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Aiyima A07 class D venture

Gaspar74

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Sorry to dig up old thread. I just acquired one of these Class D amps. My second venture into class D in a few years. Wasn’t impressed couple years ago with offerings. So then I’d seen reviews and talk of this new TI Chipset and it sounding excellent and rivaling much more expensive amps even class A/B. Ordered Aiyima A07 from Amazon and came with 32v 5amp.
Quite impressed with sound I’m getting from this. It’s on par or better than some other Amps I have had or even have now for loooot less.
So I am wondering if this power supply I picked up cheap on eBay will be a good match.

It’s 50v 5amp switching supply used in telecommunications.

Innovative Circuit - ICT12048-5A - Comm Series 120VAC - 48VDC / 5 Amp Power Supply.​

“High efficiency switchmode design for small size and clean output power- Extra input and output filtering effectively removes interference- Isolated outputs are compatible with negative or positive ground equipment- Automatic current limiting protects power supply and connected loads- Built-in fuse for extra protectionDEPENDABILITY- All ICT power products are manufactured in North America- Our deliveries are typically measured in days, not weeks- All ICT products are supported by our in-house engineering teamFLEXIBILITY- Wide selection from 50 to 720 watts of power- 12, 24 and 48VDC outputs”

I’ve been using to power with stock 32v a set of Elac Unifi UB5 which aren’t easy to drive. It drives them pretty good.

Would this supply be a good match?
 

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Doodski

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Sorry to dig up old thread. I just acquired one of these Class D amps. My second venture into class D in a few years. Wasn’t impressed couple years ago with offerings. So then I’d seen reviews and talk of this new TI Chipset and it sounding excellent and rivaling much more expensive amps even class A/B. Ordered Aiyima A07 from Amazon and came with 32v 5amp.
Quite impressed with sound I’m getting from this. It’s on par or better than some other Amps I have had or even have now for loooot less.
So I am wondering if this power supply I picked up cheap on eBay will be a good match.

It’s 50v 5amp switching supply used in telecommunications.

Innovative Circuit - ICT12048-5A - Comm Series 120VAC - 48VDC / 5 Amp Power Supply.​

“High efficiency switchmode design for small size and clean output power- Extra input and output filtering effectively removes interference- Isolated outputs are compatible with negative or positive ground equipment- Automatic current limiting protects power supply and connected loads- Built-in fuse for extra protectionDEPENDABILITY- All ICT power products are manufactured in North America- Our deliveries are typically measured in days, not weeks- All ICT products are supported by our in-house engineering teamFLEXIBILITY- Wide selection from 50 to 720 watts of power- 12, 24 and 48VDC outputs”

I’ve been using to power with stock 32v a set of Elac Unifi UB5 which aren’t easy to drive. It drives them pretty good.

Would this supply be a good match?
Yes, that power supply should be a good match and supersized as per this review at ASR and these results into 4 Ohms and 8 Ohms. You will have more power output than these test results due to your new power supply having more current output at full power output.
index.php

index.php

Max output power dependent on power supply used.>
aiyima a07.png
 

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Gaspar74

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I opened my unit up and it has the 50v caps. This supply Is 48v +|-150mv so it’s tight tolerance. Can anyone confirm it being safe at that. Not sure if I can turn this supply down some. I’ll know once I get it. I scored it for cheap money so. Also have some orig
OPA2134 I plan on trying out. I know the topic of OP amp rolling here is a non starter but in other gear I’ve changed op amps there was a noticeable difference. Either good or bad but always could tell. I’m using my Yamaha CA1000 at moment as pre Amp
 

Doodski

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I opened my unit up and it has the 50v caps. This supply Is 48v +|-150mv so it’s tight tolerance. Can anyone confirm it being safe at that. Not sure if I can turn this supply down some. I’ll know once I get it.
It will be OK to operate up to 50VDC. It will put added strain on the caps compared to say a 35VDC power supply but the caps are rated to 50VDC so no worries. Yes, those power supplies sometimes have a voltage adjustment.
OPA2134 I plan on trying out. I know the topic of OP amp rolling here is a non starter but in other gear I’ve changed op amps there was a noticeable difference. Either good or bad but always could tell.
Op amp rolling is good practice for working a PCB, reading technical electronics literature and stuff so enjoy! After you are done with OP amp rolling you can move onto more sophisticated electronics stuff and have that as a basis to work from. :D
 
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Gaspar74

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Ill need to make a DC power cable any suggestions? Im guessing something can handle higher current be good.
 

Doodski

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Ill need to make a DC power cable any suggestions? Im guessing something can handle higher current be good.
Ensure it has a sufficient gauge and good high temp dielectric so if something goes south the plastic does not melt and the wires short out and cause a fire. TPFE dielectric is good as is some of the rubberized and silicon type dielectrics.
 
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Gaspar74

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Any suggestions. I do have a lead with same barrel jack connector already on from one my linear power supplies. The cable is pretty robust but after opening it up The gauge is very thin. I’m thinking like 22 gauge or thinner. Amazon has some pig tail leads 16awg with the dc barrel jack connected. I’m thinking it’s 5.5mm x 2.1. I’m thinking this should be suffice.
 

Tangband

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Sorry to dig up old thread. I just acquired one of these Class D amps. My second venture into class D in a few years. Wasn’t impressed couple years ago with offerings. So then I’d seen reviews and talk of this new TI Chipset and it sounding excellent and rivaling much more expensive amps even class A/B. Ordered Aiyima A07 from Amazon and came with 32v 5amp.
Quite impressed with sound I’m getting from this. It’s on par or better than some other Amps I have had or even have now for loooot less.
So I am wondering if this power supply I picked up cheap on eBay will be a good match.

It’s 50v 5amp switching supply used in telecommunications.

Innovative Circuit - ICT12048-5A - Comm Series 120VAC - 48VDC / 5 Amp Power Supply.​

“High efficiency switchmode design for small size and clean output power- Extra input and output filtering effectively removes interference- Isolated outputs are compatible with negative or positive ground equipment- Automatic current limiting protects power supply and connected loads- Built-in fuse for extra protectionDEPENDABILITY- All ICT power products are manufactured in North America- Our deliveries are typically measured in days, not weeks- All ICT products are supported by our in-house engineering teamFLEXIBILITY- Wide selection from 50 to 720 watts of power- 12, 24 and 48VDC outputs”

I’ve been using to power with stock 32v a set of Elac Unifi UB5 which aren’t easy to drive. It drives them pretty good.

Would this supply be a good match?
I would say :

1. Its not safe to drive the amplifier with 48 V when the power caps are 50 V . 36 V-42 V is the sweet sounding spot for this amplifier, where it also have some headroom for driving lower impedances. You should have at least 5 V margin to the 50 V rated power caps if the amplifier should be safe for more than one year.

2. With my two Aiyima a04 and one Aiyima a07 , I have tried 4 different IC:s and the one that gained the best sound, at least for me, was the LM4562. Better sound than opa 2134 and better than opa1612. The stock 5532 is not a fake one ( we have measured it in the Swedish forum faktiskt.io - it was my amplifier ) , but I would say anyway there is a slightly sound improvement with lm4562. It also measures slightly better as PMA have shown . Audiophonics is a good dealer to buy from, as I did.

3. The power supply you have mentioned is rated 5 A - its not enough. A 36 V - 8 A would be better If your speakers are hard to drive. This is also about the same as the inbuilt power supply in the more expensive Aiyima a08 - 36 V , 9,6 A.
 
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Doodski

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3. The power supply you have mentioned is rated 5 A - its not enough. A 36 V 6-8 A would be better If your speakers are hard to drive.
When the amp is driven to max output with either the 36V 6-8A or the 48V 5A the end result is about the same power output because of the loosely regulate power supplies this device is using and the difference in the voltage versus current when the power supply is loaded down. If the owner really wants to get max power output then the 48V 10A power supply is required. It won't hurt the 50V DC capacitors.
 

Tangband

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When the amp is driven to max output with either the 36V 6-8A or the 48V 5A the end result is about the same power output because of the loosely regulate power supplies this device is using and the difference in the voltage versus current when the power supply is loaded down. If the owner really wants to get max power output then the 48V 10A power supply is required. It won't hurt the 50V DC capacitors.
Agree that he need more amperes. Its a single regulated power supply driving two current hungry loudspeakers.
One often see measurements on this small amps with only one channel measured. If rated only 5 A , its gonna suffer with two low impedance speakers. A 48 V 10 A power supply will be more expensive than the amplifier.

He should try both power supplies he have, and listen to see If there is any gain in sound quality.
 
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Gaspar74

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Thinking cancelling and getting a 48v Drok adjustable. Or a 36v 11 amp
 

Doodski

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Thinking cancelling and getting a 48v Drok adjustable. Or a 36v 11 amp
This one?
 
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Gaspar74

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Gaspar74

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Well I received the 48V 5amp and it definately improved sound output, more power more dynamics, doesnt even appear to be hot, albeit just feeling top of case that is. Its a very clean low noise supply so it claims 40mv max ripple. For the low cost, I tihnk Ill keep it as its plenty loud enough for me as I dont play at bleeding ear levels lol. Im old ha
 

dr_mick51

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I'm not sure if people understand how much power they really need. Please measure average or max voltage at the speaker outputs. P=V^2/R. Or if you have a clamp meter then measure the current on the positive cable. Then P=I^2*R. Or if you measure both, then P=V*I. You will be amazed by how little power you need.
A 1A 36V power supply is enough even considering losses due to heat. Don't bother with bigger power supplies.
What you need is a cleaner power supply with very low ripple and noise.. you can achieve this by using smooth capacitors in parallel to the output(a big Electrolytic one, of 1000uF and two film capacitors, one of 1-2uF and the other 0.1uF)
 

Tangband

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I'm not sure if people understand how much power they really need. Please measure average or max voltage at the speaker outputs. P=V^2/R. Or if you have a clamp meter then measure the current on the positive cable. Then P=I^2*R. Or if you measure both, then P=V*I. You will be amazed by how little power you need.
A 1A 36V power supply is enough even considering losses due to heat. Don't bother with bigger power supplies.
What you need is a cleaner power supply with very low ripple and noise.. you can achieve this by using smooth capacitors in parallel to the output(a big Electrolytic one, of 1000uF and two film capacitors, one of 1-2uF and the other 0.1uF)
Amirms measurements ( done with only one channel ) shows there is current clipping before voltage clipping at a certain point if there is not enough current when drivning 4 ohm speakers. In real life, there is always two loudspeakers connected making this problem 100% worse. A single power supply that just enough for one loudspeaker regarding current, ( maybe 3 A ) needs twice the amount of current with two loudspeakers ( maybe 6A ).

I agree that people who listen at 80 dB average sound level ( most people do, I believe ) , and uses normal loudspeakers, dont need much more than 20 watts / channel. A cleaner power supply may sound better and may not pollute the mains and other units with HF .
 
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dr_mick51

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Amirms measurements ( done with only one channel ) shows there is current clipping before voltage clipping at a certain point if there is not enough current when drivning 4 ohm speakers. In real life, there is always two loudspeakers connected making this problem 100% worse. A single power supply that just enough for one loudspeaker regarding current, ( maybe 3 A ) needs twice the amount of current with two loudspeakers ( maybe 6A ).

I agree that people who listen at 80 dB average sound level ( most people do, I believe ) , and uses normal loudspeakers, dont need much more than 20 watts / channel.
Again. Have you measured how much power you use during your listening sessions?. People who listen at 80db need less than a watt per channel. I, during my listening sessions need 50mA per channel. That's 20mW per channel. Now add some headroom for dynamic range x 10. That means 2w maximum per channel.
I really welcome people to do their own measurements and realize they don't need as much power as they believe.
Again , it's about clean power not raw power.
 

Synrgy87

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With my A07 i was using a 24v 4amp supply since changed to a 48v 12.5amp being fed by 240v mains (live neutral earth all connected), The A07 does get a lot warmer with the bigger power supply.

Inside it I've upgraded the op-amps to Burson v5i-Ds (same as I used in my DAC-X6) I've also replaced the thermal compound for the amp chip, and changed all of the capacitors, all now 105c rated, the two larger 1000uf 50v caps were changed to some Rubycons although a different profile that keeps a bit more space between the caps and the heatsink, changed all of the other electrolytics, panasonic/rubycon 105c rated.

For the poly caps I thought I'd experiment with some old stock, physically larger ITT 1uf 100v and some old stock philips 250v 1500nf 5% axials.

More of a fun project than anything, What i may still do is put on some different binding posts / RCA connectors, change the 1uf 100v to some WIMA 1uf 250v and also change the 1000uf 50v caps to something higher rated, also considering adding a fan and some vent holes, Volume pot may also be worth looking at but I've not had any problems with mine seems to work well so I've left that alone. How much difference any of this makes well ymmv, I've taken no measurements other than listening and voltages etc via multimeter, Power supply made the most difference but as stated I was using a 24v rather than the usual 32/36v then jumped right up to the 48v.

Note: When I purchased my A07 it is not Aiyima branded, only has "power" and "volume" labels internally though it seems identical. The AUX jack at the back of the unit has left/right reversed but i don't use that, could be fixed though without too much trouble.
 
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