Hi,
I have an Ibanez ORM1 and have noticed then when plugged into my amp with a standard guitar jack I don't get any background noise. However, if I use a stereo low noise microphone cable there is suddenly a huge amount of hum, if I put my finger on the jack the hum is massively reduced which made me think it might be a ground issue.
I realise you're not supposed to use these sorts of cables if you can help it in a guitar but I was wondering why this happens?
I also have a fender jaguar and when I use the same microphone cable from the jag to the amp there isn't any noise at all, same case when testing it with a 335.
Does it have something to do with the way the ORM1 is wired/is this normal, or is there some kind of underlying grounding issue?
Not familiar with the ORM1 & don't have a schematic, but my bet is that it's the way Ibanez chose to wire the jack. Most long-barrel 1/4" jacks are setup with 3 conductor TRS termination capability. Setup to work with a 'normal', unbalanced 2-wire TS cable the 'R' termination on that jack will be grounded by thru contact with the 'S' contact of the cable/equipment termination. If you connect a 3-cond, TRS cable, the 'R' contact of the jack will mate with the 'R' ring on the cable...which is connected to a TS/2-wire termination at the equipment end & will be open, as the cable 'R' connector has nothing to hook up to.
The Fender Jag circuit utilizes a Switchcraft type jack, which is 2-wire TS. Same for the Gibby 335. TS to TS utilizing a TRS cable works because the 'R' is bypassed on both ends.
Ibanez is usually very good at providing schematics on their products should you want to delve in deeper as to how they did what they did.
