Ok, guys, I finally got my GM40 and when I first plugged it in, I gotta say, it sounded nasally and very thin. I could dial in the feel of a decent tone, but there was no bass or resonance to it at all. I honestly thought I had made HUGE mistake. However, after fiddling with the connections, I realized the issue: the impedance to the speaker cabinet was all kinds of wrong.
I have an old (late 80's - early 90's) Jackson J412 4x12 speaker cabinet that has no switching for the impedance. You can run it in (2x input) stereo at 8 Ohms per input or (2x input) mono at only 4 Ohms per input. I've always run my heads in stereo so there's never been an issue. However, the GM40 only has the one output, and the mono stage of the cabinet, plugged in to one of the two mono inputs, I only get straight AM radio tone. When I plug into one of the 8 Ohm inputs I get thick, heavy, warm tone for days. But, as should be obvious, the amp is only driving two speakers.
So, though I've been playing for 37 years now, I have what I am sure is the ultimate newb question: How do I run this speaker cabinet in mono with all 4 speakers going? Do I need some kind of adapter or maybe a Cab-Link? Help would be appreciated.
Picture of cabinet inputs:
h-t-t-p://jereth.dyndns.org/Linked/Jackson412SL.jpg
I have an old (late 80's - early 90's) Jackson J412 4x12 speaker cabinet that has no switching for the impedance. You can run it in (2x input) stereo at 8 Ohms per input or (2x input) mono at only 4 Ohms per input. I've always run my heads in stereo so there's never been an issue. However, the GM40 only has the one output, and the mono stage of the cabinet, plugged in to one of the two mono inputs, I only get straight AM radio tone. When I plug into one of the 8 Ohm inputs I get thick, heavy, warm tone for days. But, as should be obvious, the amp is only driving two speakers.
So, though I've been playing for 37 years now, I have what I am sure is the ultimate newb question: How do I run this speaker cabinet in mono with all 4 speakers going? Do I need some kind of adapter or maybe a Cab-Link? Help would be appreciated.
Picture of cabinet inputs:
h-t-t-p://jereth.dyndns.org/Linked/Jackson412SL.jpg