Tone/Volume problem.. is it the pups?

Discussion in 'Pickups & Electronics [BG]' started by Grangur, Dec 10, 2012.

  1. Hi All,
    I've just bought a Warwick Corvette Std 4 with MEC passive J pups. I like the sound generally, but there's a problem with the output.

    On this bass I have 3 pots - Volume, blend and tone.

    If I max the volume pot on the bass the tone pot works as expected.

    If I turn the volume down to 3/4 and the tone to full treble it sounds ok. If I then turn the tone pot to increase bass, the output volume colapses and the output from the amp gets so low I can hear the twang of the basses strings.

    Someone told me I need to change the pups, but to a noob like me that sounds odd. Anyone here have any ideas?

    btw I do like the sound of SDs :bassist:
  2. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    The problem you're describing does NOT sound like a problem with the pups, to me. In fact whoever suggested they were the problem may not be somebody you want to take advice from generally. ;)

    Sounds to me more like a problem with the preamp, and particularly I'd suspect a problem with the EQ pot--maybe a bad solder joint on it, or the pot itself is dirty or faulty, or it's miswired somehow.

    This model does come with an active preamp, yes?
  3. Kmonk


    Oct 18, 2012
    South Shore, Massachusetts
    Endorsing Artist: Fender, Spector, Ampeg, Curt Mangan Strings
    Sounds more like a preamp or pot problem. Not pickups.
  4. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    Ah OK--based on the edits to your post and the wiring diagram, there's no preamp, but the problem is probably still in the pots/wiring and not the pups.

    Has anyone "fixed" the wiring (i.e. messed with it) at any point? Do you see any wires that look like they might not be securely soldered, or any solder that looks dry or crumbly?
  5. iiipopes


    May 4, 2009
    There's always the option of J-bass V-V-T. Proven circuit.
  6. WarwickOfficial


    May 15, 2012
    Warwick & Framus Social Media
    I'd guess there is a loose wire, cold solder joint, or bad pot. I doubt it would be a problem with the pickups, based on your description. I would recommend taking it to a skilled tech if you're not able to diagnose/fix the problem yourself. Thanks!
  7. I'd asumed the pots would be ok(ish) as they seem to function to some degree.

    I just checked out the impedances of the tone and volume. The tone seems to go ok when out of circuit, but the volume one is strange. It goes low impedance both ends!?!

    I recon it's worth changing both pots - for what it's worth.

    I've checked the rest for dry joints. Thanks guys
  8. SGD Lutherie

    SGD Lutherie Banned Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    The tone pot does not increase bass, it removes treble. There are two ways to wire up a tone pot. One way it interacts with the volume control, which is what you are talking about.

    You should keep the volume all the way up anyway.

    If you want more bass, turn up the bass knob on your amp.
  9. I think I've been spoiled. Up to now I've had a 3-band eq on my Ibanez. I got too use to it, and not always kept the vol up :D

    Thanks guys.