Extremely low output from Seymour Duncan active/active setup

[brentonbassist]

Hi guys,

I just swapped out my active MEC pickups and preamp in my 99 Warwick Streamer LX 5 for active Seymour Duncan pickups (AJB-5) and preamp (STC-3a). I wired this setup as 18V (wired a second 9V battery in series with the first one) and the only other thing that I did that differed from the SD wiring schematic is that I grounded the grounds from the pickups onto the back of one of the pots (this wasn't shown on the schematic, but I couldn't imagine leaving pickups ungrounded!).

The output is so low that I have to dig in very hard for my tuner to pick up any notes at all. On my TC RH450, I've gone from my gain sitting on about 10:00 to being fully maxed out, and I still think it's probably less than half the volume that it was before with the master set the same.

Any ideas as to some things to try? The majority of the preamp came prewired from Seymour Duncan (other than having to attach the pickup wires, jack, and battery). I inspected the quality of the solder job before I installed it all and it looked pretty clean, but I have to admit that I didn't check that they had soldered everything in the right place (but I imagine they would have). I'm lost as to where to even start.

Thanks in advance!

[brentonbassist]

I have moved this thread to the luthery forum.