I’ve been noticing a really high frequency whine coming out of my amp and finally tracked down the source - it was the LCD screens on my MC8 Pro. There’s no noise when the screens are set to 100% brightness, but it shows up when you dim (peaking at about 60% brightness and then disappearing again down at 30% brightness).
Has anyone else noticed something like this? Any ideas about how to get rid of it (besides setting display to max/min brightness)?
Thanks!
What pedals do you have connected to the MC8 PRO? It is likely one of them isn’t isolated at the MIDI Input. Also, are all running on isolated power supplies?
There’s a bunch of stuff — a Keeley Halo via the relay port, a couple Chase Bliss pedals via Omniports, 2 Red Pandas via a USB hub, Ventris Artifakt (and then a Boss DD-200) off the 3.5mm TRS, and then a few pedals downstream of a WIDI Jack connected to the 5-pin DIN port.
Everything has a dedicated, isolated power supply from a Strymon Zuma or Ojai.
It sounds like if I disconnect each pedal from MIDI one by one, I should be able to narrow it down to the one that’s passing through noise from MIDI to the signal chain.
I’d look into those TRS MIDI pedals first from chase bliss.
Thanks, James. You were 100% correct — it’s the CBA non-standard MIDI implementation coupling noise on their TRS jack with the signal path. Once I unplugged MIDI from those two pedals, the noise went away.
Looks like I have to bite the bullet and buy a MIDI box to control the CBA pedals. I was looking at the CBA MIDI Box and the one from Morningstar. Yours is nice because it gives me more flexibility with more ports than the CBA one. Question for you… do you know what kind of cable I would need to go from the 3.5mm TRS on the Morningstar MIDI Box to the 1/4” MIDI on the CBA pedals? Do I need something special that leaves tip disconnected, ring active, etc., or is that all taken care of within the Morningstar Box and I can just run a normal 3.5mm to 1/4” TRS cable?
