1966 Fender Pro Reverb Recap job ??

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by daveS, Feb 1, 2008.


  1. daveS

    daveS lefty dude on hiatus Gold Supporting Member

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    I'm picking up a 66 BF Fender amp sight unseen and it may need a recap (not sure yet).

    - How do you tell if you need a recap job ?

    - Does it affect the value of the amp to recap (i.e. like a refinshed or frefretted vintage guitar) ?

    - Are there any specific things to keep in mind when doing a vintage BF recap (I am going to have an authorized Fender tech do it) ?

    Any thoughts, advice ?

    Thanks
    -Dave
     
  2. doublee

    doublee Member

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    The only thing I know is that "Authorised Fender Tech" doesnt mean all that much necessarily. I had ridiculous work done by one a year ago...
     
  3. slider313

    slider313 Silver Supporting Member

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    A few thing stand out: 60 cycle hum, lack of bass, motorboating pre amp, etc.
    If the amp hasn't been serviced it's way over due. A cap job really doesn't lower the vintage value, unless the buyer is OCD Anal. If your going to use the amp and not keep it for appreciation and resale, service it even if it's dead mint. If you had a mint '56 Chevy Belair would you leave the points, plugs, wires, condenser and original oil and filter in it ??
     
  4. daveS

    daveS lefty dude on hiatus Gold Supporting Member

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    Yeah I plan on having it done if it needs it for sure...I bought the amp to play it. I'm not really a vintage collector and this is my first old amp.....I was just wondering how or if it affected the value. It's a Pro Reverb and The Utahs were replaced with Rolas.

    What exactly is "motorboating" in the preamp ?

    -d
     
  5. slider313

    slider313 Silver Supporting Member

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    Motorboating is usually caused when your cathode bypass caps drift out of spec and produce a sound which mimics the sound of a motorboat.
     
  6. jackaroo

    jackaroo Member

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    Keep the old parts when you're done- and be careful, some guys just clip stuff out and replace old components instead of checking to see if they need replacing.

    Welcome to the pro reverb club, great amps.

    J
     
  7. Tonefish

    Tonefish Member

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    If you've got the old caps and they are blistering, that is another sign of replacement needed.

    Changing from the original caps does effect the value, but not as much as the potential damaged that can be caused from caps that need replacing.
     
  8. TheAmpNerd

    TheAmpNerd Member

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    **** slider you are one lucky man.

    Had you been in possession of the 55 Chevy Belair, I would
    call you out on the filter!

    Since The General and their infinite wisdom thought the new
    small block was so good right out of the box, they would just
    delete that requirement and save some beans!

    Of course as soon as it was realeased, you could her the grumblings...

    ...and in 1956, the Chevy smallback came standard with and oil filter.

    Yea!

    Engineers 1 Bean Counters 0

     
  9. Wakarusa

    Wakarusa Member

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    To quote Inigo Montoya: "You keep using that word. I don't think it means what you think it means"

    Motorboating in a guitar amp is the result of poor regulation in the power supply (bad isolation resistor, bad filter cap, etc.), or an unintended feedback path (usually caused by poor lead dress or layout). Not sure how a preamp bypass cap going bad gets you there.
     
  10. Blue Strat

    Blue Strat Member

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    The only thing being "authorized" necessarilly means is that the tech is willing to work for virtual poverty level wages on warranty work and has a lot of the (mandatory) Fender parts in stock.

    If the electrolytic caps are original they're about 20 years overdue to be replaced.

    Replaced caps might diminish the value for some collectors. If that's your concern, sell the amp as is and find a beater amp that you can turn into a "player". It's potentially dangerous (to the amp) continue using a blackface amp with original electrolytics. You can do worse damage which will decrease the value of the amp for EVERY potential buyer down the road.
     
  11. TheAmpNerd

    TheAmpNerd Member

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    In summary:

    Old electrolytics can lead to the following failures:

    final coupling cap failure
    runaway output tubes and meltdown
    power tranformer failure
    burned resistors on the output tubes sockets
    burned wiring in the output sections
    fried output transformer
    **** all over the inside of your amp.

    Huge loss of value, now you do have a non original
    amp that can be restored to be a player.


    ...and the beat goes on,

    ...and the beat goes on.





     
  12. Tonefish

    Tonefish Member

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    How about the potential for acid to leak onto a 40+ year old paper speaker cone?

    I guess I should also mention that I have an all original '64 DR and I'm not touching it because I don't want it to decrease in value....but I'm not playing it either. If it does have enough problems (like acid leakage) that forces me into action, I will gleefully turn it into a player.
     
  13. TheAmpNerd

    TheAmpNerd Member

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    With proper maintenance though,
    you CAN have a wonderful vintage amp and play through it!

    Which is the BEST of all worlds and what most of the techs
    here endorse.

    Fill'er up, check the oil and fluids, then off you go!
     
  14. daveS

    daveS lefty dude on hiatus Gold Supporting Member

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    Well guys...I got the amp today. I'm no BF expert, but I think I scored. I got it local and it's super clean. I am the third owner....the guy I bought if from had it stored for years. He bought it from a friend in 1976 and the friend (who bought it new) had it stored for years too. The seller just had it checked out by Mojotronix in Northern Cal and it go a clean bill of health. I noticed that there is a bit of a "clicking" sound that comes through the amp when the vibrato is engaged. The frequency of the clicking sound speeds up and slows down with the increase or decrease of the speed knob. Other than that, the amp sounds really good. Apparently the original Utah speakers fell apart and were replaced in 1978 with Rolas. It's got the original Telefunken and RCA tubes. I am amazed at how clean the amp is and it even has the original cover and footswitch. From what I can tell, its pretty much unmolested. Here are some pics:

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  15. JDJ

    JDJ Supporting Member

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    Very nice indeed! I've got that amp's slightly older brother, and I couldn't be happier. Find the best tech in your area and get it fixed up... and enjoy!
     
  16. Wakarusa

    Wakarusa Member

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    The ticking is easy to solve and a common problem. But you'd have to install a part and thus "modify" the amp :)


    PS: The fix is a small cap (.01uF, .022uF) either from the neon driver plate to ground or from the 10M in parallel with the neon bulb to ground. This is actually included in later Fender designs (like AA270 etc.).
     
  17. slider313

    slider313 Silver Supporting Member

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    WOW !! Real clean !!! Enjoy it.
     
  18. guitarmind

    guitarmind Supporting Member

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    That's one minty looking amp, and with cover and footswitch!!
    I have a '65. These are great amps.
     
  19. burner

    burner Member

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    Very nice amp!
    I'd say you scored.


    Back to the re-capping....

    I've seen guys go so far as to drill out the old caps and insert the new caps into the old cardboard tubes to "preserve the integrity of the amp"
    Seems a bit far to me but yeah....it still looks original. ;)
     
  20. booj

    booj Member

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    Motorboating can be caused by old worn out output tubes, or other tube related problems. I agree with the thought of getting all old parts back if the amp is serviced.
    I myself was a Fender Tech at a local music store. The thing he can do is get a direct answer from Fender on what they think about your issue. That is a great resouce, and one you should use for an experienced viewpoint on your amp. They'll be glad to help you. Sometimew it takes a tech. more than one 10 - 20 min. try to reach somebody, that could put a hang on things for a little while, but you'll get a good answer
    Booj
     

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