Pcb amp issue

[Burnt circuitry]

How do I wire in a mono(to supply small sub) to a dual channel that will supply the other speakers? The input on the mono only has 2 wires in whereas the dual channel has 3 wires( L- R- G.) Or is there an alternative I can do?

 

[JMFahey]

To go in the proper sequence:

First you have a stereo signal, so Left and Right, coming out of your Bluetooth module.

There is also Ground involved, but "all Grounds are the same" so the G letter means all those are connected and present everywhere.

You connect Left out from BT to left side of your TPA3116 and its output to Left speaker.

You connect Right out from BT to right side of your TPA3116 and its output to right speaker.

So far so good.

Now you need to "fabricate" a Mono signal for your woofer speaker.

You do that by mixing Right and Left signals.

You can´t just twist right and left wires together because that´s too drastic and destroys your stereo separation, so you join them using mixing/separating resistors.

This box uses 4 resistors to mix Left+Right into Mono, as a bonus it has two Mono outputs, not really needed, so you can use just two resistors to mix L+R and their joint go straight to a third RCA connector you label M

With due credit to the original project:
Passive Stereo to Mono Resistive Mixer

Of course, you CAN build it as is, just use ONE M output.

As a side note, he chose 680 ohm resistors, in my view somewhat low, I would use two 2200 ohm resistors as an easier to drive combination, and connect their joint to one or two M RCA connectors. .

 

[Burnt circuitry]

Thanks for your help. So please correct me if I'm wrong, a 2200 ohm resistor is red, red, red, then gold stripe is that correct? i have everything under the sun except red, red, red, gold. I have red, black, orange, gold,--- brown, green, red, gold.--- brown, black, orange, gold or silver.--- yellow, purple, gold, gold.--- brown, black, red, gold---Green, blue yellow gold--- yellow, purple, red gold---red, red, orange gold---yellow, purple, red, gold---green, blue, yellow, gold---blue, silver, red, gold---red, red, brown, gold---, is there any of those combinations i can use?

 

[MikePP]

Thanks for your help. So please correct me if I'm wrong, a 2200 ohm resistor is red, red, red, then gold stripe is that correct? i have everything under the sun except red, red, red, gold. I have red, black, orange, gold,--- brown, green, red, gold.--- brown, black, orange, gold or silver.--- yellow, purple, gold, gold.--- brown, black, red, gold---Green, blue yellow gold--- yellow, purple, red gold---red, red, orange gold---yellow, purple, red, gold---green, blue, yellow, gold---blue, silver, red, gold---red, red, brown, gold---, is there any of those combinations i can use?

You need to learn your colours



Here for instance:


Blocked

 

[Burnt circuitry]

Thank you for that site. its so much easier to use than figuring out otherwise. Now back to my question, would it be okay to have a value between 680(original post) and 2200(JMF's) since I don't have any red, red, red, gold resistors? For instance a Brown, black, red, gold= 1000 or Red, black, red, gold=2000 or brown, grey, red, gold= 1800?

 

[PRR]

brown, green, red is 1500 which is "between 680 and 2200", which is what you want. Perfect.

 

[Clueless but avid]

This isn't bad, either > Reverse Widerstand Farbcode Rechner. 3,4,5,6 ringen