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Pacific's Restorations You can see all of Pacific's vintage gear restorations here.

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Old 10-17-2013, 04:24 PM
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Pacific Stereo Pacific Stereo is offline
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Rare and Beautiful Luxman L580 Integrated Amplifier

It's time for another journey into the universe of vintage stereo repair and restoration. This time, it's a gorgeous Luxman L580 integrated that uses the same output transistors (2SB706A and 2SD746A) as the Pioneer SX-980, SX-1280 and SX-1980. What a beautiful piece. Here she is, after everything was done. And yes, that is an adult beverage in a genuine Pacific Stereo glass!



I don't think I have ever seen one of these in the wild, but if you ever get a chance to hear one or buy one, you are in for a treat. This is a very good-sounding integrated, and I'd be happy to own it. It's full of dual FETs where they belong and is exceptionally well-designed from a topology standpoint. However, there are some issues, mainly to do with heat. Like Pioneer, Luxman likes to run things hot, and this beauty is no exception. It has been repaired at least once, and there are many cooked components, heat-stressed solder connections and other heat-related issues to deal with. So.... let's have a look inside, shall we?



Something you'll notice are both the bypass caps and the bleeder resistors across the main capacitors. This product is full of nice little touches like this. One of the things that's interesting about this design is that the main board is upside-down, meaning that the components are on the bottom. This makes for some heat issues, for sure. And this definitely has some. You can see the brown areas around those devices in this close-up view of the main board:



And here's an even closer view of one of the troublesome areas:



Oh, crispy, crispy, crispy. And the bottom of this area fares no better:



Just look at the powdery solder joints in various places, and the trace repair where those transistors are. These run so hot they like to desolder themselves right off of the board. And the heat also causes the copper traces to delaminate from the substrate. And LOOK at that tacked-on capacitor. Hot, hot HOT!

So, the first order of business to to remedy this problem. Those devices get replaced, and the traces get repaired. I like to use silver-bearing solder in high heat areas because it tends to be less prone to breaking down and turning to powder. Somehow, I did not get a photo of the repaired traces, but take my word for it, they're fixed. We also change out capacitors, the bias and offset adjustment parts (the noise-floor pots were not changed), and a few other components. One of the things I did change were the 4559 op-amps, since they control offset and are suffering from silver-lead syndrome. We want those to be absolutely reliable, and they're cheap. And Luxman likes to use that damn glue even on small capacitors that have no chance of breaking off during shipping, so I spend a lot of time removing it, as well. The last thing I do is add heat-sinks to those transistors (they're been replaced, as well) to eliminate their problem. After some work, here's what we get:



You can see the new heat-sinks in this photo. They are RTV'd together only to provide strength, as the devices are insulated from the heatsinks and it wouldn't matter if they banged together.



So that's done. The next thing to address is the power supply. Here's a look at it before:



The detail-oriented will notice that some parts look like they are in spots where they do not belong. For example, the zener diodes are in a place labeled for a resistor. There's no good explanation for this, other than to surmise that the design got changed after the board was made, and Luxman saw no reason to waste perfectly good boards. This occurs on several boards in this unit. Here's the supply after:



New capacitors, new zeners, and no more carbon glue. Let's move on!

Now, it's time to start working on the low-level boards. Luxman did some interesting things to make the servicer's life easier, most notably that the front panel area comes off and will tilt! How cool is this??



Wow! This definitely makes for easier access, but in our case is not enough. So we go on to the next stage. Here are the front boards, filleted. Look at all of the dual-FETs on that board in the middle. One area FETS really shine in are line-level stages. Luxman knew this.



Holy component explosion, Batman! Well, NOW we can get to everything... I won't document everything here, as it's pretty much more of the same. But there are some interesting things to look at. First, here's the volume stage, before.



Just LOOK at that precision attenuator. The L-580 doesn't have a -20 dB muting function, because it doesn't NEED one. This control tracks so beautifully at the bottom end as to be almost orgasmic. And why not? Alps (Luxman) made the control! It's no surprise that they used the best controls for themselves. This board has its own local power supply, and here's what it looks like after some new caps, and new zeners:



The turnover board is part of the tone circuit, and allows the user to choose where the tone-controls operate. Here is before:



And after. Helooooo, Wima!



All of the other boards here are pretty much more of the same. We put nice film caps where they belong, and make sure everything is as good as it can be.

In all high-power units, the power switch is an issue. This one is no exception, and we go there next. I wish the L580 had a surge-reduction scheme like some other products, but it does not. So we have to service the switch (or replace it, which is often terrifically expensive). This switch was solid black inside (on the top, which is the amp side) and almost welded in the ON position. Since the contacts for the switched outlets were essentially unused, I refurbished all of the contacts and then switched wiring around so that the unused contacts are now powering the amp. I also added my improved snubber (not shown) to cut down on contact erosion. I expect this one to be good for at least another 30 years.



And with that, you've seen just about everything. Oh... here's the Pile-O-Parts:



This amp is quite special and I spent several hours listening to it, which is something I ordinarily do not do. While I always intensively evaluate everything I service, I don't normally do it for six hours. But I was mesmerized. She has a punchy-yet-easy characteristic to her that is just exceptional. I loved her bass performance, was romanced by the very silky midrange (thank you, FETs!) and was transfixed by the speed and openness of the high frequencies. Wish I could keep it, indeed. But her owner no doubt wants it back.

The only thing left to do was take some glamour shots!







Oh, yeah. One more time!



Make your own kind of music.


All photos, copyright 2013 Pacific Stereo. All rights reserved, no use without written permission. I better not see these on eBay!
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I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net

Last edited by Pacific Stereo; 05-26-2014 at 05:06 PM.
  #2  
Old 10-17-2013, 07:30 PM
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Ricardus Ricardus is offline
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Nice!

I would love to see a pic of those or some other repaired traces someone.
  #3  
Old 10-17-2013, 07:43 PM
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....(choked on drool)....God is that a beauty!!!!! Rob
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Old 10-17-2013, 07:50 PM
Dan Ruddock Dan Ruddock is offline
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An L480 I looked at once had the same over heated transistors in it. The problem was not just with the L580. Dan
  #5  
Old 10-18-2013, 12:29 PM
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Wow, wow that is just so beautiful.... wow
  #6  
Old 10-18-2013, 01:25 PM
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Kind of like that face design, not quite as much as say an L31 or L80V, but it is still cool.

Can't say the same for the innards though. I'll have to get some pics of my 5L15 internals; suffice to say it's way better constructed than this later model from the looks of things.

Nice restoration work as always...

John
  #7  
Old 10-18-2013, 08:03 PM
Warped Bezel Warped Bezel is offline
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I've never seen anything like it. Maybe I should pay more attention to them.

I really enjoyed my time with the R-105 receiver I got for before packing it for a member trade. Has three inputs for video sound but not video and a surround mode of sorts.

A NON-AV AV receiver!
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File Type: jpg Luxman R-105.jpg (145.9 KB, 16 views)
  #8  
Old 10-19-2013, 12:45 PM
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Thanks much for posting so many details, PS. I really enjoyed reading it. I'd be terrified of all the detail work in getting everything back together exactly - I always much preferred building stuff versus restoring/repairing, so I have a lot of respect for what you do.

A beautiful, unusual looking amp indeed. Never paid much attention to Luxmans - my loss!
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  #9  
Old 10-19-2013, 09:23 PM
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Is there any way to add a cooling fan inside the case to alleviate some of that heat build-up?
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  #10  
Old 10-19-2013, 10:12 PM
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I expect the LRS integrated amp to be much more solid than this unit. This was the first series of gear from Luxman that seemed to Americanize the equipment. Gone were the rosewood cabinets, replaced with the gorgeous rosewood vinyl used on the previous receivers. Build quality was down a bit, too, but when compared to the LRS, it is not even close. Each piece of LRS gear I have ever lifted seemed like a full, solid block of metal, way heavier than expected. All well build statement pieces by Luxman.

The L-580 is a nice amp, I've had one since I got one used (retail) from the store where I used to work. It did a wonderful job but burned up a bit. PS, I'm hoping you can provide a good bit more info to help inspire me to move forward with a rebuild of this unit. I know it is not possible to get pics of parts that you did not already capture because it is being/was returned to the lucky owner. But maybe...

Excellent work on that unit. Did you do anything about the heat problem? I have mounted the offending transistors to the cross member so they have a sort of heat sink. Be nice to know what the pros do for situations like this.
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  #11  
Old 10-20-2013, 07:48 AM
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Pacific Stereo Pacific Stereo is offline
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The parts I replaced are shown in the photo. Yes, moving those transistors to a frame member is one way of solving a heat problem. One issue with doing that is the possible introduction of oscillation or other noise because those parts are now connected with what is essentially an antenna, plus we've changed capacitance and inductance to unknown values. So my preferred solution is local heat-sinking if possible, like I did. And again, using 2% silver-bearing solder will help to alleviate the powdery-solder issue.

@Scorp: I suppose one could always add a fan. Would also need a speed-control circuit to keep noise down. You don't need to move that much air. Moving air might add other complications, however, such as a moving target for the bias point that was not there before.
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I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #12  
Old 10-20-2013, 08:33 AM
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Very nice!



Dave
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  #13  
Old 11-10-2013, 11:19 AM
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So I wonder what one of these things would be worth? That said I've never heard a punchy Luxman amp yet, so it would be a first for me to hear one. Then again any Lux amp I've heard was the 100 series, so that might be the reason why.
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Old 11-11-2013, 09:46 AM
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Pacific,
For overheated TO92 transistors, or the extended case versions like 2SD667, I use pcb mount GMA sized fuse clips as heatsinks.
  #15  
Old 11-11-2013, 02:08 PM
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Pacific Stereo Pacific Stereo is offline
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Doc, that's an interesting idea. Not much metal there, but probably at least doubles the dissipation of the device! I've put some to-92 sinks that MOuser has in my restock order, so we'll see how I like those.
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I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #16  
Old 11-11-2013, 02:21 PM
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I'm pretty certain that if my stereo gear was out where you could see it instead of in a cabinet with doors (just the turntables sit on top), I would have no choice but to hunt down something in a lovely vintage piece like that instead of the plain black amp I'm using. Very nice work. It is heartening to know someone out there is bringing these things back to life.
  #17  
Old 11-18-2013, 08:31 AM
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I like the funky ones like this! really pretty amp nice job on the restore!
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  #18  
Old 11-18-2013, 10:16 AM
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Thanks. This was really a fun one, and I loved the way she sounded. Just got feedback from the customer last night, who is as happy as could be. Love that!
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pacificstereo.net "Make your own kind of music!"



I RESTORE VINTAGE AUDIO AND VIDEO GEAR. Master technician for Concept, Quadraflex, Calibre, Pioneer and Sony. Endorsed by Richard Schram for Concept product restoration. Factory technician for both Yamaha and JVC. Sonics consultant for Denon. Pacific Stereo store manager, service manager, Central Service lead tech, liquidator at our demise. Pacific Stereo curator. Infinity IRS dealer. Music buyer for one of the first CD retailers in the USA. Authorized servicer for virtually every brand on the planet at one time or another. Music addict. Mastering & recording engineer, weaned on a Neve (no other console sounds like a Neve!). Industry-respected ears. Head Tapehead.

Need vintage audio & video repair and restoration, or unobtanium semiconductors and parts? Ask me! And do visit the website: pacificstereo.net
  #19  
Old 11-18-2013, 10:36 AM
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ive got a old luxman integrated sitting in its original box buried deep in the garage of doom. ive never even powered it up. this thread makes me want to seeing how beautiful they are restored.
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Old 11-19-2013, 04:39 AM
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Hmm...am I weird for noticing the "Pacific Stereo"-labelled whiskey glass?
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