Aiyima A07 PRO

[conradj]

You subjective experience would be good for me if you can't provide a thermometer measurement. (Maybe there are things that doesn't need a measuring tool, but don't expect me to trust your "feelings" about SNR of the device )

i find i can only put on my critical listening hat for short stretches. It gets unreliable otherwise. Once i come to some conclusion abt what i'm hearing i just switch the critical listening off and go enjoy the music.

Found that the LM4562 which you can order the A07 non-Pro with and which i did, is worth getting. The OPA1656, the ones i got which i think are genuine but i didn't buy them from a certified TI distributor, isn't all that different from it. Used in this A07 Pro amp, i hear a wider dynamic range with the OPA1656 and more emphasized treble with a little better detail, along with a more defined low bass. They're small if distinct differences that show up best at high sound volumes, not big differences.

Right now, when i'm just playing music to enjoy it, i can't swear to you that i hear any differences between them.

Neither of these op-amps will give you a tube amplifier sound. They're solid state neutral, don't introduce any harmonics as tubes will.

The AD827 seems to be a mixed bag. i've not been using them for a bit and don't have any conclusions abt them when plugged into this now broken in A07 Pro, because i haven't done it.

For a lovely, smooth and silky solid state sound from a cheap device, check out the Fosi Audio BT30D Pro. It's also a TPA3255 amp. It's a 2.1 amp with separate volume and frequency controls for a passive subwoofer. It's unusual in that it uses a second TPA3255 just to drive the sub. Didn't unscrew the heatsink when i had it so can't confirm that.

 

[jbl590]

I wish I had time to read this rather colorful thread to find the answer I am looking for, but I don't.

Can someone tell me if you input via Bluetooth, does it output sound to the aux output so that subwoofer works with bt like it does with RCA?

I have an original a07 and another version of the a07 that has BT and it doesn't do that.

 

[T&T]

i find i can only put on my critical listening hat for short stretches. It gets unreliable otherwise. Once i come to some conclusion abt what i'm hearing i just switch the critical listening off and go enjoy the music.

Found that the LM4562 which you can order the A07 non-Pro with and which i did, is worth getting. The OPA1656, the ones i got which i think are genuine but i didn't buy them from a certified TI distributor, isn't all that different from it. Used in this A07 Pro amp, i hear a wider dynamic range with the OPA1656 and more emphasized treble with a little better detail, along with a more defined low bass. They're small if distinct differences that show up best at high sound volumes, not big differences.

Right now, when i'm just playing music to enjoy it, i can't swear to you that i hear any differences between them.

Neither of these op-amps will give you a tube amplifier sound. They're solid state neutral, don't introduce any harmonics as tubes will.

The AD827 seems to be a mixed bag. i've not been using them for a bit and don't have any conclusions abt them when plugged into this now broken in A07 Pro, because i haven't done it.

For a lovely, smooth and silky solid state sound from a cheap device, check out the Fosi Audio BT30D Pro. It's also a TPA3255 amp. It's a 2.1 amp with separate volume and frequency controls for a passive subwoofer. It's unusual in that it uses a second TPA3255 just to drive the sub. Didn't unscrew the heatsink when i had it so can't confirm that.

I have tried 5 opa1656 and lme49860 and my final decision on the cheap side... for op amp all dual to mono, at front 2 opa627 in the middle 2 opa2604 and at the back opa445bm ...surprise the opa1656 was not the winner in any position but is the best sounding in the non Pro 07 amp. I would said the most important are the 2 in the middle opa2604...2 opa627 in the front will improve about 8% and in the back 1 opa445bm will improve like 4%. I just get the opa1692 but I like better the opa2604 in the middle. I use the the Wiim Pro for tone control, the 07 Pro both controls at 12

 

[Sasquatch]

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.

Get 48V fan and solder it directly to DC input? It will run at 36V.
or
use additional 7812 connected to onboard 7812 regulator input to feed fan olny.
connecting it to onboard 12V will itroduce a lot of noise to OpAmp suppply.

The additional supply capacitance may take out the secondary smps' rectifier diodes at switch on, or pop the internal primary fuse rendering the supply dead. Unlikely, but possible, as the caps are essentially a short at switch-on of the SMPS.

If that happens it's for the best, any half decent smps will "tolerate" shorted output on power-on by simply curent limiting or switching off and restarting in 10-30 seconds.(even some el-chepo aliexpress ones)
It is important though to ALWAYS plug everything in BEFORE plugging smps to the mains

If D5 is a series polarity protection diode (most likely), you are losing voltage (Po) and that voltage drop (whatever it is) will vary as the current through diode increases. It could also be connected across the supply as polarity protection, but would short in that situation (a less likely implementation)

It looks like unipolar TVS to me smbj48A or similar... can't see the marking though.
.

 

[YesChickenNuggets]

Dear Scrufboy:

Going through the thread right now. What a roller coaster ride, from nonsense to mystery to theft to redemption back to nonsense. I can understand the frustration of other members, but the thread itself has been entertaining even if the science may only be half-baked.

Most audiophile banter is validating each other's snake oil anyway. Sinad has become as much an artifice of deceitful marketing as any measurement taken too far. I'm off that horse. Value is king, in that respect these products seem like home runs.

I must add Scrufboy, you should not glue copper slugs to the heatsink then to the regulator, increasing the interface distance like that can only make it worse not better. In this case, using regular silicone caulk or window seal is perfectly adequate for gluing the heatsink directly to the regulator. It's also easily removable later.

On my own A07 (non pro) I have a 4mm thermal pad above the heatsink fins that connects it to the top of the case to get the heat, out. This is the best and easiest method without drilling holes. My amp only gets slightly warm, I just did this for fun.

 

[Sasquatch]

Dear Scrufboy:

Going through the thread right now. What a roller coaster ride, from nonsense to mystery to theft to redemption back to nonsense. I can understand the frustration of other members, but the thread itself has been entertaining even if the science may only be half-baked.

Most audiophile banter is validating each other's snake oil anyway. Sinad has become as much an artifice of deceitful marketing as any measurement taken too far. I'm off that horse. Value is king, in that respect these products seem like home runs.

This is by far the least audiophile nonsense riddled audio forum I've read trough in years.
It's quite refreshing not seeing directional cables, hearing substation noise and other bull.s.h.i.t. in every other thread.

 

[YesChickenNuggets]

This is by far the least audiophile nonsense riddled audio forum I've read trough in years.
It's quite refreshing not seeing directional cables, hearing substation noise and other bull.s.h.i.t. in every other thread.

Of Course Sasquatch, I completely agree, we are the TRUE audiophiles, those other audiophiles are dog-sh**.

ASR Banzai !

 

[Joe Smith]

Dear Scrufboy:

Going through the thread right now. What a roller coaster ride, from nonsense to mystery to theft to redemption back to nonsense. I can understand the frustration of other members, but the thread itself has been entertaining even if the science may only be half-baked.

Most audiophile banter is validating each other's snake oil anyway. Sinad has become as much an artifice of deceitful marketing as any measurement taken too far. I'm off that horse. Value is king, in that respect these products seem like home runs.

I must add Scrufboy, you should not glue copper slugs to the heatsink then to the regulator, increasing the interface distance like that can only make it worse not better. In this case, using regular silicone caulk or window seal is perfectly adequate for gluing the heatsink directly to the regulator. It's also easily removable later.

On my own A07 (non pro) I have a 4mm thermal pad above the heatsink fins that connects it to the top of the case to get the heat, out. This is the best and easiest method without drilling holes. My amp only gets slightly warm, I just did this for fun.

Hey, YesChicken, where did you get the 4mm thermal pad from? I'd been thinking about such a thing as an approach to get more heat dispersion via the case, but hadn't done anything yet.

Something like this?

 

[YesChickenNuggets]

Hey, YesChicken, where did you get the 4mm thermal pad from? I'd been thinking about such a thing as an approach to get more heat dispersion via the case, but hadn't done anything yet.

Something like this?

At 4mm, the difference between the highest quality, fujipoly, and the cheapest blue/grey generic pads are minimal. I recommend whatever is cheapest in your locale. Don't overspend $.

This methodology of putting pads ontop of heatsinks is sound because the contact area added together above the fins is significantly larger than that of the chip's area in contact with the heatsink itself.

To save money in the future, you can also buy bulk 2mm and 1.5mm pads and stack them to account for different heights. If you need more than 7-8mm, use a metal slug spacer, it can be scrap metal, makes very little difference.

 

[T&T]

Hey, YesChicken, where did you get the 4mm thermal pad from? I'd been thinking about such a thing as an approach to get more heat dispersion via the case, but hadn't done anything yet.

Something like this?

I just get that pad is fine for the 07 non Pro, for the 07 Pro the cover in the back is raised like 2 mm and, I will not put pressure to close so, I will let the heat works. For the 07 Pro 3 mm I think is better.

 

[Joe Smith]

I just get that pad is fine for the 07 non Pro, for the 07 Pro the cover in the back is raised like 2 mm and, I will not put pressure to close so, I will let the heat works. For the 07 Pro 3 mm I think is better.

I got the same 4 mm pad yesterday. Cut to fit and installed in the "regular" A07. I did have to put a slight pressure on the case top to screw it back together. Have not used yet, though.

 

[T&T]

I got the same 4 mm pad yesterday. Cut to fit and installed in the "regular" A07. I did have to put a slight pressure on the case top to screw it back together. Have not used yet, though.

I use a pen and rolled to squeeze it on the top case, now the whole case get hot...really hot, so I am debating is leaving the cover out while playing and use my ceiling fan will be better... now sure...time will said

 

[grogi.giant]

I use a pen and rolled to squeeze it on the top case, now the whole case get hot...really hot, so I am debating is leaving the cover out while playing and use my ceiling fan will be better... now sure...time will said

If it is hot, the improved heat conductive solution is working.

 

[jokan]

In reply... TLDR... The "Thread-Ender"

XLR's have nothing to do with the purpose and use of tone controls. And in regards to the A07 and A07 pro, neither of these units have XLR input so the statement is just irrelevant. Did the A07 Pro need tone controls? Not really. But Aiyima sells these units to make money. They obviously decided to reach a wider audience and it really feels geared toward a mobile audience if you ask me. But even then the Bluetooth is a poor implementation because it lacks LDAC. So we do agree... "Pro" is just a word tacked on to a "not-so-pro" unit.

Your statement about "it"not being unthinkable to see A07 and A07 Pro...

Being unthinkable is not the issue. Of course it isn't unthinkable, but it is not practical, leads to confusion and should be discouraged.

Separate, dedicated forum threads for separate discussions on different items is necessary to keep the confusion down and to lead readers down clear, concise paths that can lead to well informed decisions.

This why we see Amir make separate forum posts for each piece of gear he reviews. This is also why those who follow and respond to those posts don't toss other gear into the discussion unless it is being brought up to show clear distinction and differences. But even then, users tend to link to these other discussions.

I am the OP of this post. I have asked people from refraining from talking about the A07 in this thread. So it doesn't matter if you think it isn't unthinkable. It is not proper nettiquette. So don't do it. Take your A07 discussion to a dedicated A07 thread. Simple.

You yourself said that you didn't even notice the "Pro" in the title. So that doesn't jive with your claim that it should be OK to mix it up. It's just you rationalizing your lack of attention to detail. Fix that instead of rationalizing it.

NOTE: THIS FORUM THREAD is NOT a REVIEW POST. The word "review" is not in the title and I have been very clear on the focus of this thread. This is moreover an "announcement" & "reveal" thread. Solely for bringing the unit to the attention of the community members. There are far better, more capable people here that could give us informative reviews. I'm not that guy.

My unit was purchased specifically for testing and for working with SparkosLabs. This has been posted clearly.

The pictures are here for those interested in seeing the changes.

As far as how it sounds... Again, this is NOT a review post.

How it sounds isn't the right question really anyway. How things sound is quite subjective. One person may like a warm sounding amp and hate distinctly analytical sounding amps and vice versa. Some people don't have trained ears, some do... Some people have terrible ears. Some people hear name brands and suffer from the placebo effect.

If I say it sounds good... That doesn't mean anything. If I say it sounds amazing... Compared to what? If you want to know how it sounds, wait for a review post or buy one and find out for yourself. Chances are still high that the general public knows nothing about this unit.

Even when Amir recommended the A07 originally, I trusted his measurements and he told us it sounds good to him.He gave us the good, the bad and the ugly. I watched a few other reviews... But ultimately, I still had to buy one and find out for myself. It definitely sounded better than what I had. Even then though, it still needed improvement to be sure.

In the realm of how it sounds... Remember, I have my own chain of components, particular speakers and a room/headphones that contribute to my experience. I don't have an A/B testing rig setup. I don't have a way to easily dismantle my setup to swap out the amps.

I, like you am quite satisfied with my A07. I have a modified and upgraded version with discrete op-amps from SparkosLabs, a modified case for convective cooling. A customized power supply, custom power cables and interconnects.

My only goal in purchasing this "Pro" unit was to have it torn down, components shown to the community, have it possibly tested by Amir and/or to work on the sound signature with some op-amp rolling by working exclusively with Andrew of SparkosLabs.

I leave the reviewing to others, specifically Amir and the select few that grace us with their input.

I do agree... That this "Pro" offering is not a pro offering at all though.

They could have simply given us a better input and output implementation. A more robust voltage regulator. better caps in both the power handling and the audio areas, better inductors and a properly vented case. I did post in another dedicated A07 thread that for what it was, at the price point, based on several people being involved with reviewing the A07, that it was nearly perfect. This thread specifically covered what I felt the A07 needed... Several members chimed in and contributed.

Aiyima had previously polled this community and asked what we would like to see in a "Pro" A07 unit. Aiyima didn't really listen. Nobody wanted Bluetooth and nobody wanted tone controls. At least that was what I saw as the concensus.

So as the OP, let's stay on topic. This is not a Review of the A07 "Pro" and for the most part... This thread is closed as I have accomplished what I set out to do.
Announce, Acquire, Show internals....

The next step is pass it off to Amir if he has not received one direct from Aiyima AND/OR proceed with op-amp testing with Andrew of SparkosLabs. 5 op-amps is quite a lot though... What swapping will do and in what combinations will be beneficial remains to be seen and the process will not be simple. We can all agree that at $80 per op-amp for a single Sparkos dual-discrete op-amp is a lot of cash.. That's $400 USD and one must ask... Will this be a better course? Will it be a waste? Why not just buy a $500 Amp?

I personally believe that there will definitely be diminishing returns. I would though be interested in how these op-amp swaps can possibly help with the SNR issues. But until Amir measures this Amp, I won't have a clear path on how to proceed. And even then.. Perhaps it should also be measured with a wide variety of op-amp combinations. Holy crap it's 5 op-amps! Am I right?

When an Aiyima A07 "PRO" review post shows up... That will effectively be the place for further discussion.

Thanks to everyone who stayed on topic, I hope in the coming days we have a nice set of real world data and options laid before us.

I am extremely curious as to how this amplifier sounds. Is it musical or is it like listening to old school class D amplifiers.
I second your opinion with not comparing the A07 and not the "Pro" iteration.
SNR is a great guideline but it doesn't always collerate to how the device sounds. I'm sure there will be updates in the future, if not I'm just going to buy the first production run. It looks interesting enough. I wish we could know which op-amps are for the tone control and which are not.
In my experience the op-amps for tone control are adequate enough.

I hope we get some real answers soon. Thanks OP for your post!

 

[YesChickenNuggets]

I just get that pad is fine for the 07 non Pro, for the 07 Pro the cover in the back is raised like 2 mm and, I will not put pressure to close so, I will let the heat works. For the 07 Pro 3 mm I think is better.

I use a pen and rolled to squeeze it on the top case, now the whole case get hot...really hot, so I am debating is leaving the cover out while playing and use my ceiling fan will be better... now sure...time will said

I used 4mm because this stuff softens and mushes down overtime.

The more it Mushes into the heatsink fins, the LARGER the contact area, it's now more intimately hugging all around the top of the fins. 3mm should be enough, but a little pressure is good to ensure contact.

Just for fun, completely unnecessary, I also spread some thermal compound on the edges of the case where the top and bottom clam shell kisses. Then after closing it, I wipe the side clean.

If you want to go Balls -> Walls. To also touch the bottom clam shell, there's the bicycle trick, measure out however much pad is needed to reach the bottom clam shell from below the PCB where the chip is. Put the pad onto the pcb, THEN, wet the bottom of it and the top of the bottom clamshell slightly with isopropyl. You should now be able to SLIDE the PCB onto the case even with the pad, which you wouldn't be able to do easily without the alcohol. The alcohol will dry on its own, and you'll have perfect contact.

Make sure the board and clam shell are held in orientations where the alcohol won't drip/roll into the electrical. give it a few hours to dry.

This method is used to put on rubber handle bar covers on bicycles.

If it is hot, the improved heat conductive solution is working.

Indeed my dude, that's how we know we are getting the 1.21 jigawatts out.

 

[grogi.giant]

Indeed my dude, that's how we know we are getting the 1.21 jigawatts out.

Jigawatt - that must be some of the star wars unit...

I'd like to remind you this forum is called 'audio SCIENCE review'. Stick to scientific units, even when your mocking....

 

[YesChickenNuggets]

Jigawatt - that must be some of the star wars unit...

I'd like to remind you this forum is called 'audio SCIENCE review'. Stick to scientific units, even when your mocking....

grogi, have you not seen Back to the Future? You need to watch it right away.

 

[Bellboy718]

I wish I had time to read this rather colorful thread to find the answer I am looking for, but I don't.

Can someone tell me if you input via Bluetooth, does it output sound to the aux output so that subwoofer works with bt like it does with RCA?

I have an original a07 and another version of the a07 that has BT and it doesn't do that.

I wish I had time to read this rather colorful thread to find the answer I am looking for, but I don't.

Can someone tell me if you input via Bluetooth, does it output sound to the aux output so that subwoofer works with bt like it does with RCA?

I have an original a07 and another version of the a07 that has BT and it doesn't do that.

I have the A07 pro and I used the aux out to another amps line in. I the rca on the a07 is an input. I hope this helps.

 

[Toku]

The A07 Pro's AUX output is simply connected in parallel with the RCA input.
Please understand the structure before using.
With such a structure, AUX can also be used as an input. In that case, it cannot be used simultaneously with RCA.

 

[Bellboy718]

The A07 Pro's AUX output is simply connected in parallel with the RCA input.
Please understand the structure before using.
With such a structure, AUX can also be used as an input. In that case, it cannot be used simultaneously with RCA.

I will test this and see what happens.