TPA3118 SANWU Stereo Mod?

[65musclecar]

Has anyone done a stereo mod on the mono TPA3118 SANWU board?

I like this little board but I need stereo and less power draw. I'm running off a 9v battery and I think running two boards is using too much battery power.

I friend mentioned that it might be hardwired to mono in a way that can't or is difficult to change.

 

[FauxFrench]

The TPA3118 is the same chip as the TPA3116D2. You find a lot of inexpensive TPA2116D2 stereo boards. Even the TPA3130 is the same chip.
Modifying the SANWU blue board is difficult, in particular because everything is so tiny.

 

[65musclecar]

Thanks FauxFrench! I found two stereo versions and this will make much more sense for testing purposes then modding the tiny board.

Amazon.com: DROK HiFi Dual-channel Stereo Audio Amplifier DC10-25V Digital 2.0 Amplifier Board 50W Output with Volume Adjustment Knob: Car Electronics

Amazon.com: Icstation TPA3116D2 2X50W Class D Stereo Digital Audio Amplifier Power Amp Board Volume Adjustable: Industrial & Scientific

 

[FauxFrench]

I have both of them and mine work.
I got the first one for about half the price of what you indicate, but I had to wait about 1 month to get it.
The second one has got slightly less good power line decoupling capacitors but is half the price.
In both cases you can expect some "hiss"-noise with the volume potentiometer in mid-position (very known problem here on the forum). The hiss can be removed with two 4.7K resistors connected from each of the potentiometer slider pins to ground.
Apart from that, the TPA3116D2 sounds really fine (considering the price).
Good luck

 

[65musclecar]

What is the gain on TPA3118 SANWU board?

I have the mono TPA3118 SANWU board and I like the gain setting.

However, I don't have a schematic and I can't tell what the gain is set to.

I believe it is adjustable via the ratio of two resistors between 20dB and 36dB.

If I can find out what it is, I'd like to set the gain of another board (TPA3128D2) to the same gain as the Sanwu. Otherwise I will have to experiment and I'm not too comfortable switching out smd parts yet.

If anyone knows what the gain is set to, I'd appreciate the help!

 

[Khron]

Cheap TPA3118D2 boards, modding them and everything that comes with it

 

[65musclecar]

Many thanks Kron! R28 on my Sanwu TPA3119D2 board is 39k Ohms which makes the gain 32dB. I've been trying to figure this one out for a while.

 

[Khron]

The absolute values don't matter as much as the ratio between the two gain-setting resistors, btw.

 

[hajj]

The absolute values don't matter as much as the ratio between the two gain-setting resistors, btw.

Not really, the TPA3116 relies an an ADC to select one of the preset gain values

 

[Khron]

Yes, an ADC that reads the VOLTAGE derived by that resistive divider from the GVDD supply.

Quote from the datasheet:
"7.3.1 Gain Setting and Master and Slave

The gain of the TPA311xD2-Q1 family is set by the voltage divider connected to the GAIN/SLV control pin. Master or slave mode is also controlled by the same pin. An internal ADC is used to detect the eight input states."

If you do the math and see what voltages you get from the various pairs of resistors mentioned on page 11 of the datasheet, you'll get eight different voltages.