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Amplifier Troubleshooting

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If you are having trouble with your Line 6 amplifier, please check the following points before taking your amplifier to your local Authorized Service Center:

Q: I am noticing that I am getting volume/tone changes when playing at a high volume?
A: Try "parking" the knobs (except master volume) at 100% to ensure that the knobs are not moving to the "current" location rather than the preset location. Recall a preset once the knobs are parked to ensure the tone you are working with is a preset rather than the current knob position.

Q: My master volume has almost no change past 6?
A: This is due to the volume pot installed on all Line 6 amplifiers. A solution to this would be to replace it with an "audio" pot, but this modification wouldn't make it louder - just smoother. Line 6 originally installed audio pots on the AXSYS, but players didn't like them because they made the amp feel "wimpy". Players also did not like the fact that they had to turn the amp up to about 4-5 before it would start "happening" and 7-8 on the gig. Even though there was still a good amount of headroom, player feedback was that they preferred the amplifier with the traditional volume pot, so that is the style used with Line 6 amplifiers.

- Perform a factory reset of the unit:

Factory Reset Procedures

Volume and Signal Troubleshooting
- turn off other volume controls not being used (i.e. volume trim pots)
- Ensure there is no debris in the CAT-5 or input jacks.
- Unplug all other units from the audio chain, as well as any CAT-5 cables and controllers.
- Use a high-quality cable you know is functional (i.e. works in a different application) directly into the instrument input, bypassing all other effect units.
- Ensure that the guitar/bass is outputting signal. Try the amplifier with another instrument you know is functional (if possible).Make sure all the input and output jacks are tight. Check the instrument with different pickup settings to make sure it is not a bad pickup connection.
- Ensure that both the positive (white) and negative (black or red) wires are fully connected to the speaker, and that the speaker output from the amplifier is plugged into the correct jack (when applicable).
- Check the effects loop (if the amp has one). If you're not getting any signal, try plugging into the RETURN side of the loop to see if there is any output. Likewise, with a source feeding the input, plug the SEND into another line level device to see if you're getting signal.

Tone and Rattle Troubleshooting
- Check the make sure all buttons on the unit are not stuck
- Be sure that all screws on the unit (handle, corners, baffle boards, speakers) are snug.
- Ensure that there are no foreign objects (i.e. silicon packs) stuck in the speaker enclosures

Q: Are the tone controls on the on a Line 6 amplifier passive or active, and where is the "flat" level?
A: Each amp model is different, and the controls behaves like the target amp. Most tube amplifiers will have a passive tone stack with makeup gain. Line 6 tone stacks are designed to behave just like the modeled amp (both the good and the not so good). Some amplifier tone stacks are the closest to flat when set B-0, M-10, T-0, but it is different for each model.

Power Troubleshooting
- Ensure that there is sufficient power coming from the power outlet into the amplifier. Try a different circuit to ensure there is not a power issue at the outlet.
- Make sure that the both ends of the power cable are snug in their sockets.

Tube Amplifiers Troubleshooting
- Make sure the tube is firmly seated in the tube socket.
- If the tube(s) make a popping sound accompanied by intermittent light from tubes, the tube is failing and needs to be replaced.
- If there is "white frost" inside the tube, the tube has cracked and it must be replaced.
- If there is a "tube" ringing (not due to loose screws), there may be a failing tube. Replace the 12AX7s individually and the matched 6L6 pairs to determine if a tube has failed.

Replacing Tubes
- Always replace power amp tubes with matched set(s) every 12-24 months depending on the amount of use, and have the bias checked and/or adjusted by an authorized Line 6 Service Center.
- Preamp tubes (such as the two 12AX7s) only need to be replaced when they are microphonic (ringing sound from tubes when tapped), noisy, or damaged.

If there is still no success after following these suggestions, you will want to visit your local Line 6 Service Center. Remember you will need to bring proof of purchase if you are within your 12-month amplifier warranty period.

Product Repair


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