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Octophonic beeping system needs advice!!!

Hi!
I'm building an octophonic beeping system and I could need some help.
My first prototype was using a basic stamp 2, with 8 pins connected to
8 speakers which worked but the sound wasn't loud enough and it was
taking too much pins of the microcontroller.
I decided to rectify this problem by using only 1 pin of the basic
stamp for the sound output and connected it to an LM386 for
amplification.
The output of the amp was then connected to an ADG508 (8 channel
multiplexer) and then off to the 8 speakers.
New problems: the ADG508 (powered with 12volts) reduces the volume
that the amp amplified.
Any hint of solution ?
 
E

Eeyore

Jan 1, 1970
0
Hi!
I'm building an octophonic beeping system and I could need some help.
My first prototype was using a basic stamp 2, with 8 pins connected to
8 speakers which worked but the sound wasn't loud enough and it was
taking too much pins of the microcontroller.
I decided to rectify this problem by using only 1 pin of the basic
stamp for the sound output and connected it to an LM386 for
amplification.
The output of the amp was then connected to an ADG508 (8 channel
multiplexer) and then off to the 8 speakers.
New problems: the ADG508 (powered with 12volts) reduces the volume
that the amp amplified.
Any hint of solution ?

Yes. The on resistance of the DG508 is what's causing the loss of volume.

You could use relays instead or an MCU with more pins.

Graham
 
Yes. The on resistance of the DG508 is what's causing the loss of volume.

You could use relays instead or an MCU with more pins.

Graham

Thanks for the insight. I hadn't tought of relays mainly because I
wanted fast and silent switching. As for the MCU, you're rightI'll
probably go with something better. But isn't there a way to only use
one LM386 instead of eight? If I'd use a demultiplexer instead of
using the adg508 "in reverse", do you think it'd work better?

Hugo
 
Thanks for the insight. I hadn't tought of relays mainly because I
wanted fast and silent switching. As for the MCU, you're rightI'll
probably go with something better. But isn't there a way to only use
one LM386 instead of eight? If I'd use a demultiplexer instead of
using the adg508 "in reverse", do you think it'd work better?

Hugo

I'll look into that On resistance thing and try a 74HC4051. It might
just work.
 
E

Eeyore

Jan 1, 1970
0
I'll look into that On resistance thing and try a 74HC4051. It might
just work.

It's still about 50 ohms.

If you have the volts to drive them with, a J108 jfet will do much better = Ron
is 8 ohms max.

Graham
 
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