IMPLEMENTED SO FAR

- Support for 4x20 LCD Display and large number display
- Brightness and contrast adjustment with remote
- (OPUS/Wolfson WM8741) DAC volume control: remote and rotary encoder
- (OPUS/Wolfson WM8741) DAC random filter selection 1 to 5 with remote
- (OPUS/Wolfson WM8741) DAC upsampling selection (L, M, H -this is the OSR setting)
- I2C level shifting (5V to 3.3V)
- Optimized power-up sequence

Thursday, May 21, 2009

Bug in Volume Value

I miss read the specification and thought volume control resolution was 1/4 dB. The specification says 1/8 dB. Thus rather than having a volume control range of zero to -99 dB, in reality it was only zero to -49.5 dB.

This is actually "good news" as my normal listening level was in the -50 dB range which in fact was -25 dB.

As discussed in a previous post, from a theoretical point of view, there is no loss of data for the upper 48 dB volume level. I was wondering why for a passive volume control, -50 dB sounded so "loud"

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