So my first help post, iam stuck and ive have tried evryting i could thick of but no sucess.
So iam building my second portable soundsystem in a suitcase.
looks like this inside
12v 7ah Mc battery
TA2021 T-amp
they are simple wired together via a swith
two 5,25 speaker connected to the T-amp.
and this works fine.
but then i added this
Wholesale Brand New 2pcs Panel VU Meter Warm Back Light Recording&Audio Level Amp with driver+Free shipping 10000598-in Other Measuring & Analysing Instruments from Industry & Business on Aliexpress.com
The Vu driver is connected right on the battery 12v
Then i get sound"line in" from the t-amp same channel as the speakers.
And then "vu-out" from the driver to the vu-meter.
Simple? yeah..
but when i switch evrything on i get no sound, just tick tick tick sound from the speakers.
And if i remove the power from the vu-driver and but it back, the t-amp shuts off.
a lot of text i know, but anyone know why it does like this?
So iam building my second portable soundsystem in a suitcase.
looks like this inside
An externally hosted image should be here but it was not working when we last tested it.
12v 7ah Mc battery
TA2021 T-amp
they are simple wired together via a swith
two 5,25 speaker connected to the T-amp.
and this works fine.
but then i added this
Wholesale Brand New 2pcs Panel VU Meter Warm Back Light Recording&Audio Level Amp with driver+Free shipping 10000598-in Other Measuring & Analysing Instruments from Industry & Business on Aliexpress.com
The Vu driver is connected right on the battery 12v
Then i get sound"line in" from the t-amp same channel as the speakers.
And then "vu-out" from the driver to the vu-meter.
Simple? yeah..
but when i switch evrything on i get no sound, just tick tick tick sound from the speakers.
And if i remove the power from the vu-driver and but it back, the t-amp shuts off.
a lot of text i know, but anyone know why it does like this?
I have a hunch but you will have to do the leg work and see how its all configuered.
The driver accepts 12 vac as an input and I can see a bridge rectifier on the PCB. Used in isolation that means that you can connect a DC voltage to the input and the polarity is unimportant, the bridge sorts that out.
Your amp will probably be configured as a bridged output with the speaker not being ground referenced. The speaker is connected between two amplifier outputs that are driven in anti-phase.
What I think is happening is that your connections to the amp are shorting one channel out. Without seeing it all I would think that you need to keep the ground of the driver connected to battery minus, and connect the inputs to one side of the speaker only.
Make sure that your connections don't introduce a short across the battery or across any amplifier output.
I assume the amp still works ? If not then the shorting out will have damaged the main Class D output stage chip.
The driver accepts 12 vac as an input and I can see a bridge rectifier on the PCB. Used in isolation that means that you can connect a DC voltage to the input and the polarity is unimportant, the bridge sorts that out.
Your amp will probably be configured as a bridged output with the speaker not being ground referenced. The speaker is connected between two amplifier outputs that are driven in anti-phase.
What I think is happening is that your connections to the amp are shorting one channel out. Without seeing it all I would think that you need to keep the ground of the driver connected to battery minus, and connect the inputs to one side of the speaker only.
Make sure that your connections don't introduce a short across the battery or across any amplifier output.
I assume the amp still works ? If not then the shorting out will have damaged the main Class D output stage chip.
Thanks for the answer and you are right!
The driver is AC and the battery is DC!
i did order a DC driver instead, BUT
you said i could set the negtive(-) on the driver to (-) to the battery.
And then i did not follow you, one side of the speaker input?
make that easier for me 😀
The driver is AC and the battery is DC!
i did order a DC driver instead, BUT
you said i could set the negtive(-) on the driver to (-) to the battery.
And then i did not follow you, one side of the speaker input?
make that easier for me 😀
The bridge rectifier means you can connect the battery either way around (as far as the driver board is concerned) because the bridge will always provide the correct polarity at its output.
The negative part of the driver circuitry (its zero volts line) can be connected to the battery negative. If you are confident identifying the connections on the board then the bridge can be bypassed and the battery connected to the circuitry directly.
The speaker isn't ground referenced, it floats. So you must connect the driver input to one side only, the input ground being the same as the battery negative.
The negative part of the driver circuitry (its zero volts line) can be connected to the battery negative. If you are confident identifying the connections on the board then the bridge can be bypassed and the battery connected to the circuitry directly.
The speaker isn't ground referenced, it floats. So you must connect the driver input to one side only, the input ground being the same as the battery negative.
Make sure that the VU meter driver board contains an audio input coupling capacitor. If you're unsure, use a capacitor (.1uf perhaps) between the output of the amplifier and the input of the VU meter driver board.
The amplifier works fine, if i disconnect the vu-driver
someone told me that i should use a galvanic ground, and that could help, will try some tomorrow and see if i get any luck
someone told me that i should use a galvanic ground, and that could help, will try some tomorrow and see if i get any luck
Update:
if i dont connect the negative on the speaker, and connect that to the battery directly it works 🙂
I dont think i get the exact vu measurement like this becouse i miss a line in.
if i dont connect the negative on the speaker, and connect that to the battery directly it works 🙂
I dont think i get the exact vu measurement like this becouse i miss a line in.
OK 🙂 Its one of those things that hard to visualise, but yes, its because the negative on the speaker is actually connected to an amplifier (because of the bridge configuration).
Look at the picture in this article. Do you see... the speaker has no ground reference. When you connect the VU circuits ground to the speaker negative you are actually shorting one amplifier out.
Bridged and paralleled amplifiers - Wikipedia, the free encyclopedia
Yeah it is hard, negative on negative should not shortcut anyting 😛
nice that this was sorted out.
And here is a picture of the "almost" finnished product 🙂
nice that this was sorted out.
And here is a picture of the "almost" finnished product 🙂
An externally hosted image should be here but it was not working when we last tested it.
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