What kind of Speakers?

[Mariner]

these seem to be a very early ATC model.
Anyone know more about these speakers?
With a switch between active and passive

[Mariner]

Oh Sorry....
I forgot to put in the link


https://www.ebay-kleinanzeigen.de/s-...m=social&utm_c ampaign=socialbuttons&utm_content=app_android

[jophill]

... https://www.ebay-kleinanzeigen.de/s-...m=social&utm_c ampaign=socialbuttons&utm_content=app_android

This looks like the S50, ATC's first loudspeaker. From here (gearspace link) we read:

From the ATC website:

"By 1978, the company was producing its first speaker systems. The bass-reflex S50 and the infinite baffle S85 establishing the naming tradition of the model number representing the internal volume of the enclosure, in this case 50 and 80 litres respectively. Another key to the ATC, studio-derived philosophy was the crossover arrangement: the S50 and S85 allowing for true active triamping. Through a rotary switch the user could access either the internal passive crossover or an external electronic device."

I think that text is no longer on the ATC website, but it seems to correspond to the images from your link. And there was a 40th anniversary limited edition S50 (ATC link).

Regards

John

[Mariner]

Hi John,
thanks a lot for this information!
They are very helpful.

[jophill]

The SCM50 with the first amp pack was released in 1985 IIRC so maybe the 1978 S50 had a seven-year run, which probably delimits the age of these (S/N 17) samples. And to use them active I assume they pre-dated the P4 or P6 so you had to provide your own six amplifiers via the pair of six-pin XLR connectors.

I can find little trace online of the original S50 and even less of the S85. They are probably quite rare.

You could do a good active-passive comparison with the S50. Just for interest ATC provided Gramophone magazine with a SCM20ASLT for review specially modified with both a passive crossover and an amp pack. If the amp pack was not powered, relays connected the drivers to the passive crossover. If you turned on the amp pack power, the relays connected the drivers to the amp pack.

[Mariner]

Hi John,
thanks again!
I have a six channel McIntosh amp! On the other side I think that the speakers might be very interesting, but a little bit to old. To bring them in modern shape, which ATC might do, could be expensive.
But I was curious, because I never saw that model before.