Hi there
Yesterday i tried to save a small basic program, from my 8300 via MIC connecter/phono-jack cable to a PC soundcard. When SAVE, only noise came into the PC’s recording program.
I discovered that no schield (GND) was connected from mainboard to the phono socket - only signal wire (center pin) was connected from board to socket.
How can it be possible transferring sound, without a reference (GND) connection?
EarMic phono connectors - no gnd?
EarMic phono connectors - no gnd?
Best regards
Jesper Petersen
Jesper Petersen
- 1024MAK
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Re: EarMic phono connectors - no gnd?
Do you mean that the PCB mounted socket has no 0V/GND connection? Or do you mean something different?
Mark
Mark
Re: EarMic phono connectors - no gnd?
“Do you mean that the PCB mounted socket has no 0V/GND connection?”
Excactly, same thing with socket “EAR”.
I will take a picture one of the upcoming days, of both Lambda 8300 and Your Computer.
Best regards
Jesper Petersen
Jesper Petersen
Re: EarMic phono connectors - no gnd?
Hi All
Disregard this question/issue.
The computer sockets are NOT Phono, but JACK SOCKETS!
I am on the right track again and will return when further testing is done.
Disregard this question/issue.
The computer sockets are NOT Phono, but JACK SOCKETS!
I am on the right track again and will return when further testing is done.
Best regards
Jesper Petersen
Jesper Petersen
Re: EarMic phono connectors - no gnd?
Hi jesperp,
You should try a MONO JACK socket instead of a STEREO one...
You should try a MONO JACK socket instead of a STEREO one...
Xavier ...on the Facebook groupe : "Zx81 France"(fr)
Re: EarMic phono connectors - no gnd?
Hi XavSnap
I am using mono jack plugs into the Lambda 8300, and stereo jack into PC soundcard.
I am using mono jack plugs into the Lambda 8300, and stereo jack into PC soundcard.
Best regards
Jesper Petersen
Jesper Petersen
Re: EarMic phono connectors - no gnd?
Hi jesperp,
As 1024MAK said :"Never use both STEREO channels to like a ZX81 !"
... Or another sound MONO input...
I usually use a "Y" link to couple the both Left/Right channels, but i can't now !
I ever experimented a shortcut on the GND and a sound wire, and the sound was very low.
Just check connector's wiring quality and test the ground/live sound channel resistor. Just in case.
Edit: Tread link to :viewtopic.php?p=47291#p47291
As 1024MAK said :"Never use both STEREO channels to like a ZX81 !"
... Or another sound MONO input...
I usually use a "Y" link to couple the both Left/Right channels, but i can't now !

I ever experimented a shortcut on the GND and a sound wire, and the sound was very low.
Just check connector's wiring quality and test the ground/live sound channel resistor. Just in case.
Edit: Tread link to :viewtopic.php?p=47291#p47291
Xavier ...on the Facebook groupe : "Zx81 France"(fr)