AIYIMA A08 Pro Amplifier Review

[amirm]

Who knows. That's Amir's job to determine when he reviews the amplifier.

And I did the job if you had read the review:

The meter is useful in this regard as the amp shuts down when the meter is almost at the end of its range.

Beyond this, I don't get paid enough to do it....

 

[PeteL]

Who knows. That's Amir's job to determine when he reviews the amplifier.

Usually one would put a sine through the amplifier, wind it up until rated power and crosscheck/calibrate the 0dB point. Trouble is, the rated power is all over the shop with these things. We also have no idea what they are using to drive the meter.

It could be rectified and a padded down single channel output, could be a summed input after the volume pot, may be filtered, may have a sophisticated driver IC that responds to millisecond transients, with excellent ballistics- (highly doubt that). There's everything from useful analogue metering to completely useless moving needle displays. This, I would expect to be the latter.

Traditionally, and I know it’s not a strict thing, but traditionally on pro equipment your 0VU both mean +4 dBu and unity gain. As always the « pro » moniker is kinda funny but anyway, never understood the use of VU on power amps. Put a Watt meter.

 

[amirm]

A watt meter has always been for show. It doesn't know the load impedance so it can't possibly be correct given varying speaker impedance. Most of them on high power amps are useless as they barely move. The good ones had a sensitivity switch to make them move in that situation. This unit is no different. It is a bit of bling which in my opinion should be offered in the line up from every amp company. Yes, it should be stereo but impossible to do at this price point and size. I would personally opt for an LCD with graphical views of a meter and spectrum analyzer.

 

[PeteL]

A watt meter has always been for show. It doesn't know the load impedance so it can't possibly be correct given varying speaker impedance. Most of them on high power amps are useless as they barely move. The good ones had a sensitivity switch to make them move in that situation. This unit is no different. It is a bit of bling which in my opinion should be offered in the line up from every amp company. Yes, it should be stereo but impossible to do at this price point and size. I would personally opt for an LCD with graphical views of a meter and spectrum analyzer.

OK, maybe, indeed it wouldn’t be easy to implement an accurate one. Fact remain that a meter should be a tool and not bling, I like them when they are useful. Why can’t it measure the load impedance? any parralel mesurments can be performed no?

 

[restorer-john]

The standard goto driver IC for ananlogue metering for the last 40 years has been the Toshiba SIP IC, the TA-7318P. It offers inbuilt rectification, compression and a hold DC amp driver with controllable ballistics.

Every manufacturer I know of, used them to drive big 'ol analogue meters with great success. Sensitivity (.01/.1/1) is accomplished by padding down the 7318 drive outputs. All very easy.

The thing is, these tiny meters have limited travel are mostly 500uV sensitivity and the ballistics of the movement itself doesn't bode well for a dynamic display.

 

[restorer-john]

OK, maybe, indeed it wouldn’t be easy to implement an accurate one. Fact remain that a meter should be a tool and not bling, I like them when they are useful. Why can’t it measure the load impedance? any parralel mesurments can be performed no?

It gests very complicated and very expensive. Some amplifier manufacturers did it back in the day and I swear the meters cost nearly as much as the rest of the amp...

I have a Luxman M-03 here with a microprocessor controlled digital power output meter with selectable peak hold times and load impedance switching all driving digital VFDs. And it can only work, like most, on a selected nominal impedance, not the actual, real time impedance of the connected load.

This is just the meter circuitry:

 

[PeteL]

It gests very complicated and very expensive. Some amplifier manufacturers did it back in the day and I swear the meters cost nearly as much as the rest of the amp...

I have a Luxman M-03 here with a microprocessor controlled digital power output meter with selectable peak hold times and load impedance switching all driving digital VFDs. And it can only work, like most, on a selected nominal impedance, not the actual, real time impedance of the connected load.

This is just the meter circuitry:

View attachment 240664

Haha yes I get it, I was outside the scope of this particular cheap amp when I made this quick comment. The thing is, we normally see watt meters on 10k$+ amplifiers, I was just not as fatalist as Amir’s comment stating that it just can’t possibly work properly and. being just for show.

 

[restorer-john]

I was just not as fatalist as Amir’s comment stating that it just can’t possibly work properly and. being just for show.

I agree. The TA7318P when calibrated are extremely useful, very fast and give an excellent indication of the extent you are driving your amplifier. They are based on absolute peak voltage, so regardless of what people think, they are showing how dynamic and how much power you are attempting to pump into your speakers at any given time.

The same TA7318 drives the meters on my Sony TAN77es amplifiers and they will easily react to an accurately display 100uS (10kHz) single cycles. Yes, they have some overshoot, but that's all fun with giant meters!

 

[Steve Rogers]

Just want to say that for me this looks really cool.

 

[Schlippwhip68]

Just want to say that for me this looks really cool.

It does look natty doesn’t it.

 

[Schlippwhip68]

So, after having this amp for 24hrs I decided to return it. Amirs measurements were confirmed during playback and the upper treble is a little…urm…’noisy’. While in general the amp does produce a somewhat clean sound it is quite a hard one too in my opinion. I compared it to my modded Aiyima A04 and there is a night and day difference in the bass. While the A08 pro hits hard with the bass, it’s quite short and cold. My A04 on the other hand with upgraded toroidal inducters absolutely wiped the floor with the A08 Pro in regards to warmth, bass and balance. The bass on the A04 is just rich and full, smooth and extended and the rest falls into place on an even keel. The one thing the A08 has in its favour in my opinion is its overall output but that is simply no substitute for actual sound quality. I will stick with my A04 and in fact ordered another today.

 

[PeteL]

I agree. The TA7318P when calibrated are extremely useful, very fast and give an excellent indication of the extent you are driving your amplifier. They are based on absolute peak voltage, so regardless of what people think, they are showing how dynamic and how much power you are attempting to pump into your speakers at any given time.

The same TA7318 drives the meters on my Sony TAN77es amplifiers and they will easily react to an accurately display 100uS (10kHz) single cycles. Yes, they have some overshoot, but that's all fun with giant meters!

It's a PPM meter, both VU and PPM had their use in the pre-digital pro world, the PPM will display the Peaks. But they where both mainly on line level equipment. Just a bit less relevent with amplification, altough if it works well on an amp, it's still useful as you say. That said I do like the look too, I just would like to know what 0 VU correspond to, what it means when you are at zero. Yes it's not hard to feed a sine, bring it to zero and measure what it means on the Aux out, on the speakers out or on the generator. Just to see the rationale. To see if it actually do serve as a clipping indicator, which is already something useful. I understand it's not a critical measurment meter and it's been put there because it's cool to watch. Your Sony amp is a heck of a looker by the way. Love it.

 

[pseudoid]

Question is, what does it show? calibrated to what?

Anything you want it show... as long as you have a screwdriver handy (or even a long finger nail)...

 

[TonyJZX]

restorer john isnt wrong here

you'll find VU meters like the above for well under $5 usd... you can bet that aiyima could well buy 1,000 for a few bucks and it would be minimal cost to drill out two facia holes, insert two meters and the associated one or two chips in the chain to get it to go.

Whether these meters actually add any USP ('unique selling point') to the Chinese or western audience is another matter. Also the more superfluous features you add ups the RMA rate.

I have one of these (integrated amp):

and the manufacturer said they have some returns due to dead meters and detached light cables, dead lights.

I personally have no idea how to even get to that area but I admit I love the look and I may not have even purchased the unit if it didnt have the dual blue meters and the glass front.

 

[mARCELOCM]

Great job at all your reviews! i like them all!

I wanna ask you a question.. i already have a pair of cambridge audio sx-50, and i want a good amplifier to them, and im seeing this new line of sabaj 2022, the a10a 2022, a20a 2022 or the topping mx5, im in really doubt, will you review them any soon?

 

[DanTheMan]

Well, I’ve got a set of 4Ohm speakers that this amp should feed well. I actually think I’ll connect this to the Qudelix and use it for room correction. Anyone see any potent problems with this set up? If I do this, I’ll run some measurements on what the tone controls do.

 

[PeteL]

Anything you want it show... as long as you have a screwdriver handy (or even a long finger nail)...
View attachment 240772View attachment 240774

OK but we should expect the manufacturer to be more apt at calibrating the meter than the end user, He designed the amp... I certainly hope he gave it some thoughts.

 

[TonyJZX]

they just slap in a generic meter and a chip that controls it and away it goes

its just a amusing party trick... no one should be expecting it to measure anything of significance

 

[restorer-john]

Anything you want it show... as long as you have a screwdriver handy (or even a long finger nail)...

That is just the mechanical zero adjust position.

The scaling and ballistics are determined by the driving circuitry. Small moving coil meters are DC, usually with sensitivity around 0.5mV FSD +/-. So, you need rectification, peak/rms/average detection, pulse/peak extenders, DC hold amps, range switching resistive dividers and damping/overshoot control. And a few calibration pots.

 

[DMill]

A VU meter provides little beyond looks that testing won’t reveal. Even with much more expensive gear. But I love them too. It really is ugly btw. But it’s a decent enough little amp and especially at its price. A nice review.