Does this sound right?

I got a Turbo Duo R a few weeks ago and have noticed a very faint high pitched whining sound that is present in the background when the machine is generating it's own sound (off chip).

Red book audio from the CD is perfect. The start of Chi No Rondo with the German monologue is crystal clear, for instance.

I've uploaded a recording of me playing Streetfighter 2 Champion Edition. You can hear the interference at the tail end of main audio segments, just as it is fading out, The best examples on the clip are at 0:13, 0:20 and 0:28.

When the machine is producing no sound there is no noise.

https://soundcloud.com/gregallan/turbo-duo-r-audio-interference

Is this normal with the Duo R? I know it is fairly minor but when the machine is connected to an amplifier with speakers and cranked up it is noticeable and is irritating.

Any help appreciated.

 

Try asking here. http://www.pcenginefx.com/forums/index.php

I am not sure if that is normal. I'd think that it isn't. Maybe interference is being picked up somewhere.

 

Ok thanks.

 

That's a normal "feature" of the PCE's internal sound hardware. Each sound channel can have its own panning / volume control, and the sound hardware has its own panning/volume setting too. However, even with both of these set to Zero, the waveforms of each channel leak out. The only way to get complete silence is to set each channel's waveform RAM bytes to all 15s (out of a range 0..31) so that a level/constant/nonexistent "wave" leaks out of them.

 

Thanks for the reply - it makes sense.

I assume then that this leak is going to be present when the sound hardware is generating a sound AND at least one channel is being set to 15 (silence). Hence why it is more noticeable during a fade out when only one channel is fading out and all the others have been set to 15.

So it is only when the sound hardware is not being asked to do anything that you get true silence?

I'll have to live with it. I was more concerned that I'd spent a little more avoiding the Turbo Duo to get the Duo R and STILL end up with a machine that needed a capacitor change.