• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Aiyima A07 Max - Aiyima's new TPA3255 amplifier with mono/stereo output

Guddu

Addicted to Fun and Learning
Joined
Feb 10, 2020
Messages
937
Likes
847
It appears like the new Aiyima A07 MAX has made out to AliExpress: https://www.aliexpress.us/item/3256805898598328.html?gatewayAdapt=glo2usa4itemAdapt

It looks nicely build with quality components with additional feature than others.
- It has vent holes at the bottom plate for cooling. No vents on the top which probably makes more sense.
- They are showing quality components
- For me, Star of the show is Mono/Stereo selectable option

* Full internal PCB pictures aren't available yet.

It's available on AliExpress at the moment only, not on Aiyima US store or Amazon US yet.
Currently available for:
Approx. 62$, after discounts, amp only
Approx. 85$, after current discounts, with 36v PSU
Approx. 91$, after current discounts, with 48v PSU
================
From AliExpress:
Specs:
Stereo Max Output Power(switch stereo mode):300Wx2 / 4Ω(48V/12A)
Mono Max Output Power(switch mono mode):600W/ 2Ω(48V/12A)
(R+ connect to speaker +, L+ connect to speaker -)

Working Voltage:DC24-48V,5A or more
Replaceable Op-Amp Chips:OPA2604AP, OPA2134, MUSEO1/02/03, LME49720NA, LM4562, AD827AQ, etc
AUX OUT: active subwoofer or power amplifier
3.5mm AUX OUT as output connect to next amplifier without volume control >>>> So, no volume control to AUX/Pre out
THD:0.007%
SNR:≥110dB
Input sensitivity:1V >>>> Should it not be around 2V?
AUX Maximum Output level:1V >>>> Should it not be around 2V?


1695909098559.png

index.php

1695909153783.png


1695909181191.png

1695909207366.png
 
Last edited:

TonyJZX

Major Contributor
Joined
Aug 20, 2021
Messages
2,067
Likes
2,003
is there a 48v 12a psu out there???

let us take bets on what this thing does with the 48v 5a psu in stereo and monoblock

interesting time to be alive if you're into TPA3255 with Fosi about to release new stuff
 

TonyJZX

Major Contributor
Joined
Aug 20, 2021
Messages
2,067
Likes
2,003
 
OP
Guddu

Guddu

Addicted to Fun and Learning
Joined
Feb 10, 2020
Messages
937
Likes
847
is there a 48v 12a psu out there???

let us take bets on what this thing does with the 48v 5a psu in stereo and monoblock

interesting time to be alive if you're into TPA3255 with Fosi about to release new stuff

48v option PSU is 5a.
 

Ron Texas

Master Contributor
Forum Donor
Joined
Jun 10, 2018
Messages
6,376
Likes
9,547
Are those power ratings 1% THD or 10% THD. Also, I'm a bit skeptical about the 48V 10A PSU. It might deliver increased power briefly, but I doubt the amplifier could deal with the heat. Getting rid of the load dependency is a big deal.
 
OP
Guddu

Guddu

Addicted to Fun and Learning
Joined
Feb 10, 2020
Messages
937
Likes
847
Are those power ratings 1% THD or 10% THD. Also, I'm a bit skeptical about the 48V 10A PSU. It might deliver increased power briefly, but I doubt the amplifier could deal with the heat. Getting rid of the load dependency is a big deal.

Totally agree with this.
For our own safety, 40v 5a PSU is better and it surely can provide enough power w.r.t. chip's abilities.

Mono/Stereo switch + load independence make it better than any other available 3255 amp at the moment, provided it measures similar or better than A07/A07 pro.
 

BeQuietZen

Member
Joined
Sep 15, 2022
Messages
25
Likes
67
There's some improvements compered to the old A07 like better cooling, mono option, substantial speaker terminals and higher quality parts. Still not "perfect" or best in class IMHO.

- Using 2200uF / 50V cap for filtering with 48V PSU is plain wrong! Fosi in their V3 amp uses two 2200uF / 63V and that is minimum voltage from safety and reliability point.

- Wima block capacitors in the output filter are 63V with 10% tolerance ("K" grade). In Fosi V3 we get 100V version with 5% tolerance ("J" grade). Both are far from ideal like some high pulse polypropylene caps (Kemet PHE426 comes to mind).

- We don't know the type of potentiometer used (Taper A or linear) and the overall amp gain. Everything matters...

- Their own THD measurements are about 0.0075%, roughly double or more compered with Fosi v3 (0.003%).

- We don't know if it's load independent or not. Maybe we just see 4 Ohm load, and not 8 Ohm with 20 KHz bandwidth. We get almost similar result with Fosi V3 if we ignore 8 Ohm plot.

3 Fosi Audio V3 stereo amplifier budget Frequency Response measurement.png


Independent measurements from @amirm and pictures from the real finished product will dispel all the unknowns.
 
OP
Guddu

Guddu

Addicted to Fun and Learning
Joined
Feb 10, 2020
Messages
937
Likes
847
There's some improvements compered to the old A07 like better cooling, mono option, substantial speaker terminals and higher quality parts. Still not "perfect" or best in class IMHO.

- Using 2200uF / 50V cap for filtering with 48V PSU is plain wrong! Fosi in their V3 amp uses two 2200uF / 63V and that is minimum voltage from safety and reliability point.

- Wima block capacitors in the output filter are 63V with 10% tolerance ("K" grade). In Fosi V3 we get 100V version with 5% tolerance ("J" grade). Both are far from ideal like some high pulse polypropylene caps (Kemet PHE426 comes to mind).

- We don't know the type of potentiometer used (Taper A or linear) and the overall amp gain. Everything matters...

- Their own THD measurements are about 0.0075%, roughly double or more compered with Fosi v3 (0.003%).

- We don't know if it's load independent or not. Maybe we just see 4 Ohm load, and not 8 Ohm with 20 KHz bandwidth. We get almost similar result with Fosi V3 if we ignore 8 Ohm plot.

View attachment 315423

Independent measurements from @amirm and pictures from the real finished product will dispel all the unknowns.

We surely need ASR review for this one to compare it against.
TBH, I don't know if they need bigger/higher caps or anything else as log as it operates well and how it is suppose to be.

But in general, I find it more useful than Fosi v3. Fosi may be coming up with monoblocks as well soon though.
For my wanting list - Decent amplifier with Balanced design, mono/stereo and volume/tone bypass.
 

Toku

Major Contributor
Joined
Apr 4, 2018
Messages
2,449
Likes
2,853
Location
Japan
It seems to be a product that is strongly inspired by Fosi V3 from the body color and design.
Adding a monaural mode expands the range of applications, but switching modes using relays can generate loud pop noises and damage speakers if the protection circuit is not adequate. This makes me a little worried.
Also, as always, a 50V capacitor is used for the 48V power supply voltage, which is a technically impossible design.
From the description, it seems that the wrong taper B is still being used for the volume pot.
 
OP
Guddu

Guddu

Addicted to Fun and Learning
Joined
Feb 10, 2020
Messages
937
Likes
847
It seems to be a product that is strongly inspired by Fosi V3 from the body color and design.
Adding a monaural mode expands the range of applications, but switching modes using relays can generate loud pop noises and damage speakers if the protection circuit is not adequate. This makes me a little worried.
Also, as always, a 50V capacitor is used for the 48V power supply voltage, which is a technically impossible design.
From the description, it seems that the wrong taper B is still being used for the volume pot.
Can you please explain more on 63v cap requirements? What issues do you expect with 50v?
I am going to order one unit tomorrow and will see how well mono/stereo function in practice.
 

Kevinfc

Active Member
Joined
May 6, 2021
Messages
221
Likes
210
Now add balanced inputs and it will be finished for around $100.
 

voodooless

Grand Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
10,533
Likes
18,604
Location
Netherlands
Can you please explain more on 63v cap requirements? What issues do you expect with 50v?
I am going to order one unit tomorrow and will see how well mono/stereo function in practice.
Capacitor voltage ratings should always include a safety margin. Sensible is at least 20%. So in case of an 48V supply, the next best thing is 63V (57V minimum). 50V caps is too low of a margin.

Possibly they upgrade the caps if you go for the 48V supply? We’ll know as soon as somebody opens it up..
 

Talisman

Major Contributor
Forum Donor
Joined
Mar 27, 2022
Messages
1,006
Likes
2,973
Location
Milano Italy
Looks like the new leader in value priced 3255’s.
Based on what?
to me it seems like a clone of fosi v3, released in a hurry after the great success of v3.
We have a detailed review of the FOSI with accurate measurements, we still know nothing about this apart from the specifications provided by the company and some dubious values on the capacitors used.
I would at least wait for an ASR review before making this type of evaluation
 

Toku

Major Contributor
Joined
Apr 4, 2018
Messages
2,449
Likes
2,853
Location
Japan
Can you please explain more on 63v cap requirements? What issues do you expect with 50v?
I am going to order one unit tomorrow and will see how well mono/stereo function in practice.
Electrolytic capacitors used in electronic circuits are sensitive to ambient temperature and vulnerable to overvoltage.
Therefore, it has long been common knowledge for circuit designers to use electrolytic capacitors at a voltage of 70% or less of their rated voltage.
Even with today's technologically advanced products, it is necessary to use them with a certain degree of leeway. I think it is desirable to use even consumer equipment at at least 80% of the rated voltage.
If it is a 50V capacitor, I think it should be used at 40V or less. For a 48V supply voltage, you should use a 63V rated capacitor. Also, in the case of small Class D amplifiers, they are often installed right next to the heat sink, creating a thermally harsh environment for electrolytic capacitors. Naturally, deterioration will continue.
Using a 50V capacitor on a 48V power supply has the risk of explosion due to the slightest accident in the circuit.
I have experienced explosions of electrolytic capacitors, but cleaning up afterwards is very troublesome.
Electrolytic capacitors are always equipped with a safety valve to keep explosions to a minimum. Small electrolytic capacitors have an X mark on the top. If it is a large block capacitor, there will be a small round hole next to the terminal. Those are the safety valves.
 
Top Bottom