ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Lounge FUD Forum Archive => Topic started by: Dave Binski on February 07, 2011, 11:46:56 am

Title: 'testing' mixing console by overloading gain?
Post by: Dave Binski on February 07, 2011, 11:46:56 am
Over the weekend I had a friend borrow one of my mixers and reported back that the pre-amps were broke on almost all the channels.  I was not aware the board had any issues, it's always sounded & performed well for what it is - an Allen Heath GL2400-24.

He determined it was broke by inserting a SM57 into each channel, turning the gain completely up and noticing a slight signal blip on LED on the neighboring channels.

When listening to the output - it sounds overloaded and crackling?  (no shit)

In 'normal' use of the board, gain/trim right round 15-20/unity.  I've never had to push it to max, on anything.  When operating at in this range, the board sounds fine.

Is this a proper technique of 'testing' a console?
Title: Re: 'testing' mixing console by overloading gain?
Post by: Tim McCulloch on February 07, 2011, 12:02:54 pm
He's full of shit.
Title: Re: 'testing' mixing console by overloading gain?
Post by: Patrick Campbell on February 07, 2011, 12:29:51 pm
Thank you Tim


1+++++++++
Title: Re: 'testing' mixing console by overloading gain?
Post by: Geoff Doane on February 07, 2011, 01:00:03 pm
Tim McCulloch wrote on Mon, 07 February 2011 13:02

He's full of shit.


Hey Tim, don't hold back!  It's the last days of the forum.

Seriously, it sounds like there could be better power supply decoupling between the channels, but I still wouldn't worry about it.  I used a couple of these consoles for well over 10 years, and never had any problems like this.  Of course, I didn't abuse the mic pres either  Rolling Eyes

GTD
Title: Re: 'testing' mixing console by overloading gain?
Post by: Jay Barracato on February 07, 2011, 01:42:26 pm
Ask him if you can "test" his car by putting it in neutral and pinning the gas pedal to the floor with a broom handle.
Title: Re: 'testing' mixing console by overloading gain?
Post by: Dick Rees on February 07, 2011, 02:11:47 pm
Jay Barracato wrote on Mon, 07 February 2011 12:42

Ask him if you can "test" his car by putting it in neutral and pinning the gas pedal to the floor with a broom handle.


I can think of at least one other appropriate use for the broom handle in this case........if he removes his head first.
Title: Re: 'testing' mixing console by overloading gain?
Post by: Dave Binski on February 07, 2011, 02:14:52 pm
Well, that answers that.  I am not nuts.  Thanks for the double check.
Title: Re: 'testing' mixing console by overloading gain?
Post by: frank kayser on February 07, 2011, 04:54:39 pm
Dave Binski wrote on Mon, 07 February 2011 14:14

Well, that answers that.  I am not nuts.  Thanks for the double check.

Twisted Evil Sorry to disappoint, Dave.  It does prove your friend is full of shit, but does nothing to mitigate an insanity plea! Laughing
Title: Re: 'testing' mixing console by overloading gain?
Post by: Joseph Mulvaney on February 07, 2011, 06:04:51 pm
What a jackass (no offense to your friend.)  Yea...every single channel is broken  Rolling Eyes

Even an H3000 will behave like that if you crank the hell out of everything.

I would think twice about lending this guy your gear.  His "torture" tests are not doing it any good.
Title: Re: 'testing' mixing console by overloading gain?
Post by: jeff harrell on February 07, 2011, 06:26:07 pm
a mic preamp has got to know its limitations ! the guy needs some edjee-cashekion<(popeyed talk) in mixing boards or something !
Title: Re: 'testing' mixing console by overloading gain?
Post by: Gareth Marsh on February 08, 2011, 12:13:02 am
Dave Binski wrote on Tue, 08 February 2011 05:46

 

He determined it was broke by inserting a SM57 into each channel, turning the gain completely up and noticing a slight signal blip on LED on the neighboring channels.



It wouldn't be inconceivable to assume that the 'slight signal blip' on neighbouring channels was, in fact, just light spill from the LEDs on the channel clipping its nut off.

In any case, the crosstalk must really bother him when he's mixing with every second channel peaking...


Gareth
Title: Re: 'testing' mixing console by overloading gain?
Post by: Darrel Harris on February 09, 2011, 12:56:47 am
He's not your friend - he's an idiot.
Title: Re: 'testing' mixing console by overloading gain?
Post by: Charlie Zureki on February 09, 2011, 07:30:59 am
Dave Binski wrote on Mon, 07 February 2011 13:14

Well, that answers that.  I am not nuts.  Thanks for the double check.



 Hello Dave,

  We haven't determined that you're "not nuts"....only that there's probably nothing wrong with your console. Razz

 Cheers,
 Hammer