Long time gl2400 user here in home studio. I have a bit of noise (like white noise) fairly low level but still annoying, in the right main output. I have tried different cables, I have de-selected ‘to LR’ on all channels, the noise still persists.
If I send my individual channels to the group 1-2 and use that as my master out, it’s fine, there is zero noise. That’s what I’m doing at the moment.
Anyone have any ideas what it could be or how to fix it please?
On a side note, the main level meters have recently been acting weird, sometimes they come on, sometimes just the left one, sometimes just the right, or sometimes they are very dim but you can just about see the levels moving into the Green/orange/red.
The noise can, of course, have many causes.
But simply check if it changes when you disconnect the right output using the INSERT R jack (e.g., with an unwired TRS connector) or short it (e.g., with a TS connector).
And/or maybe does the noise change when you switch your signal generator from PINK to 1 kHz?
If I put an unconnected TS jack in the insert R the noise completely goes. what does this tell me? (note also same on the master out L, the noise is just not as loud)
One thing that I did notice was, if I press down a little bit with my fingers on the console by where it says ‘listen wedge’ and ‘M source’ - the noise completely disappears.
The same is true if I press down with my fingers on the grey area of the board where the L-R, group1-2, group3-4 sliders are.
I’ve opened the back up and reseated the ribbon connectors, also sprayed some contact cleaner in the master faders.
Fixed - it turned out there is a brass/copper bar going across the channels/ circuit cards on the inside, some of the screws were quite loose (especially the master channel one where I was getting noise from) - when I tightened them all up, the noise disappeared.
Hope this helps anyone in the future if they run into a similar issue.
To answer your question despite the problem being solved:
This narrowed down the problem to something else: It was not in the right main output modul, as I had suspected, but somewhere before it.
However, since group 2 wasn’t noisy, it wasn’t a problem with the input channels either, but somewhere in the routing to the right main output.
Having a mechanical loose connection that changes when tapped or pressed is, of course, ideal for troubleshooting, and it’s usually a cold solder joint - or, as in your case, loose screws.
I thought I had fixed my issue, XLR out put lead was trapped between center bracket an top of power supply. Sorted that, and full output fader into my Speake system, the slightest of background noie, as expectewd, little more if FX fader up, again as expected.
Re-assembled, tightened last screw laid desk down, phut noise - dead desk, no lights at all.
Main input fuse ok, are their other fuses associated with the power supply internally?
Not that I know of.
But have you checked where the voltage is being lost?
That should be the first thing you check - provided, of course, that you have the necessary qualification, especially regarding mains voltage !!!
If not, you absolutely must hand the problem over to a qualified service technician!
There is a thermistor on the primary side, but it doesn’t usually fail on its own.
Actually, the kind of “loose connections” you described, which are even reproducible, are ideal for troubleshooting, but I can’t really imagine that the original problem had anything to do with the power supply or even the mains voltage.