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Topic: amplifying DAC signals enough (Read 499 times) previous topic - next topic

zibrazibrazibra

so i have a project using an 8bit dac made from 10k and 20k resistors, the output is quite low, and i need an onboard speaker.

using a single 2n3904 doesn't seem to boost the signal enough....

what other options will i have? the less components the better really.



Grumpy_Mike

Quote
using a single 2n3904 doesn't seem to boost the signal enough....
In what configuration?

What voltage do you get out of the D/A when it is unloaded?
What impedance are the speakers?

DVDdoug

It's not that easy to make a linear amplifier with a single transistor, especially a "power amplifier" designed to drive a speaker.

For starters, try connecting some computer speakers.   They are "powered" with a built-in amplifier.

Then, look for an "audio power amplifier" IC.  The LM386 or LM380 is fairly easy to use.

electricalhobbyist

Maybe your speaker has low impedance than the transistor circuit. Law of maximum Power Transfer.
 Try to use speaker that has high impedance or design transistor amplifier with low output impedance. 1 transistor is not enough, maybe 3 can do.

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