Marantz 6300 Project

Discussion in 'Marantz Audio' started by Echoplex, May 2, 2014.

  1. mikezing

    mikezing Member

    Messages:
    60
    I ended up cleaning the solenoid and cylinder to raise and lower the arm. I put it all back together and put a little bit of fresh 500k grease on the little cylinder (NOT the solenoid). I would say you could definitely get away with a slightly less viscous grease. It ended up working well enough. Thanks for all the help guys!!!
     

     

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  2. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

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    Very Nice!!!!!! Dr. Echoplex

    Love the detail of your work....with lots of Pictures.
     
  3. Echoplex

    Echoplex AK Subscriber Subscriber

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    Thankyou sir!
     
  4. bd1886

    bd1886 Super Member

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    3,133
    Location:
    Puget Sound/Cascade Foothills
    Very well done! Every nicer Marantz turntable from that era is important and appreciate this thread. What a beautiful outcome.
     
  5. Echoplex

    Echoplex AK Subscriber Subscriber

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    Thanks for the kind words sir!
     
  6. kmp14

    kmp14 Active Member

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    308
    Location:
    Chicagoland
    Wow, just ran across this thread....makes me feel inadequate :)

    I re-did my 6300 a few years ago, but really just did a recap and replaced the pots - my first project of this type. I did completely disassemble it and do a new veneer though. After reading your awesome diary, I wonder if I should have done all the other stuff you did, like thyristor, resistors, microswitches, etc. I can say that mine runs perfectly right now, but....well I just feel lame compared to all that you did :)

    My 6300 is actually a combination of 2 6300's, and have all the parts to make another one, so I think I will use this thread as inspiration to make another 6300!
     

     

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  7. Echoplex

    Echoplex AK Subscriber Subscriber

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    Thanks for the kind words. Glad this thread has stayed alive and that other 6300 owners are finding it useful.

    I kind of went a little over-board with things, but figured I might as well replace all of the old components while I had it torn apart.:D

    I would love to see pics of your veneer and how you did it etc. I've often thought of re-veneering my spare parts 6300, but I'm a complete novice and wouldn't know where to start?

    I'm planning on posting some more goodies in this thread when I get some free-time. I get questions every now and then on how I repaired my photo unit and how to install an RCA jack without altering the plinth. I've done the photo unit repair countless times and have the RCA jack plate to install, but just haven't had enough time to get started on it.
     
    Last edited: Apr 1, 2015
  8. kmp14

    kmp14 Active Member

    Messages:
    308
    Location:
    Chicagoland
    6300 Veneer

    I did a Cherry veneer from Rockler, but it was my first time, so I did a pressure sensitive veneer (self stick) because I was worried about messing with adhesives my first time. I figured if it didnt stick well or started to come loose I would try the the other way, but after a couple of years there are no signs of peeling. I do have some tips:
    • Use a heat gun to remove the old veneer on the 4 sides only (not the top). The veneer peels off the sides real easy when heated.
    • Continue to heat the 4 sides even after the veneer is off and scrape way the old adhesive until you feel that you got most of it...it seems to keep coming!
    • The top is not glued on (at least for me, not sure if they changed that with different versions), at least not in a way that a heat gun will loosen (I learned this the hard way). I assume it is more like a plywood type veneer on the top. I just sanded the top with a hand sander and medium grit paper (maybe 220 grit, don't recall) and applied the veneer directly to the old sanded veneer on top.
    • On the bottom of the plinth, front right, make sure to leave the black metal plate screwed to the plinth, otherwise when you rout the bottom right edge, the router will ride up into the void where the plate should be and rout out some of the side (learned the hard way too :nono: )
    • I mounted my router in a router table and used a straight cutting bit to trim the veneer.
    • I simply used an exacto to trim out the holes in the top of the plinth.

    I decided not to put the "servo control..." badge back on the front. I just figured it was unnecessary and took away from the lighter wood color I went with.

    I went with a Tung Oil finish, but it does not really pop so I might someday re-stain and do a polyurethane.

    I have attached some pics of the plinth in progress.

    Here is a video of my 6300 in action with an Ortofon MC 3 Turbo but I found it very harsh in the highs. I have since switched to a Denon DL-103 and it really sounds great. The 6300 and DL-103 really seem to like each other!

    https://youtu.be/s0VrTmKtvTk
     

    Attached Files:

  9. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    Nice work! Those edges look perfect and the stain is a nice color. I like how the figure in the wood comes out. I may give this a try sometime, so thanks for the tips!

    Yeah, I've heard that about Denon carts. I've often thought of trying the DL-110 or DL-103 because they have a solid following, but want to get a separate phono preamp first. My 2325 phono pre only has a gain of 40db, and I'm afraid I won't hear the Denon at its full capability. I've been researching the Pro-Ject tube box DS preamp and so far, the reviews have been quite good. So....looks like a new toy is in order for the man cave! :D

    For now, I'm using an SAE 1000LT w/Sumiko HS-12 headshell and I like it a lot. It tracks beautifully; has a nice balanced sound overall and eliminates sibilance on the toughest passages with no problem.

    Thanks again for posting this!:thmbsp:
     
    Last edited: Sep 6, 2016
  10. bd1886

    bd1886 Super Member

    Messages:
    3,133
    Location:
    Puget Sound/Cascade Foothills
    I automatically have this knee jerk reaction to keeping things original but have never not vastly preferred veneering to improve lifeless grain or severe damage. What is it about wood and beer anyways?!

    Very nice improvement!
     
  11. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    Hi everybody! It's been a long time since I've been on AK, but I promised I'd add more stuff to this thread eons ago, so here goes....LOL

    I wanted to try and clear up some confusion on component layout/locations between the two different 6300 versions and the schematic errors for USA/Canada models, so that the next novices like me won't have to go searching all over the place for answers.:D

    First, there are three schematics available for the 6300. Version II schematic (6/1/76) is the most accurate.

    · Service Manual Schematic (no date)
    · Version 1 Schematic (date: 9/25/75)
    · Version II Schematic (date: 6/1/76)


    Schematic notes:

    · Version 1 schematic has the incorrect tonearm wiring diagram and is missing electrolytic caps C806 and C807. Pitch control potentiometers are 1 KΩ and the incoming power terminal (J001) has .1uF/125V film caps.

    · Service Manual schematic has the correct tonearm wiring diagram, but is missing electrolytic caps C806 and C807 as well. Electrolytic cap C803 has incorrect value at 3300uF; should be 330uF.

    · Version II schematic has included all caps correctly with the following updates: Pitch control potentiometers were changed to 5 KΩ pots and the incoming power terminal (J001) caps were changed to .1uF/250V film caps.

    Component Layout/location notes:

    If you happen to have both 6300 versions, you’ll notice that the photo unit (H002) and power supply (P-800) component configurations will have slight variations to them, but otherwise function the same. The motor was also changed from a discrete type on Version I to an IC type (Matsushita AN620) on Version II models. (See post #17 for motor types).

    · C806: 470uF/50V electrolytic cap: On Version I, this cap is soldered to a mini-terminal board that sits next to the solenoid. The positive (+) side of the cap has one purple wire routed back to J807 on P-800. The negative (-) side has a lug screwed down to the metal chassis/mini-terminal board, which routes a wire back to the four-pin ground/earth terminal also used for the tonearm and RCA interconnects.

    · C807: .47uF/25V electrolytic cap: On Version I, this cap is soldered across junction pins J812 positive (+) side and J814 negative (-) side. On Version II, it has been moved onto P-800.

    · C003: 1uF/25V tantalum cap. On Version 1, this cap is placed in parallel with the darlington phototransistor at the photo unit location. On Version II design, this cap is moved to the power supply and it's designation changed to C808.

    V1 Component Layout
    [​IMG]

    Version 1 Power Supply: *Note C807 .47uF/25V cap is soldered across J812 and J814 and does not have its own foil trace.
    [​IMG]

    Version II Power Supply: *Note: C003 (blue tantalum cap) formerly on the photo unit; now on the PS board here and called C808. Also caps, C806 and C807 were added to PS board. Junction pin J810 was omitted.
    [​IMG]
     

    Attached Files:

    Last edited: Dec 21, 2016
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  12. Echoplex

    Echoplex AK Subscriber Subscriber

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    I get asked every now and then about how to repair and adjust the Auto-Shut-Off/Lift circuit, so thought I'd try to condense it down to layman's terms from the Service Manual.

    Photo Unit (H002) Assembly:

    The optical components are soldered onto two mini-pcb's that are fastened onto a small plastic housing with eyelet holes on either side; one side has the red LED, the other side the darlington phototransistor. Depending on the version you have, it may also include the tantalum cap on the same side as the phototransistor.

    The eyelet housing is mounted onto an adjustable sliding sub-frame, which sits on top of a base frame that bolts down to the plinth. The spring-tensioned adjustment screw (located on the back side) is what allows the user to preset the photo unit’s sub-frame into position so that when the tonearm reaches the end of the record, the tonearm light shield passes between the optical components, thus blocking light and triggering the auto shut-off/lift at the designated setting*.

    *Since all records have large variances in dead wax and/or run-off areas, I would recommend adjusting both the photo units’ sub-frame and the angle of the tonearm light shield to trigger the auto shut-off/lift function as it reaches the end of the record, closest to the label-side. It might take a few tries to get this adjusted just right, but will cue the trigger function at the same position regardless of the variance in records you’re playing.

    [​IMG]


    Version I Photo Unit (H002):
    [​IMG]
    · NPN Darlington Phototransistor
    · Red LED (rectangular body)
    · 1uF/25V tantalum cap


    Version II Photo Unit (H002):
    [​IMG]
    · NPN Darlington Phototransistor
    · Red LED (rectangular body)


    Auto-Shut-Off/Lift doesn’t work or works intermittently:

    The phototransistor and LED are likely failing due to their age, as well as, the photo unit sub-frame and tonearm light shield needing to be re-adjusted. I have found all cases to be true. For a few dollars worth of parts and peace of mind, it's worth it just to replace both components.

    The LED should emit enough light onto the phototransistor causing it to conduct, but if the emitted light isn’t strong enough, then no conduction occurs and the circuit will not work. Replace the LED with the same rectangular type shown here, or use a standard dome-shape type like this guy did from Vinyl Engine in second photo. Either will work fine.
    [​IMG]

    In my case, I kept the original LN25 LED and replaced the old phototransistor with a new Optek 535b phototransistor. It's close enough in specs to the original, though not exact. All I had to do was trim the leads down a bit, bend them to fit onto the pcb and place the component inside the eyelet hole. This has worked great for me, hopefully it will be the same for you.

    phototransistor.jpg

    [​IMG]


    [​IMG]

    According to the Optek535b datasheet, the phototransistor schematic should be as follows:

    Pin 1 emitter
    Pin 2 collector

    When you solder the component onto the photo unit mini-pcb, understand that you've got to follow the 6300 schematic orientation in order for it to work correctly.
    That being said, terminal 1 (on the mini-pcb) receives the collector (component flat side) and terminal 2 receives the emitter - which goes back to ground (black wire) and is run all the way back to J814 on the power supply pcb.


    Optek OP535B - Photodarlington
    Mouser part # 828-OP535B

    [​IMG]


    Stay tuned...
     

    Attached Files:

    Last edited: May 1, 2018
    IGSTER and bikehomero like this.
  13. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    Update on the 6300 DD motor....

    For those who may be interested, I just found an enormous thread regarding DD motor testing over at Vinyl Engine and the Pioneer PL-71 is mentioned which lead me to the original threads found here:
    http://www.pinkfishmedia.net/forum/show ... hp?t=70027
    http://www.pinkfishmedia.net/forum/showthread.php?t=128190&page=18

    Long story short, this same DD motor was used in early 6300's until they were updated sometime around 1976 to the Matsushita AN620 IC types. Interesting to learn about the innards of the motor and how it works.

    Below are a few photos showing changes in spindle/bearing design.
    Many thanks to Vinyl Engine and pinkfishmedia for the info/content.

    Motor Diagram
    [​IMG]

    Rotor/Spindle Assembly: Recessed end which sits on ball bearing.
    Early 6300 DD motors use this design.
    [​IMG]

    Updated Rotor/Spindle Assembly: spindle shaft now includes rounded bearing end.
    [​IMG]

    Why the change in spindle and bearing design? Advantages & Disadvantages?
     

    Attached Files:

    Last edited: Aug 28, 2016
    bikehomero and bryans12v like this.
  14. kmp14

    kmp14 Active Member

    Messages:
    308
    Location:
    Chicagoland
    Echoplex,I just want to thank you for sharing this info! Since I completed the restore, my 6300 is spinning along like a dream with stable speed and beautiful sound coming from the nicely matched Denon DL-103. That being said, this thread is such a valuable resource and I am sure these latest additions will be of much value to keep our 6300s spinning in the future. Thanks again!
     
    Echoplex likes this.
  15. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    kmp14, my pleasure man!

    Heck, you contributed your 6300 re-veneer in this thread. You should definitely do a detailed step by step video or blog for that. That would be cool!

    This has been a fun project to do. I'm glad to have contributed something of value on AK for folks looking to repair, improve and keep their 6300's going.
    It's a great 70's turntable, and when freshened up can hold it's own.

    I certainly cannot take all of the credit for this thread, so a big "THANKYOU" to these fine folks:

    restorer-john - thanks much for all the helpful info/tips on the DD motor, micro-swicthes, and photo unit components.
    Montycat - your blog on the 6300 helped me out a bunch and directly contributed to me starting this thread.
    markfig - your 6300 thread lead me to try my hat at repairing mine and in the process better understand it and share my own findings.
     
  16. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    Ok folks! More goodies...

    Do you want to upgrade those old crusty looking RCA interconnects? Then read on...

    [​IMG]

    Some custom 6300 RCA jack plates I found on Google...
    These are all impressive looking designs, BUT they require using a router and removing additional material from the plinth...and their pricey...

    This one is really nice...
    [​IMG] [​IMG]

    Exotic wood RCA jack plate....has a nice look to it, but the adjustment screw for the photo unit is covered up and no longer useable.
    [​IMG]

    In my case, I decided not to alter the stock look, and chose the KAB PC-1200 RCA jack plate; it's good quality and a bargain @ $29 dollars!

    Going with this option, I only had to make two small changes:

    1. Cut the length of the Kab RCA jack plate down so that it sits even with the inside ledge of plinth and doesn't overhang into the tonearm wire cavity.
    2. Widen the bottom cover slot an adiitional 1 1/8" to accomodate the new RCA jack plate using a pencil, 6" ruler, Dremel tool and small precision file set.


    KAB PC-1200 RCA jack plate
    [​IMG]

    Before you begin...

    Try to obtain some strong polyurethane foam and make yourself a turntable repair stand like this one below. It's a great little DIY stand that provides sturdy cushion for your beloved equipment w/o damaging it, provides clearance of all essential parts and most importantly, removes any risk of putting weight onto the tonearm gimbal bearings.

    [​IMG]

    OK, let's get started...

    1. First, remove the platter mat, platter, 45 adaptor, dustcover, then secure tonearm, remove cartridge and tie all loose cables.

    2. Flip deck over and remove the bottom cover and screws. After removing cover, remove the old interconnects, cable bracket, clasp and screws. Keep the screws for the new RCA jack plate.

    3. Using a small ruler, align it to the outside edge (from left to right) of old RCA slot on bottom cover and measure and additional 1 1/8" out to mark the new spot for the vertical cut you'll make. (You'll need to flip/invert the bottom over so that the flanged ends are facing up towards you.)

    4. Using a Dremel tool, make your vertical cut until you are just about even with bottom edge, then make your horizontal cut staying even with bottom edge until you intersect with the vertical cut.

    *This widens the old 1" RCA slot to approximately 2 1/8" total. Since the new RCA jack plate is 2" wide, you'll need a little space on either side so it doesn't get hung up on the bottom cover.

    5. Take a small file and smooth out any uneven shards in the bottom cover, then check it. If good, it should come out looking like this.

    [​IMG]

    6. Using either a Dremel tool or small hacksaw, secure the jack plate down to a bench vise and cut the length of it down to 3/4" so that the end of the plate sits flush with the inside edge of plinth. File edges down.

    7. Take the bottom cover, RCA jack plate and check to see how they align with one another.

    [​IMG]

    8. Mark the RCA jack plate location, then mark your drill holes for jack plate and plinth, and drill pilot holes using small drill 1/16" drill bit, then using the same screws from the old RCA clasp and bracket, bolt new RCA jack plate down to plinth.

    [​IMG]

    When finished, it comes out like looking like this:

    [​IMG]

    Installing the rca jack plate was fairly simple to do and didn't require any drastic cosmetic changes to the plinth. And the best part...I now have some nice RCA interconnects.
     

    Attached Files:

    Last edited: Mar 13, 2017
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  17. Mikem704

    Mikem704 New Member

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    Wow great work. I have a 6300 I purchased new that needs lots of TLC No feet, broken rest post (kids), broken dust cover (me), no strobe and the speed varies. One day I'll restore it but the feet and the rest post are hard to find.
     
    Echoplex likes this.
  18. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    Thanks.

    And yes, finding an original set of feet and a tonearm rest intact for the 6300 is usually a very expensive road to travel. Keep your eyes peeled for a parts unit though. They pop up on-line fairly regularly and you'll save yourself money going that route as opposed to buying all of the parts individually. New dust covers are the way to go also; the acrylic material used today is ironically more flexible, yet stronger and way less brittle, and the catch-all benefit is that it resonates far less than the original cover, plus it looks really nice too!

    Most of the repairs for your unit should be fairly straight forward, save the feet of course.

    Speaking of the feet....
    As you've no doubt noticed, they're the weakest link on the 6300 by a long shot. They look nice aesthetically, but it terms of actual functionality, they fall well short of the mark. They're cheaply made out of brittle plastic, and the rubber grommets meshed between them don't do that great of a job of isolating out vibration rumble/noise. But, I don't want to criticize on the 6300 too harshly. It's a great looking 70's deck and I do love mine, but with a few caveats...
     
    Last edited: Dec 31, 2016
  19. BrandonS2185

    BrandonS2185 New Member

    Messages:
    27
    Could you tell me which cap you purchased to replace the original C807? Mouser only seems to have 47uF/25v not .47uf listed on the site.

    One more very, very ignorant but important question. Are the values listed on the caps VAC or VDC? Don't want to screw that up.

    UPDATE: I found a 0.47uF 50V electrolytic cap on parts express. The brand is Lelon. Operates up to 85*C. I'd assume that's sufficient.

    Thanks!
     
    Last edited: Aug 20, 2017
  20. Echoplex

    Echoplex AK Subscriber Subscriber

    Messages:
    173
    Hi Brandon,

    Yes, all the electrolytics used on the power supply are for DC volts.

    For C807, I used a Nichicon PW series cap .47/50V. Don't worry about the increase in voltage on that cap, as it's just the voltage rating for the cap itself and not the actual voltage the cap is going to have on it per se.

    Here's the info from Mouser:

    Mouser Part #: 647-UPW1HR47MDD
    Manufacturer Part #: UPW1HR47MDD
    Manufacturer: Nichicon
    Description: Aluminum Electrolytic Capacitors - Leaded 50volts 0.47uF 5x11 20% 2LS
     
    Last edited: Sep 21, 2017

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