Guys
The bottom line is that if you're used to the JJC sound system then you'll probably be a bit disappointed with the ACTion one. Allow me to try to put the thing into perspective (any lapses into techno-babble will be strictly minimal!).
Jim's units are based around actual recordings of diesel engines which are held in digital form and reproduced through an amplifier. Moving the Tx throttle stick will modulate the recording to sound like the revs are increasing and decreasing. It's quite loud and very expensive. It will also operate from any ESC.
Craig Talbot designed the original P15 ACTion Diesel sound to be run from an ACTion ESC - quite naturally. It, too, changes revs with the throttle stick and it will run using any other ESC which uses a relay to reverse the motor e.g. the older Electronize one, but you can forget using a Viper or Proteam etc. Latterly he introduced a PIC-based diesel sound which avoids that problem by taking its signal from the Rx, not the ESC. This means it will run on most if not all ESCs.
Limitation No 2 is that the sound isn't a recording of a diesel engine; rather it's just a series of generated clicks which are modulated and filtered to sound a bit like a diesel. If you're after a start-up routine and the whistle of a turbo-charger then forget it, although you can adjust it to sound like either a 4, 8, 12 or 16 cylinder engine and also adjust what Craig called the "character" (i.e. the lumpiness"). There is also a version which reproduces the single cylinder pop-pop of a small workboat or canal narrowboat.
Limitation No 3 is that it was designed for small models so it's not very loud, The little on-board TDA7052 amplifier is rated only at a maximum of 1W on 6v into an 8 Ohm speaker, so if you run it constantly on full volume the amp chip gets VERY hot (they've even been known to crack). There's not enough room in the case for an adequate heat-sink to dissipate the power at this level. We are working on a 6W booster mixer/amp but it's early days yet.
Not that it's terribly relevant, but just before he died Craig was working on a Robbe truck kit. This was a wondrous beast with working lights, fifth wheel, hydraulic rams.........and a diesel sound sim. This had the key-start-up routine and a glorious bass burble. When I asked him if it was an ACTion unit he gave me a very old-fashioned look.........!
To sum up, if you're happy to have the engine sound more "character" than "actual", and you don't need it to be any more than background (like the real things) then you'll be happy with our units. If you're after a cut-price JJC job then forget it............and, no; we're not going to develop one either!!
Richard - you're more than welcome to try one and return it if you're not happy. Contact details are on the website or PM me here.
FLJ