This is not the ultra monster R-117, but its much younger brother at 80 w/ch. It is a recent thrift store acquisition with this startup problem. When started from cold and volume set low, one channel is completely out. No dc at all on the dead channel, the other is fine and measures 4.5mv at the speaker terminals. If I leave let alone for about 1 minute OR turn up the volume abruptly, some static and crackling and the channel kicks in. For that evening, it starts up nicely, output from both channels immediately after the relay kicks in. Next day, though, same problem, the right channel is dead on startup, eventually wakes up. I've cleaned the volume pot and wiggled everything, it does not appear to be either the volume or any other pot or switch.
Blanket resolder, and replacing all the electrolytics is always a good start with a faulty old amp.
The unit is of 1988 vintage, is it really necessary to do a blanket cap replacement? As far as resoldering, will reflowing the existing solder suffice or is more involved? What temp would you recommend I do this at?
DreadPirate said:
Yup, it's worth it on anything over about 10-15 years old.
Reflowing should be fine. I don't do that temperature stuff, I just have a 20w iron for little stuff, and a 50w for bigger stuff. 😉
DreadPirate said:
Have yet cleaned even the relay contacts? Old relays with oxidixed contact often show itself with the simptoms you described for your Luxman (on channel intermittent or creaky). A cleaning with usual contact polishing sprays may solve the problem.
Try it before throw it... ;-)
Hi
Piercarlo
Hi DreadPirate,
Piercarlo has given you the correct answer in most cases. Make sure that no cleaner remains on the relay contacts when you are done, or buy a new relay (best solution).
If you still have problems, resoldering as Al suggested is a very good idea. I would do that as well if I were you.
-Chris
Piercarlo has given you the correct answer in most cases. Make sure that no cleaner remains on the relay contacts when you are done, or buy a new relay (best solution).
If you still have problems, resoldering as Al suggested is a very good idea. I would do that as well if I were you.
-Chris
I have deoxit, I plan on wetting a strip of cloth, sliding it back and forth between the contact surfaces, then following up with a dry cloth. Is this the best way to clean contacts?
And has anyone encountered the volume control issue on this series of Luxman? What are the symptoms? I have the opportunity to pick up a replacement volume control unit and a set of knobs for $35.
And has anyone encountered the volume control issue on this series of Luxman? What are the symptoms? I have the opportunity to pick up a replacement volume control unit and a set of knobs for $35.
Hi DreadPirate,
Follow the cleaning of the relay up with a non residue cleaner. Electrowash 2000 PX would do nicely.
-Chris
Nope
It's worth it for the knobs alone.
Follow the cleaning of the relay up with a non residue cleaner. Electrowash 2000 PX would do nicely.
-Chris
Sure enough, I was able to duplicate the symptoms by rocking the relay cover. The solder looks good on this board, its one of those vertical ones mounted off the speaker connectors. Tapping around yielded no results, looks very likely its the relay. Am I to guess that this part is not obtainable at this point? Will there be info on it to order a replacement or is the schematic necessary?
Hi DreadPirate,
Check out MCM or some other vendors like that.
You can also take them apart and clean them. Desolder and remove them from the board first.
-Chris
Check out MCM or some other vendors like that.
You can also take them apart and clean them. Desolder and remove them from the board first.
-Chris
I moved the transformer out of the way and unscrewed the board to get at it easier. Actually looks pretty clean the part is:
Matsushita
JR2a-DC24V-Y3
AJR39040
5A 125V AC
Made in Japan
902 17P
I'll wipe the contacts clean and re-install. Maybe I'll hold off and see if I can get a replacement. Wouldn't it be hard to find identical pin locations for insertion?
Matsushita
JR2a-DC24V-Y3
AJR39040
5A 125V AC
Made in Japan
902 17P
I'll wipe the contacts clean and re-install. Maybe I'll hold off and see if I can get a replacement. Wouldn't it be hard to find identical pin locations for insertion?
I got everything together, and I'm still getting some cutout on one channel. The relay looked quite clean and didn't really show any wear. So I moved on to the volume pot and balance pot, these are most accessible and worked on them quite a bit with deoxit and turning. This was the first thing I had done, thought I'd do it some more. Still a bit of cutout. Went around punching all buttons and controls and may have found the culprit: the Tone Defeat button. When pressed, it results in the same symptoms, losing one channel completely. It is the only control where sound is lost when pressing. Worked the button about 50 times, unit seems to be working fine now, but haven't had enough time to really gauge it. Unfortunately, it is buried and inaccessible, I may not be able to get at it other than flooding from the front. Time will tell.
Thanks all for help, learning something new all the time...
Thanks all for help, learning something new all the time...
Hi DreadPirate,
Yeah, switches can really mess things up. My Nak TA-2 has the same problem exactly. I have to rip it apart to get to it.
-Chris
Yeah, switches can really mess things up. My Nak TA-2 has the same problem exactly. I have to rip it apart to get to it.
-Chris
I have an R-115 that exhibits this same issue.
I've found that either of the Tone Defeat or CD Direct switches can affect the right-channel cut out. I've only been able to address this in a short term manner, by working these switches and trying to get contact cleaner down into them. As you noted, these switches are underneath a lot of other components and hard (impossible) to access inside the case without a lot of disassembling.
You can see how closely these controls (volume, tone defeat, cd direct) are wired by looking at the schematics and PCB layout diagrams in the service manual:
Login | HiFi Engine
I've found that either of the Tone Defeat or CD Direct switches can affect the right-channel cut out. I've only been able to address this in a short term manner, by working these switches and trying to get contact cleaner down into them. As you noted, these switches are underneath a lot of other components and hard (impossible) to access inside the case without a lot of disassembling.
You can see how closely these controls (volume, tone defeat, cd direct) are wired by looking at the schematics and PCB layout diagrams in the service manual:
Login | HiFi Engine
I just picked up this great sounding unit however the right channel may be a little weaker than the left. Not cutting out, just a little lower power/volumn. I have been reading that tone control or speaker relays may need cleaning. I already deoxit the tone controls and all switches and pots, except volume control . I wasn't sure how to clean that since it wasn't your typical pot. But my question is...if there is no apparent discrepancy between the channels when I have headphones on, only when using the speakers, does this mean tone control is probably ok and its more likely the speaker relays?
I just got one of these - but mine isn't clicking the relay at all.
I'll tear into it, but is there an obvious weak spot ? Like that tone defeat can defeat all the sound ???
Thanks.
Srinath.
I'll tear into it, but is there an obvious weak spot ? Like that tone defeat can defeat all the sound ???
Thanks.
Srinath.
It could be the tape switch or any other. Try and operate the switches and controls slowly to see which need cleaning. Use the minimum amount of cleaner as it washes out the lubricants. That can wreck the control. Do not clean slide controls. There is a special way to do that.
-Chris
-Chris
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