I have a luxman L-100 amp that when turned on no longer engages the output relay.
For some time now it has been taking longer and longer for the relay to stay latched on, sometimes taking up to 15 mins with the relay clicking on and off before it latches on for good.
Does anyone have a schematic of this part of the amplifier that you could email me or any ideas as to what the problem could be?
What is the purpose of this relay and why does it take time for the amp to latch the relay when first turned on?
Any help appreciated,
Jason.
You have a capacitor in the relay circuit that has dried out.
Due to the age of the piece it would be worthwhile to replace all of the electrolytics in the amplifier.
Digi-Key and Mouser are good places to buy from, call and get a catalog on paper.
You're in OZ so you're on your own for parts.
Due to the age of the piece it would be worthwhile to replace all of the electrolytics in the amplifier.
Digi-Key and Mouser are good places to buy from, call and get a catalog on paper.
You're in OZ so you're on your own for parts.
As for the purpose of the relay it is to avoid turn on thumps and possibly DC out on the speaker terminals. Some amplifiers also have overload protection of the output stage via the relay.
Hi Jason,
It looks like about a 47uF at 50V. I think it's charged through D902. I can hardly make out the printing on the schematic. This is the most likely one. Some of the small caps in the same area may have failed as well. Try this before going on a cap changing blitz.
-Chris
It looks like about a 47uF at 50V. I think it's charged through D902. I can hardly make out the printing on the schematic. This is the most likely one. Some of the small caps in the same area may have failed as well. Try this before going on a cap changing blitz.
-Chris
bad guess, the bi-polar caps filter out audio from tripping the circuit, the main RC time constant cap is the more likely culprit.
Now if he had said that the relay was tripping on loud bursts of audio I would tend to agree with you.
Now if he had said that the relay was tripping on loud bursts of audio I would tend to agree with you.
Hi djk,
You've seen this before too huh. Djk is right, power supply cap for the relay circuit or any of the timing caps.
-Chris
You've seen this before too huh. Djk is right, power supply cap for the relay circuit or any of the timing caps.
-Chris
It's a low noise 22V zener.
If you can't find it you might try 1N4115 or the BZV39 series equivalent.
/Hugo 🙂
If you can't find it you might try 1N4115 or the BZV39 series equivalent.
/Hugo 🙂
Hi ozaudio,
please check if there is no DC Offset in your output
stages. Probably is is drifting more than usual,
and the protection circuit just does it's job and
disconnects the speaker from the output if a
given DC threshold is passed.
Regards,
Stephan
please check if there is no DC Offset in your output
stages. Probably is is drifting more than usual,
and the protection circuit just does it's job and
disconnects the speaker from the output if a
given DC threshold is passed.
Regards,
Stephan
Hi Jason,
I betcha a lamp is burnt out. The input selector lamp and power lamp (if equipted) serve as a load across the zener. If the lamp goes out the zener takes all the current and may short. The series resistor will then cook too.
Normally I would change the lamps, resistor and zener. That and some of these caps in the power supply and protection circuit.
-Chris
I betcha a lamp is burnt out. The input selector lamp and power lamp (if equipted) serve as a load across the zener. If the lamp goes out the zener takes all the current and may short. The series resistor will then cook too.
Normally I would change the lamps, resistor and zener. That and some of these caps in the power supply and protection circuit.
-Chris
I've a rather badly repaired L100 and would like to fix it up...has anyone here got an emailable schematic for this unit?
a) protection switches in after about 10 minutes
b) somebody removed all the connectors and soldered bare wires to the pin headers.
c) one power amp has poorly-done pwr xstr repairs
Lots of work to do on this, but worth it if I can find schematics somewhere!
a) protection switches in after about 10 minutes
b) somebody removed all the connectors and soldered bare wires to the pin headers.
c) one power amp has poorly-done pwr xstr repairs
Lots of work to do on this, but worth it if I can find schematics somewhere!
Hi plcamp,
I can try to give you a hand, but my schematic is very poor.
The first thing to do is clean up all the problems you know about. On the messy repair side, replace any semi's that are ECG, NTE or North American types. If the outputs have been replaced, do the drivers also.
Either solder the wires directly to the main PCB or reterminate the wires. If you can, post a couple pictures so we know what we are dealing with.
-Chris
I can try to give you a hand, but my schematic is very poor.
The first thing to do is clean up all the problems you know about. On the messy repair side, replace any semi's that are ECG, NTE or North American types. If the outputs have been replaced, do the drivers also.
Either solder the wires directly to the main PCB or reterminate the wires. If you can, post a couple pictures so we know what we are dealing with.
-Chris
Hi plcamp,
I am still looking around a bit myself. I'll let you know.
Nice little unit though. You'll enjoy it when you are done.
-Chris
I am still looking around a bit myself. I'll let you know.
Nice little unit though. You'll enjoy it when you are done.
-Chris
L110
I've been following this thread today, as I just joined the DIYaudio forum today. I also have an L110 that will not fully turn on. One channel seems to come on. I tested the preamp and power amp separately and the power amp works as intended. Whatever the problem is, it seems associated with the preamp side of things. Are the suggestions offered so far still valid in my case? Is there somewhere else I should look for the problem? Patrick
I've been following this thread today, as I just joined the DIYaudio forum today. I also have an L110 that will not fully turn on. One channel seems to come on. I tested the preamp and power amp separately and the power amp works as intended. Whatever the problem is, it seems associated with the preamp side of things. Are the suggestions offered so far still valid in my case? Is there somewhere else I should look for the problem? Patrick
Hi Patrick,
Your problem is more likely related to switch contacts. If there are any signal relays in there, give them a good tap.
You may even have a cracked solder joint on a jack connection to the PCB.
Right now, you need a signal generator and oscilloscope to trace the signal through the preamp section.
-Chris
Your problem is more likely related to switch contacts. If there are any signal relays in there, give them a good tap.
You may even have a cracked solder joint on a jack connection to the PCB.
Right now, you need a signal generator and oscilloscope to trace the signal through the preamp section.
-Chris
Thanks for the feedback. Work has kept me too busy to play with it yet. My first attempt at a repair will be to spray everything with turner cleaner. Before the one channel went totally bad, there was a delay circuit that would turn everything on after about 3 seconds. It came to pass that occasionally only one channel would come on. It makes me think there must be a relay somewhere that has dirty or bent contants. Does anyone know if I'm on the right track. From reading this thread, I am also considering wholesale changes of electrolytic capacitors. Patrick
Hi Patrick,
The cleaner may destroy the seals on electrolytic capacitors. Desolder the relay and clean the contacts with a business card and cleaner. Then use a no residue cleaner to wash everything out and remount the relay. The contacts must be dry with nothing on them. If they are pitted, you need a new relay.
-Chris
Don't do that!!!!!
The cleaner may destroy the seals on electrolytic capacitors. Desolder the relay and clean the contacts with a business card and cleaner. Then use a no residue cleaner to wash everything out and remount the relay. The contacts must be dry with nothing on them. If they are pitted, you need a new relay.
That's a good plan. Take a few pictures of the board before you start.
-Chris
Luxman L-100 Output PCB.
Probably a longshot. I was just given a Luxman L-100 from the metal recyclers. It appears that whoever wanted it cremated decided to remove the heatsinks with outputs and PCBs. Is there a practical solution or is this amp finished?
Probably a longshot. I was just given a Luxman L-100 from the metal recyclers. It appears that whoever wanted it cremated decided to remove the heatsinks with outputs and PCBs. Is there a practical solution or is this amp finished?