Pioneer SX-750 Repair/Restoraition in LA?

Discussion in 'Pioneer Audio' started by K-Shaps, Sep 30, 2014.

  1. K-Shaps

    K-Shaps New Member

    Messages:
    23
    Location:
    Los Angeles, CA
    Hi all,

    I have a Pioneer SX-750 that I picked up off Craigslist 2 years ago. The unit works fine and sounds great, but was in storage for a long time. I cleaned it up and it's in decent condition, but the caps could use replacing and the board a deep cleaning.

    Can anyone point me to someone in LA that could do this for cheap or an in-depth restoration/maintenance guide for this model?

    Thanks in advance!
     
    Last edited: Oct 1, 2014
  2. K-Shaps

    K-Shaps New Member

    Messages:
    23
    Location:
    Los Angeles, CA
    Bumping this as I really want to get this cleaned up and restored. Thanks!
     
  3. jobrewer1983

    jobrewer1983 AK Subscriber Subscriber

    Messages:
    2,982
    Location:
    San Jose, CA
    Hi K-Shapes,

    Not to be a Debbie downer, but for the price you would pay to have the 750 recapped, you might as well invest in an upgrade or more powerful amp.

    You will pay more to have it restored than it will be worth once restored.

    Have you tried cleaning the pots with Deoxit? That's something you can do yourself and could be an improvement to the sound quality.

    Audio work is not that cheap, you will be hard pressed to find someone who will do it cheaply. You also have to take into consideration the tuner alignment, that's where you will spend your money.

    Id say do a pot cleaning, and enjoy the receiver.

    Hope that was of some help.

    Kind Regards,
    John
     
  4. rcs16

    rcs16 Super Member

    Messages:
    3,120
    Location:
    Baldwin, Ontario, Canada
    Kind of with John there. It would cost you probably more for someone to service it than what you paid for it. Even the service parts maybe be more than what you paid for it. It is a case of economics how much $ you want to have invested in it.
    It might work for years the way it sits now, it is a bit of a crap shoot.
     
  5. tubed

    tubed Lunatic Member

    Messages:
    13,118
    Location:
    Aztlan
    Northridge Electronics
    Simi Valley
    AK member
     
  6. two.dogs

    two.dogs Active Member

    Messages:
    272
    Location:
    Denver, CO
    Meet Watson. She's a terrible financial investment and frequent pain in the rear. But we're great friends and that face never fails to make me smile. She's a rescue dog and I sometimes wonder what her life would be like if we hadn't found her and taken her in. I'll never recover the time and money I've spent on Watson, but I don't care in the slightest. She's my buddy.

    So why should payback ratios govern our vintage audio decisions? Many people won't hesitate to plop down $800 for a new receiver at Best Buy. They use it for a few years then donate it to Goodwill or sell it for $50 on Craigslist. And a new receiver can't come close to matching the audio entertainment of an SX-750. I say go ahead and restore the SX-750 because it will make you smile. I restored mine, and its one of my favorites.

    John

    IMG_4013.JPG
     
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  7. larryderouin

    larryderouin You can be sure if it's Westinghouse??????? Subscriber

    Messages:
    20,422
    Location:
    Glen Burnie Md.
    I'm with TwoDog's. You can do a SX-750 (minus the tuner) yourself for about $50-60 in parts. There are plenty of guys on AK who have done rehab's, restorations, rebuilds. Google SX-750 and one of the hit's will be an AK thread. Just under the listing will be a link to MORE SX-750 Threads from AK. Click on that and you'll get most everything that is on AK for the 750 (as long as it has SX-750 in the title. Some have links internally to other links for rebuilds.

    You didn't tell us your skill level so I'll presume you are not skilled in soldering, reading a schematic, etc. Basic tools are your greatest outlay of $$$$. Soldering Iron, Digital Multimeter with Diode setting, side cutters, alligator clips, needle nose pliers, etc. Practice soldering on a cheap expendable, board to learn how to remove and install caps, resistors, transistors, etc. Learn how to read the markings on the boards for orientation of transistor legs, + or - on caps, Diodes, etc.
    Also learn how to read the schematics. Note that the schematic shows the circuit electrically, not how it is in the unit. You'll find resistors, caps, etc. in places that are counter intuitive, but they are electrically in the same place in the circuit. These are just a few of the things you'll need to learn BEFORE You dig into the 750.

    Deep cleaning is fairly simple. Get a 1" chip brush and some 91% Isopropyl alcohol. CRC QD Electronics Cleaner (Home Depot) is used on the fins of the tuner Variable capacitor. Nothing else. This gets sprayed on the fins (both sides) with the fins UNMESHED. DO NOT USE WD-40, Oil, DeOxit, or other materials on the fins. Capacitance is air tuned and any dust, dirt, or any other material changes the capacitance and now you have a tuner NOT in Tune. So CRC QD Electronics cleaner ONLY (It's a NON RESIDUE CLEANER). There are some slide springs on the grounds of the V.C. at the shaft that need lube so you do this. Away from the unit, spray some DeOXIT FADERLUBE (F-5) into the lid. Using a toothpick, dip the toothpick and get a drop of Faderlube on the pick. Then touch the slide spring where it touches the shaft at the separator walls. Each spring get a drop. DO NOT let it get on the fins. If it gets on the fins, you need to re-do the fins withthe CRC.

    With the rest of the unit, scrub the board(s) with the paint brush and a vacuum cleaner. With all the dust, dirt, etc. removed, wet the brush with the alcohol, place the 750 on it's side (transformer on bottom) and start from the top. a small spray bottle with alcohol will help keep the alcohol from drying out while scrubbing. When finished, rinse it from top down with the CRC QD Electronics cleaner. Place a fan close to it and put the fan on high and let it blow on the unit for overnight.

    Once it's clean, plug it in to a DBT with a 75W bulb on it. NO SPEAKERS, All controls centered. Volume All the way down, LOUDNESS and TAPE MONITORS OFF, Selector on AUX. Turn it on watching the DBT. If everything is ok, the bulb will flash bright and over about 3-5 seconds will dim down. If it stays bright there is a short or the bulb is too small. Try the next size larger (100W) bulb. Incandescent bulbs only. NO CFL's, HALOGEN, LEDS, etc. Good old fashioned Incandescent bulb only. But a 75W should be just about right for the 750. Try the 100W. If it now dims and stays dim the 75W was too small.

    Hook up a pair of expendable speakers and test the unit in all modes. If everything is ok, then you can start on the rehab/resto/rebuild. There are parts lists for the 750. http://www.audiokarma.org/forums/index.php?threads/recap-question.334748/ The list in Post 6 is 6 years old, but Mark the Fixer will update it if asked to do so.(He'll vet the list and post the updated list with a BOM so you get one stop shopping @ mouser.) Post the list in and ask for a vetting.
    There are probably updated lists off that but this one is in the
    "Pioneer Recap Lists" Sticky suggestion! http://www.audiokarma.org/forums/index.php?threads/pioneer-recap-lists-sticky-suggestion.457663/ Thread
    If you want a newer list you'll have to dig a little for one of the newer threads. They're out there but I don't have the time to dig for them.

    There are a bunch of guys who have 750's here and they'll be glad to give you some help and guide you along on this journey. Spending $400-$600 for a shop to do a complete recap is out of the realm of reality. And you don't know what you get at the end. Doing it yourself you know what went in to the unit, and you know the builder/tech, and it's way cheaper on the wallet. Plus doing it yourself builds your confidence, and you get the satisfaction of showing it off to your friends and telling them "I rebuilt this".

    Two Dog's; My "LUCY" is also a rescue Dog. Jack Russel Beagle Mix. I've never had a dog who can go thru toys as fast as she does. Even the KONG stuff has no chance with her. She's hard headed, obstinate, and a typical female(changes mind more than I change socks. Don't leave shoes, slippers, or hats where she can reach them or they will end up in the back yard, shredded to hell and back. But she's totally loyal to my grand-kids, and lets then play with her. Their dad (#1 son) she doesn't like and will get between him and the kids and let him know that she will tear his head off and s*%^ down his neck if he does anything to them. I think it's due to him having a male pit bull mix rescue. I get the same response from her after going over their house. #2 son she tries to lick off his face. Go figure. The only thing I would change is her energy level. She's a bit too energetic for us. She's a great dog (I've only had one other female dog in my life) potty trained, and is smart as hell. I'd rather have a male dog, but the wife and son brought her home without my input. LUCY has become my shadow and constant companion. And she has separation anxiety so i take her everywhere I can get away with it. She's good in the car. She needs her nails ground down every 3-4 weeks or she'll tear your skin up. But she loves going to get them done and has her own manicurist. She's 4 in May. This pic taken at about 7 months.

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  8. two.dogs

    two.dogs Active Member

    Messages:
    272
    Location:
    Denver, CO
    My wife gave me a coffee mug labeled "soft spot for beagles". But they are stubborn and energetic - I can only imagine adding Jack Russel to the mix!

    Agree that a diy restoration of an SX-750 is possible for a newbie. This first recap I did was a $10 SX-434 (thanks for the help, Larry). The second was my $40 SX-750 that hummed loudly because of a bad cap in the power supply. However, I wouldn't scoff the notion of having it recapped by a tech. Remember that these cost $400 in 1977 which is $1700 in today's dollars. Even if it costs $600 to restore (which it probably won't), its still a hell of a deal. It could be kept for a lifetime, or sold in a couple of years for $300 easy, maybe $400. Net cost of ownership is really quite reasonable. That's why I focus on the smile factor. Vintage audio is a pretty cheap hobby - way better than a boat!

    The 750 is a really good receiver.
    http://classicreceivers.com/pioneer-sx-750
    Sure its not an SX-1250 but I'd take Mary Ann over Ginger any day.

    TwoDogs
     
  9. zebulon1

    zebulon1 Cleaned up the shop and half finished sets. Subscriber

    Messages:
    4,152
    Location:
    Las Vegas Nevada
    The 750 is a great receiver to begin this crazy hobby with.
    If you ever head up to Las Vegas for the weekend, I could probably have it done by the time you leave on Sunday.
     
    jobrewer1983 likes this.
  10. two.dogs

    two.dogs Active Member

    Messages:
    272
    Location:
    Denver, CO
    That's a great idea. He could finance the entire weekend and the receiver with his winnings!
     
  11. jobrewer1983

    jobrewer1983 AK Subscriber Subscriber

    Messages:
    2,982
    Location:
    San Jose, CA
    Hi two.dogs, and Watson!!

    So why should payback ratios govern our vintage audio decisions?

    Simple, because most of us would upgrade to the 850/950/1050/1250 Ect. That is if you are sticking with the 50's series.

    The 750 is a great receiver, but the idea would be to upgrade/invest in a better vintage receiver.

    Again, not trying to be negative. I'm a Pioneer freak just like the rest of us. If it were up to me, I'd be recapping any and all SX series Pioneers. I'm all for recapping, I recapped my 1250 myself, and that was worth the investment.

    Id take Zeb 1 up on his offer!!!

    Kind Regards,
    John
     
  12. jobrewer1983

    jobrewer1983 AK Subscriber Subscriber

    Messages:
    2,982
    Location:
    San Jose, CA

    Yes, Doing it yourself is worth the time and money. That is the best course of action on something like this.

    Kind Regards,
    John
     
  13. paultlaw

    paultlaw Active Member

    Messages:
    251
    What is preventing you from trying it yourself?
     
  14. K-Shaps

    K-Shaps New Member

    Messages:
    23
    Location:
    Los Angeles, CA
    Wow thanks for all the feedback everyone, didn't expect so many replies which is why I haven't checked the board in awhile.

    I would be open to doing it myself, but I really wouldn't know what I am looking for in terms of what needs to be replaced and what does not. I don't have any soldering experience nor do
    I have scopes and voltage measurement tools. I have built my fair share of electronics, but attempting a receiver would be new territory for me. I can post pics of the unit in detail for guidance from the AK gurus. For all I know maybe nothing needs to be replaced.

    The receiver is in perfect working order, I am just wanting to do this as a preventive measure. That and to make a new custom real wood case as the case that it currently has looks like shit. The veneer is peeling on the corners.
     
  15. K-Shaps

    K-Shaps New Member

    Messages:
    23
    Location:
    Los Angeles, CA
    Alright - well it may now be time to finally get this repaired. After going through one pair of speakers I'm beginning to think that the receiver itself needs fixing - my left speaker seems to be muffled as you increase volume but only at certain frequencies. Imagine you are teaching someone with no experience how to recap/do a full restore - what should I read/watch? For all equipment and parts what is this going to cost me? Also if I were to have this repaired (anyone willing :) ) what would that cost me. At the end of the day I would love to do this myself - but whatever the cheapest solution is may be what I go with. I can't take this to any shops in LA without them trying to upcharge the hell out of me for a repair.
     
  16. kln138

    kln138 AK Subscriber Subscriber

    Messages:
    35
    Location:
    Bakersfield, CA
    I second Northridge Electronics in Simi Valley. Go for it and try the restoration yourself. Lots of information and help here. If you are successful Tom could align it for you.
     
  17. K-Shaps

    K-Shaps New Member

    Messages:
    23
    Location:
    Los Angeles, CA
  18. loweran

    loweran AK Subscriber Subscriber

    Messages:
    921
    Location:
    Austin, Texas
    Here is the first one I did a few years back. I think I invested less than $200 for tools and supplies but since I have done 6 amps and receivers, recapped 4 pairs of speakers and restored two turntable, I can amortize that cost across them all. Probably set me back $40 in parts for the 737. I started from nothing. No soldering skills, no experience in electronics, nothing.

    The guide I had was pretty hard core about soldering, but I learned a lot, and I have a completely restored SX-737.

    http://audiokarma.org/forums/index.php?threads/pioneer-sx-737-rebuild-bom.692191/
     
  19. K-Shaps

    K-Shaps New Member

    Messages:
    23
    Location:
    Los Angeles, CA
    I just did a deoxit of the entire unit spare the fuses and main relay per the idiots guide on the forum. That helped immensely. Definitely still want to have the caps replaced and board cleaned but this will suffice for now...

    Also total side note but based on my system is my TT/stylus the biggest bottleneck soundwise? Once I have the receiver performing at it's best I want to make sure I have a TT/Stylus that will truly get the best out of it. Thanks!
     
  20. loweran

    loweran AK Subscriber Subscriber

    Messages:
    921
    Location:
    Austin, Texas
    TT/Stylus will have an impact but the speakers will also have a major impact as well.
     

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