Hi guys,
I thought some of you might enjoy this dinosaur: the UTV-652 by Yleisradio, the Finnish National Radio:
“UTV” stands for "ulkotuotantovahvistin" (outdoor production amplifier). The 6 refers to the number of channels, and 52 to the year. These mixer-amplifiers were developed specifically for the 1952 Helsinki Olympics, and a large part of the broadcasts went through units like this.
Thanks to some clever original safety features — including two summing amplifiers instead of one — my tech friend was able to convert this from the original mono configuration into a 6-to-2 mixer, which makes it far more usable in a modern studio context. A few things were lightly modified during restoration (for example, the original A/B mic switches are now L/C/R panners), and two lamp-based compressors were added. Sonically, though, this thing is essentially exactly what it was 74 years ago.
The main unit alone contains 20 tubes, mostly EF40s, with even more tubes in the large, two-section external power supply. It’s massively over-engineered; clearly designed so that even a minor technical failure wouldn’t stop an Olympic broadcast.
I was also told the unit uses “Jensen” transformers, but these are not from the modern U.S. Jensen Transformers company. If anyone here has information about this earlier Jensen manufacturer, I’d love to learn more.
Best,
James
