"Manufactured by Philips High Fidelity Laboratories Ltd. USA"
Philips' penultimate super high-end lineup, the HFL big mini-series is impressive, rare, and it was made in America : Greenville, Tenessee !
In 1978, Philips was then very busy perfecting its VLP/ALP system that would quickly become CD (with Sony) and the future Magnavision / Laservision with a few other partners.
Trying to corner the market, too, with low-end catalogs, high-end catalogs, MFB speakers, television sets and, of course, video recorders !
Philips was also just about to buy Marantz from Superscope, a move which gradually depleted Philips' own high-end offerings which managed, however, to remain available (with highs and lows) until the early 90s.
As per Philips' habits, the real name of the units has a 2-digit code added in front of the "regular" name and all three units were available in black as well, with a "1" added.
So, the HFL series consisted of the :
(22) AH673 / AH6731 : tuner
(22) AH572 / AH5721 : preamplifier
(22) AH578 / AH5781 : power amplifier.
Despite intersting engineering and very busy design (a definite plus in '78), the HFL series didn't sell as probably expected.
Perhaps having offered a dedicated HFL turntable and recorder could have helped, alongwith better marketing and visibility in the increasingly crowded market hifi was becoming in the late 70s...
But Philips always had a distant relationship with "high end audio" and that is why Marantz very quickly embodied Philips' audiophile ambitions.