I don't know who ctmullins is referring to as making things hard as the first response in this thread said exactly what he said...
Anyway, there is nothing wrong with wanting balance between two instruments with each at full onboard volume.
Like line6man said, if you want to be sneaky you could install an internal trim pot at the output of your onboard preamp and attenuate your output level however you'd like. I'm not qualified to state exactly how this would affect the tone but if the attenuator (grounded trim pot) is on the buffered output I think it would be largely transparent like a passive 25K volume pedal.
Also, I'm not familiar with Spector preamps but there is some very small chance it has an output trim on the pcb (probably not).
Aside from that, like I said, an external active mixer pedal is easy, non-invasive, and future proof.
Last edited by aphexafx : 02-15-2014 at 05:15 AM.