B. J. Love Posted September 28, 2014 Share Posted September 28, 2014 I’m having ground noise problems with the USB and main outputs. Usual set-up:MacBook Air connected to Belken Dock via ThunderboltPresonus Firebox to Dock via Firewire; unbalanced 1/4” audio to Mackie 1202PX-5 to Dock via USB; unbalanced 1/4” audio to Mackie 1202Mackie 1202 monitored via balanced cables to Rockit 5s and EV ZXa-1sWhenever the PX-5’s USB and audio outputs are connected simultaneously, the Firebox emits a high-pitched “whine.” Fairly low-level, but definitely present and decidedly annoying. The noise will disappear if either the PX-5’s USB or audio output cables are disconnected. I first suspected a problem with the Firebox - an older interface.I tried removing the Firebox AC adapter and powering it with Firewire - no help.I tried lifting all the grounds in the system, individually and collectively - no help.I tried new cabling: 1/4” audio, USB, Firewire - no help.I tried connecting the PX-5 directly to the Mac, bypassing the Dock - no help.I didn’t have a Firewire/Thunderbolt adapter, so to eliminate the Dock, I pulled out an older MacBook Pro; connected the PX-5 USB directly to the Mac, the Firebox Firewire directly to the Mac - no help.So, gotta be the Firebox, right? Wrong. I pulled the Firebox and replaced it with a spare Lexicon Omega USB interface - connected directly to the Mac and powered via USB. Exit high-pitched whine; Enter good ole 60 cycle hum - from the Lexicon. Different noise, same cause. Only present when PX-5 audio outputs and USB are connected simultaneously. The problem is a ground loop somehow created between the USB connector and audio connectors.One more interesting thing: the problem exists whether or not the PX-5 is powered On or Off, or even completely disconnected from any power source. It exists solely as a reaction to the USB and 1/4” audio outputs being connected simultaneously - to anything.I experienced the same problem with a PX-330 before I bought the PX-5. I wasn’t concerned with using the 330's internal sounds and controlling soft synths simultaneously at the time so I ignored it and didn’t do such extensive testing. But I really want to incorporate that kind of flexibility with the PX-5. The PX-5's internal engine is too good to sacrifice in favor of soft synths - I want both. Together. Without whines or hums. Has anyone else experienced this ground noise issue? Any solutions I haven’t tried? Quote Link to comment Share on other sites More sharing options...
User 29303 Posted September 28, 2014 Share Posted September 28, 2014 yes same to me ...if i plug my USB midi in the ipad and the audio out to the input of the px5 i have noise if i plug of the usb all its gone...there is a problem in the px5s with usb... Quote Link to comment Share on other sites More sharing options...
Brad Saucier Posted September 28, 2014 Share Posted September 28, 2014 Yes. It's a usb ground loop. It's a problem with the USB system in general. A quick scan with google shows it happens with quite a few devices that use USB and analog audio at the same time. It's not specific to the PX-5s and you're not the first person to have this issue. I get it myself on one computer and not on another. Solving this...... Whenever possible, use the standard midi ports and not the USB. A USB to Midi converter cable like the E-MU Xtab 1x1 cures the noise. And yes..... the data editor will work with the standard midi ports. 1 Quote Link to comment Share on other sites More sharing options...
B. J. Love Posted September 29, 2014 Author Share Posted September 29, 2014 Thanks. At least now I know it's not some ground problem unique to my system that I had to hunt down. My issue with using the standard MIDI connections is that I'm using the Input for a pair of MidiSolutions Pedal Controllers. (Don't get me started about the lousy pedal implementation...) USB made it easy to plug my live rig into my studio with a minimum of fuss. Losing it means futzing with multiple MIDI cables several times a week. Minor PITA, but a PITA just the same... Thanks again. Quote Link to comment Share on other sites More sharing options...
Joe Muscara Posted September 29, 2014 Share Posted September 29, 2014 Does it happen when the power adapter is disconnected from the MacBook? IIRC, some have found that's where the ground loop is. I know with bus-powered devices that's not really a solution, but it would answer part of the question though. Quote Link to comment Share on other sites More sharing options...
B. J. Love Posted September 29, 2014 Author Share Posted September 29, 2014 Yes it does. Seems to be unavoidable when USB & audio outputs are used together. Quote Link to comment Share on other sites More sharing options...
User 29303 Posted September 30, 2014 Share Posted September 30, 2014 same to me yesterday i tried all kind of switches, midi cables and the noise was terrible then today i did something completely new i tried to connect my ipad mini to the m-track audio usb card and then the midifrom the px the m-track .....and voila....nothing....power to low..so i decide to use a itecom USB Hub and the setup was running but,,still noises even without the PX5S USB....so the noise was generated by the USB AUDIO INTERFACE finaly i tried my old Belkin USB Hub for the mini-mac and ,,,,,WOW no noises nothing ,,silence,,,pure ,,,only the Ipad Mini DAW and the PX5 Sounds.... so i think using a hub with Power Adapter can help but ..it must be a good one with high graded chips inside,..... Maurix Quote Link to comment Share on other sites More sharing options...
piattica Posted September 30, 2014 Share Posted September 30, 2014 I had a similar problem before a concert. I was playing a VMachine and here was a lot of noise from output.The man at mixer told me that the cause is because the "zero" level of USB unite is not referred to ground; he conneced the outer metal shell of USB plug to the ground of a socket with a temporary cable and the noise disappeared.He told me: it is only to convince you, the right solution is to buy a power supply with zero referrable to ground. Quote Link to comment Share on other sites More sharing options...
Mike Martin Posted October 1, 2014 Share Posted October 1, 2014 The issue is a USB ground loop. There are several solutions to this if you use Google. This is more related to your computer and USB not the PX-5S specifically. Dave Smith and other designers of the MIDI Protocol are not fond of USB MIDI because unlike the standard MIDI ports there is not a ground. I have two identical systems with a PX-5S and an audio interface. On one system, I have a USB ground loop and the other does not. The only difference is the computer itself. 1 Quote Link to comment Share on other sites More sharing options...
User 29303 Posted October 1, 2014 Share Posted October 1, 2014 yes but i also had usb noise with the PX5S and a Ipad MINI .. Quote Link to comment Share on other sites More sharing options...
Display Name Posted October 1, 2014 Share Posted October 1, 2014 yes but i also had usb noise with the PX5S and a Ipad MINI .. The iPad mini is a computer. 2 Quote Link to comment Share on other sites More sharing options...
User 29303 Posted October 2, 2014 Share Posted October 2, 2014 of course Scott but if it not connected to the wall using battery there should not be a train running in my homestudio suspect there was a production error and someone by Casio forgot totake off the WHITE NOISE SAMPLE from the usb Port or was itt a pink noise...hmmmmm Quote Link to comment Share on other sites More sharing options...
Display Name Posted October 2, 2014 Share Posted October 2, 2014 of course Scott but if it not connected to the wall using battery there should not be a train running in my homestudio suspect there was a production error and someone by Casio forgot totake off the WHITE NOISE SAMPLE from the usb Port or was itt a pink noise...hmmmmm I don't think so because I run my iPad mini into my PX-5S all the time.. plugged in or on battery I do not have any noise issue. . The USB port can not transmit audio, so your contention that a white noise audio sample is somehow being sent does not make sense. If the noise issue can not be eliminated by running both units on battery power, I suspect some kind of environmental interference is the culprit rather than a USB hum. Quote Link to comment Share on other sites More sharing options...
User 29303 Posted October 3, 2014 Share Posted October 3, 2014 OMG that was a Joke with the. White Noise Sampler.....but i will Record the Noise and Upload a file... Quote Link to comment Share on other sites More sharing options...
Display Name Posted October 3, 2014 Share Posted October 3, 2014 OMG that was a Joke with the. White Noise Sampler.... Oh I see. Just realize when you hint at a production error causing noise not everyone reading it will realize you are joking. I sure didn't. Quote Link to comment Share on other sites More sharing options...
User 29303 Posted October 3, 2014 Share Posted October 3, 2014 Sorry Quote Link to comment Share on other sites More sharing options...
B. J. Love Posted October 3, 2014 Author Share Posted October 3, 2014 Thanks for the replies. I went with the standard midi connection solution. Minor inconvenience, but problem solved. 1 Quote Link to comment Share on other sites More sharing options...
User 29303 Posted October 15, 2014 Share Posted October 15, 2014 well after putting al my equipment to one Power Adapter on the Wall did the trick for me no more noise........ Quote Link to comment Share on other sites More sharing options...
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