Hello fellows,
I have been working on my last Luxman L100 amplifier (I will not do one anymore). So far the amplifier is behaving great and very fine. But,
I have one minor problem with the muting circuit only, and that is that the muting relay will not stay on when mute is touched. I don't exactly know how much the voltage is that comes from the psu but about 12volts should be right.
I get about 10volts at the muting relay which disappears when mute (volume knob) is touched. It really looks like a floating voltage but I haven't got the original relay (missing, as a lot more was).
Is there anyone who had an issue, about the same, I am experiencing with the touch-mute circuit in the L100 ? I would love to get this solved since everything else of the amplifier is very fine. I have spend a lot of time to get this burned and butchered one getting alive. Only this last small issue ….
Thanks in advance if anyone could point me to the solution.
I have been working on my last Luxman L100 amplifier (I will not do one anymore). So far the amplifier is behaving great and very fine. But,
I have one minor problem with the muting circuit only, and that is that the muting relay will not stay on when mute is touched. I don't exactly know how much the voltage is that comes from the psu but about 12volts should be right.
I get about 10volts at the muting relay which disappears when mute (volume knob) is touched. It really looks like a floating voltage but I haven't got the original relay (missing, as a lot more was).
Is there anyone who had an issue, about the same, I am experiencing with the touch-mute circuit in the L100 ? I would love to get this solved since everything else of the amplifier is very fine. I have spend a lot of time to get this burned and butchered one getting alive. Only this last small issue ….
Thanks in advance if anyone could point me to the solution.
12 volts sounds about right as there is a 16 volt cap on that rail. That voltage should be always present on one side of the relay. If it isn't then check D903 and C915. The circuit could be relay dependent and I can see there is an unmarked resistor on the emitter of Q309. If in doubt then replace the relay with say a 220 ohm and see if the voltages then latch/reset correctly.
Hello Mooly,
On PB647 (power supply board), almost everything has been renewed.
Also C915 and D903. This output (about a little under 12 volts) is going to point 334 on the mute-relay board and measures about 9,8 volts. That one's stable with enough power to drive the relay. I can remember that the original relay has a certain impedance. And that Q309 has an unvalued resistor at its emitter.
Perhaps it is completely out of balance ?
I will follow your advise and do some testing with a resistor to see if I can find the original resistance of the relay. (MAT 2B-CR). Thank you.
On PB647 (power supply board), almost everything has been renewed.
Also C915 and D903. This output (about a little under 12 volts) is going to point 334 on the mute-relay board and measures about 9,8 volts. That one's stable with enough power to drive the relay. I can remember that the original relay has a certain impedance. And that Q309 has an unvalued resistor at its emitter.
Perhaps it is completely out of balance ?
I will follow your advise and do some testing with a resistor to see if I can find the original resistance of the relay. (MAT 2B-CR). Thank you.
Hello mooly,
Yes, what you say is correct, but you must have missed the led, which is 'in between' that wire (showing muting is on or off). Supply goes into 334 and 302 on PB638, and 302 comes back as 304.
I think you have given me the golden answer with your 200 ohms.
Putting in a value of 220 ohms and the circuits works, and stays on. It is working fine. So I took a very small 5v relay, which is about 120 ohms, and made a voltage divider with a resistor of 130 ohms. … YES ! The muting circuit is alive, and so is the whole amplifier now 🙂
Thanks for 'ze golden resistanze' answer !
Yes, what you say is correct, but you must have missed the led, which is 'in between' that wire (showing muting is on or off). Supply goes into 334 and 302 on PB638, and 302 comes back as 304.
I think you have given me the golden answer with your 200 ohms.
Putting in a value of 220 ohms and the circuits works, and stays on. It is working fine. So I took a very small 5v relay, which is about 120 ohms, and made a voltage divider with a resistor of 130 ohms. … YES ! The muting circuit is alive, and so is the whole amplifier now 🙂
Thanks for 'ze golden resistanze' answer !
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