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

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daftcombo

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By the way, I have a generic TPA3255 amplifier from AIYIMA which was released before AIYIMA A07 was released.
I paired it with a generic chinese 32V 5A power supply I ordered from aliexpress.com
I don't hear white noise at my listening position which is roughly 40 centimeters from the speakers.
Man, are you trolling? I said that the AD18 was "worse measuring" generally. But it has less noise at low wattage (see 100mW). Go check.
We are speaking about Aiyima A07, aren't we?
Hearing noise or no depends on you speaker sensitivity, also.
 

abdo123

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Man, are you trolling? I said that the AD18 was "worse measuring" generally. But it has less noise at low wattage (see 100mW). Go check.

But the Aiyima graph (the actual topic of this thread, you know?) showed one powersupply with a much higher noise floor than the other.
 
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Something doesn't add up. I'm not seeing -96dB in THD+N vs power graph for LOXJIE A30 which is supposed to be a good amplifier.

01.png
02.png
 

daftcombo

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But the Aiyima graph (the actual topic of this thread, you know?) showed one powersupply with a much higher noise floor than the other.
Yes, that's whay I wrote : "-68 dB at best". It is worse with the other PSU and for the other channel.

Still, I have the unit at home, and because it came without PSU, I use it with a good one, made by Globtek and with all the certifications required (Meanwell PSU are not better) and I hear noise. Whereas I don't with the AD18 coming with a generic PSU.

My conclusion is that OP would be lucky if swapping the PSU reduced noise to the point it gets lower than what I have with my AD18.
 
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Because noise floor is even worse with it: -50dB!
And yes, you don't even see it at 5W because distortion is already taking over.

Look at SNR figure. It says 96dB at 5W. I'm not seeing 96dB at 5W on the power vs distortion graph.
 

NTK

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Something doesn't add up. I'm not seeing -96dB in THD+N vs power graph for LOXJIE A30 which is supposed to be a good amplifier.
The upper graphs are signal-to-noise ratios. The lower graphs are THD + signal-to-noise. THD dominates the THD+N, and therefore gave the significantly worse numbers.
 

daftcombo

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Look at SNR figure. It says 96dB at 5W. I'm not seeing 96dB at 5W on the power vs distortion graph.
Yes, because of distortion. At 5W it reaches around -76dB in the audible band.

1629207656595.png
 
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So, I'm not going to escape noise by buying LOXJIE A30?
 

daftcombo

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Which amplifier do you recommend for low noise floor and higher SNR? I don't need much power because speakers are on my desk where I sit.
 
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Usually the DAC that has the biggest portion of the the total noise anyway.

External USB DACs have lower noise floor than most amplifiers. You can expect higher SNR than 96dB from decent USB DACs.
 
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By the way, I'm currently using a generic AIYIMA TPA3255 amp with this power supply.

32v5a power supply.jpg


I think this is the power supply AIYIMA sells with AIYIMA A07.
 

abdo123

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External USB DACs have lower noise floor than most amplifiers. You can expect higher SNR than 96dB from decent USB DACs.

a typical amplifier has around 29dB of gain. That is a voltage gain of 28 times. So the DAC contribution to the noise will be roughly 28 times more than what Amir actually measures in a review. ;)

My setup is DAC limited for example. The further i raise the volume knob of the amplifier (increase gain) the more noise i hear.
 

daftcombo

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That is a voltage gain of 28 times. So the DAC contribution to the noise will be roughly 28 times more than what Amir actually measures in a review.
It is true only at full blast. And "28 times more" means nothing. It just mean +28dB. For instance, if a DAC has a SINAD of 100dB, "28 times more" is -72dB.
 

daftcombo

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Which amplifier do you recommend for low noise floor and higher SNR? I don't need much power because speakers are on my desk where I sit.
Well, I am also searching for an amp that:
- is small like my Aiyima A07
- doesn't hiss in my speakers, like my AD18 or my Hypex S500NC
- is cheap.
 
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Well, I am also searching for an amp that:
- is small like my Aiyima A07
- doesn't hiss in my speakers, like my AD18 or my Hypex S500NC
- is cheap.

You should consider LOXJIE A30. It is cheap enough. What about AIYIMA D03?
 

daftcombo

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You should consider LOXJIE A30. It is cheap enough. What about AIYIMA D03?

From the graph I already showed, the Loxjie will probably hiss more than the Aiyima A07.
I'm waiting to see here a test with a cheap powerful amp having -80dB noise at 100mW before pulling the trigger.
 
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