How to prevent popping sound on power on on TDA7492P Amp?

[gec]

doctormord,

Regarding reprogramming the Bluetooth, is this CSR programmer / "BlueSuite" software usable for the Sanwu TDA7492P & TPA3116 boards?

Change Bluetooth Audio Amplifier Name or Audio Tone

What about the TPA31116 2.1ch variants? Seems like the version with four knobs on it uses the same CSR module.

 

[Danielsan99]

Fixing the power-on-plop is as follows:

R21 = 820k
R22 = 680k

If you don't care for the line in, it's also possible to implement an automatic power-down when no bt transmitter is connected.

Hi, I joined up to ask this question: can you point out the R21 & R22 on the board? I'm unable to find it in the high res pictures

 

[Danielsan99]

How does one replace one the resistor of that size?

 

[ltdf]

How does one replace one the resistor of that size?

Search youtube- solder smd, desolder smd, many good videos, technics.

https://www.youtube.com/watch?v=3NN7UGWYmBY

603 resistor solder @ 1:48, desolder @ 7:09

 

[theb0b]

Seems like they're aware of this, so they changed the 33k to 100k already.

Its the resistor marked in the green box.

Could you tell me what "size" these resistors are please.

I've ordered some boards that it seems that I'm going to have to change some resistors.

I want to order an assortment but I don't know if they are 1206, 0603 or 0805 or whatever.

How about smd capacitors? What sizes are used on these boards?

 

[davidluab]

these is a best option??

https://es.aliexpress.com/store/product/New-Arrival-Durable-Quality-Digital-Bluetooth-CSR4-0-Audio-Receiver-Amplifier-Board-Module-TDA7492P-25W-25W/1748488_32699554689.html?isOrigTitle=true&isOrig=true#extend


i think fix the problem

 

[ryk]

Hi, i have this board TDA7492P 50W+50W Wireless Bluetooth 4.0 Audio Receiver Digital Amplifier Board | eBay
It hasn't the popping noise as described, but I hear a light hiss noise (coming form the twitter) when it plays music. When not playing, it is dead silent. How can i fix this?
I tried to play with the gain dip switch, but ....no go. When the gain is low, I have to turn volume up, so the hiss is present.
For the history, the speakers are a pair of new Heco Victa 202 (never played anything before)

 

[doctormord]

doctormord,

Regarding reprogramming the Bluetooth, is this CSR programmer / "BlueSuite" software usable for the Sanwu TDA7492P & TPA3116 boards?

Change Bluetooth Audio Amplifier Name or Audio Tone

What about the TPA31116 2.1ch variants? Seems like the version with four knobs on it uses the same CSR module.

You will need an "USB SPI" CSR programmer to do that.

https://de.aliexpress.com/item/CSR-Bluetooth-Burner-USB-To-SPI-Downloader/2044446484.html

Haven' tested the cheaper one without the pinout printed on them. They differ from internal hardware.

Hi, I joined up to ask this question: can you point out the R21 & R22 on the board? I'm unable to find it in the high res pictures

It's these two:

0603 is the sizecode.

It hasn't the popping noise as described, but I hear a light hiss noise (coming form the twitter) when it plays music. When not playing, it is dead silent. How can i fix this?

Removing the Opampstage (Diff2SE) should normally fix this. (Direct connection of the BT modules output to the amps input) This only works for the boards WITHOUT the additional Line-In.

 

[ryk]

You will need an "USB SPI" CSR programmer to do that.

https://de.aliexpress.com/item/CSR-Bluetooth-Burner-USB-To-SPI-Downloader/2044446484.html

Haven' tested the cheaper one without the pinout printed on them. They differ from internal hardware.



It's these two:

0603 is the sizecode.



Removing the Opampstage (Diff2SE) should normally fix this. (Direct connection of the BT modules output to the amps input) This only works for the boards WITHOUT the additional Line-In.

Thanks, but give me some details (photo?). Do you mean to bypass the NE5532?
Also, shouldn't I try to change the output filter (15mH instead of 33mH and put some good film capacitor?)

 

[doctormord]

The output-filter is most likely not your source of noise as it is quite when not playing.

 

[doctormord]

Try this:

Untested, but should do.

 

[batlaman]

You will need an "USB SPI" CSR programmer to do that.

https://de.aliexpress.com/item/CSR-Bluetooth-Burner-USB-To-SPI-Downloader/2044446484.html

Haven' tested the cheaper one without the pinout printed on them. They differ from internal hardware.

Hi... are there any visual instructions or easy instructions to follow in order to do this? ...the dumbest the better

 

[blueknight32]

Thank you everyone! This is very informative and helps a lot! The TDA7492P is great and everything but still seems of lower quality. In your opinion what is the best transistor based amplifier board out there? Is it a LM3886 board? The reason I ask is I plan to build a good quality amplifier with a 24 volt toroidal transformer and want to know what the best option would be for the amp its self. I was thinking something like this

NEW LM3886 amplifier board Full DC servo Redux Immersion Gold Process | eBay

and I wanted a dedicated bluetooth module. So I saw you guys mentioned a KRC-86B. Would this work good for my setup? As I would like bluetooth abilities and auto switch over when the aux is plugged in.

KRC-86B CSR8630 Bluetooth 4.0 Module Stereo Audio Receiver Amplifier Board USB | eBay

 

[nyoman]

Thank you doctormord

Try this:

Untested, but should do.

I want to thank doctormord for his excellent advice! I have this exact board and was really annoyed with the hiss and pops when turning on (and a bit when turning off or pressing pause button).

For me only bypassing the opamp cures the start up pop. I didn't have to replace the resistor value of the mute circuit. Admittedly the hissing noise is still there when you pause the music, but it is not that annoying anymore.

So happy with this $9 board (and free shipping to Indonesia)

cheers!

 

[tibotiber]

Fixing the power-on-plop is as follows:

R21 = 820k
R22 = 680k

If you don't care for the line in, it's also possible to implement an automatic power-down when no bt transmitter is connected.

Thanks for the advices with great details provided. I replaced R21 and R22 as indicated just now and the pop is mostly gone. I still get a single power-on-pop when the amplifier is set at maximum gain (which I just avoid anyway so it's not an issue) and I also get one single pop when powering down, no matter the gain I set. Any idea on this?

Also do you have any advice on the best power source for this amplifier? The small brochure I got with it (mine is from "elegant audio") recommends 12V but I am under the impression that 24V would be better, am I wrong? And in any case, what kind of current should I plan for?

 

[esqueue]

Seems like a design/implementation problem. Change this 100k for 750k-1MEG and see if it's properly muted then.

I registered to say thanks. I had the older board with a 39k OHM resistor and swapped it out for a 1M Ohm. That virtually fixed my issue along with getting rid of that annoying beep.

 

[nodnub]

I registered to say thanks. I had the older board with a 39k OHM resistor and swapped it out for a 1M Ohm. That virtually fixed my issue along with getting rid of that annoying beep.

Were you able to get rid of that bluetooth startup beep?

 

[nodnub]

I replaced R21 and R22 with some 0603 resistors I scavenged from an old wireless mouse. This eliminated the power on "startup thump". Is it possible to remove the power-off "pop" noise as well?

Does noise like this actually cause damage to speakers?

 

[Nenola]

I'm building a portable speaker with TDA7492 and the hiss and other annoying sounds are very audible. First I'm going to try to bypass the opamp for a fix, then for the resistor swap. But I have a slightly different layout, missing some components, but can I still follow the same instructions? Look at the attached picture, yellow ones to remove and green ones for wiring?

 

[doctormord]

Yes.

(You maybe should keep the bottom cap of the four which is connected by via to somewhere else.It actually is not connected to the audio in it seems)