Ooo - that's asking ! A bit of flexibility of course - to give an idea of scale it's nearly 2m high, 600mm deep and just over 3m wide all constructed in 18mm Contiboard (Maple) all supported on 2 pieces of 35mm (? the thick stuff anyway) kitchen worktop laminated together with epoxy. One central unit with record storage below, 3 x 19" rack units in the middle and 3 shelf 'boxes' on top. A 'shelf' unit either side.
What's going on it... phew where to start - several TVs all Philips 16" portables (mid 1980s, excellent picture, incredibly reliable) plus a couple of tiny Maxim monitors - oh and a Sanyo 14" univerasal - any voltage / any analogue standard. Several VCRs incl 'cheepie' VHS and poss a couple of Panasonic NV-FS88 SVHS and some Sony VO-7630 U-matics and some freeview receivers for when the switch analogue off.
TVs will be used for off-air / videotape / DVD and eventually also wildlife cameras, security and experimental area monitoring (outside in a separate building).
Big bunch of VDAs and ADAs mainly Leitch 19". One output from each drive will feed a modulator for an internal aerial feeder for TVs remote from the rack.
Though not actually on the rack - video cameras - some reasonable ones (600+ TVL) but mostly cheepies, some decent lenses but again mostly commercial stuff.
There's space for up to 3 record decks - 'main' deck is a DRS (Japanese direct drive) with an SME 3009 Mk2 fitted with a JVC MD-10X cartridge (that's a quadrophonic so the response is flat from 15Hz to 60KHz). Variety of other decks - nothing special - available to suit other cartridges such as the Deram (which surprisingly works very well with the fairly heavy armed Garrard 1000 deck) and the Sonotone 9TA-HC which needs a very light arm such as on the Garrard 3000. I also have an old Collaro 'studio' cartridge... hmmm we shall see

Different decks for different purposes - I'm not going to play singles and 78s on the JVC cartridge.
I'll probably build new disc preamps using some ideas from Morgan Jones (used to work for the same company he did for a while - not all of his ideas are in his books) though I have been using a Crown tape preamp modified to RIAA.
Amps I'm not sure about - been using a 'Mainline 70' which is good (0.001% harmonic distortion) but I might go for class A amps this time. Speakers are again ready for a re-hash - I've got several Stentorian HF1012 drivers but they're not powerful (10Wmax per) and there may be better options. Tweeters - again might change - Ive been using ceramics with a Dmax of 1% but I may get better results from electrostatics - combined with class A amps that might just be cleaner.
1/3 octave graphic equaliser by Behringer.
Reel-to-reel - A crown 800 4 channel 1/4" and I'm sure one of the Truvox machines will find it's way up there too. I have a Crown 700 (deck only) so that might get some electronics fitted or get converted to half inch.
There will also be a computer or 2 and an old A3 laser printer - one of the rack functions is to control some electrostatic / magnetic experiments which will be housed outside because some of the experiments may go pop
I'm sure I've missed something out
