Yup...I just sat there listening to his amp with LLC PSU and just kept saying “Wow!” It’s like the amp doesn’t get in the way of the music/recording.
Pete
Every time I listen to my playlist on this amp, I get the goosebumps, and I'm serious! I compared this amp to amps that are worth ten times its price! Verdict, this little DrMordor is exceptional in every way! Devouring musicality, incredible sound reproduction across the entire spectrum, bass deeper than my Hypex Ncore, and finally the best for last: an absolutely sublime soundstage !
I am also in the process of getting a new Purifi dual mono amp with a custom Buffer, it will be available by end of December. It will be the best basis to compare, the Purifi do not lie)
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I finally got to the environment where I could test the two Infineon MA12070 amp boards I bought on Aliexpress the other day, and immediately listened to the sound.
The amp setting is the default BTL 2CH. The power supply uses 26V / 10A. Connect Topping E30 and SMSL M500 to the input source.
The push button type connection terminal used in this machine is very difficult for me with thick fingers.
For the time being, I compared the sound quality while switching between the 3e audio TPA3255 amplifier board and the SMSL SA300, but I don't feel a big difference. The amp gain is lower than the 3e audio unit. Perhaps because of this, the noise when there is no input signal is so quiet that you can hardly feel it even if you attach your ear to the speaker.
As for pop noise when the power is turned on / off, a large pulse noise appears for a moment when the power is turned on. The noise sounds like an electric spark. On the contrary, there is no pop noise when the power is turned off.
I've been testing it 24 hours a day with the power on, and I don't feel the heat when I touch the heatsink. The heat generated by this amp is really low.
Input is unbalanced connection with RCA, R-ch is connected to IN0A-GNG, Lch is connected to IN1A-GND. The unused IN0B and IN1B are directly connected to GND. If IN0B and IN1B are not connected to GND, a large noise will be generated.
Also, when the SMSL M500 is connected to the input, noise is added to the signal and distortion is felt. It is normal when the Topping E30 is connected. Is there a problem with how the inputs are connected? I haven't tried balanced connection yet.
These symptoms were exactly the same for the two units I purchased.
The amp setting is the default BTL 2CH. The power supply uses 26V / 10A. Connect Topping E30 and SMSL M500 to the input source.
The push button type connection terminal used in this machine is very difficult for me with thick fingers.
For the time being, I compared the sound quality while switching between the 3e audio TPA3255 amplifier board and the SMSL SA300, but I don't feel a big difference. The amp gain is lower than the 3e audio unit. Perhaps because of this, the noise when there is no input signal is so quiet that you can hardly feel it even if you attach your ear to the speaker.
As for pop noise when the power is turned on / off, a large pulse noise appears for a moment when the power is turned on. The noise sounds like an electric spark. On the contrary, there is no pop noise when the power is turned off.
I've been testing it 24 hours a day with the power on, and I don't feel the heat when I touch the heatsink. The heat generated by this amp is really low.
Input is unbalanced connection with RCA, R-ch is connected to IN0A-GNG, Lch is connected to IN1A-GND. The unused IN0B and IN1B are directly connected to GND. If IN0B and IN1B are not connected to GND, a large noise will be generated.
Also, when the SMSL M500 is connected to the input, noise is added to the signal and distortion is felt. It is normal when the Topping E30 is connected. Is there a problem with how the inputs are connected? I haven't tried balanced connection yet.
These symptoms were exactly the same for the two units I purchased.
At first I was disappointed with this pop noise.
After that, when I connected the MUTE terminal of the connector to the ground and turned on the power, I found that there was no pop noise.
This amp board does not come with a manual or schematic, but it has almost the same configuration as Infineon's MA12070 reference board,
and I think it is a copy product. Therefore, I refer to the manual of MA12070 reference board.
This amp board uses a multi-layer ceramic capacitor for the audio signal coupling capacitor, so I was worried about the sound quality,
but it doesn't seem to be a problem.
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Yes, the Enable pin is connected to GND in the PC board by default and will not work out of the box.
The Mute pin is pulled up to +5V and works if connected to GND.
I'm going to test connecting the Mute pin to GND with a small capacitor and connecting it to GND with charging current only for a moment when the power is turned on.
@Toku,
Pardon me, i don't really understand this:
"Yes, the Enable pin is connected to GND in the PC board by default and will not work out of the box."
Can you please explain further on the comment that it will not work out of the box ?
I have received my 2 boards from Aliexpress too and hope to overcome the pop noise.
Pardon me, i don't really understand this:
"Yes, the Enable pin is connected to GND in the PC board by default and will not work out of the box."
Can you please explain further on the comment that it will not work out of the box ?
I have received my 2 boards from Aliexpress too and hope to overcome the pop noise.
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When the Enable pin is connected to GND(Lo), the amplifier goes into operation mode, and when it is connected to +5V (Hi), it goes into reset mode.
The product is connected to GND in the default state and is in operation mode so that it can be used immediately after purchase. Therefore, the reset operation cannot be performed.
To enable this, you need to find and remove the chip resistor connected to GND. Or turn off the power and leave it for a while.
However, I don't think there is actually a chance to reset the amp.
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We get that you like the TPA3255, I like it too, but this thread is not about that amp. Let’s keep the discussion to the Infineon amp please. If you have comparisons to make between the Infineon and the TPA3255 that’s fine but raving about amp “Y” in amp “X” thread adds no more info to amp “X”.
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If you add a MOSFET between the PSU input and the amp wired as a cap multiplier with a slow ramp up (10sec), you can avoid the turn on thump. The circuit is quite simple (handful of parts under $3) but has a 3v drop. So a 24v supply gives 21v. Using a variable step up DC-DC converter or a variable SMPS can compensate for this by increasing voltage by 3v.
Here is the cap multiplier circuit:
Juma's Easy-Peasy Capacitance Multiplier
Yes, that's how Infineon manufacturer guide to start-up procedure in the datasheet (page 30)
Same with shut-down:
Microcontoller (especially for MA12070P version) may help to do the stuff with Enable/Mute pins with described sequence
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$1 ATTiny86 DIP8 MCU is perfect for this. Can be programmed easily via Arduino interface. It’s kind of annoying that some state of the art amps don’t have this very basic functionality of proper startup/shutdown built in automatically. 10years ago, the TPA3116 did not have this and it was annoying but forgivable. Now, to have a new chip cone out with all these lessons learned and still make people do it with an external MCU is beyond me. There should be a single logic pin that if selected enabled smart soft turn on and off. If you don’t enable it, you can manually do all of this timing yourself with an external MCU.
I immediately challenged how to eliminate pop noise.
As a result, I was able to eliminate the pop noise when the power was turned on by connecting a 100uF/10V or 68uF/10V capacitor between the Mute pin and GND.
Even if you connect a capacitor, the Mute pin will continue to work as before. When using an electrolytic capacitor as the capacitor, connect the + side to the Mute pin.
The principle is to connect the Mute pin to GND by the charging current to the capacitor for about 1 second after the power is turned on.
It's just this very easy method, but the effect is outstanding. It works well even if the power is turned on/off in a short cycle.
Other ideas
The power consumption of this amplifier board when there is no sound is very small and there is almost no heat generation.
Therefore, you can use the Mute pin like power ON/OFF while keeping the DC power supply always connected (Power ON).
I would like to incorporate both methods when licking this amp board in the case.
(Sorry, I'm not good at English. I think it's a strange sentence.)
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I think that infineon deal with its i2c interface in two ways: 1. They make it cheaper as a chip without microcontroller under the hood and 2. Give to developer full controll over the initial setup: protecton status (DC, overcurrent, etc.), power mode profile, I2S format, etc. Believe me, you'll not like the sound coming from speakers if ma12070p will start in wrong I2S format
For ma12070 it's more safe to run without initial setup, but anyway, it is better to do so
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I mean let's stay realistic. I guess the design background of the amplifier was never with the goal to fit best for cheap chinese mini-AMP boards.
For any serious application you have usually at least a small uC for overall system-control. It's so standard today that it is fast uncommon to not have a uC.
So I don't see that as a problem that you definitely need some external control
For any serious application you have usually at least a small uC for overall system-control. It's so standard today that it is fast uncommon to not have a uC.
So I don't see that as a problem that you definitely need some external control
It is a strange sentence, but very funny. That the amplifier would look good enough that you'd like to lick it after putting it in a case. Must be a pretty good amplifier!
I think there's not enough "colour" shining through if everyone is trying to write everything in a very neutral way, better to have a bit of diversity. Your English is excellent btw, no need for excuses.
Oh, and good solution for the on/off muting.
Are you talking about the same MA12070 as mine ,here ?
Module amplificateur 1.0 / 2.0 / 2.1 / 4.0 Class D MA12070 160W 4 Ohm - Audiophonics
IF YES : I disagree with you, because I have absolutely 0 pop noise when switching ON / OFF neither any input noises when connected in full balance mode (XLR). Tested it via my Double AK4497 Dac and my LG V30 with internal Quad Dac = 0 issues, no noises, no pop... This amp is absolutely dead silence.
I guess our setup is just different, maybe we are using different SMPS PSU, etc etc
As reminder : I am using it in dual Mono Mode with 2 SMPS PSU (one per module) :
IN0A and IN0B - for the left channel of the mono amp
IN0A and IN0B - for the right channel of the mono amp
Can you share pictures of your finished amp ?
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