I am using the MA12070 amplifier board (Aliexpress) with RCA unbalanced input, but when I disconnect the input cable (input open), white noise is generated with a slightly louder sound.
There is no noise generated by the XLR balanced connection.
The RCA unbalanced input connection is SPEAK0A (R-ch), SPEKA1A (L-ch), and SPEAK0B and SPEAK1B are connected to GND. Is there a problem with this connection method?
There is no noise generated by the XLR balanced connection.
The RCA unbalanced input connection is SPEAK0A (R-ch), SPEKA1A (L-ch), and SPEAK0B and SPEAK1B are connected to GND. Is there a problem with this connection method?
Toku, i think you mean input connection to IN0A and IN1A, with IN0B and IN1B connected to ground?
Yes, that's right.
SPEAK0B and SPEAK1B are connected to the GND pin to be the common GND for SPEAK0A (R-ch) and SPEKA1A (L-ch).
For this connection, I referred to the connection method of the unbalanced input of the EVAL_AUDIO_MA12070 evaluation board of inFineon.
On another topic, I received the MA12070 amp board that I ordered two more from Aliexpress today. This time too, the version was Ver. 1.4.
SPEAK0B and SPEAK1B are connected to the GND pin to be the common GND for SPEAK0A (R-ch) and SPEKA1A (L-ch).
For this connection, I referred to the connection method of the unbalanced input of the EVAL_AUDIO_MA12070 evaluation board of inFineon.
On another topic, I received the MA12070 amp board that I ordered two more from Aliexpress today. This time too, the version was Ver. 1.4.
Last edited:
I think you are wrong, no one speaker pin have to be connected to GND.
Attachments
@Toku: it is not that strange with a "open" amplifier so no volume potentiometer or anything else terminating the inputs. Like zen pointed out the speakers should not be connected to GND as well.
BTW what is the difference between V1.3 and V1.4 except for the jumper wire?
BTW what is the difference between V1.3 and V1.4 except for the jumper wire?
Last edited:
I made a ridiculous mistake in my post.
When I turned the board over and looked at the socket terminals, I looked at the position in the opposite direction.
It should be read as IN0A, IN0B, IN1A, IN1B, not SPEAK0A, SPEAK0B, SPEAK1A, SPEAK1B, respectively.
It's a really embarrassing and sad mistake. So sorry!!
When I turned the board over and looked at the socket terminals, I looked at the position in the opposite direction.
It should be read as IN0A, IN0B, IN1A, IN1B, not SPEAK0A, SPEAK0B, SPEAK1A, SPEAK1B, respectively.
It's a really embarrassing and sad mistake. So sorry!!
No problem. It is only embarrassing when it becomes defective. Now it is just a slight mistake.
Hi,
I was interested in the MA12070 PCB, but wanted to try before the MA12040 which is already in a box and with a Qualcomm QCC3003 bluetooth chip (not the best but handy in my workshop). So I bought from Douk and the delivery was quick. The amplifier is very quiet and no pop when opening.
Mini Bluetooth 5.0 Digital Amplifier Stereo Receiver 2.0 Channel Car Speaker Amp | eBay
From the power on I liked the sound. I prefer it to my stock 3eaudio TPA3251 (not modified), more dynamic and lively, more definition. Currently I have a SMPS of 12vdc 2.7A, not great but I have several transformers and PSUs, I will put 17-18vdc max. With 12vdc, in 4ohms it is 13w / c and in my living room at normal listening power, it does not lack power. I am very amazed and even shocked at the sound quality and the tonal balance versus the price it costs. I will surely buy the MA12070 PCB and try it too.
I was interested in the MA12070 PCB, but wanted to try before the MA12040 which is already in a box and with a Qualcomm QCC3003 bluetooth chip (not the best but handy in my workshop). So I bought from Douk and the delivery was quick. The amplifier is very quiet and no pop when opening.
Mini Bluetooth 5.0 Digital Amplifier Stereo Receiver 2.0 Channel Car Speaker Amp | eBay
From the power on I liked the sound. I prefer it to my stock 3eaudio TPA3251 (not modified), more dynamic and lively, more definition. Currently I have a SMPS of 12vdc 2.7A, not great but I have several transformers and PSUs, I will put 17-18vdc max. With 12vdc, in 4ohms it is 13w / c and in my living room at normal listening power, it does not lack power. I am very amazed and even shocked at the sound quality and the tonal balance versus the price it costs. I will surely buy the MA12070 PCB and try it too.
Attachments
Last edited:
I have a question,
Does the MA12040 amplifier generate any pop noise when the power is turned on / off?
Is there any pop noise even if the power supply unit is turned off while the power is on?
Does the MA12040 amplifier generate any pop noise when the power is turned on / off?
Is there any pop noise even if the power supply unit is turned off while the power is on?
D
Deleted member 148505
For MA12070/MA12040 PMP1 and PMP2 modes, they have a lower 6.67kHz THD+N compared to TPA3251, so hearing better sound has a basis.
Having PFFB for TPA3251 can even out the THD difference. Or for non PFFB like 3eaudio, use 7uH inductors for TPA3251 to get lower THD+N.
Current price + shipping cost at ALI is actually high since there are no other competition. Expect lower prices if this chip gets the hype.
Thanks JLesterP for the info about the PFFB, I had read that it decreases the distortion rates. Ok I'll look for 7uH inductors.
As long as I have 3251, I will make the modification. For the rest the smd are too small for my eyes with the solder.
As long as I have 3251, I will make the modification. For the rest the smd are too small for my eyes with the solder.
Toku I haven't forgotten you, let me check the last point, I'll get back to you shortly
When opening the amplifier, there is a very slight click. When closing, it's more of a pop but also light.
I unplugged and re-plugged the SMPS while the amplifier is open the volume to max, there is no noise.
In addition the amplifier is very quiet, the volume at max and the ear close to the ribbon tweeter, no hiss or other total silence, we can not detect if the amplifier is on.
Thank you for the detailed report.
We will use it as a reference for purchase.
I'm currently buying and testing four MA12070 amp boards and I've become more and more fond of this chip.
We will use it as a reference for purchase.
I'm currently buying and testing four MA12070 amp boards and I've become more and more fond of this chip.
It's great I'll read your comments.
Today I did a listening session, without being the best amp, I am still impressed with the ease that this chip reproduces music with dynamism and musicality.
Today I did a listening session, without being the best amp, I am still impressed with the ease that this chip reproduces music with dynamism and musicality.
Hi denbret,
one question: Would you be so kind to open that device and make some detailed photo of the PCB?
This would be so nice.
Merry X-Mas to everyone