Gard loved the Aggie with Bart’s but I wasn’t ever crazy about the sound of them together. Bummer about the Nord being out of stock. I waited 3 months for mine. Give the Aggie a try with the Bart’s and if you don’t like it just live with it until you can get the Nord. It’s a simple install.
I think I will just have him leave the Aguilar preamp with the Bart’s he’s putting in as I liked the tone roll off better than the Bart preamp tone control. I’m thinking about ordering the Nordstrand preamp wired exactly as I need it from Bestbassgear. I’m not good at wiring but hopefully it wouldn’t be to hard.

