700 Series : super-high bandwidth, swift slew-rates, discrete components only, DC design and minimal use of NFB make for a nice low-TIM set of separates.
The 700 Series was actully made by the Shin Shirasuna Corporation and its main components were :
hk715 : digital tuner
hk725 : preamplifier
hk770 : stereo power-amp
hk775 : mono power amp
hk705 : k7 recorder
hk740 : receiver
hk720 : turntable
The 700s were also available in some markets under the Silver brand, Shin Shirasuna's own "visible" brand : same components with tiny minor visual mods.
The president of Shin Shirasuna, Mr Makoto Shirasuna, inaugurated the new decade by advertising its own 700 Series - a very rare "public" appearance which most OEM brands never cared (or needed) to risk.
Shin Shirasuna also built the contemporary Citation XX, Citation XXP, Citation X-I, Citation X-II and most of h/k's 1980s products - and probably beyond as well.
Electronically designed as per Dr. Matti Ottala's precepts regarding bandwidth, NFB and TIM - and with Dr. Robert Odell, too.
According to the lit', Odell was in the Navy in 1969 and modded his HK Citation 11 and 12 during his spare time ; he managed to show his upgraded HKs to Sidney Harman and his mods were integrated to the production models !
Odell was subsequently hired as a consultant for models such as the 670, 560, 450, 505 and 503 - and the 700 Series :)
In Japan, these separates had an added letter prefix : P725 / M770 / T715 / T710 / C705 / A750. They however were tagged Harman/Kardon and not Silver.
I believe the hk740 receiver, T710 tuner and A750 integrated to not have been available in many places ; the hk775 monoblock seemingly was an export-only item.
The Silver versions had different names : OEM duplication has its limits :)
MSRPs for all these ranged from 36,000¥ (T710) to 99,800¥ (M770) - not high-end audio by japanese standards but the hk770 and hk775 seem to still be worth lending an ear.