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michaelm33
Joined: 26 May 2011 Posts: 1 Location: Houston
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Posted: Thu May 26, 2011 8:21 pm Post subject: m50 60-cycle hum problems? |
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I just bought 2 m50's and both have major 60-cycle hum noise when I connect the L/MONO output to any amp. I did all the normal troubleshooting (changed cables, amps, etc.). None of my other synthesizers or keyboards do this (using the same cables and amps).
Any ideas as to the cause? My old TR61 never did this either. |
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kimu Platinum Member
Joined: 29 Aug 2007 Posts: 1133 Location: Italy,Milan
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Posted: Thu May 26, 2011 9:22 pm Post subject: |
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have you tried balanced cable also?
you have the problem whenever you plug the PUS? i mean have you tried in other houses or rehearsal room? |
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DoctorMo
Joined: 10 May 2010 Posts: 41
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Posted: Thu May 26, 2011 9:26 pm Post subject: |
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Are both the keyboard and the amp on the same AC circuit? If not, try putting them together in the same power strip.
mike |
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billbaker Platinum Member
Joined: 31 May 2006 Posts: 2206 Location: Vienna, Virginia, USA
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Posted: Fri May 27, 2011 1:10 pm Post subject: |
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The hum is 99% a grounding problem.
Things to try:
Ground lift (changes 3 prongs to two).
"Conditioned" power - usually these units have circuitry to eliminate the ground problems, and sometimes to let you know when they're there.
(prev post) Same power for keys and amp - should be SOP for gigs and studio set-ups.
Direct box with ground lift for signal path - you may be able to fix the audible problem without fixing the source of the problem directly - that's enough for some folks.
Depending on amp, you may have issues with mic vs line level signal strength - get advice on the send levels and gain at the amp - setting it correctly has a big impact on signal to noise ratio.
Make sure you are not using speaker, vs instrument cables - they look pretty much the same, but speaker cables may cause similar noise.
BB _________________ billbaker
Triton Extreme 88, Triton Classic Pro, Trinity V3 Pro
+E-mu, Alesis, Korg, Kawai, Yamaha, Line-6, TC Elecronics, Behringer, Lexicon... |
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dgk89
Joined: 11 Apr 2013 Posts: 2
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Posted: Tue Apr 16, 2013 6:44 am Post subject: |
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I also have an M-50 with a very noticeable and annoying hum. Tried all the usual fixes but no luck. I have a Yamaha Motif XS8 and two Roland JV880's in the same midi loop and they have no hum at all.
I like the machine but can't use it for recording with this problem. I will keep experimenting. Haven't tried the old three prong into two trick yet but its worth a try. I will report back with results if any. |
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Yatrix Senior Member
Joined: 11 Nov 2010 Posts: 281
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Posted: Tue Apr 16, 2013 7:23 am Post subject: |
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Hum could be due to bad power supply unit.
I had similar issue with audio on my notebook.
After replacing power supply the annoying hum disappered completely .
So, try to replace it by any unit with 18 stabilized voltage and see what happens.
If it works then the original power supply should be changed by warranty.
Normally there should not be any hum issue never matter on condition of outlets, grounding or voltage fluctuations in power network. _________________ Developer of Aldan III for Korg M50, KROME.
Please find the app at :
http://korgpatches.com/patches/m50/aldan_iii_trial
Documentation included in setup. |
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dgk89
Joined: 11 Apr 2013 Posts: 2
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Posted: Wed Apr 17, 2013 6:42 am Post subject: |
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Something interesting about the mysterious hum coming from my Korg M-50 is that turning the volume down to zero on either the Korg or the mixing board that it is plugged into does not affect the hum. The only way to stop the hum is to turn the machine off or kill the volume on the amplifier.
If I just plug a pair of headphones into the headphone jack and don't use any external amplification there is no hum! At least in the headphones anyway. That is why I first assumed it was a bad cable or possibly a bad channel in the mixing module. I just didn't think it could be a problem with the synth.
The dealer that I bought the unit from does not have an in house repair service or I would have taken it in by now. |
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Ajbbklyn Senior Member
Joined: 16 Oct 2009 Posts: 258 Location: New Hope, PA
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Posted: Wed Apr 17, 2013 12:44 pm Post subject: |
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Refer to Bill Baker's post from 2011. This is almost certainly caused by improper grounding. _________________ KORG Kronos2-61, Yamaha Motif ES6, KORG Minilogue, Farfisa VIP233, Axiom 49, BOSS RT-20, Neo Ventilator
andy-baum.com |
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Bartholomey
Joined: 02 Dec 2016 Posts: 1
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Posted: Fri Dec 02, 2016 3:48 am Post subject: m50 60-cycle hum problems? |
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Isolate the problem by first turning off computer monitors or other electrical equipment in the area. I have a Samsung monitor that causes my M3 to produce a loud hum. Make certain the M3 still has a hum present when no other equipment is on. |
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