I've noticed this for months, but I only notice it when I'm getting in the car, so by the time I sit down with the BBS I've long since forgotten it. Finally I remembered to post this.

When using the Voladj kernel with the Selecter program (I don't know which of the two is responsible?), there is a speaker pop at the moment Selecter is invoked. It's intermittent, it doesn't happen every time.

It sounds like the old days of programming the C-64, when you would write a bunch of 00's to the SID chip to reset it. If you did this without first turning down the volume, you'd hear a similar pop.

Any clues?

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Tony Fabris

Interesting. I've not yet noticed it (the pop). I just tried ten or so times playing through my computer speaker (yes, there's only one of them!) with no success. I would expect you might get such a thing if there was still music coming out of your speakers when you called the little selecter program, because there might be a sudden change in the multiplier. However, when the player stops, the output buffer gets filled with zeroes, I think. By the time the selecter program runs, I would expect only silence, so changing the multiplier won't affect anything. Have you noticed any patterns as to when it happens? During a particularly soft piece of music, for example? Does it happen only when booting the player, or only when you select "Quit" from the menu, or both?

Richard.

To answer your questions:

I only notice it in the car, not at home.

I only notice it when booting the player, not when selecting quit from the menu.

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Tony Fabris

One more thing. I don't know that it's Selecter or not. It could be the kernel?

It's just that around the time that the pop happens, that's when Selecter is available for me to press the button. I can't tell exactly since selecter offers no visual feedback when it's invoked.

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Tony Fabris

Touche!

I really can't see selecter doing anything that would cause a pop at this stage. The ioctl() simply sets the current multiplier to 1. If you were already playing music with a much higher multiplier, then a pop might happen. But at this stage the player hasn't even been started yet, so that can't be the case. It might exacerbate an existing pop, but I think even that's unlikely. I wonder if it would still happen using the stock released kernel.

Richard.