 5A supply. It'll run cooler at 32V too. To see the benefit of the higher voltage you'd probably need a more powerful supply.

 

[pma]

You may be happy, but with only 3A the power would be severly limited. You would need 6 - 10A from 48V power supply.

 

[Anthony Rehm]

You may be happy, but with only 3A the power would be severly limited. You would need 6 - 10A from 48V power supply.

Isn't broadly W = V x A? Which means that 32V x 5A (160W) is better, but overall not so far away from 48V x 3A (144W)?

 

[Zek]

The power calculated in this way is the maximum possible, but for both channels.

 

[Anthony Rehm]

The power calculated in this way is the maximum possible, but for both channels.

Yes, that's clear. Let me test an example. Assume there are 2 models of Mean Well power supply -

A) LRS-350-48 - 350W 48V 7.3A
B) LRS-350-24 - 350W 24V 14.6A

Do I understand correctly that they will return exactly same results and experience with AIYIMA A07?

 

[Guddu]

Yes, that's clear. Let me test an example. Assume there are 2 models of Mean Well power supply -

A) LRS-350-48 - 350W 48V 7.3A
B) LRS-350-24 - 350W 24V 14.6A

Do I understand correctly that they will return exactly same results and experience with AIYIMA A07?

I would wait for someone else to comment as well, but just to add that Aiyima have recommended to use a 48v PSU with it on their website.

 

[Raindog123]

Into a fixed load R, by using the Ohm’s law (V = R x I), the power W = V x I formula can be written either as W = V^2/R or W = I^2 x R. The max power will be the lower of either the max current or voltage limits (or in-between). Practically, for a low-impedance load the supply’s max current is the limit, for high-impedance the voltage.

 

[Raindog123]

A) LRS-350-48 - 350W 48V 7.3A
B) LRS-350-24 - 350W 24V 14.6A

Do I understand correctly that they will return exactly same results and experience with AIYIMA A07?

In your example, into a 8Ohm speaker, a 24V power supply would only offer up to 72W of power (24*24/8). And only 3A of current will be drawn (out of possible 14.6A - that requires a lower-impedance load to achieve). A 48V power supply will support up to 288W (!) at 6A of max current. [All neglecting amplifier efficiency, for the sake of this discussion.]

 

[pma]

Isn't broadly W = V x A? Which means that 32V x 5A (160W) is better, but overall not so far away from 48V x 3A (144W)?

Amplifier output power with respect to speaker load ..... P = R * I^2 (load resistance times current squared)
and P = V^2/R (output voltage squared divided by resistance)
In both cases we speak about amplifier output voltage and amplifier output current. However, if the output current is limited by the power supply,

with 3A max. current and 4ohm speaker, you get 36W, is that clear?

 

[Guddu]

I would wait for someone else to comment as well, but just to add that Aiyima have recommended to use a 48v PSU with it on their website.

So,
48V 7.3A with 4R load, we get 213.16 watts being lowest ?
48V 7.3A with 8R load, we get 288 watts being lowest ?

48V 3A with 4R load, we get 36 watts being lowest ?
48V 3A with 8R load, we get 72 watts being lowest ?

32V 5A with 4R load, we get 100 watts being lowest ?
32V 5A with 8R load, we get 128 watts being lowest ?

24V 10A with 4R load, we get 144 watts being lowest ?
24V 10A with 8R load, we get 72 watts being lowest ?

 

[pma]

So,
48V 7.3A with 4R load, we get 213.16 watts being lowest
48V 7.3A with 8R load, we get 288 watts being lowest

48V 3A with 4R load, we get 36 watts being lowest
48V 3A with 8R load, we get 72 watts being lowest

32V 5A with 4R load, we get 100 watts being lowest
32V 5A with 8R load, we get 128 watts being lowest

24V 10A with 4R load, we get 144 watts being lowest
24V 10A with 8R load, we get 72 watts being lowest

Sorry, this is a nonsense, completely. Available output voltage does not equal to supply voltage. Available current does. From 24V and BTL, you get 72W/4ohm but only in theory. Even if there was unlimited current capability, you get voltage clipping. Try to think about it. 24V makes 8.48Vrms in one branch and 16.97Vrms in BTL mode. 16.97^2/4 = 72. In theory. In practice, there is some drop.

 

[Guddu]

Sorry, this is a nonsense, completely. Available output voltage does not equal to supply voltage. Available current does. From 24V and BTL, you get 72W/4ohm but only in theory. Even if there was unlimited current capability, you get voltage clipping. Try to think about it. 24V makes 8.48Vrms in one branch and 16.97Vrms in BTL mode. 16.97^2/4 = 72. In theory. In practice, there is some drop.

View attachment 114550

My post was actually a question, but not the answer.
I should have added "?" with my comments there... my mistake.
But you answered.. thanks.

 

[SAC_2]

I would wait for someone else to comment as well, but just to add that Aiyima have recommended to use a 48v PSU with it on their website.

I see that...

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

Would I need a case for it?

 

[Guddu]

I see that...

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

Would I need a case for it?

I would say putting it in a case is a good idea considering the open wiring in play, provided case is ventilated.
Picture shows input and output power cables which should get you going straight away.
If you can connect cables safely and securely, and keep the PSU so as it is safe with such bare wires then you may not need case.

But you also have cheaper (and probably better) available on Amazon: