Good to see your Quad IIs and happy to hear that you like them. I bought a pair 2nd hand in 1969 and have used them almost continuously ever since, and they always sounded good (at least on straight ahead Jazz and classical). About 10 years ago I replaced ‘the usual suspects’ and installed phono sockets and binding posts etc. Bass can be improved I recall by increasing the value of the cathode bypass cap (which often dries up anyway), they are also on (mostly) original valves.
I use them with a pair of ELS57s (naturally).
Marantz CD/DA12, HHB 'burnit', Yamaha CT7000, Magnum Dynalab FT101A, Garrard 401, SME 3009, Dynavector 100R and 30C, AT F7, Trichord Dino, Audio Research LS7, Quad 303 or Leak Stereo 20, Harbeth P3ESR, BK sub, DIY passive with PG faders, Quad II's, Quad ELS57's, Townsend Ribbons, Crown IC150, HH AM8/12, Tannoy Monitor Gold in Lancaster, Stellavox SU8, Nagra T-Audio, Dolby 361's, Sony D50, Pro Walkman, Dat Walkman, Slee Solo, Sennheiser HD650 + Equinox, Lambda Sig. Pro., SRM-T1, Sr001