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Marantz 7T Restoration

Discussion in 'Marantz Audio' started by CohibaJoe, Oct 13, 2017.

  1. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    I have been thinning the heard and saving the penny's for a new set of speakers (more on this later). I would like your thoughts on a Newly purchased Marantz 7T (which I will be getting next week). As much as I Love to Recap myself...I will be sending this out to Stephen Mantz (Zed Audio)... Looking to get the following work done:

    Power supply upgrade, Transistors replaced, Resistors replaced with 1% MFT, Small signal electrolytic capacitors and add bypass film, Film coupling caps, Replace Volume potentiometer with Alps Blue Velvet, Replace Balance potentiometer with Bourns conductive plastic.

    Parts are the Good stuff (of course).....Now I know some will say to Leave it alone..but this is not how I roll.

    Your thoughts ???

    Update....Not going to Zed Audio...
     
    Last edited: Oct 19, 2017

     

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  2. Steven Tate

    Steven Tate AK Subscriber Subscriber

    Messages:
    2,955
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    N. Richland Hills, TX
    My only thought is I'm green with envy. Keep us updated and see if you can get some pics from the tech along the way. This would be a fun one to watch.:thumbsup:
     
  3. elgrillo

    elgrillo El Grillo

    Messages:
    163
    Location:
    Indonesia
    Hi there, It would be very cool if you can post some fotos of the process, I just bought a Marantz 7T also, and would like to treate her the right way. At least recap it but I will need some help because I just know how to solder and use the multimeter. Good luck with the overhaul !

    Cheers.
     
  4. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    I will ask Stephen to take pictures of the process...Unit was just shipped. I will inspect 1st then send this out to Zed Audio.

    Update...Not going to Zed Audio
     
    Last edited: Oct 19, 2017
  5. nj pheonix

    nj pheonix AK Subscriber Subscriber

    Messages:
    10,060
    Location:
    New Jersey
    Joe,
    You're not squeamish about melting solder.
    Just curious why you're farming this one out?
    (No knock whatsoever on your choice)
     
  6. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    I hear you...I am going this route as to a Full Restoration with the Upgrades being offered. This is not just Caps and Resistors.

    All Caps, Resistors, Diodes and Transistors replaced (Rotary Switches, etc.) Brands will be reviewed
    Replace all film coupling caps with High End
    Volume Control replaced with Blue Velvet Alps Control
    Balance control replaced with Bourns
    RCA jacks replaced with Tiffany Type Gold Plated
    New Regulator circuit and Regulator replaced
    Clean Face Plate, Switches, etc.
     
    Last edited: Dec 1, 2017
    elgrillo likes this.

     

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  7. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    :idea:...Now you have me thinking on this.....I Email a Site Sponsor (Wargo's) to inquire about the above work...Time to put together a Part List.

    I just got in the 7T...time to open the covers.
     
  8. elgrillo

    elgrillo El Grillo

    Messages:
    163
    Location:
    Indonesia
    It looks like you are going to invest a lot in this lady, congratulations!
     
  9. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    I am sending this out Monday to John Wargo (Wargo Electronic Services). He will go over this 1st then will call to discuss the Upgrade Path. Thank You John!!!!!
     
    Last edited: Oct 19, 2017
  10. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    Unit has arrived at Wargo Electronics....Will be on the bench for a evaluation. Once we go thru on what parts to
    replace....I will ask John to take Pict's on this Restoration.
     
    Noahpdavis likes this.
  11. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    The Marantz is done...John said the 7T is Sounding Fantastic. He will be shipping out this week.
     

     

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  12. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
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    The unit will be here Wednesday. Will be posting Pics.

    Making a List of Films and Resistors as Parts Connexion (Site Sponsor) is having a 25% sale.
    After much of the day going over Brands and reviews...This is my list:

    Resistors: TAKMAN REX Carbon
    Films: ClarityCap CSA, ClarityCap ESA
    RCA Connectors: Switchcraft Gold Plated
     
    Last edited: Dec 27, 2017
  13. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    Here is the returned 7T:
    I am going to listen to this know thru the weekend. While Nichicon FW's are used....I will replace the Power Supply cap
    and C602 with ELNA Silmic II after a 12hr listing session.

    While John and I discussed using Films...Would this really benefit as to Sound/Price ratio? Granted you can go Crazy
    with Upgrades. So I have ordered the Films and Resistors to be used later for a Winter Project I will work on. The worn down RCA jacks
    will also be replaced.

    Marantz7Ta.png

    Marantz7Tb.png
     
  14. jstang

    jstang Honey,I can't hear you... Subscriber

    Messages:
    3,527
    Location:
    Northern Jersey.....
    I have done a lot of work on 7Ts.... and mods.... they need the electrolytics tested.... But, I prefer Silmics in the audio path, to each their own. Their are a few Tantalums in the feedback path in the amp boards.... best to ditch them.

    But I would say I have a had a few 7Ts that were outstanding after just a basic De-Ox cleaning.... Have two in systems today... One is modified driving a 500 with Ohm Fs and the other is stock driving a Model 15 with Ohm Walsh 4s.....

    About to built a Model 9 / 7c system.... Had the 7c for some time... The modified 7T can hang with the 7C..... they each have their strengths.... But a stock mint shape 7T in not up to a 7C.

    Just my 2 cents....
     
  15. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    John Wargo from Wargo Electronics has gone thru this Board by Board and replaced the parts that should be. We had talked about moving into Films but I was reminded would it be worth it spending 100's
    just for the parts? I have been listing to this much of the day and boy it's sound real good. So I will be going into the next step on Resistors, Films and RCA jacks. Resistors 1st, Films 2nd then RCA jacks last. I can take this project on from here.
     
  16. jstang

    jstang Honey,I can't hear you... Subscriber

    Messages:
    3,527
    Location:
    Northern Jersey.....
    They already have precision metal film resistors in most of the critical locations that matter the most. I swapped a few others and swapped back...just didn't like it. Your mileage may vary...

    Keep in mind very few of the resistors in the unit are even in use at any given time. Same is true for the Caps...

    Jk
     
    Last edited: Dec 3, 2017

     

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  17. JBL Rich

    JBL Rich AK Subscriber Subscriber

    Messages:
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    Well, how is it going? Inquiring minds want to know!
     
  18. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    Well....My parts order is delayed..:(...The ClarityCap ESA films will be in 3-4 weeks. I told Parts Connexion hold the rest of the order until
    the Films arrive. But....I am working on the RCA jacks....Need to pickup some Gold Plated screws.

    This seems to be a 60's thing to many manufactures. The Aluminum is to THIN...It's the sound that ROCK's...I am not a
    case guy...but this one will need it. Time to start looking. Stay Tune...Until January 2018!!!!

    Marantz7Tc.jpg Marantz7Td.jpg
     
  19. jstang

    jstang Honey,I can't hear you... Subscriber

    Messages:
    3,527
    Location:
    Northern Jersey.....
    Yum.....
     
  20. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,485
    Location:
    Central Jersey
    Did get 98% of the order. 3 Films are on Backorder (2nd week of Jan).

    Power Supply Board is done. Can you "I Spy" to what is Replaced/Added?

    Next is Main Output RAEF Board.

    Marantz7Te.png
     

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