Hi gents,
My recently purchased Yamaha tuner won’t output stereo , at first I thought it was just the led but it’s not , signal is very good and I’m only hearing mono, any ideas please?
My recently purchased Yamaha tuner won’t output stereo , at first I thought it was just the led but it’s not , signal is very good and I’m only hearing mono, any ideas please?
Is it a lamp or LED? Some stereo decoder ICs will not decode stereo if the lamp burns out or the LED is open. Odds are that the Yamaha doesn't use one of these decoder ICs though.
Post a schematic if you can.
Signal strength meter is at the bottom of the scale, you may be below the threshold for stereo reception. Do you have an antenna (aerial) connected?
Post a schematic if you can.
Signal strength meter is at the bottom of the scale, you may be below the threshold for stereo reception. Do you have an antenna (aerial) connected?
My guess is given vintage it needs to be serviced, and perhaps a few electrolytic capacitors are bad.
Are you able to do rudimentary troubleshooting and read a schematic?
Are you able to do rudimentary troubleshooting and read a schematic?
Concentrate on the multiplex decoder area and its immediate caps.
Don't go re-adjusting anything unless you are skilled, and have all the needed alignment tools.
Don't go re-adjusting anything unless you are skilled, and have all the needed alignment tools.
Its possible that just the local oscillator in decoder (38kHz) is off. It may just drifted with age. Typically all it takes is to move with one trimmer close to the pll chip.
Tell us the markings on the chips. Once we id the stereo decoder chip, finding the trimmer should be easy.
If it sounds good in mono, i would wait with random capacitor change...there are literally dozens!
Still, fix the stereo indicator light first. You will need it.
Tell us the markings on the chips. Once we id the stereo decoder chip, finding the trimmer should be easy.
If it sounds good in mono, i would wait with random capacitor change...there are literally dozens!
Still, fix the stereo indicator light first. You will need it.
Note the position of trimmer before you move it.
While listening with headphones, gently turn the trimmer, left/right, sudenly you will hear stereo.
Find the safest position for stereo for most of the stations.
While listening with headphones, gently turn the trimmer, left/right, sudenly you will hear stereo.
Find the safest position for stereo for most of the stations.
Likely yes. PL.C perhaps? Phase lock something?
Definitely not Sep.B...separation balance.
Cant read any other.
Definitely not Sep.B...separation balance.
Cant read any other.
Do not forget to change the indicator light. You can use led with resistor for time being.
Good luck.
Good luck.