I have the documentation for the "ASR-10 Proper SIMM Installation" as released by Ensoniq.
The SIMMS you require should EXACTLY fit the following criteria else you run the risk of an unstable ASR10 at best.
1MB (8 chip) 35 pin or
4MB (8 chip) 35 pin
The SIMMs must be in groups of 2. That is there are 4 slots. 1 & 2 must be identical SIMMs and so must 3 & 4. If you are mixing 2x1MB & 2x4MB, the 4MB bank must be in the first group.
Also, if you are going to use all 4 slots, change the jumper from STD to EXP.
Be warned, the ASR is a very fussy creature when it comes to SIMM installation. If you are confused or even slightly unsure, email me and I will scan my documents and send to you.