Distorted sound/Stereo sound now fixed!! *UPDATED*

[xenepp]

**UPDATE**

Success!

I am now the proud owner of one TRUE stereo Radica... with NO distortion!

I located the outputs directly from the chip and have deduced we have L/R/GND attached to three capacitors. Because this is a raw as possable there's no distortion! However the occasional sound effect is still MEGA loud, but the problem's at a minimum now.

I'll get a diagram drawn up once I get access to my scanner.

-Joel

I have now modified my Radica to include *drum roll please* .....

STEREO SOUND!!

This is a nice enough feature by itself, but it has highlighted one other interesting side effect.

The Radica, as with most stereo devices, uses the right channel of audio for mono. This was pretty stupid for the most part anyway since the GOAC generates stereo so any information from the left channel is lost (which is a contributor to the sound being wrong anyway) but while playing Alien 3, I noticed... the left channel is not distorted at all.

I'm pulling my audio directly off the LM358 amplifier, so I'm guessing (and it's just a guess) that the distortion that occurs to the right channel is because of something attached to it before the amp. I say this since the left channel's just fine and I don't see why, if it were a fault with the amp, that it'd affect every radica.

I'm gonna investigate it further but for now, here's the pinout of the LM358 you need if anyone else wants to give this a go:

Code: Select all

1OUT - |1       8| - VCC
1IN  - |2       7| - 2OUT
1IN+  -|3       6| - 2IN-
GND  - |4       5| - 2IN+

-Joel

[usbcd36]

The Radica, as with most stereo devices, uses the right channel of audio for mono.

Wrong, most stereo devices use the LEFT channel for mono, ever notice how monaural devices have a yellow plug for video and a WHITE plug for LEFT audio?

Can't help you with your Radica problem though…

W00t 600th post!

[xenepp]

Well, in the UK most use right

However I was wrong completely. I was not getting stereo at all, the audio channels are merged long before they hit the amp

I'm guessing the signal comes off the glue chip at line level.

I'm gonna poke around a little more

-Joel