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

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Old 12-14-2012, 06:28 PM
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Pacific's Concept 16.5 restoration (LOTS of pics!)

EDIT: More units, more work, more photos on following pages!

Well, it's that time again. Time to put up another Concept. This time, it's the beast, the one and only 16.5. For the uninitiated, this was the top of the Concept line. And for those that know, well... yeah!

This unit came in working, but it had a number of problems that I uncovered and that also cropped up later after the burn-in. On these old beauties, 12 hours of burn-in is a minimum. So let's have a look!

On removing the cover, there were some things I definitely did not like. The most troubling is the rust and flaking on the power transformers. It looks like water has gotten down into the unit. Fortunately, water had not gotten onto boards or into other sensitive areas. The chassis was pretty dirty and there was some black corrosion on it that I ended up not removing.



The first thing we tackle are the power amp boards. Because they are the most dangerous and unpredictably troublesome, I always start on those first. The 16.5 is built in the same wonderful unpluggable way as the 11.0 is, and that makes working on them easier than other giant receivers from other manufacturers. Here's one of the boards.



Similar to the 11.0 boards, for sure. But definitely different. And here's what one looks like afterwards.



You'll notice a few differences. One is that we get rid of the back-to-back 100uF caps and sub in a bipolar 47uF part. We also get rid of the input electrolytic and install a nice Wima film cap. Another change is that we swap out the differential transistors for new, but also remove the capacitor that's in between them (it gets relocated to the bottom of the board) and physically couple the parts together. That makes for much better thermal tracking between the parts and helps keep offset low. Also, see the new heat sinks? Those parts run quite hot, and installing these are now part of the standard list of things to do. It's not done in this photo, but I RTV them to keep them from contacting each other, even though the parts are also insulated from the sinks. Of course, we change out the old bias and offset pots for new.

I also ran across something unexpected and that was bias transistors that had gotten so tired that they had no gain. This made bias impossible to set on one channel (too high) and unstable on the other. Those got changed. Oooh! Original devices. I like that.



The next area is the power supply and protection circuits.



Nothing too exciting here, except for a couple of obviously cooked capacitors. Here's what it looks like after.



Power devices get changed out. I don't change those pots because they just set the meters and don't do anything critical. I just clean them.

So what's next? Why, the phono board of course.



It gets film caps where it matters. And now, we should have a look at the control amplifier.



Here, we use a combination of mostly film and audio-grade electrolytics. And now it's time... for power switch overhaul.

Unfortunately, the 16.5 does NOT use the high-power microswitch that the 11.0 does. I wish it did. It uses an unobtanium switch. And they get ugly inside. This is a look at the contacts after I take the switch apart.



Uckey. The first thing I do is get the moving contacts as good as I can get them without removing too much material.



Not perfect, but much better. We then put the switch back together. Easy-peasey!



NOT!! This is an exceptionally difficult switch to reassemble. What I've done is put the unused stationary contacts where the pitted used ones were. I seriously thought about reversing the moving contacts. My engineer brain says this is a mirror image and should work just fine that way. However, since this unit is being shipped, the last thing I want is for something I didn't think about rearing its ugly head when the customer has his unit back. So I play is safe and assemble the switch they way it was. I will caution anyone thinking about doing this to their switch to NOT DO IT. This switch is very, very difficult to reassemble, and you will end up sending it to me (that is, if you don't break it).

After these operations comes AM, FM and MPX alignment. This is a 5-gang tuner, and is wonderfully sensitive. It aligns right up, and I play with it for an hour or so. Then I put the unit aside to burn in for 12 hours.

I come back to find that all is not well. FM muting isn't working any more, FM audio is distorted, the disicriminator is wonky and there's no FM stereo. Ruh-roh. I take the cover off of the AM/FM board and the unit starts working almost immediately. Egads! Heat does it. Stereo doesn't come back, but everything else starts to work. So I change out the IF part, align the IF section again and wait overnight. Success! But still no stereo. That turns out to be the other IC, the MPX processor. Not sure why it refuses to work anymore, but a replacement restores normal operation. Sheesh! I touch up separation and all is well.

That's the trouble with vintage stuff. It's OLD. And just when you think you've got everything licked, the set goes, "No. I'm not ready to leave yet." But now, this one is. And she's lovely.

And... heeeeeeeeere's the Pile O Parts!



That's 94 capacitors, if anyone cares to count.



She's gotten BeautyMaker and the metal cover has been repainted. And oh... shorting plugs on the phono inputs are REQUIRED on these, and they are always missing. I make a set out of a cheap patch cord.



Oh, and well... a little bit of refurb on the inside, too.

Before...



and after.



I reproduced and applied the Concept stickers after I had the transformers looking nice.



She is just gorgeous, as beautiful as she can be.



And of course, NOW (because everyone expects it), I had to take a "lit up" shot. This was done really quickly, because it's 30 degrees outside, it's starting to snow and I had to work fast.



What a beauty.


All photos, copyright ©2012 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; 09-14-2014 at 05:31 PM. Reason: Sheesh, found a typo after a YEAR!
  #2  
Old 12-14-2012, 07:12 PM
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Gorgeous PS!
  #3  
Old 12-15-2012, 09:58 AM
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Another beautiful P.S. restore. Richard Schramm really did his homework with his design. The 16.5 in stock form is in my top three of Silver Era receivers. I can only imagine how much better the P.S. restored 16.5 must sound. I've gotten rid of many brands of receivers in my collection including Yamaha, Sansui, and Pioneer but the 16.5 will always have a place here.
  #4  
Old 12-15-2012, 10:17 AM
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Wow, nice work. someday I'll send you mine for a rebuild.
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  #5  
Old 12-15-2012, 09:33 PM
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Thought it might be fun for everyone to know that Mr. Schram visited us to see this one. How cool!
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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
  #6  
Old 12-15-2012, 10:55 PM
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That is simply amazing PS. I wish I was around when these were on the shelves, but I was a toddler then.

It's great to see the love and care you put into bringing these back to their glory. Superb work sir.
  #7  
Old 12-16-2012, 09:31 AM
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Quote:
Originally Posted by Pacific Stereo View Post
Thought it might be fun for everyone to know that Mr. Schram visited us to see this one. How cool!
It must have been a real pleasure discussing the design with the designer. I spoke to the chief designer of a very well known brand and actually saw him working on it. The explanation of why he did this or that was totally fascinating. Without question, that was the most privileged and best day of my audio hobby.
  #8  
Old 12-16-2012, 06:58 PM
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Smile

wow, amazing work!


simply outstanding Job you did!!!

amazing, Bravo!
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  #9  
Old 12-17-2012, 11:02 AM
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How to you get the circuit boards to look so clean? They look like new. Do you dip spray or scrub them ? With the new components, paint, and stickers installed it looks as if it came off the assembly line today. Your work is nothing short if amazing!


Thanks for sharing the process and the results!

Philip
  #10  
Old 12-17-2012, 12:55 PM
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I wish I had a "magic" way of making boards look nice. I just detail them as I work on them, and they tend to come out pretty nice. There's someone who sells vintage gear and has something he calls "MintShine" (or something like that). I've seen a unit treated with this stuff, and it's some sort of waxy material of which the true composition escapes me. One thing I can say, however, is that it certainly doesn't belong on circuit boards.
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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; 12-17-2012 at 03:21 PM.
  #11  
Old 12-17-2012, 02:24 PM
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WOW!!... That is some beautiful work you do. Pretty brave getting out in that 30 degree temperature for pictures. I can see the snow on the bushes in the background.

Great Pictures!

I just pulled my 16.5 out of itís cubby hole a couple of weeks ago so I could start working on it a little.
It seems to have a stuck relay in the power circuits; when I turn the power switch off the panel lights go off OK but itís still playing music from the speakers. I have been turning it off and on through a line stabilizer box that has relay power switches. The 16.5 draws so much current at power-up I didnít want to arc-up my AC plug prongs buy just plugging it in and unplugging. Itís like this for about a year now, Time to fix it.
I bet itís the same switch you just overhauled on your referb.

So my 16.5 has been sitting on the end of my kitchen counter for a few weeks now and the 6.5 is in where it was, doing TV duty for now.

Jeff
Attached Images
File Type: jpg DSC_0919.jpg (60.8 KB, 45 views)
File Type: jpg DSC_0920.jpg (63.8 KB, 44 views)
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Looks like some sort of secreted resin. Yeah, but secreted from *what*?
  #12  
Old 12-17-2012, 03:22 PM
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Oh, I suspect you are going to find welded contacts on the output relay in question (there are 3 relays). Either that or a shorted relay drive transistor.
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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
  #13  
Old 12-23-2012, 07:10 AM
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Beautiful work as always.

My question is, have you ever had a piece of equipment fall off that stool you use and roll down the mountainside?
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Old 12-23-2012, 08:41 AM
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Once. It was a $5000 Audio Research preamp that a gust of wind came up and blew over while I was trying to get a shot of the inside. The scuffs took a significant amount of value off of the unit, but happily, nothing got broken.
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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

Last edited by Pacific Stereo; 12-23-2012 at 08:44 AM.
  #15  
Old 12-23-2012, 03:52 PM
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Quote:
Originally Posted by Pacific Stereo View Post
Once. It was a $5000 Audio Research preamp that a gust of wind came up and blew over while I was trying to get a shot of the inside. The scuffs took a significant amount of value off of the unit, but happily, nothing got broken.
Ouch! That must have been "A Mighty Wind"... Get it?! LOL

Sorry.
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  #16  
Old 01-22-2013, 05:50 AM
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Nice job on the 16.5. Looks fabulous.

A question for you. I've a 16.5 that gave my usually unflappable tech fits. It was cleaned and refurbished and worked well except when doing a 48 hour burn in, would randomly and inexplicably go to rail voltage on one channel (left I think), taking out a couple of test speakers with it. No clear explanation. The board was scrubbed, and rebuilt with appropriate parts twice and still it did the same thing.

I've received the unit back and its been sitting waiting for me to decide what to do with it. We thought that there might have been a couple of rouge high impedence paths on the board somewhere but we just couldn't find it.

Also, isn't there a decent way to install a power switch to then turn on a power relay for powering up? Seem like it should be an important mod to relieve the power switch of passing that much current.

Thanks for your dedication to the Pacific Stereo and Concept lineage.

BTW, I thought you used to be in Orange County, when did you move to Central California?
Welcome Bart! Good to see you over here!!
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Old 03-07-2014, 04:54 PM
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How many watts per channel were these?
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  #18  
Old 03-07-2014, 06:50 PM
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How many watts per channel were these?
165w rms to a 8 ohm load, or 250w rms to a 4 ohm load
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  #19  
Old 03-07-2014, 06:52 PM
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Concept model numbers followed their FTC rated outputs. In this case, 165 watts per channel.
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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
  #20  
Old 04-04-2015, 06:11 PM
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Well, finishing up yet another one... whew! I think this one has been the dirtiest, with the most things wrong with it of any 16.5 I have ever done. Corrosion, super dirty with sticky gunk all over it and inside it, busted FM stereo, power switch contacts beyond gone, cosmetically damaged, and on and on and on. But she's now in burn-in and sounding really nice and looking damn decent.

This time, it's not scotch in the Pacific glass, I'm more in a gin mule/copper mug kinda mood. Waiter! Bring the New Amsterdam!
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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
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