Can anyone identify this weird output jack?

[AsylumSeaker]

I picked this up the other day for a few bucks:

http://img255.imageshack.us/img255/7114/mixer1.jpg
http://img651.imageshack.us/img651/4388/mixer2.jpg

It's old but I'm pretty sure it works. Lights come on, the inside is all nice and clean.

Thing is, the output is weird:

http://img217.imageshack.us/img217/9458/mixer3.jpg

The one with "600 ohms" above it, pretty sure that's the line out. Wtf plugs into there?

The letters around it are L, L and E.. presumably line, line and earth indicating it's a balanced output and the holes probably lined up with the letters once, they don't anymore since the jack is a bit loose and turns.

I'm probably gunna take the jack out and replace it with an XLR or 1/4" jack so I don't need to hunt down some weird oldschool cable. Still I'm interested to know how it was supposed to be used.

Anyone know how old this thing might be?

[DECI4]

Can you get a closer picture of the plug? It kind of looks like a midi out but I'd think that would be on the back with the others.

[ShutMeUp]

something like http://en.wikipedia.org/wiki/DIN_connector or http://en.wikipedia.org/wiki/XLR_connector ?

edit - so I opened the pics (i'm using my phone) and it's nothing like either of those :facepalm:

[MunkeyQ]

Looks like a 3 pin Bulgin socket...used on lots of older British gear and a bit abroad too. It's used for a number of purposes as there's no standard surrounding it, unlike something like an XLR connector which only carries low level audio (well, it does nowadays anyway...). Bulgins can be used to supply mains power, DC, speaker level or line level. Mindfuck eh.

A 600 ohm output impedance is either to drive a loudspeaker from an output transformerless tube amplifier, or more likely it's line level output designed to feed something with a very high input impedance like a power amplifier. Cheaper mixing desks may have a problem with such a low output impedance though.

However, to be sure...could you pull the lid off and take a few photos of the guts?

From the looks of the RCA connectors and the Bulgin socket, I'd guess that it's late 60's. It's an installed mixer - the sort of thing used in shops for the paging system or piped music.

[AsylumSeaker]

Looks like a 3 pin Bulgin socket...used on lots of older British gear and a bit abroad too. It's used for a number of purposes as there's no standard surrounding it, unlike something like an XLR connector which only carries low level audio (well, it does nowadays anyway...). Bulgins can be used to supply mains power, DC, speaker level or line level. Mindfuck eh.

A 600 ohm output impedance is either to drive a loudspeaker from an output transformerless tube amplifier, or more likely it's line level output designed to feed something with a very high input impedance like a power amplifier. Cheaper mixing desks may have a problem with such a low output impedance though.

However, to be sure...could you pull the lid off and take a few photos of the guts?

From the looks of the RCA connectors and the Bulgin socket, I'd guess that it's late 60's. It's an installed mixer - the sort of thing used in shops for the paging system or piped music.

Bulgin socket eh.. cheers.

So you reckon it's probably part of a paging / pa system? From a school or shop maybe? Hrmm.

I'm hoping the 600 ohm output is a line level output which I can just plug into one of my soundcards line ins.

I'll pull the lid off and take some photos later :)

[AsylumSeaker]

http://img808.imageshack.us/img808/6586/mixer4.jpg
http://img251.imageshack.us/img251/6696/mixer5.jpg
http://img818.imageshack.us/img818/6109/mixer6.jpg

So looks like that's the date on the date on the schematics which were on the inside of the case.

Can ya tell me anything about it Munkey?

I was kind of wondering whether this is a DI mixer, Ie direct input mixer, or if "DI" is simply the brand name. Also wondering if those are preamps in it - for each channel or the whole mix, or if not preamp(s) wtf is all that stuff in there?