YEs to CL-80 in the 800B or 400. The amperage is too high and the ohms are too low on the CL-70. With any of the 400-500-800 B/C models a 3amp 47ohm gives the best results. You want a ramp up of voltage of about 3-7 seconds. The 47ohms will give you that and the 3a rating is enough for all of them, plus 90%+ of the integrated and straight amps out there that Fisher made. The CL 70 is rated for 16ohms and 4A. Too little in resistance and too much in amps. In the FISHER's the CL-70 ramp up is almost instantaneous and really does no good. The CL-80 is the best compromise between slow startup and a fairly short ramp time plus handling the amperage. Just remember if the unit has been running the CL is HOT and takes a fair amount of time to cool down and reset. Otherwise you get a normal startup with a hot CL of any type.