Busy front panel, ain't it ?
The 3-head N2554 was built to outlast a lot and very much like the CD100 would be made : solid metal, aluminium diecast allover and serious "no frills" engineering.
However, of the three heads, one is an MRH pulse-head for the CCS-system - not for monitoring.
If the two motors are tachymeter controlled and the the tape path mechanics are magnet-coupled for lowest friction, C-MOS Computer was the word, and the N2554 boasted a micro computer that allowed computer-coded search, computer-controlled counter, computer-organized programming storage and computer everything.
Included are a built-in mixer with post-fade, pitch control, METAL tape compatibility, MPX and RF filters, Dolby NR as well as Philips' own DNL and a frequency response worthy of a fair open-reel.
For real three heads, look for the N2552 - but give up on the CCS.