AIYIMA A08 Pro Amplifier Review

[Doodski]

Yeah, but not that much. See my post. And I know you know that, but going from 36-48V isn't even close to a 3dB gain.

In this case with the anemic low voltage power supplies that some peeps are using on these Aiyimas going to the high voltage/current supply means more dynamic headroom and more current for difficult loads. If we are talking full ON power output yes the increase in total volume is not huge but it is there. Make sure you get the high current supply because the power supply gets loaded down and then there is a reduction in wattage output because the current is not sufficient. Buy the biggest and highest current supply that you can afford that works with the Aiyimas.

 

[NoxMorbis]

Yeah, but not that much. See my post. And I know you know that, but going from 36-48V isn't even close to a 3dB gain.

In this case with the anemic low voltage power supplies that some peeps are using on these Aiyimas going to the high voltage/current supply means more dynamic headroom and more current for difficult loads. If we are talking full ON power output yes the increase in total volume is not huge but it is there. Make sure you get the high current supply because the power supply gets loaded down and then there is a reduction in wattage output because the current is not sufficient. Buy the biggest and highest current supply that you can afford that works with the Aiyimas.

My idea is that if you need more volume, you probably need a different amp, because if you are reaching the amps/power supply's limit, you are driving the amp to near it's maximum power output with that power supply, and you won't even get +3dB using the max power supply the amp can handle. Otherwise, there would be plenty of power left over for the dynamic sub needs using 70% volume or even more, or less?

 

[NoxMorbis]

36-48V @ 8ohms;

36V = 162 watts
48V = 288 watts
+126w increase in power.

 

[Doodski]

My idea is that if you need more volume, you probably need a different amp, because if you are reaching the amps/power supply's limit, you are driving the amp to near it's maximum power output with that power supply

A bigger amp is desirable for sure. The Aiyimas are good value for the money and a great exercise in amp and power supply matching but otherwise they are a little amp.

you won;t even get +3dB using the max power supply the amp can handle.

You are too focused on the 3dB stuff when the higher current will improve the usual listening volumes.

Otherwise, there would be plenty of power left over for the dynamic sub needs using 70% volume or even more, or less?

Not sure about the subs stuff. I dropped into this chart recently.

 

[Doodski]

36-48V @ 8ohms;

36V = 162 watts
48V = 288 watts
+126w increase in power.

36VDC rails comes to 81W RMS.
48VDC rails comes to 144W RMS.
I use RMS because near all if not 99.9% of amps are rated in RMS power and not apparent watts.

 

[NoxMorbis]

A bigger amp is desirable for sure. The Aiyimas are good value for the money and a great exercise in amp and power supply matching but otherwise they are a little amp.

You are too focused on the 3dB stuff when the higher current will improve the usual listening volumes.

Not sure about the subs stuff. I dropped into this chart recently.

Sub doesn't matter. I meant low frequency woofers taking more power.

How would +126 watts improve normal listening volumes? That's not even +2dB in loudness.

 

[NoxMorbis]

36VDC rails comes to 81W RMS.
48VDC rails comes to 144W RMS.
I use RMS because near all if not 99.9% of amps are rated in RMS power and not apparent watts.

That's a lot different than doing it in watts. How do you get RMS?

I didn't do the math, but the %age increase in power the same or nearly?

 

[Doodski]

Sub doesn't matter. I meant low frequency woofers taking more power.

How would +126 watts improve normal listening volumes? that's not even +2dB in loudness.

I already explained much of the idea(s). Also the power supply output voltage will droop. Meaning the voltage is reduced as more current is output to the load(s). So that number of voltage and amps is not exactly what the speakers will see.

 

[NoxMorbis]

I mean wiht the 36V pwoer supply, these amps can power efficient speakers that are extremely uncomforatable listening leves. These guys must have some really high volume needs, or are trying to full a pretty large area with pretty large sound?

 

[Doodski]

The woofers will benefit from higher current and voltage to their max limit of course. Again you are focusing on max SPL and dB of increase. At this range of amps it is more about the voltage and current output of the power supply and not the max SPL.

 

[Doodski]

That's a lot different than doing it in watts. How do you get RMS?

I didn't do the math, but the %age increase in power the same or nearly?

Watts RMS = (Vpeak * 0.707) ^2 / R load

 

[Doodski]

I mean wiht the 36V pwoer supply, these amps can power efficient speakers that are extremely uncomforatable listening leves. These guys must have some really high volume needs, or are trying to full a pretty large area with pretty large sound?

Or the speakers are a difficult load and require high current.

 

[NoxMorbis]

I already explained much of the idea(s). Also the power supply output voltage will droop. Meaning the voltage is reduced as more current is output to the load(s). So that number of voltage and amps is not exactly what the speakers will see.

Excuse me for asking, but where did you explain (going from 36V to 48V) would "improve the usual listening volumes." I'd like to understand that.

 

[NoxMorbis]

The woofers will benefit from higher current and voltage to their max limit of course. Again you are focusing on max SPL and dB of increase. At this range of amps it is more about the voltage and current output of the power supply and not the max SPL.

I understand that but only if you are driving the PSU at the given voltage near max power needs (no headroom)? Then, like you said, you can get more out of the 48V supply, but only if you are running up against the 36V PSU limits? Are your really going to even notice the difference? It's liek we're trying to squeeze the last ounce of juice from 100 already squuezed oranges at the cost of a lot of power.

 

[Doodski]

Excuse me for asking, but where did you explain (going from 36V to 48V) would "improve the usual listening volumes." I'd liek to understand that.

I simplified and explained all over in different posts. It's there it's just that there is something that is not known and it's causing more questions to be asked. This stuff can get pretty complicated pretty fast so I am trying to keep it simple and not get too techy.

 

[Doodski]

I understand that but only if you are driving the PSU at the given voltage near max power needs (no headroom)? Then, like you said, you can get more out of the 48V supply, but only if you are running up agasint the 36V PSU limits?

The 36VDC power supply is maybe loaded down and droops to a rough guess of maybe 30VDC so the actual power output is less than 36VDC.

 

[NoxMorbis]

I simplified and explained all over in different posts. It's there it's just that there is something that is not known and it's causing more questions to be asked. This stuff can get pretty complicated pretty fast so I am trying to keep it simple and not get too techy.

Yeah I remember reading your past posts so got that, sure.

 

[Doodski]

Have you read the power output tests for this amp's review? using a 36VDC 6A power supply this is what the amp actually puts out.

 

[JayGilb]

While I cannot vouch for the individuals you mentioned, I am familiar with Randy Cheap Audio Man. From my observation, he does not conduct tests, but rather sells his opinions on Youtube in a conversational manner, often suggesting to his audience to "grab a cup of coffee." Unfortunately, he lacks scientific evidence to support his opinion. I do not intend to criticize him as a person, but when it comes to the science of audio, he falls short of credibility. In simpler terms, he sounds like a communication major who has no understanding of audio science. Like most of those types, it's just his subjective opinion.

I remember his 08 review on Youtube, saying he thought it was a little hot in the higher frequencies, which is what Amir's tests show. Yeah, Randy, you can hear .4 dB at 10kHz and 1dB at 20. Riiiiight. "Grab a cup of coffee," indeed.

My suggestion is to ignore anything anyone says about anything, unless it's backed up by science. Sure, if they say it sounds great, and you can get a near consensus, it's probably decent enough. But anything greater than a general listening opinion is really just an open cakehole spraying frosting.

Maybe he is related to Rob Watts and has super human hearing.

 

[NoxMorbis]

The 36VDC power supply is maybe loaded down and droops to a rough guess of maybe 30VDC so the actual power output is less than 36VDC.

Yeah true and understand that too. It's matter of how efficient it is. But the same thing will be the case with the 48V, unless you spend a lot of cash on it.