The AS-401 is an advanced Sinfonica bass model.
| Top: | Well-seasoned spruce |
| Back, Rib, Neck: | Mildly flamed maple |
| Purfling: | Inlaid |
| Fingerboard, Nut, Saddle: | Ebony |
| Peg, Chinrest: | Ebony |
| Rod: | Solid nickel- plated steel with boxwood plug & rubber tip |
| Varnish: | Medium gloss spirit varnish with medium brown to red-brown hue |