I am getting electrical interference from the power supply on a DELL laptop when I attempt to record using the lineout from my mixer. The power cord has the 3 prong plug coming out of the power supply. If I disconnect the power from the PC and run on battery, no interference occurs. How can I solve this problem. Thanks..
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As the manual suggests, the 1st step is to RESET your pedal board. I know, you 'll have to erase 20 custom presets of yours but hey, they're already lost anyway!... So just reset the on board chip by pressing the TAP and STORE buttons together for 5 seconds while you power ON the X V-amp. That's it! Now the board sounds good as new!
The unit is SUBJECT to radio interference from other systems in the area such as high power taxicab radios for example and other services. 30 seconds might be about the time for a radio transmission. The system, while being interfered with, likely will NOT generate audible sounds and due to the squelch algorithm may MUTE the system.
Sorry, but you are a SECONDARY user per FCC definition and they are licensed and you are sharing bandwidth. You cannot interfere with them, but they can interfere with you. You should probablly get a UHF system that has less chance of interference. While recording, frankly I would be wired, not wireless. I am both an electrical engineer nd a HAM so I am aware of these problems.
Likely the filter caps or the rectifier diodes have shorted. Power supplies are easy to work on unless the are switching type.
To work on this, replace the fuse and put a 25 watt light bulb in series with the hot side of the inout power... saves fuses and will send enough current in to troubleshoot with a meter. Use SAFE procedures when working on electrical equipment. For switching power supplies you need to use a line isolation transformer for personal safety.
Hum is always connected with the presence of AC interference into the signal path of the amplifier, which means the audio amplification is mixed with the ac ripples.
So this can be a break down with the power supply as a possible tank capacitor or a stabilizing capacitor in the main power or the sub sections of the amplifier or pre- amplifier.
All amps make a small amount of noise (system hiss) but the amps own power supply should not cause a problem on it's own.
However if the frequency is around 50hz (the G 2 1/2 octaves below middle C on a piano) it is most likely due mains electricity interference or an earth (grounding) issue.
Here are a few things to try to identify the source.
Could be a lack of earth (grounding) This is potentially VERY DANGEROUS and could result in electric shock if you touch a metal part of the amp or touch some other metal object (like a microphone stand at the same time as your guitar strings). Check the earth wire is firmly attached at both ends of the power supply lead.
Could be a defective mains socket - try plugging it in to a different one, preferably on a totally separate circuit.
Could be an earth loop. These can occur if you are using the amp with an output to a public address system or mixer that is also earthed because of a 'potential difference' between the two earths. Solution - use the balanced (xlr) output which incorporates an earth lift rather than the unbalanced jack output.
Unplug any effects pedals, foot-switch etcetera to see if that eliminates the problem. Turn off any internal effects, including bass intensifier.
Make sure any signal cables (guitar leads) have good quality screening and that the screen is well soldered to the jack plugs at both ends.
Ensure signal leads do not lay along side (parallel) close to mains electricity cables but are well separated and only cross at right angles.
Move the amp away form other electrical equipment that may have a powerful magnetic field (especially CD or DVD players, hearing loop amplifiers, radio microphone transmitters / receivers, mobile phones
Turn around or stand in a different position - it might simply be the pick-ups in your guitar causing interference in the magnetic field of the power supply.
Does plugging in or unplugging a signal lead / guitar make any difference? This particular amp requires only mono jack plugs a stereo (trs) plug may be shorting across terminals
Does it change when you touch the strings with your hand? If yes check internal wiring and screening within the guitar.
All amplifiers make a little bit of noise (hiss) but it is normally slight and drowned out by playing. However, assuming that this is not normal system hiss, here are a few simple steps to try and locate the source of the problem by process of elimination.
SAFETY FIRST - a common cause of a humming or buzzing sound can be a lack of earth (grounding) on the mains supply. With a 240volt AC supply this hum will be at 50hz (in the UK) - frequency may vary in other countries but should be similar. Check the earth first because of risk of electric shock. Until you are satisfied that this is not the cause of the problem DO NOT touch any metal parts of the amp. Remove the mains lead and try a different one. Try plugging the amp into a different mains outlet socket (preferably one on a completely different circuit).
Turn off other electrical equipment in the vicinity that may be causing interference. Move the amp a bit, try rotating it by 90 degrees to change relationship to things like mains electric cables in the floor.
If you are using the line-out socket to give a feed to a mixer, slave amp or p.a. system unplug this. Sometimes double earthing (through the mains lead of your amp AND the mains lead of the MIXER / PA) will cause an 'earth loop' due to a different resistance at each end. Putting a DI box with an 'earth lift' in between may eliminate this problem. Alternatively there are little gadgets you can buy to do this (I found one intended for car audio systems on Amazon that works very well)
Unplug any instrument leads - to eliminate possibilities of interference affecting cables, effects pedals or guitar pick-ups. Also unplug the foot-switch.
If that stops it plug a lead in without a guitar on the other end - does the noise return? If yes change the lead. If no plug the guitar in.
Try moving the guitar in relation to the amp (turn it around 90 or 180 degrees) - this will be pick-up to amp power supply interference.
Does the sound get better or worse if you touch metal parts of the guitar with your hand? This may be a screening issue within the lead or the guitar itself.
Try turning all the individual channel tone and gain controls to zero, turn off any effects on the amp panel. If that eliminates it only turn up the controls on channels that you are actually using.
Unless something has suddenly happened to your guitar (like being dropped) start by eliminating as many external factors as possible.
If you are using an effects pedal plug straight into your amp to see if that cures it.
Turn off any other electrical equipment in the vicinity that could be causing interference.
Try changing your guitar lead - it may be just poor screening or cracked insulation in the cable.
Try switching back and forth between the different pick-ups and also fully rotate all the volume and tone control knobs quickly several times - the contacts may have got dirty over time.
Pull the jack plug in and out several times to make sure it isn't dirty contacts in there too - if it is give it a little squirt of 'switch cleaner' spray - available from most electronics suppliers or online via Amazon E-Bay etc.
Check the screw bezel (threaded ring-nut) that holds the jack socket in the body of the guitar. Sometimes these work loose over time and then the jack plug doesn't quite go in far enough resulting in poor electrical contacts.
If your guitar has active circuitry pick-ups also replace the battery - use high quality batteries (Duracell Ultra or similar) never re-chargeables as they don't hold high enough voltages.
Try a different guitar to see if the problem is in the amp. Stand or sit in a different position, move about, turn round 90 degrees to see if it is just interference between the guitars pick-ups and the power supply in your amp.
If none of the above works then it is likely to be a problem with the guitar's electrics - don't tamper if it is still in warranty. Carefully remove the back plate to see if any wires have come loose - it might be a dry solder joint on the jack socket or one of the control knobs so may not be immediately obvious. If the screen wire (sleeve of the jack plug) has come off it may not stop the guitar working but it may cause the noise problem.
Beyond that I can only suggest taking it to a qualified guitar technician who can fully check the electrics with a test meter.