My MCX has suddenly developed a problem when the Echo effect is engaged; a terrible distorted digital noise which increases in volume, as if feeding back through the Echo effect. I’m posting here to see if anyone else has experienced this issue, and if anyone has found a fix.
Details of fault: when the Echo effect is engaged (on either Deck 1 or 2) in Standalone mode and when using the effects on a line/phono input (on channels 3 & 4), and the effect level knob is turned clockwise (even slightly) the distorted noise appears.
Happens even when the channel volume is at zero (and therefore no audio should be present).
Is much louder than the echo effect usually would be if affecting music as normal.
Is sending this out to both Master Out and Master Monitor in the headphones (not sure about Booth, haven’t checked yet).
Adjusting Tap Tempo and Echo time interval (1/4, 1/2, 1 etc) does change the “rhythm” of the distorted noise (which has lots of pops and clicks).
If using a longer Echo time (eg 8 or 16 measures) then the noise doesn’t begin until the end of the first measure, only once it “loops” back and begins a second pass, if that makes sense.
Haven’t tried with computer attached/Serato.
Both Phaser and Noise effects unaffected.
Happens even if all connections are disconnected, no USB drives connected, with only power to the MCX and headphones.
This happened out of the blue, whilst using the Echo on a channel that had a turntable playing through it. I’ve been using my MCX as a mixer with turntables for many years now, without ever having an issue with the effects (I do use the Echo a lot on the turntable inputs).
The issue happened suddenly whilst in a mix, and as I was adjusting both the Echo level and using the filter simultaneously; noise just came from nowhere.
Power cycling several times didn’t resolve the issue, although after 24 hours, the issue wasn’t present on power up, or for the remainder of that session. Next day I powered up and issue was there again, several power cycles again made no difference. Haven’t yet done a Factory Reset, but that is now on the cards (although I’m worried about that failing if there’s a hardware issue).
If anyone has any info that can shed any light on what might be going on, then thank you in advance for sharing. Cheers.
Go ahead with the factory reset - it doesn’t do anything except change any yes’s or nos that you set in the user parameter, back to their original settings.
However I doubt it’s got anything to do with firmware or settings - it sounds like a hardware fault. For example one of your rotary controls for the fx could have a dry joint and is now only offering full on/max as a signal , rather than dry , medium etc
Thanks for the response @Pasha. I did consider the idea that the pot could be causing the issue (as it was being turned when the fault appeared), but I dismissed it based on the fact that the fault is happening on both Echo effects, on both sides. If I decide to go as far as disassembling the unit to check for loose connections etc, I will certainly look at the solder pads on the pots.
Just tried a factory reset (although I now realise that this just resets the settings to default, as pointed out by @Pasha) which has made no difference.
I have been using the MCX8000 units since 2017 (I have two of them) and there can be issues where the ribbon and pin connectors inside can come loose. I know it’s a bit of a pain getting them apart but the first thing I’d try is reseating all the connectors from the main central output board to the screens and deck boards. I’ve had a few random things happen over the years and reseating the connectors has fixed it every time.
The other less destructive thing you could do first is going back to a previous unit firmware (if you can find one) then going back up to version 2.5 as that will wipe the MCU and not just be a soft reset.
Thanks for your reply @Homeland101, and for your suggestion regarding the ribbon connectors. I’ll probably go down that route, although I may try rolling back the firmware first, as you suggested. I have backups of most versions that were released, so it would make sense to give that a try first.
Thanks @SlayForMoney for the kind words! To clarify, the problem does persist when using the Echo effect on both Decks, with tracks loaded from a USB drive in Standalone mode.
Update… I couldn’t find info on how to roll back the Firmware, so decided to get the tools out and take the MCX apart (using a very handy PDF from iFixit).
With the unit powered up and the Echo engaged, I poked around to see if any of the ribbon connectors might be causing the issue, but the problem persisted. Couldn’t see any obvious signs of component failure, or dry joints on the potentiometers/rotary encoders on either deck’s FX section.
I disconnected every ribbon connector and reseated them, weirdly the noise didn’t seem as bad after this, but was still present. I messed around with the effect parameters for a bit with no change, and then suddenly whilst I wasn’t touching anything, the noise stopped!
I carefully reassembled the MCX whilst it was powered on and listened out for the noise, which didn’t rear its ugly head at all. I reconnected my turntables, powered everything up and played around for 10 mins without any issues. Then after turning the Echo off and switching it back on, the noise was back, aargh!!
I am stumped. It’s obviously an intermittent fault. Hopefully means that it’s a dry joint/loose connection somewhere, although I suppose it could be a failing component.
I didn’t screw the case back together thankfully, so will continue investigating, but may end up taking it to a specialist (I believe The Bench, at Resonance Studios in Stockport - not too far from me - is a Denon DJ repair centre, so might give them a shout).
As already mentioned, the distorted noise is present on Master Out and Headphones when Echo is engaged and Echo level is increased above zero, even if the channel fader is all the way down. But oddly the volume of the distorted noise is affected by the crossfader; cutting out if crossfader moved across to the other channel (as expected if you were playing music through the channel) even with channel fader down, and reducing in volume if using a ‘smooth’ crossfader curve.
I’ve got schematics, so hoping to narrow the problem down through careful investigation
