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Aiyima A07 PRO

Holmz

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Wow, that's nice.

i've been looking at various single voltage SMPS modules on aliexpress, 45V-48V, 350W-600W. But, a variable voltage 0-48V power supply, that'll be generally useful to me besides just plugging an amp into it.

Pretty sure at this point that upping the PS voltage from 36V will let the A07 Pro sound cleaner and better at high volumes. Heat will become an issue.

How will it sound cleaner?
 

conradj

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How will it sound cleaner?
Just from a reduction of THD from the amp. With a 36V 10A power supply the distortion becomes discernible as i crank the volume past -15db on the Topping E30 II. It flattens out as well; the sound gradually loses its dynamic qualities as i turn it up.

i experimented yesterday with the speaker EQ, putting a big dip in the frequency response between 40Hz to 160Hz, cutting them from -5db to -9db, and adjusting the subwoofer to compensate. Just to free up some power reserve in the amp. And lo and behold the speakers sounded much better, still ok-ish at 0db. The EQ's all wrong for the size of my listening room at those volumes, will have to move the system somewhere bigger if i want to keep playing with cranking it up that far.

Will keep a smaller dip in the bass frequency response. It was too prominent before anyway.

With my general set up and room space and shape. i'm no expert-- just having fun messing around, and am sure other folks will do much better than me.
 

Holmz

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@conradj
I suspect that it is simply “more clipping”.

It sort of sneaks up as one usually turns up the volume until it starts sounding loud, and it always starts sounding loud when the clipping starts to happen a greater %-age of the time. It does not take a great deal of time that it is clipping, just a the peaks.

If both amps/supply’s were below clipping then they should be the same.

….

i experimented yesterday with the speaker EQ, putting a big dip in the frequency response between 40Hz to 160Hz, cutting them from -5db to -9db, and adjusting the subwoofer to compensate. Just to free up some power reserve in the amp. And lo and behold the speakers sounded much better, still ok-ish at 0db. The EQ's all wrong for the size of my listening room at those volumes, will have to move the system somewhere bigger if i want to keep playing with cranking it up that far.

Will keep a smaller dip in the bass frequency response. It was too prominent before anyway.
….
And your scheme ^here^ is in-line with that.

You could use two of these amps with the 36V supply and high pass filter the amp that is not on the woofer, and that would help even more.
One would need a speaker that bi-wire capable. And somethng on the order of an active XO.

You’re definitely on a proven amd l poem path.
 
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Scrufboy

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Wow, that's nice.

i've been looking at various single voltage SMPS modules on aliexpress, 45V-48V, 350W-600W. But, a variable voltage 0-48V power supply, that'll be generally useful to me besides just plugging an amp into it.

Pretty sure at this point that upping the PS voltage from 36V will let the A07 Pro sound cleaner and better at high volumes. Heat will become an issue.
On the Drok.. Yep, I have two. Quite versatile. If you are interested - They make a 24v that you can dial in both the V and the A. Could be versatile for other projects.

As far as heat being an issue... Yep, you are correct.

In the NON pro version that I run off this supply, it has 2 Sparkos SS3602's, it has the better thermal paste. The caps are actually wrapped with some really good heat reflective tape and the case itself was vented for me. It does not get hot, not really. But in fairness, I have a Noctua slim 120mm fan running and pushing air across and through the A07.

However, Andrew at Sparkos was right. 5 of these SS3602's, based on how they work, do indeed cause huge heat increases in the Pro version. This is why heatsinks were necessary for the voltage regulators.

I have now added vents on the side. They look OK, but I accidentally made them 5/8ths apart center to center instead of 3/8ths. This is not enough for intake. Not for me in this setup. I will need a whole new row of vent holes on the sides of the bottom part of the chassis. And like my NON pro version, it needs a row across the back to pull air in over the inductors. The ASR member that posted on vents for the A07 non PRO version really nailed it. He could have added more intake holes on the side... But his ratio proves to be sound in that you want air jetting in as fast as possible to cool the unit. So you need to have the right amount of venting of the heat to facilitate that intake.

It is super important to get convection right. It is also important to note that more efficient heat removal from components will cause a case to get hotter. This is why the venting of the case is important. But even with venting, as the hot air flows through the holes, it will heat the aluminum chassis. The heat you feel on the chassis is just that. It has already been removed from the components. I have placed an 80mm noctua over my vents and it pulls the heat out nicely. I can further this by mounting a slim 92mm fan with silicone grommet and finger guard to the top of the case. But this is only ideal if you can attach the fan directly to the circuit inside the Aiyima A07 Pro. If anyone here knows where to solder those wires on the PCB we will all benefit from that knowledge.

I do believe after this... With my current fan setup in my gear though, that things will be OK... But having the 5 opamps in my rig as all SS3602's isn't the way to go without real venting and without fan cooling. I know for a fact that without venting this case and putting heatsinks onto the voltage regulators, you cannot use these SparkosLabs opamps in every slot.

With that... I believe that it is important for us to stumblu, or ebark upon discovery of the best combination of opamps. I know we will find that 2 or 3 types in the right configuration will lead others to be able to repeat the results and we can go from there.

Knowing the specs of each opamp we use in regards to voltage increases with heat concerns and SNR/THD+N in regards to noise floor will be paramount.

We, in essence though, could invariably find that using 5 different opamps could work extremely well. Because it is actually 10 opamps. I do see a place for the SS3602 in the mix. And possibly in the two "math" positions it may fare to be the best choice. Remember, it wasn't until I put the SS3602 in those two sockets that I noticed a significant difference. Which does follow what others find in higher end gear when they pair the Burson V6 Vivid with the Sparkos. One way works great, the other not so much.

We are getting closer. I propose that the thread now lean toward finding this combo. It is a big job for one guy, and It could get expensive. But if a few of us look into this together, cohesively, I am sure that there will be a perfect combo for this amp. Again, we are getting closer.

I am confident in the members of this thread. Assuredly, I know that we don't necessarily need to do this, but if done with care, it can be fun and we could be surprised by what we find.

Encouragement to all... Keep it on point, be concise, post your findings and share your links. Only through your diligence can we prove that this A07 should exist and can be a cut above its predecessor.

Keep on, keeping on gang...
 
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Scrufboy

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Interesting...
@conradj
I suspect that it is simply “more clipping”.

It sort of sneaks up as one usually turns up the volume until it starts sounding loud, and it always starts sounding loud when the clipping starts to happen a greater %-age of the time. It does not take a great deal of time that it is clipping, just a the peaks.

If both amps/supply’s were below clipping then they should be the same.


And your scheme ^here^ is in-line with that.

You could use two of these amps with the 36V supply and high pass filter the amp that is not on the woofer, and that would help even more.
One would need a speaker that bi-wire capable. And somethng on the order of an active XO.

You’re definitely on a proven amd l poem path.
 

conradj

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@conradj
I suspect that it is simply “more clipping”.
o yes, for sure. Waveform clipping is almost certainly the cause of the increase in audio output THD here, when the amp begins to run out of juice. So i wanna give it more juice!
 

T&T

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I forgot to turn off the Pro yesterday for 24 hours with a 48v 5a power supply...glad nothing happened, I have the top cover laying on top, open 1 cm each side so don't get too hot, I think sounds better now after accidentally break in...
 
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Holmz

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o yes, for sure. Waveform clipping is almost certainly the cause of the increase in audio output THD here, when the amp begins to run out of juice. So i wanna give it more juice!
OK - but what is that?
(3dB more SPL juice?)

I forgot to turn off the Pro yesterday for 24 hours...glad nothing happened, I have the top cover laying on top, open 1 cm each side, I think sounds better now...
Maybe you can have someone put the cover on and take it off and ‘see’ if there is a trend when you don’t know?
 
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Scrufboy

Scrufboy

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Maybe you can have someone put the cover on and take it off and ‘see’ if there is a trend when you don’t know?
It's not about it sounding better with the cover on or off. I can't tell if you are being serious or not. The sound improvements are in regard to the amp being left on for a burn in period. Some swear by this... Others don't get it and then there are outright naysayers. I however have experienced this "Burn In"

But you sir... You really should stop taking part of a persons statement out of its context. You took his phrase, butchered it and made it say something different. That is disingenuous and dishonest.

@T&T Said - I have the top cover laying on top, open 1 cm each side so don't get too hot.

@Holmz - You changed this and posted - I have the top cover laying on top, open 1 cm each side, I think sounds better now...

Stop doing this....
 
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conradj

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That's his style of humour i guess. A bit of the needle going on there. He does show that he knows what he's talking abt. He's not wrong abt a bigger PSU just getting me a few dbs of headroom, given the limits of what the amp will take.
 
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Scrufboy

Scrufboy

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Trust me... That is not humor. That's just an ass.
That's his style of humour i guess. A bit of the needle going on there. He does show that he knows what he's talking abt. He's not wrong abt a bigger PSU just getting me a few dbs of headroom, given the limits of what the amp will take.
 

conradj

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OK - but what is that?
(3dB more SPL juice?)

If that, if you're talking abt what the max the smaller SMPS will provide compared to what additional dbs the bigger one will permit.

But then, when you play the amp at lower volumes, the additional power will give you much better transient headroom if the pre-amp/amp combo is good enough to permit the response, and if the speakers are good enough to convey that.

That's one of the main things we're looking for, music that's not a steady drone, but something alive, active and kicking.
 

conradj

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I forgot to turn off the Pro yesterday for 24 hours with a 48v 5a power supply...glad nothing happened, I have the top cover laying on top, open 1 cm each side so don't get too hot, I think sounds better now after accidentally break in...

Aiyima specs the A07 Pro to take a 48V power supply so i don't think there's any need to worry. And if the amp's quiescent and not playing anything it should draw no more than a couple watts, so no issues with heat.

Me too, i've noticed a lot of the amps i've used sound better after a couple days of continuous operation. No idea if it's just me. Don't think so.
 

Holmz

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If that, if you're talking abt what the max the smaller SMPS will provide compared to what additional dbs the bigger one will permit.

But then, when you play the amp at lower volumes, the additional power will give you much better transient headroom if the pre-amp/amp combo is good enough to permit the response, and if the speakers are good enough to convey that.

That's one of the main things we're looking for, music that's not a steady drone, but something alive, active and kicking.
I want to believe it, but the amp(s) sound pretty decent with the lower voltage supply.
(The main reason I see for the higher voltage is that it is rated into 4-ohms so one it getting 1/2 the power onto 8 ohms.)

Some time domain graph showing it better could be convincing That what you are describing as really happening… but just throwing the higher voltage unit on it also makes sense.
 

conradj

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What i'm doing with this amp at the moment is to run 3 sets of speakers at the same time with it in stereo; 3 speakers per channel. i don't point them all at the listening position. i've played with that and there're too many audible probs. Correctly point the pair i like best towards the main listening position. Second pair aimed outwards at around a 35 degree angle, and the third pair abt an additional 35 degree angle outwards from that. i fix the speaker connections so each channel has a 4ohm overall resistance.

It sounds like one pair too many for the amp to drive with a 36V PSU. Prolly should put in a bigger capacitor into it too.

As i said earlier, i'm enjoying messing around with this thing, finding out lots.
 

Holmz

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Or have the lead feed a buffering cap outside of the unit between the SMPS and the input?

Without an O-scope though, it is hard to tell if it is needed or helping…
 

conradj

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o yeah, capacitors proliferating. i've seen that done and thot it was superfluous. No more. i like multiple speakers per channel. They're all pretty cheap, the best i could get when they come on sale. The cumulative sound is nice. The best pair are the ELAC Debut 2.0 B6.2's.

Am finding that set up this way the sound's pretty good almost anywhere in the room, not just in the listening position. The EQ i have to do is for the loudest pair. The only time the speakers really over-reinforce each other is in the bass frequencies and i end up putting a big dip in the EQ there. Which is nice for giving the overall set up more headroom. Overall it sounds nicer than any particular single pair of these speakers does in this room. Of course if you want the best imaging you'll have to plunk down in the listening chair.

The Aiyima A07 Pro is handling it pretty nicely. Switching the op-amps help. i hear the better details everywhere in the room, distinctly. Transients are better too tho they don't hit as hard as i think they should, therefore a desire for a higher volt SMPS.
 

restorer-john

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300 Watts per channel. I have seen this claim. Please explain under what conditions this amp produces this power.

I believe 300 Watts of energy is released when you burn it.
 
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conradj

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There you go. The inevitable end to the tragic tale of Frankenstein and his Doomed Creation.
 
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