jeseyfloyd89 Posted February 3, 2022 Share Posted February 3, 2022 Okay so, im having a massive amount of hum coming from my Marshall JVM410h, using a 4cbl method with the helix LT. I’m using a MIDI cable from the helix into the JVM to change from Clean to OD1 to OD2 depending what snapshot I’m using within a preset. Had this Hum for a while posted a few questions about it and not solved anything. However, I noticed this evening that when I take the MIDI cable out the hum drastically reduces, to a level I think is more than acceptable for a pushed valve amp. Why is it doing this? Using the midi to change the channels is kind of the point of the whole preset, and the point of me actually owning this unit. many ideas? Could the midi ports be broken in either the JVM or the Helix? cheers. Quote Link to comment Share on other sites More sharing options...
rd2rk Posted February 3, 2022 Share Posted February 3, 2022 Sounds like you either have a ground loop or really dirty power. Are both devices and anything else connected to them, including the computer that the LT's USB is connected to plugged into the same circuit? Is that circuit one which is not shared by appliances, fluorescents and rheostats? Are they also plugged into a quality surge strip with emi/rfi filtering? Are any of the connected devices within 10 feet of a wireless router? Are you using quality shielded cables everywhere including 4cm? 1 Quote Link to comment Share on other sites More sharing options...
jeseyfloyd89 Posted February 4, 2022 Author Share Posted February 4, 2022 7 hours ago, rd2rk said: Sounds like you either have a ground loop or really dirty power. Are both devices and anything else connected to them, including the computer that the LT's USB is connected to plugged into the same circuit? Is that circuit one which is not shared by appliances, fluorescents and rheostats? Are they also plugged into a quality surge strip with emi/rfi filtering? Are any of the connected devices within 10 feet of a wireless router? Are you using quality shielded cables everywhere including 4cm? Thanks for getting back to me, in answer to your questions; nothing else connected apart from my studio led lights, which I’ve turned off and unplugged from the circuit, still no joy. and no computer plugged in either. as for surge strip, my power comes from a Samson PB10 power conditioner. My wifi router is downstairs well away from my studio. Yes I have brand new cables from a reputable company, I’ve also tried different midi cables and standard cables but still no joy. i genuinely think this is a Helix issue as I have some normal stompboxes that I ran in place of the helix through the effects loop of the JVM with no problems at all, very close to selling the unit and just going back to that to be fair. Quote Link to comment Share on other sites More sharing options...
rd2rk Posted February 4, 2022 Share Posted February 4, 2022 1 hour ago, jeseyfloyd89 said: i genuinely think this is a Helix issue as I have some normal stompboxes that I ran in place of the helix through the effects loop of the JVM with no problems at all, very close to selling the unit and just going back to that to be fair. Don't know what the problem is with your amp, but it's not a Helix problem. My Helix is totally silent in 4cm with my amp. Many thousands of others have the same experience (silent 4cm). I also use MIDI both with my Powercab and Plugins in my DAW. I sold all of my pedals and bought my Helix back in 2016 in part because my pedals were WAY too noisy. Hum, buzz, switch pops, the whole 9 yards. Not cheap pedals either! Maybe your amp just prefers pedals? However, if you do choose to blame Helix, you can probably buy a couple of nice pedals with the money. I've been thinking about a Revival Drive myself, but $600!!! I'll just keep stacking the 38 drives/fuzzes that come in Helix. No hums, buzzes or switch pops. To each his own! Best of Luck! EDIT: One last shot: you said you had some pedals that you ran in the loop without problems. Were they stomp type pedals? Did your FX Loop Level settings in Global Settings>Ins/Outs somehow get reset to LINE? If so, set them to INSTRUMENT and see if that fixes it. You said that you're not connected to a computer, so it can't be USB problems (they're a REAL PITA!). That's all I can think of! Good Luck! 1 Quote Link to comment Share on other sites More sharing options...
soundog Posted February 4, 2022 Share Posted February 4, 2022 I've run into MIDI-cable based hum problems before, especially when combining USB and MIDI on one device. I now keep a MIDI cable handy that I isolated the ground wire on. To do so (if you have a spare cable), cut the cable screen/shield connection to pin 2 (the middle pin) at the MIDI IN end. It may fix the problem. If not, you've got a nice test cable. Keep it labeled so you know which one it is. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.