Have any of you had personal experience with Great Northern Sound's PASI devices?
I have been using one for about 2 years. Running balanced in and out. I like what it does, eliminating some digital nasties before they get to the preamp or amp. A little pricey perhaps, try a B-stock with minor cosmetic defect for $ savings.
Have been using for 2 years as well. I second Rja's impression. Talk to them, they may offer you a B-stock. In my case, nasty hum from tube amp is gone as well.
Rja, Khokugo
Did you find the overall volume lowered? I have the Ortho spectrum AR2000 which is similar but i've never used my PASI. I wonder if i should try both together...
Tabl10s, I did not notice a drop in volume. I had Bybee filters on everything when I bought the PASI. As I experimented with the system I found that it sounded more open with the Bybees removed. Just my personal opinion, I would definitely experiment if I had the PASI in addition to other inline filtration. Truth be told I was never overly impressed with the Bybees (deluxe balanced and deluxe speaker). They were very expensive and to my ears in my system their audio effect was minimal at best. The PASIs effect was much more noticable. The sale of the Bybees more than paid for the PASI.
I would like to buy the PASI. However I contacted the Great Northern Sound three times by email and I never got a reply. Are they still in business? I agree with Rja on using the Bybee filters, they actually disimproved my system.

Sounds to me like your emails got blocked or something...we never got them. Be sure to use a subject if you send us emails...they go into the delete bin if not. We're happy to discuss the PASI with you and most certainly are in business.
To hold the PASI is to love it...solid.
Tellenbach, GNSC has responded promptly to every email I have sent them. There's got to be another explanation for your lack of response. These guys are consciencious and dependable and I recommend them.