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Old 18th June 2011, 10:56 PM   #1
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Default simple question about sure 2x2w board

This board has volume control in the form of buttons right on the board. Would it remember the volume/gain setting after restart?

I am hoping to use it as a pre-amplifier, but I need for it to remain at the same volume level. I think this is nessesary for my build because I am building a 2.1 channel system and will be running my line level input signal through as many at three pots and spiting it between two class-d amplifiers.

There is a rotary volume kit for this board, but I wouldn't need it if the volume setting on the board doesn't reset.

Does any body know about this?

Also, I am very new to amplifiers, class-d or otherwise. Dose what I have said here sound like it is sensible?

Thanks for any input.
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Old 18th June 2011, 11:46 PM   #2
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Here is a link.
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Old 19th June 2011, 12:28 AM   #3
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Don't have first-hand knowledge of this module, but I've seen it around and wondered if it'd make a decent headphone amp or to power a pair of little Philips SBP1100 speakers I have. Anyway, I had to dig to find your answer, but the PAM8803 datasheet says the power-on or reset gain setting is just 2.6dB. It's gonna do that no matter what type volume control you have.
I take it you're concerned with having to set the channel balance each time you turn on your amp.
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Last edited by sofaspud; 19th June 2011 at 12:29 AM. Reason: typos
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Old 19th June 2011, 01:28 AM   #4
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Thanks for your response. It looks like with the rotary encoder the volume might stay at the same level. There are some switches that disable the volume buttons.

This small preamp would just boost the line level input signal of an MP3 player. I think that it is necessary because I must split the signal for two different amps, and I want each of these on an independent volume pot, plus a master volume pot. I think that the full output of the Sure 2x2w amp would be way too much. I'm imagining it running at about 15-20% output. I don't want anyone turning up both the master vol and the preamp vol, and/or both Sat. and Sub volumes and damaging the bigger amps. Perhaps I could use the rotary vol board and just leave it inside the amp enclosure, set to an appropriate level.

Here is a diagram of what I mean (attached).

I was also thinking of putting a resistor in line after the sure amp to cap it's volume in addition to the master volume pot. Not sure if that is how those things work.
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Old 19th June 2011, 01:50 AM   #5
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The volume control is built into the PAM8803. Just move your master volume control (again, the one built into the PAM8803 that resets to 2.6dB) to the input of the Sure amp. Or if you feel the Sure amp won't work as you'd like, don't use it. Your drawing is missing functional blocks so I can't say much more.
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Old 5th July 2011, 11:55 PM   #6
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I decided to buy one of these to test and play with it. Wow!!! What a value at $9 for the 2x2w board and the volume control board (plus the shipping from China which was about $9 again). The packaging was very nice, like that of a nicely finished electronic product, like an i-pod or some thing. It comes with an auxiliary cable that might have cost almost as much on it's own at a radio shack. There is no manual in the box.

So far I have determined that this board does retain it's volume setting after shutdown. If the K1 switch is set to on than the volume controls don't work and the volume output defaults to a lower setting, I think it says 4db in the manual. I have only been shutting down the unit by cutting the powersupply but it has been starting back up to the same volume level that it was at at shutdown. Hooray!!! This will work perfectly as a preamplifier in my setup, with the volume set at the appropriate level.

EDIT: unfortunately the above is inaccurate. After a sufficient amount of time for the board to shed it's residual power the volume resets to a lower level.

Last edited by birdyfoot; 6th July 2011 at 12:13 AM.
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