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Alembic products => Alembic Basses & Guitars => Topic started by: 5a quilt top on November 14, 2016, 10:44:10 AM

Title: Series II Question
Post by: 5a quilt top on November 14, 2016, 10:44:10 AM

I recently reconfigured my small/medium room and rehearsal bass rig and have been using an AER Amp One with the built in line out on the rear panel feeding a QSC K-12 powered monitor.


I've used this rig with my non-Series Alembic basses over the last few weeks with very good results, so at rehearsal yesterday I decided to try it with my Series II in mono mode. Output from blue box feeding input to AER.


No bueno.


LOUD hum from the K-12.


So, I uncoupled the K-12 from line out on AER and used AER alone, which sounded great.


What would cause this hum?

Title: Re: Series II Question
Post by: FC Bass on November 14, 2016, 03:12:51 PM

That was most likely a ground loop, I've encountered some when building my rig... :-)

Have you tried it with the 1/4 output on the bass? That should eliminate the ground loop if that's the problem. (and tell you for sure, the problem is caused by a ground loop)
 

Title: Re: Series II Question
Post by: 5a quilt top on November 15, 2016, 07:15:53 AM

Thanks for the response - yeah, it was definitely ground hum.


I'll check it with 1/4" output from bass.



Also, I've since remembered that the AER has a ground lift switch on the back and a different output for a powered sub.


If I was thinking more clearly (gonna blame the gig the night before - finally got to bed at 3am) I would've also checked those options along with using a ground lift on one of the plugs.