Is there any interest? I saw refurbs on Fleabay for a hundred or so... seems kinda silly to be throwing money at older EOLed components. Kinda surprised Rottendog or others haven't provided a replacement.
I'm currently redesigning the AS-2815-3x/51 soundcard with modern replacements.
I'm replacing the TTL PROM and 4bit counter which are both getting rare / expensive with a single MAX 3000 CPLD in 44pin PLCC. The CPLD cost 1.50 is single units... where the TTL PROM and 4bit counter are in the 5-6 range. The CPLD has just enough room to replace all the logic chips and house both sound PROMs for AS-2815-32 and AS-2815-51 designs. The -51 proms can be selected via a jumper wire. "In theory" it should work with any game listed with the AS-2518 boardset:
http://www.ipdb.org/search.pl?mpu=18&searchtype=advanced
I'm also adding hooks to include "background" and sound effects to switch shots on my Star Trek : Mirror Universe http://pinside.com/pinball/forum/topic/star-trek-mirror-universe-pinball
project. The sound effects tie into the existing switch matrix and run off of a raspberry pi.
The card should be a drop in replacement for existing card using mostly SMT components to keep PCB costs down.
Is there any interest in seeing the design here? I haven't finished the PCB layout... so still need to work on product... build it, and then debug it.