Mystery Box

[morls]

Hi,
I picked up this at an auction a while back, and haven't been able to find out anything at all about it. I know it's a long-shot, but maybe someone has come across something like this?
There's a 6-pin socket at the back marked "power supply", which I don't have unfortunately. I do have a cable that fits though. It's in great condition, and looks to be very well put together...

 

[rock soderstrom]

The T119/1 transformers are most likely from Haufe.

Edit:

I found this. A Haufe model T119 with the following data. This could be a very similar model, as Haufe often marks a split secondary winding with the /1 addition.

But this is a guess, only Haufe knows it all. They are still in business and if you are lucky they will give you a data sheet for this model.

 

[morls]

Wow, that's a great find! Thanks rock

 

[scott2000]

Neat. Some kind of powered mixer like the Altec 1607A..etc.. maybe....

 

[morls]

Yeah, it's the 4 mic/line inputs with compression that have my interest. It was $10 at auction, thrown in with some other gear I got. I'm going to have to figure out the power issue. It looks like a mains transformer? Keen to get this up and running...

 

[Tubetec]

Looks like the kind of amp you'd find in a commercial premesis , interesting that it includes simple compressors per channel . Variable z speaker out to power 100v line speakers and even proper balanced line output too .
Might make a neat studio talkback system . The big transformer is speaker output . If you check the voltage rating of the caps it might give some indication what the supplies should be , roughly 50% of the cap rating should be a safe place to start . The poweramp most likely will run off a single rail 40v or more supply ,
although with all the extra pins a subsidiary supply for the preamps is also likely .

 

[morls]

Great info, thanks Tubetec

 

[okgb]

If the pres turn out to be interesting you you can try adding direct outs, worst case strip and make you’re own mixer.

 

[Boomerang]

An interesting find. The amplifier section, with the second transformer and speaker impedance switch implies it is a public address amp for 100V (or 70V or 50V) line speakers. There is no conventional mains input. The 6 pin power connector looks like an ITT Cannon EP series. The 3 pin ones were used on some mics by the BBC and 8 pin ones were commonly used for console power supplies. Some versions were occasionally used for mains for cue lights, but I don't think that is the case here. I think Tubetec is right, the smaller transformer is for the line output. I conclude that there was an external power supply (or multi-tapped transformer), probably with multiple rails for the mixer and power amp parts. You will need to follow the power rail wires. It shouldn't be too hard. Start with the fuse and big caps (which will go to the power amp board) and then look for busses joining the four preamp cards to identify mix bus, ground and preamp power rails. If there is a bridge rectifier for the power amp (connected between power socket and smoothing caps), then you know the external box just had a transformer (or two). If there are two bridges, then there will have been a lower voltage rail(s) for the preamps. If you have no need of a mono 100V line PA amp, you can probably easily disconnect the power amp, use a much smaller external transformer, and just use the mixer. With balanced mic inputs and compressors, it could be very useful. And yes, you could add channel direct outputs to use it as a 4 channel preamp. Have fun.

 

[morls]

Thanks Boomerang, lot of great info there.
Here are the cables that came with it. I'm assuming the 3-pin was to the power supply, and the 6-pin from power supply to preamps.

 

[Boomerang]

Yes, I think the 6 pin lead joined the extern PSU to the mixer/amp. I don't think those are ITT Cannon EP3 and EP6 connectors, but may be a compatible brand. They certainly look very similar. The 3 pin lead may (possibly) have carried mains to the power supply or it may have been a car battery supply input for when mains was not available - but that seems unlikely. Perhaps there was once a matching PA speaker that used the same family of connectors. Perhaps there was another 3 pin output on the power supply to power something else. You may never know.

 

[Bo Deadly]

Hi,
I picked up this at an auction a while back, and haven't been able to find out anything at all about it. I know it's a long-shot, but maybe someone has come across something like this?

Love it. Great score. Nice PA mixer with mic and line, line distribution amp, well built. What's not to like. Hook up a variac and figure out what the supply rails are supposed to be. Then run it through the analyzer to see where your at. If it's clean enough, recap it and put it to work as a little personal mix station with some old alnicos with line distribution transformers on them. Or use the speaker outs to drive a pair of spring reverb tanks stuffed in a remote closet and back over some CAT6.

 

[mjrippe]

I don't think those are ITT Cannon EP3 and EP6 connectors, but may be a compatible brand.

Certainly look the same size/shape. I believe Amphenol made them too.

 

[morls]

put it to work as a little personal mix station with some old alnicos with line distribution transformers on them.

You’ve got me with this one, haven’t heard of alnicos with line distribution transformers before…

 

[Bo Deadly]

You’ve got me with this one, haven’t heard of alnicos with line distribution transformers before…

Alnico speakers with a line matching transformer mounted on them used to be very common. You can find them cheap on Ebay all the time. Like this:



This is a very elegant system actually. You can transmit a lot of power long distances over relatively thin wire. P = V * I of course so if the voltage is high, the current can be lower and therefore the wire can be thin (same principle as power company transmission lines). No power supply is required at the speaker. It's also less likely to start a fire if some wires get shorted out and the driver amplifier can be much smaller. You can still buy new line matching transformers cheap on various websites. Not sure about their fidelity though. A cheap transformer usually equates to limited bandwidth and higher distortion. But for a PA or delivering some light music next to the pool, it's quite satisfactory.

I actually like the limited bandwidth of these old alnico speakers. They're brick-wall filters above 4kHz which can be just right for certain content. A lot of very popular old music doesn't have much HF content. Full 20-20 bandwidth can be overwhelming. If you want to curb that guy's Moog keyboard or whatever thing that generates a lot of obnoxious highs, this old speaker might be just the trick to make that fuzzy pedal sound sweet. I have two Jensen P12Qs connected to a high-fi amp that I can engage on a little monitor controller when I'm listening to Them and I want to add some mid-range honk.

 

[morls]

Sound like I've gotta check these out. Thanks Bo.