1980's Australian designed, manufactured by "Aunty" i.e Australian Broadcasting Corporation Workshops
Solid well laid out construction and yes, it works! (all channels)
This type of equipment is invaluable in the studio environment or even perhaps at live gigs - we only used this in our Studio 1 (Archival Audio) where we needed to flexibility and quickly sorting out balanced/unbalanced low level signals.
Perfect for the studio or gig where you need to convert balanced to unbalanced (or vice versa) inputs and outputs
Australian Broadcasting
Made by ABC Workshops
Still has the old ABC logo on the front (formica) panel strip - nice nostalgic touch!
Standard rack size, 1RU
Quad Balanced to Unbalanced and vice versa amplifiers
No model number - "in house" custom made, never for commercial production
DESCRIPTION (DETAILED)
Nothing much on the front panel, just the power ON-OFF red indicator bezel
Note the lack of a power switch, this is intended to be always ON.
Rear panel has all the action ...
4 totally independant channels
Each with XLR female (inputs) and male (outputs) connectors and RCA connectors
No external adjustable gain controls, I haven't checked this but I would believe these are currently set to unity gain. That is how we used this equipment in our studios although someone may have changed it since then (been in storage for a few years now)
Each of the 2x PCB's (one for each set of 2 channels) have onboard pots, this is where I would assume gain adjustments can be made.
Active devices are all the NE5532 Op Amps (3 per board)
Power supply is linear in design and uses a couple of very nice ROE electro's (Germany high spec)
Casing is pressed steel with extruded metal upper and lower shielding. The shielding looks like copper sheet but looking closer it seems to be anodised aluminium but the copper effect is pretty realistic!
COSMETIC CONDITION:
Clean (front panel, connectors etc)
Casing is undamaged (and so it should be! this is one very tough 1RU case)
TESTING:
We used this equipment for a number of years and then closed down our business (audio post production and archival specialists) and put this (and many other pieces of equipment) away in storage but its time to find a new home for this equipment.
Powers up (red led on)
Power supply measurements:
AC Secondary 17-0-17V AC
Dual rail (independant adjustment available) 15.00 - 0 - 15.00
NOTE: there is a small PCB mounted trimpot for each supply rail. I could easily change the voltages on each rail although I must say, EXTREMELY touchy! I know that previously we always tried to achieve EXACT balance of the DC supply but this is not an easy task with these trimpots. I suspect a good clean or even replacement (nothing special about these) might be in order if you intended playing around with these trimpots. At the moment I have left them at exactly 15.00 on each side of the supply rail.
Pushed audio into all four channels of both "flavours" (balanced and unbalanced) and checked I had correct audio output without any obvious audio issues or degradation - all fine.
Nice piece of very useful rack gear
