gibbothegreat Posted May 5, 2015 Share Posted May 5, 2015 Hi all, Our LS9 is nearly 6 years old, has been rock solid but has now started doing something odd, which is generating hiss across all 16 of the local inputs. With nothing connected and the gains wheeled right down, if I take the faders up to 0 with the master at 0 also, the hiss is noticeable. It is then affected by the gain on individual channels, in other words it appears to be pre-gain. Changing the word-clock to an external source doesn't make any difference, neither does removing the ADAT card. We've reinstalled the lastest firmware, this too made no difference. Anyone experienced anything like this before? Cheers, Link to comment Share on other sites More sharing options...
Shez Posted May 5, 2015 Share Posted May 5, 2015 Changing the word-clock to an external source doesn't make any difference, neither does removing the ADAT card. Have you tried clocking it from an external source? If memory serves, switching from internal clock to an (absent) external clock normally introduces a lot of hiss so if changing that setting doesn't change the hiss level, I wonder whether it's something to do with the internal clock. Link to comment Share on other sites More sharing options...
gibbothegreat Posted May 5, 2015 Author Share Posted May 5, 2015 Sorry, wasn't very clear - have tried it on the internal WC, on an external one, and via the ADAT card - no difference with any of them. Link to comment Share on other sites More sharing options...
themadhippy Posted May 5, 2015 Share Posted May 5, 2015 have you tried loading an old show file,someone may of turned all the inserts on or something simalry stupid Link to comment Share on other sites More sharing options...
gibbothegreat Posted May 5, 2015 Author Share Posted May 5, 2015 Yes, checked that, then re-initialised the board to start from scratch too. Link to comment Share on other sites More sharing options...
Oldradiohand Posted May 5, 2015 Share Posted May 5, 2015 Presumably you're listening on the desk analogue outputs? Is it on all outputs? Could it be a noisy power supply making the analogue outs noisy? Link to comment Share on other sites More sharing options...
chelgrian Posted May 5, 2015 Share Posted May 5, 2015 Anyone experienced anything like this before? We've seen single channels on an M7CL do this. Since we had nothing to lose an attempt was made to replace discrete components on the input board however this didn't help. Which means it must have been a fault which developed inside the IC. We had to replace the input board to fix it. I've not seen anything where all the channels do it at once. Link to comment Share on other sites More sharing options...
gibbothegreat Posted May 5, 2015 Author Share Posted May 5, 2015 Presumably you're listening on the desk analogue outputs? Is it on all outputs? Could it be a noisy power supply making the analogue outs noisy? It appears as if it's the inputs that are generating the noise - if they are muted, or the fader down, there is no noise. But even with the gain dialled down to minimum, raising the faders to 0 generates a significant amount of white noise. We've seen single channels on an M7CL do this. Since we had nothing to lose an attempt was made to replace discrete components on the input board however this didn't help. Which means it must have been a fault which developed inside the IC. We had to replace the input board to fix it. I've not seen anything where all the channels do it at once. No, neither have Yamaha's support engineers, apparently. And if I've understood what they've said correctly. then even if a board went it would only affect 8 channels, not all 16. Thanks for ideas all, will bundle it off to an authorised repair centre and see what they make of it. Link to comment Share on other sites More sharing options...
Electrolytic Posted May 5, 2015 Share Posted May 5, 2015 does this happen on headphones? what are you playing back through, a pa system? Link to comment Share on other sites More sharing options...
chelgrian Posted May 5, 2015 Share Posted May 5, 2015 No, neither have Yamaha's support engineers, apparently. And if I've understood what they've said correctly. then even if a board went it would only affect 8 channels, not all 16. Yes, each input board provides 8 channels, the bigger the console the more boards. You'd have to be really unlucky to have two boards go simultaneously unless there was an outside cause. Link to comment Share on other sites More sharing options...
cedd Posted May 5, 2015 Share Posted May 5, 2015 Do you have an external power supply that you could try running it on? Could be the internal PSU? It's the only thing I can think of that'd be common across all input cards. Link to comment Share on other sites More sharing options...
cedd Posted May 6, 2015 Share Posted May 6, 2015 Do you have an external power supply that you could try running it on? Could be the internal PSU? It's the only thing I can think of that'd be common across all input cards.Just remembered that we're talking about an LS9 not an M7CL - Ignore all of that! Sorry Link to comment Share on other sites More sharing options...
billy jim Posted May 6, 2015 Share Posted May 6, 2015 I had a hire LS9-32 that showed identical symptoms to this recently; unfortunately on that gig there wasn't the time to investigate, so I just had to muster through as best as possible and label the desk when I sent it back. However, slightly refreshing to see that it's not the only one. Link to comment Share on other sites More sharing options...
gibbothegreat Posted May 6, 2015 Author Share Posted May 6, 2015 does this happen on headphones? what are you playing back through, a pa system? Happens on headphones and any output that the input channels are routed to. Link to comment Share on other sites More sharing options...
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