Warwick Thumb Hiss!! (Help please)

Discussion in 'Pickups & Electronics [BG]' started by ChipChipperson, Jul 14, 2013.

  1. ChipChipperson


    Jul 14, 2013
    Hi guys,
    Last year I inherited a Warwick Thumb Bass NT 4 string (late 90s model). Recently I have had more free time, and started playing with the bass, and quickly discovered a constant hiss from my tweeter whenever the bass is in active mode (Regardless of the volume level).
    It is important to note I have all EQs flat, and the only way to get rid of the hiss is to turn off the tweeter (which takes away all my pretty highs), or put the bass in passive mode (which eats the battery and takes away my EQs).
    I recently learned all warwick amps use "low z" circuitry, which i'd imagine is an attempt to address this issue. Is this hissing problem because my preamp (stock MEC) is not set up properly (was done by Warwick Custom Shop)?
    Should I try to change the preamp for something more quiet (and is that possible)? Or do I have to get a Warwick Amp :( (currently using GK gear, though the warwick's hiss is evident through any GK/Ampeg amp I've ever used).
    This bass sounds amazing and I really want to have a preamp, but the hiss is driving me crazy >.< :crying:

    Any help or advice is appreciated, Thanks!
  2. Bass_Nishi


    Jul 14, 2013
    If you can't fix it, try a Boss NS-2 Noise Suppressor and it should cut out all the excess noise :)
  3. ChipChipperson


    Jul 14, 2013
    Hey Nishi, thanks for the reply. I looked around and that may help to deal with the issue. I've also read about people only using the bass in passive mode and using an external preamp. Looking for someone who knows a decent amount about Warwicks to give me more info!
  4. Warpeg


    Jun 20, 2005
    I'm not sure if it's related to your issue or not, but why would your battery be draining while in passive mode? When you pull up on the active/passive push/pull pot's knob, you are disconnecting the battery from ground; the battery is no longer part of a closed circuit and cannot (read: should not) drain. Perhaps you have a short?

    As far as the hiss goes:
    - Have you been using fresh alkaline batteries or rechargeable batteries?
    - Do other active basses have this hiss issue on your rig? What about passive basses?
    - Do you get this hiss just at home or is it present in multiple playing locations?
    - Are you using quality instrument cables?

    I owned a '98 Thumb NT a few years back. It did have a small amount of hiss. Unfortunately, the MEC preamp design has a high noise floor. Unless your hiss issue is louder and/or more defined than what I encountered, the hiss will fade away into the background in a band situation.
  5. ChipChipperson


    Jul 14, 2013
    Hey Warpeg, thanks for the reply!
    I always use fresh Duracell batteries. From my readings I think that when my Warwick is put in Passive mode, it still uses a small amount of the battery.
    (If i leave it in passive mode for a few days, I come back to a dead battery. Also if I try to play in passive with a dead battery, it sounds very distorted).
    I also have a Carvin lb70 (active preamp and pickups) and a Musicman Stingray (active preamp) and have never had any hiss whatsoever. My cables are brand new, and I have had this problem in a variety of locations, so it's not the outlet.
    It sounds like you had the same problem with your Warwick, and although the hiss is drowned out in a band setting, I still would like to get rid of it, if possible.
    It is also important to note I am not completely satisfied with the MEC preamp, and I have been reading about the aguilar obp 3.

    Anyone know if switching the preamp may address the hissing problem?
  6. thewildest


    May 25, 2011
    Florida, USA
    Hi there, a few additional hints:

    Hisss may come from multiple sources within the circuitry, and in most cases is from 'moving parts' such as jacks, selector switches and potentiometers. Check your knobs, and try figuring out which one you work with that reduces/eliminates the hissss, get the pots clean/lubricated with potentiometer cleaner (or visit a luthier, they all have that)

    Same with the jack and battery connector

    I have a 6 String old thumb with the original mec preamp, and it sounds like a cannon, would not change it for anything
  7. ChipChipperson


    Jul 14, 2013
    Hi thewildest, thanks for the reply!
    Interesting, I'll have to look into that. Lowering the Treble slightly reduces the hiss, and increasing the Treble past the middle setting GREATLY increases the hiss.
    I called the Warwick Custom Shop, and they told me the MEC preamps are notoriously loud, but the battery life problem sounds like something is not connected properly.

    My new plan is to check out an Aguilar Tone Hammer, and see if it gives me some enjoyable EQs and reduces the hiss. If I like it, the Aguilar OBP 3 might be the way to go.

    Thanks for the input, and if anyone has any additional suggestions, please let me know :)
  8. hiredlenz


    Apr 19, 2013
    I have the same battery problem with my 1997 Warwick Corvette Standard 5 string. It eats batteries really fast, even in passive mode (it's an active bass). Has anyone found a fix for this problem? ChipChipperson, did you get yours fixed and if so, what was the cause?
    Thanks very much!!
  9. Rano Bass

    Rano Bass

    Sep 9, 2006
    Tijuana Mex.
    MEC pickups are active, there in no passive mode on you bass it is just a preamp bypass not a real active/passive switch.
  10. JP Morin

    JP Morin

    Mar 15, 2011
    +1 if you have active pus you need a battery any time, pre amp by-passed or not...

    For the battery life I found MEC eat more than emg's i have in my basses. I can hear a difference in the sound a month ago may be after I put a new battery in, but still way to go until the battery goes dead. Wiring them in 18v may help, but I'm not sure if all MEC pre can handle 18 volts. I would ask on the warwick forum here or on the official. High instance at warwick may answer you better than I !! Anyway I change my battery twice or 3 time a year, when I change my strings. There is nothing like fresh strings and battery !!
  11. I replaced the pickups and preamp with some bartolini J's and 2 band bartolinin preamp. To me the MEC electronics were nearly unuseable - very harsh highs. I feel the level of 'hiss' is acceptable with the bartolini electronics.
  12. Means2nEnd

    Means2nEnd Supporting Member

    MEC preamps can be wired 18 volts.

    Battery or batteries should last 6-12 months or so at least.

    Many times guys bring me bass to work on they bought "used" and some guy who thinks he knows what he or she was doing has wires to the jack wrong or bad solders etc.. I'm not saying that's what your issue is but I have owned over 20 German Warwicks and hiss has never been an issue when wired correctly IMO.
  13. So any of the MEC preamps can be wired to 18volts?

    Your preamp should have a small dial you can rotate that adjusts the output, it's possible yours is set full and causing some noise?

    I've had my 5 string thumb NT for many years and have had many issues with the preamp and I've never been totally happy with it, think it's time for a change...

    +1 on the pickups being active so even in passive mode it will still drain the battery if left plugged in. If it drains when unplugged you have a short somewhere that could also be responsible for the hiss
  14. hiredlenz


    Apr 19, 2013
    Well, I found out what my problem was. It looks like someone in the past had changed out the input jack and two of the wires were in the wrong place. Switched them to the correct places on the jack and everything is working perfectly. No more battery drain and the sound is awesome and quiet. Hope this might help anyone else out there with the same problems I was having. Thanks to everyone for all their input on this also, you were all very helpful!!!
  15. mmbongo

    mmbongo I have too many basses. Supporting Member

    MEC's generally are not active. None of the MEC's I've owned are active.
  16. tylerwylie


    Jan 5, 2008
    Dunwoody, GA
    There are active MEC picups and passive MEC pickups. Thumb NT bass has active MEC pickups, the singlecut model has passive MEC pickups. Corvette $$ has passive MEC pickups too, but the active Corvette has active MEC pickups, but the passive Corvette has the MEC "Dynamic Correction" passive pickups. I'd say their models are more likely to have active pickups but they have a lot of passive pickups as well.
  17. jonnybass1


    Dec 9, 2011
    Brampton, On
    Incase anyone does a search for future note the MEC pickups that have gold writing are active and the ones that have silver writing are passive.
    And regarding the hiss there will be a ground problem or it could just be a bad patch cord (sorry had to add my personal experience lol) all MEC pickups and preamps it have tried or used are totally quiet.
  18. LenMinNJ


    Dec 22, 2010
    I had a hiss problem in active EQ mode on my 2000 Warwick Thumb NT.

    I researched it on the Web and found that it was not uncommon for the years around 2000.

    The solution is to change the TL-062 (8-pin) integrated circuit to either a TL-072 (lower noise, but slightly higher power consumption) or, even better, an AD-822 (even lower noise, but a bit higher consumption than the TL-072).

    And change the TL-064 (14-pin) to a TL-074.

    The trade-off is slightly shorter battery life. But the reduction in hiss is worth the trade-off.
    Last edited: Jun 29, 2017
  19. Acmak


    Jun 21, 2017
    Hey, new thumb nt 2001 owner here, how would i go about doing this? Could you post a link to a tutorial or something? I'm not much of a technician but less hiss is always a good thing so i'd like to give it a shot.
  20. There's more than one way to do this. Plus it depends on whether the opamp is surface-mount or through-hole. I'm guessing that a bass pre from 15 years ago would be a through-hole, so here's how I would do this...

    Take note of its orientation.

    Cut the legs one by one. (It is possible to remove a dip8 intact, but there's more risk to the board and surrounding parts. Plus the 062 is only worth a few cents these days.)

    Heat each joint, and pull out the cut leg. Do this quickly so you don't damage the board.

    Use a desolder pump to clear the holes. (Again, don't linger or you'll cook the track and it will peel from the board. If you don't clear all the solder in one shot, don't keep reheating the same hole. Move on to the other seven holes and come back.)

    Install and solder an IC socket. (The socket will also have a notch to indicate the opamp's orientation.)

    Check your new opamp's orientation, then push it into the socket. (Sometimes you will have to bend the legs in slightly as they will be too splayed for the socket.)

    FWIW, they bring out new opamps all the time, and these days there's many better choices for noise and current than the 072, but yeah, this will give you lower noise. And they're easy to buy. But the 072 draws around 7 times the current of the 062 so your battery life will be much reduced. Thankfully, 9V batteries have also come a long way in the last 15 years so this isn't really a huge issue for a preamp with just one (dual) opamp IC.
    Last edited: Aug 1, 2017