Which TPA3255 amp do you recommend?

[Alesi]

I assembled HanZao TPA3251. However, pop noise when the power is turned off is severe. Is there any way to improve it?
Is standby and MUTE effective at ground when the DC power is off using a two-circuit power switch?
Shui Yuan TPA3255 has no noise due to the addition of capacitors that Toku-san taught me. Thank you Toku-san.

 

[ModDIY]

Hi, I too have added a capacitor on the Shui Yuan and it works fine. Maybe you could try the same.

What do you think of the
HanZao TPA3251 vs Shui Yuan ?

 

[trunkline]

I assembled HanZao TPA3251. However, pop noise when the power is turned off is severe. Is there any way to improve it?
Is standby and MUTE effective at ground when the DC power is off using a two-circuit power switch?
Shui Yuan TPA3255 has no noise due to the addition of capacitors that Toku-san taught me. Thank you Toku-san.

The MUTE doesn't work for me.

 

[Toku]

I assembled HanZao TPA3251. However, pop noise when the power is turned off is severe. Is there any way to improve it?
Is standby and MUTE effective at ground when the DC power is off using a two-circuit power switch?
Shui Yuan TPA3255 has no noise due to the addition of capacitors that Toku-san taught me. Thank you Toku-san.

Now I'm thinking of giving you some advice, but I can't think of a good idea because it was previously reported that the MUTE for this product wasn't working.
Please check once if MUTE does not work for the amplifier board you purchased.

 

[Alesi]

Thank you everyone.
Mute and ground short. But pop noise remains the same.

 

[Toku]

Thank you everyone.
Mute and ground short. But pop noise remains the same.

That means that even if you connect MUTE to GND while playing music, the sound from the speakers will not stop, right?

 

[Alesi]

That means that even if you connect MUTE to GND while playing music, the sound from the speakers will not stop, right?

I tried connecting MUTE to the ground while making a sound, but the sound did not stop.

 

[trunkline]

According to the seller you have to connect to positive. Connect to 9V from the same socket.

 

[Toku]

I tried connecting MUTE to the ground while making a sound, but the sound did not stop.

The TPA3255 and TPA3251 chips do not have a MUTE terminal. So I thought I was substituting RESET for MUTE operation, but from the reports of your operation test, it seems that nothing is actually connected to the MUTE terminal of the connector.
To prevent pop noise when the power is turned on, I think that the startup step sequence is organized by the chip circled in red in the photo.
If the MUTE terminal of the connector is connected to this chip, some idea may come up, but at present it is not possible.
You need an accurate schematic to solve the problem.

 

[Toku]

According to the seller you have to connect to positive. Connect to 9V from the same socket.

I remember previously reporting that connecting MUTE to + 9V did not change the behavior.
Am I wrong?

 

[Alesi]

Thanks to everyone.
Toku-san,There is no photo, but it's difficult so far.
It is scary to connect to the speaker as it is.

 

[Toku]

Thanks to everyone.
Toku-san,There is no photo, but it's difficult so far.
It is scary to connect to the speaker as it is.

Thank you for pointing it out. I added a photo immediately.
TI's TPA3251/TPA3255 evaluation board uses a dedicated chip called TPS3802K33DCKR.

 

[Alesi]

Thank you for pointing it out. I added a photo immediately.
TI's TPA3251/TPA3255 evaluation board uses a dedicated chip called TPS3802K33DCKR.

Thank you.
Is it difficult to put a relay in the speaker output?
I think this is because the power of the operational amplifier in the first stage is turned off before the circuit in the final stage. It may be alleviated if the power of the operational amplifier is turned off later when the power is turned off.

 

[Toku]

Thank you.
Is it difficult to put a relay in the speaker output?
I think this is because the power of the operational amplifier in the first stage is turned off before the circuit in the final stage. It may be alleviated if the power of the operational amplifier is turned off later when the power is turned off.

If the power supply of the OP amplifier is lost before the main power supply of the TPA3251, it causes a large pop noise. I have already experienced with other amplifier boards.
I checked the circuit of TI's EVM module, but there is no special countermeasure for pop noise when the power is off.

This is a suggestion from me.
Does pop noise stop once the OP amplifier is unplugged from the socket and the power is turned on / off in that state? (I don't think there is a problem with the operation of the amplifier even if there is no OP amplifier)

 

[Alesi]

If the power supply of the OP amplifier is lost before the main power supply of the TPA3251, it causes a large pop noise. I have already experienced with other amplifier boards.
I checked the circuit of TI's EVM module, but there is no special countermeasure for pop noise when the power is off.

This is a suggestion from me.
Does pop noise stop once the OP amplifier is unplugged from the socket and the power is turned on / off in that state? (I don't think there is a problem with the operation of the amplifier even if there is no OP amplifier)

When I unplugged the ope amplifier, pop noise came out when the power was turned on and off. The amount of off noise does not change.

 

[Toku]

When I unplugged the ope amplifier, pop noise came out when the power was turned on and off. The amount of off noise does not change.

Thank you for testing. Unfortunately, my guess was wrong.

The amplifier you made does not have a power switch. Is the power ON / OFF operation performed by an external power supply?
At that time, does it come out at the same time when the power is turned off? Or will it come out a little late? (for example. 0.1 ~ 1sec)

 

[Alesi]

Thank you for testing. Unfortunately, my guess was wrong.

The amplifier you made does not have a power switch. Is the power ON / OFF operation performed by an external power supply?
At that time, does it come out at the same time when the power is turned off? Or will it come out a little late? (for example. 0.1 ~ 1sec)

Yes,The power on / off is an external power supply.
The noise comes out a little late. It's less than a second.

 

[Toku]

Yes,The power on / off is an external power supply.
The noise comes out a little late. It's less than a second.

From the information obtained so far, I propose the addition of the following circuit as the easiest way to eliminate pop noise when the power is turned off.
If you have a schematic, a smarter way may be possible.

Add a DPST (Double-Pole Single-Throw) or DPDT (Double-Pole Double -Throw) toggle switch and an ON / OFF relay for the speaker output of the amplifier to your amplifier.
One circuit of the toggle switch is used to turn on / off the main power supply of the amplifier, and the other circuit turns on / off the relay of the speaker output.
The power supply of the relay is a 3-terminal Linear Regulator that steps down the voltage from the connection connector of the external power supply to the coil voltage of the relay.
By adding these, the speaker output is instantly turned on and off at the same time as the power is turned on and off to avoid pop noise.

 

[Alesi]

From the information obtained so far, I propose the addition of the following circuit as the easiest way to eliminate pop noise when the power is turned off.
If you have a schematic, a smarter way may be possible.

Add a DPST (Double-Pole Single-Throw) or DPDT (Double-Pole Double -Throw) toggle switch and an ON / OFF relay for the speaker output of the amplifier to your amplifier.
One circuit of the toggle switch is used to turn on / off the main power supply of the amplifier, and the other circuit turns on / off the relay of the speaker output.
The power supply of the relay is a 3-terminal Linear Regulator that steps down the voltage from the connection connector of the external power supply to the coil voltage of the relay.
By adding these, the speaker output is instantly turned on and off at the same time as the power is turned on and off to avoid pop noise.

It seems difficult to make a circuit.
Do you use such a relay?
https://ja.aliexpress.com/item/1005002305755967.html
I am worried about sound quality deterioration.

 

[Toku]

It seems difficult to make a circuit.
Do you use such a relay?
https://ja.aliexpress.com/item/1005002305755967.html
I am worried about sound quality deterioration.

It is difficult to prevent pop noise by simply adding the speaker protection unit to your amplifier.
Even if you use this unit, you need to add a power switch between the DC connector and the amplifier board as I explained last time.
If you want to know the reason, I will explain later. I'm going to bed already.