Did get a hold of Ibanez support but they couldn't tell me anything about the part and were going to do some digging. In the meantime I looked at the circuit and didn't see anything special about it so put in a 100k linear pot. It seems to work fine. Decent sounding little amp. While I was doing that Ibanez did get back to me and said they did have the part in stock in case anyone else is looking for one and wanted the original part. The Ibanez part number is actually 32S01749.