Volume control

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Joined: Dec 20 2003
Posts: 354

This continues a thread from the old forums. I am trying to figure out how to control the sound volume through the a/b connector for sound from a line level source. I looked at the datasheet for the amplifier chip (TDA7052A) and read the pins directly. I checked the various pins on the amplifier chip itself while raising and lowering the volume, and I'm a little baffled. Nothing changed at all! The power-in is 5v, the positive signal pin stays steady at 2.5v, and the volume control pin stays steady at 4.9v. The data sheet implies, as far as I can tell (being the amateur I am) that the volume is controlled by varying the voltage on the volume control pin, but this is not happening. Any ideas?

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Joined: Dec 20 2003
Posts: 180
Are you sure it's not done by

Are you sure it's not done by pulses, that your meter isn't registering? Just a guess - no evidence for my theory!

Stuart

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Stuart Bell,
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Jon
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Joined: Dec 20 2003
Posts: 2804
That would be a case to try a

That would be a case to try an analog meter ovre a digital. You'll see the needle wiggle more likely than to see the digital change the readout to register a short pulse.

Jon.

No one should be protected from the effects of his own stupidity. - Anton Szandor LaVey in 1988 (There is a certain irony in this quote... Tongue)

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Joined: Mar 2 2004
Posts: 1
volume control

If the input is controlled in an earlier stage,Mobo?, than the end amp setting don't alter.
If you change the volume control voltage of the chip, the volume should change, I guess.