Bass guitars can be very sensitive to things that alter how their strings vibrate, leading to all sorts of issues from not sounding right to strange warbling after tones.
Your active bass may have died due to either its battery dying (replace it if necessary) or one of its wires having suffered damage due to broken solder joints inside its structure.
Battery
If the bass begins to buzz or cut in and out, this can be a telltale sign that its battery needs replacing. Locate its battery compartment; typically a small panel on its back that needs unscrewing; once old battery removed place new one and you should be set.
If your bass is still buzzing after following these instructions, this could be an indicator of a malfunctioning output jack. Repairing this requires more advanced skills; for instance soldering may need to be performed. If this is too complex for you to manage on your own, I suggest visiting your local music shop where they will probably provide this service at an affordable rate.
Reasons may exist why your bass may no longer sound the way it once did, such as its battery being dead; changing it out should solve this problem quickly and easily.
Your bass may not sound quite right due to faulty pickups. Pickups are used to convert mechanical energy into electrical energy and are composed of magnets in a cylindrical container called a “bobbin,” wrapped multiple times with conductive wire. As strings vibrate they generate magnetic flux which is picked up by magnets inside the pickup and converted into electrical signals which travel along your wiring, instrument cable, amplifier cable and finally into your amplifier for sound creation.
Bass guitar pickups come in various forms. Common options are single-coil, split coil and double coil (commonly referred to as humbuckers). Each has their own set of advantages and disadvantages but all possess the ability to alter your tone significantly.
Note that not all batteries are created equal, even though they might look the same and come from the same brand or age group. High-quality 9V batteries stored in a cool, dry environment may extend their lifespan significantly; keeping spares on hand will ensure you never find yourself without power when you need it most.
Wiring
Your bass has one or multiple pickups and its wiring must transfer power between them all. If these wires become disconnected, this could lead to no sound being produced at all – or worse still – complete silence!
Starting off by inspecting each pot’s lugs to make sure they are securely connected to their socket connections on the jack socket is a great place to begin. Also make sure that any wire ends being soldered have been tinned prior to soldering – this provides stronger mechanical bonds while decreasing electrical failure risk.
Check that your guitar’s jack socket hasn’t become oxidised over time, which could prevent proper contact between it and its plug.
If the ohm meter registers zero, there may be a problem with either an open or broken coil on a single-coil pickup, or with solder joints in your circuit. You can test for this by connecting another guitar cord and seeing if no sound comes through.
Your pickups could also be misphasing. This could happen if their magnets have become out-of-phase on a Gibson P-90 style pickup or the wiring has fallen out-of-phase with each other; an easy solution for this issue would be switching the polarity of their poles.
Use a small capacitor (0.047uF or 0.068uF) to restore the phase between your neck and bridge pickups. This will restore phasing.
Add a Push Pull Volume Pot To add some flair, try installing a Push Pull Volume Pot that acts as a series/parallel switch for your pickups. In effect, when opened up it puts them both into series increasing overall output and midrange for a fuller tone.
Important to keep in mind is that this work requires advanced soldering expertise and should only be performed by experienced users of a soldering iron. If this is your first time soldering, start off practicing on less costly components and wires to gain experience and reduce the risk of burning out expensive pots or switches which would cost thousands to replace.
Pickups
Pickups are at the core of bass sound, and there are countless varieties to choose from. Everything from wood type and placement on body and neck to magnet type and magnet strength can impact tone; as a result, changing up your pickups could unlock an entirely new world of tone and phrasing possibilities for your instrument.
Single-coil, split-coil and humbucker pickups for bass guitar offer three main construction types. Each offers different tones used across various musical genres.
Single coil speakers consist of two coils wired together in parallel to minimize noise output from each individual coil. Coil configuration can vary significantly depending on its winding process or shape of pole pieces; and its sound output can range from warm, clear and crisp to gritty with lots of midrange growl.
Split-coil bass pickups were first popularised on Fender Precision Bass models since 1957. These double coil pickups feature only one coil working with E and A strings while another coil works on G and D strings; these have warmer sound characteristics than single-coils and add midrange depth and growl for greater musical expression.
Humbucking pickups consist of two single coils wired together in series to cancel out their mutual noise, making these an excellent choice for bass guitars as they offer an array of sounds ranging from warm and transparent to aggressive and snarling.
Piezoelectric pickups found on some acoustic-electric basses offer additional innovations, using light beams to convert string vibrations to electrical signals for more focused sound output and cleaner audio performance than magnetic pickups; however, installation may require professional services.
Connections
Step two in testing any circuit is to ensure all its connections are functioning as intended. This involves inspecting the output jack to make sure its contacts are undamaged from use and all soldered into place; this connection sends signal from guitar to bass amp and should remain unsullied by exposed wires or bends in their contacts.
One common cause of no bass sound can be damaged cables between the bass and amplifier. To make sure these are in working condition, test with an ohm meter to ensure zero resistance ohm readings – otherwise replace immediately!
Another essential step is ensuring that the polarity of your guitar battery is correct and all switches and potentiometers are in their appropriate positions. Tin all terminals that require solder connections for stronger mechanical and electrical connections.
As well, it is crucial that no broken leads exist. A broken lead should usually be visible and easy to repair; if none can be identified there may be an unsolvable solder joint somewhere within your circuit that needs attention.
One common issue on bass guitars is interference between pickups, particularly on humbuckers. This issue usually stems from an imbalance of magnetic fields; often this can be resolved by raising or lowering polepiece height; but sometimes replacing pickups altogether is best solution.
Some equipment is “protected” against this by adding a diode across their power input, creating an emergency short circuit in case of reverse polarity that would otherwise harm amplifiers and other equipment connected to them. This approach provides an inexpensive yet simple means of protecting against potential issues – although this doesn’t always work!