Soundcraft LX7

[Miha Blaze]

great thread!!!

 

I have recently bought (used) lx7ii (24ch) and noticed one problem... sometimes few channels are distorting (like you put your voice through guitar distortion pedal or something similar), or not realeasing the signal at all... and after I touch mic pre pot a bit, problem dissapears... anyone know what is wrong? I am not electronically educated so this is all I can tell you about this issue....

 

Cheers!

 

One more thing... when sound dissapears, it seems like the mic pre (or sth else) has "gate" on it, and after you push signal to some thrashold (some limit) signal starts to appear... first as distorted, and after you (push signal on mic by raising your voice) raise your input, it starts to be clear as it should be...

 

is this mic preamp problem? some board conections problem??? help needed ;)

[timsabre]

It's a dirty contact somewhere ... as you push the volume up, the audio voltage gets higher and eventually becomes enough to break through the dirt. Hence the gate effect.

 

As I said earlier it's the insert jacks cause this on our LX7, pushing a jack in and out of the inserts a few times clears it up. But in your case it may be elsewhere - still, can't hurt to try the inserts.

[Sound Man]

Try a stereo jack plug with the Tip and Ring connections joined together plugged into a faulty channel's Insert socket.

 

This would bypass the switched connections of the Insert socket.

 

David

[PAforMusic]

Just reporting another case of a faulty board interconnect, 32-channel LX7. Group 1 intermittent (before its Insert) - it could be fine, gone or anywhere in between (low level, noisy, etc). It was the cable from the master section board to the right-hand rear board, at the master section end. Everything else was solid, despite very old unit (the initial version) heavily used. Decided best way to solve permanently in this case was to cut the affected wire right at the header and solder it direct to the board (perhaps not so advisable for newer units). Secured with zip ties & hot glue. Sorted. No probs at all with the Insert contacts on this desk, despite most of them probably hardly ever used - must have been decent quality sockets!

[dan slv-tech]

Ive just aquired an LX7 - and I need to replacement faders for it - anyone know what they are? cant get a schematic they look like tyco, but cannot be sure.

Anyone got any they want to part with? know a source?

 

any help would be appreciated

 

Dan

[KevinE]

If you are having problems with pcb interconnects like this, it might be an idea to replace them with new ones! It will make it easier to dismantle the desk if you put it all back together and then find there's something else wrong with it and it all has to come apart again. The pcbs on Soundcraft mixers are quite easily damaged and the tracks come away if you're not careful.

 

I often see desks like this with both modular and non modular construction in for repair and what the customer saved on the previous repair by hard-wiring the boards together, they will end up paying for later when it has to be snipped all apart just to get the faulty board out and back in again. This is particularly so on the LX7's because the boards are so close together.

 

If a mixer that's been hard-wired leads an active life, it may need servicing several times in its lifetime and the pcb tracks wont last long if they're soldered together and unsoldered apart more than a couple of times.

 

Mixers fail quite often for faults other than the jumper cables; particularly the soundcraft LX&'s with flimsy Alps potentiometers (another source of AUX outs failing...the aux master pots drop the audio out intermittently).