New SVT-4 Pro... Ready for Cleaning

Discussion in 'Amps [BG]' started by jd_watt, Dec 29, 2013.


  1. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Hi All,

    I'm the proud new owner of an SVT-4 Pro. I found a great deal for a used amp on Craigslist for $500. It's in good working condition, however, the graphic eq is really dusty and the input jack my need replaced (it's a little touchy/scratchy). I would like to pop the top and give it a good cleaning.

    Does anyone have experience with this, and are there any good rules of thumb to avoid potential shock from any voltages? I'm a bit new to this, but I'd like to get started soon. Thanks for having a look!
  2. Pearldiver

    Pearldiver

    Joined:
    Apr 30, 2005
    Because of the potential shock, I'd really recommend you have a professional do it. No disrespect to you. :)
  3. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Hey, thank you. No offense taken... That's why I asked really. If this is something for a pro to handle, I prefer to send it out and have it done right. Like I said, I'm not real sure what's involved there. I appreciate the input.
  4. JimmyM

    JimmyM Supporting Member

    Joined:
    Apr 11, 2005
    Location:
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps, EMG Pickups
    Eh, just play while you turn it off and the power fades and that should discharge the caps enough to keep you from getting killed. Besides, you're not going anywhere near the caps to clean it, so I say have at it. Use a good cleaner, though...most folks use Deoxit because it won't ruin pots.

    As for the input jack, it may need retensioned. That's easy enough, though...stick something pointy in it and gently bend up the metal pieces that touch the jack. That should take care of it. If it doesn't, best to have a tech replace it unless you can solder on PCB's.
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  6. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism Gold Supporting Member

    Joined:
    Dec 22, 2010
    Location:
    Saskatoon, Saskatchewan
    I think all cleaners ruin pots, DeOxit definitely ruins pots so it should always be a last ditch effort. DeOxit is like heroin for your pots, it will fix them but the grease it leaves eventually requires more grease. I had this explained to me by a well known luthier and his crew.

    Do not get me wrong, I still use DeOxit and it is the first product I recommend, but it should only be used if the old fashioned method doesn't work. That would be turning it/moving it a bunch to see if the dirt works loose.

    Personally OP I would clean them at home just disconnect the power, I would not touch anything on the amp beyond cleaning. You can score some circuit board wash from your local electronic supplier, I usually run some of that and some compressed air as well when cleaning out old heads.
  7. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Thanks, Jimmy... much appreciated. I haven't turned the amp on since yesterday. Your saying (specifically) that playing/sending signal through the amp while I power it down discharges the caps?
  8. JimmyM

    JimmyM Supporting Member

    Joined:
    Apr 11, 2005
    Location:
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps, EMG Pickups
    For the most part it does.

    Diabolous, this is the first I ever heard of Deoxit ruining pots. A major selling point of theirs is that it won't ruin pots. I agree that working them is always your best bet, but I've not heard of Deoxit acting like pot heroin, though I do think the comparo's funny ;)
  9. SirMjac28

    SirMjac28 Patiently Waiting For The Next British Invasion Gold Supporting Member

    Joined:
    Aug 25, 2010
    Location:
    The Great Midwest
    +1 I would have said Meth but that's just me trying to be hip and current like the young folks. :)
  10. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    So I popped the top, and it looks like on of the lugs(?) on the input jack is bent and not making contact. Any thoughts?
  11. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Pic

    Attached Files:

  12. JimmyM

    JimmyM Supporting Member

    Joined:
    Apr 11, 2005
    Location:
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps, EMG Pickups
    Simple...bend it back!
  13. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    lol That's what I wanted to hear :) Seriously, I just didn't want to break it. Looks like the culprit though, eh?
  14. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Also, just another quick question: I'm cleaning dust from the sliders of the graphic eq. Would a light vacuum cause any harm (static etc)? Right now I'm plucking out dust and dirt with tweezers
  15. B-string

    B-string Supporting Member

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    Nov 21, 2008
    Location:
    Lake Havasu City, Az USA
    A lite vacuum is fine for the sliders and as a note don't use DeoxIT on the sliders. There is a product from Caig called "Fader Lube" that is made for them.
    I find the discussion on using products on pots interesting. They are manufactured with a "lubrication" layer applied already. If dry fitted the "wiper" would damage carbon or conductive plastic pad pretty quick and even wire-wound rheostats don't survive metal to metal contact for long without something to reduce friction. Moderation is key, if a little is good, a lot is not better
    I guess you could also say motor oil is your engine's heroin by the same token, I'll keep replacing and adding to my engine thanks ;)
  16. WingKL

    WingKL

    Joined:
    May 12, 2007
    I use MG Chemicals's 801B Super Contact Cleaner which cleans and lubricates. From what I've read, if the pots (usually carbon ones) get noisy quickly after being cleaned, they are pretty much toast and should be replaced.
  17. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Thanks everyone. I got in there and got most of the dust removed. I'll hold off on any contact cleaner for awhile. It doesn't look too necessary at the moment. Now, if I could just figure out how to bend that part of the jack back down. That's the part that has me stumped...
  18. B-string

    B-string Supporting Member

    Joined:
    Nov 21, 2008
    Location:
    Lake Havasu City, Az USA
    Straighten the contact first. Use a 90 degree "pick" to gently lift at the "loop" part of the contact. See if the tension is restored. If not lift again and press down at 1/4 of the distance between the loop and the free end of the metal contact. Try a couple times and if you can't restore contact/tension the jack would need to be replaced as the tensile strength has been lost before you got it.
  19. jd_watt

    jd_watt

    Joined:
    Mar 22, 2013
    Got it - thanks guys!

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