Trying to restore or at least fix a Luxman L-11 Stereo DC Integrated Amplifier

[13Hertz]

Hello.  I am trying to determine if there are any drop in replacement speaker relay units for this old and incredible Japanese Amplifier.  It needs to be gone over completely and restored, something which I don't have the knowledge or skill to do -  but I have come to believe that the main problem is that one or both of the speaker relays are malfunctioning.  It powers on and plays but the right channel cuts out sporadically and also the left but more rarely.

 

Anyone know anything about this that you might be able to share with me?  I believe that the relays in some of these old amps might also be able to be refurbished - but I'm not sure.  If I could remove them, perhaps cleaning the contacts might make them work correctly again.

 

If I could find a tech to work on this Amp, I might be inclined to ship it to them to have it restored.  It's a MONSTER - weighs about 35 lbs.

 

Thanks for any feedback, advice or comments.

[billybob]

Digikey is a source I remember for one. Just get the correct one. A service manual will assist.  Info on the relay itself should be visible.. Welcome!

@13Hertz

[13Hertz]

billybob - thanks for the response and helpful info!  I will see what they might have.

 

It's a small victory this morning - but I just managed to get a new power indicator bulb soldered into the L-11 and it's good to see it light up at power on again.

 

[billybob]

Good job! Yes, they had mine in stock. Sounds like your on/off relay/circuit is working.

Some speaker relays have dual small fuses nearby to check.

[billybob]

A common relay like mine is 24 volts.

Not saying this one fits your amp but, a Google brought up this and other new ones on eBay. Quite abit of info online on the Luxman.

Attempted to fix my relay contacts by removing cover.

It was too far gone.:

 

https://www.ebay.com/itm/115131162291

[MC39693]

@13Hertz the audio tech who did a complete refurbishment on my Luxman R-117 said that some relays are easily removed, cleaned and otherwise refreshed NOT replaced. Perhaps a good tech can help if you don’t go the replacement route? Good luck.

[henry4841]

38 minutes ago, MC39693 said:

@13Hertz the audio tech who did a complete refurbishment on my Luxman R-117 said that some relays are easily removed, cleaned and otherwise refreshed NOT replaced. Perhaps a good tech can help if you don’t go the replacement route? Good luck.

Correct. I have cleaned many of those relays even some sealed ones. Cut them open with a hacksaw and then glue them back together. Hard to find a direct replacement. Better to try and clean but one must be sure the relay is the problem and not the relay doing it's job protecting the speakers from a problem in the receiver, amp. 

[henry4841]

Just thought I would mention how I take apart a relay. First you have to get the cover off. Pretty easy to do most of the time. Then more than likely, what I have found on those old gear, you are going to see a spring. Remove that spring and the points will come apart. What needs cleaning are those points. If they are corroded real bad the relay may have to be replaced but what I have always found is they just need cleaning. At least speaker relays. Those relays such as those sometime found on an AC circuit can be burned pretty bad but speaker terminals not so much. Not a lot of current going through them. A little alcohol on a piece of paper or cloth works well. One can polish them with an abrasive if necessary but not with anything aggressive. Just the way I have always done it. 

[13Hertz]

You folks are awesome in providing all of this helpful info to me.  I really appreciate it.

 

I believe that the best course is to remove the stock relays - and attempt to refurbish/clean/restore them as MC39693 and henry4841 suggest.  I want to believe that they are just old and corroded and can be brought back to good working condition.  If not, I'll be looking for replacements.

 

Here are a few pics of the area and relays - it's a maze of multi-colored wires that will be very difficult to disconnect and resolder (for me) but I'm going to give it a shot.

 

Also, as you guessed billybob - there are two fuses situated near the terminals and relays - both are good/not blown.  I get sound through both channels - but right channel cuts out quite a bit and sometimes left.  Truth of the matter is - I'm a long way from knowledgeable about electronics this complex - so, there might be multiple problems - but I don't think it's going to hurt at all to refurbish these relays.  Then see what she sounds like.

[henry4841]

You sure you need to unsolder all those wires. Try removing some screws first. If not be sure and take some pictures of how they are wired along with sketches. All you want to do is get where you can remove the covers and leave those wires alone if possible.

[billybob]

Some cleaning and  contact Cleaner on the controls may help with the channel dropping out. If you have air, maybe a good dusting.

Are you certain relay is not working ? You should hear it click a short moment after powering on.

 

[13Hertz]

1 hour ago, henry4841 said:

You sure you need to unsolder all those wires. Try removing some screws first. If not be sure and take some pictures of how they are wired along with sketches. All you want to do is get where you can remove the covers and leave those wires alone if possible.

Understood - definitely going to look at it carefully and see what wiggle room I have if I take out all of the associated screws on the terminals and the relays.

[13Hertz]

26 minutes ago, billybob said:

Some cleaning and  contact Cleaner on the controls may help with the channel dropping out. If you have air, maybe a good dusting.

Are you certain relay is not working ? You should hear it click a short moment after powering on.

 

Yep, when this issue first started, first thing I did was get some DeOxit into the controls.  Sadly, that did not fix the issue.  That's when I began to research other possible causes.....and eventually landed on Relays.  If I do manage to fix this - it will, I assure you, be solely due to Blind Beginner's Luck. 

[henry4841]

30 minutes ago, 13Hertz said:

Yep, when this issue first started, first thing I did was get some DeOxit into the controls.  Sadly, that did not fix the issue.  That's when I began to research other possible causes.....and eventually landed on Relays.  If I do manage to fix this - it will, I assure you, be solely due to Blind Beginner's Luck. 

One thing for sure you will never fix it unless you try. If it is the relays cleaning will get them working properly again.  At least it always has for me. 

[captainbeefheart]

I doubt it's the relays that are the problem.

 

First you need to determine if the protection is telling the relays to go open. Probe the coil side while listening to music and see if power is present when the channel goes out. I haven't looked at the schematic but what often happens is the large value signal shunt caps going to the protection IC fail no longer shunting all the signal to ground, especially low frequencies. The IC thinks there is DC at the output and opens the relays. Very common issue.

[13Hertz]

So, here is some more info on the behavior of the amp:  last time I fiddled with it (and spent quite a bit of time getting DeOxit into the controls) - after that, it was still cutting out sporadically and I started looking for other possible causes.  That's been probably 10 months ago or more and today, I repeated pretty much the same routine (DeOxit) and really worked all of the controls on the front after spraying with DeOxit.....I think I did a less than effective job the first time.......after doing that today, I wired in some speakers and it's no longer cutting out sporadically - but it won't play both channels in Stereo mode or Reverse Mode. 

 

In the Pic I've attached, I've red boxed a knob that these L-11's have that has 3 settings:  MONO, STEREO AND REV.  Both channels will now *only* play when in MONO mode.  When I switch to Stereo, Right channel only, Switch it to Rev. and Left channel only.

 

This is totally new behavior since I last did troubleshooting on it.

 

So, if the relays weren't working as designed or failing to react properly part of the time, I think I'd be hearing it cut out still - and for some reason, that symptom is gone.  

 

Or, Is it possible that one of the Relays is causing it to not play Stereo?

 

 

[billybob]

Have you had the top off to look at the push button(?) In question.

It may need a deoxidize also.

Some inputs/controls easier to access. Also, want to look into the inside/outside speaker connection for any sign of corrosion. Some even choose to clean the rca inputs being used.

 

[13Hertz]

18 hours ago, billybob said:

Have you had the top off to look at the push button(?) In question.

It may need a deoxidize also.

Some inputs/controls easier to access. Also, want to look into the inside/outside speaker connection for any sign of corrosion. Some even choose to clean the rca inputs being used.

 

Yes - cage is off and faceplate too - has been for over a year.  All told, there are 4 "pushbuttons" on the Amp:

(Left to Right)

1.  Low Boost

2. Phono impedance 1 (push for 100k)

3. Phono impedance 2 (push for 100k)

4.  Power button

 

With the face off, and a straw, it's no problem to get DeOxit down into those switches.  Others are quite difficult to get to from behind - so, I turned the Amp vertical yesterday and sprayed generous amount of DeOxit down into the switches spindles that I can't gain access to (without partial/substantial disassembly).  Doing that definitely helped - because overnight, I now have **zero** static on any of the controls when I work them during playback.

 

The switch I was asking about in my last post is a 3-way.  

 

So, here's what I learned TODAY..............LOL..............I was testing the Amp using Aux input jacks and my phone connected to RCA cable.  Wondering if one of those jacks might have crapped the bed, I moved the RCA cable to 'Tuner' and was very happy to hear that now, in Stereo and also Rev modes, both channels play fine.

 

So, the Left AUX input jack is inop.  Solders look good, it's not the RCA cable.

 

I was considering selling this amp for parts - glad that after joining this Community I was inspired to work on it again and now it's at least working at an acceptable level.  It definitely needs full restoration from a qualified tech - I can tell the fidelity is not what it was when I purchased it off of Ebay back in 1998.  I may still sell it - there are so many components I'd like to hear/try.

 

Thanks again folks for all the comments and info.

 

 

[billybob]

Lol, cool...always learning more all the time. Sweet!

[billybob]

At 100wpc...I may be interested, lol.