20 Most Recent Allen & Heath Allen and Heath GL2400-32 32-Channel Mixer Questions & Answers

Auxiliary output sockets (AUX 1-6) would usually be used for connecting to an FX unit input, with the signal levels sent to the FX unit governed by the AUX SEND pots from each input channel, setting the AUX MASTER at a level that will prevent peak signals from the various channels (sent to the FX unit) from clipping the AUX bus rails. The output of your FX unit can be then be returned to stereo line input sockets (ST1-4). For details see the GL2400 User Guide: AUX OUT 1-6 (p.15), AUX SENDS (p.17/18), AUX MASTERS (p.19), STEREO CHANNEL LINE IN (p.14). If you require more precise EQ parameter control of FX return signals - and you have sufficient spare channels on the desk, connect to 2 x mono channel inputs: one from left FX return, one from right FX return, with each of the console's input channels panned hard-left/hard-right (this assumes the FX unit has a stereo return).

You may secure it with some adhesive.If it will be of help you may download the service manual for free from Elektrotanya com.

send a signal thru the sub 4 insert and see if it comes out the sub 4 output. You may have jarred a ribbon cable loose in transport.

Is this for live sound? You can use your aux outputs as sends if you're not using them for monitors and return to spare channels. If any units are being used for only one channel, either run them in-line (use the effect unit's wet/dry settings) or use the channel's direct out and return to a spare channel.

If one effect is applied to several channels you could put those into a sub group, take that sub output to the unit and return the 100% wet mix to a spare channel.

Be careful not to send the return channels back to any auxiliaries you're using for effects.

Hey tifly415, did you ever fix this problem? My church has the same mixer and last night it did the same thing twice during a congregational meeting. No fan noise, but the meters all peg and we get this horrible descending squeal which gets louder as you pull the faders back in a moment of sheer terror and panic. Power it off and back on and it's ok for a while then it happens again. It's happened to me a few times during rehearsals in the past and it definitely is not mic feedback because no one was near the console or doing anything at the time. It seems to be totally random and unpredictable.

I, too, suspect a power supply problem, but it never seems to happen when my troubleshooting gear is nearby. The only thing unusual yesterday was that the mixer was left on almost all day, so it may have been warmer than usual.

Anyone else have the same problem, or better yet, know of a solution?

There can be any number of reasons for this problem - solve it diagnostically by starting with something that you know is working and work through systematically to the other end.

1. Test a microphone on a separate amp to make sure it works okay. Check amp and speakers working. Check that all output cables from mixer to amp are working by testing separately.
2. Plug microphone into a channel on mixer. Also plug in headphones and turn headphone volume control up.
3. Make sure input sensitivity knob is turned up a bit (say half way) and main output faders (yellow) are up.
4. Check that channel is turned on (little button just above the channel fader- needs to be pressed down)
5. press pfl (pre-fade listen) button (next to button to switch channel on)- do you get any sound on main output or headphones or any indicator lights on mixer to show signal is getting that far (eitehr the individual channel metering lights or the main ones in the central section)?
6. turn off pfl - make sure channel fader (slider) is up - normal position is ) - about 3/4 of way up. Check lights again on individual channel and main output section - any signs?
7. Is the sub mix button for the channel pressed down - in which case you will need to bring sub mix (red) output faders up as well as main faders.
8. If you have got signs of signal on the individual channel but not main see if the channel has been routed somewhere odd (like a subgroup of channels).
9. Plug a working amp and speakers into one of the auxiliary outputs and use the relevant auxiliary send knob (on each channel just above the faders and pfl switches) to pan some signal to that auxiliary out - do you get anything? There is also a headphone socket for listening to the auxiliary channels (with a selector switch /knob to determine which one - make sure it is in the right position) try listening to the auxiliary output with headphones - anything? If yes the problem lies in the main output section.
10. Check that there is not a jack plug in the insert socket (to route signal through an external effects unit) without a matching return jack being plugged in - if appropriate is relevant effects unit switched on and correctly set up - if unsure remove the insert plug to take it out of the system.
11. Make sure any mute buttons are not switched in on main outputs.

You can download a full user manual here http://www.allen-heath.com/gl/gl2400

Check the insert sockets.

cachepe.samedaymusic.com/.../gl2400ug_ap5597_2-42fad5e2de1bc79db38576be174464d4.pdf - United States
Above is your user manual below is a service and repair manual.
http://www.performanceaudio.com/cgi/product_view.cgi?products_id=16696

Indeed i would suspect something around your Final Output semiconductors, and any associated resistors?
You really must obtain a service manual, here there are the troubleshooting steps required to isolate and hopefully allow repair of your unit.
Look for any discolored components etc, check if any are overly hot... use a temperature probe on suspected components. Freeze spray may also be useful in diagnosis.
Use your eyes & nose to isolate the bad burnt overheated components, I sometimes use a straw up a nostril and selectively go over suspect parts, and "Sniff" to try and detect the overheated smell... it works.
http://www.allen-heath.co.uk/uk/TechnicalSupport.asp
Above is your tech support link, contact them for any info you require.

The most likely case is that one of the main output transistors (if which there are many) is shorted. When the protect circuit senses DC on the final output, it will not allow the output relay to come on to protect the speakers from raw DC. With the power removed, you can check between each outputs Emitter and Collector and you will probably find close to zero ohms. From that point you need to unsolder each of the pins of the bad channel until you find the shorted device(s) and replace them.

'pianoforte'

BREV. N. 838420

See page 22 troubleshooting of this manual. It may help you. dd501 (yamaha.com)

Depending on the model, there are four around that date, it could be the insert jacks are tarnished reducing the signal flow between the pre amp stage and digital power amplifier. It could be the power amplifier has failed. It could even be customer error in wiring. This assumes there is the correct level of signal entering the input sockets of course.

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It's a Line 6 and probably requires a software update from Line 6.