It's an old enough model to have either of those, dual 14-bit TDA1540P or single 16-bit TDA1541. Got the same rudimentary LED display from the early dual 14-bit machines but I saw web pics of one with a 1986 mfr date which would likely have been a 16-bit machine by then. Does seem likely it's using one of those two Philips solutions though, and neither is too shabby.
John