Saba HiFi Studio Freiburg Stereo Receiver (Built in W Germany, circa 1967) скачать в хорошем качестве

Saba HiFi Studio Freiburg Stereo Receiver (Built in W Germany, circa 1967)

This is a Saba HiFi Studio Freiburg Stereo receiver. A rare bird, I've been dreaming about it for about 5 years... this year I managed to find it; I didn't even hesitate to negotiate with the seller, I bought it immediately, about 2 hours after the ad was posted :) I believe it’s the only one in Romania anyway. I would be really curious to find out if anyone else has something like this... they were extremely rare even back in Germany. Now, what can I say about it – it's a monster, the largest and heaviest receiver I own – over 27 kg, and the dimensions... wow. It's heavy to carry around, let alone troubleshoot; it's literally heavy... the casing has a lot of metal. The designers didn't skimp on anything. For the time of its design, around 1965, everything is top-notch. It was created as a kind of dream receiver, following a survey conducted by a German HiFi magazine. But the designers didn’t rush. Ironically, when it hit the market in 1967, its concept was somewhat outdated (Grundig had already introduced full silicon transistors in the RTV 600, plus FETs in the FM tuner). But still... for what it was, its class, a receiver with 65 germanium transistors, I don't think it had competition at the top level, at least in Europe. My work on it – well, its issues were mostly mechanical; the poor thing had "rheumatism," to use a medical term. Because it has so many contacts inside, plus springs, gears, and relays, you can imagine how stiff or oxidized nearly everything had become after almost 60 years. Once I put it to the test, it sounded horrible, losing audio on both channels... sometimes it would start with sound, sometimes mute. The owner told me it was defective, so... I started pressing buttons, and it perked up. Then I started listening to it, and it sounded quite good when it worked. Then, I turned up the volume a bit more and "pop," "puff," the right audio channel died. Damn, I was annoyed. I should have changed the electrolytics and adjusted the idle current, cleaned the potentiometers, but no, I had to listen to music right away. That's it; mistakes have consequences. Of course, there was no way to find 2N2147 transistors. With a bit of luck, I found someone in town selling ASZ 15, 16, and 18 transistors. I bought 6 ASZ 16 pieces with somewhat similar beta, 4 Romanian and 2 Tesla, just in case I had another mishap. Naturally, I paid almost as much for them as I did for the entire receiver. Because, well, where there's no competition, that's how it is. I then changed the electrolytics, cleaned the potentiometers, installed the new finals, everything was okay, it sounded good, but the heatsinks were getting a bit hot. I checked the idle current... it was about 300 mA instead of 50. Good, I said, let’s check the other channel, the good one – everything was okay, it was even a bit less than 50. Let’s adjust... damn, with the potentiometer at minimum and nothing. I don’t know; the ASZs don’t seem to match well with the audio amplifier. I had to experiment for a few hours; in the end, I put some power resistors of about 100 ohms, I think, to hell if I remember where, somewhere near the bias adjustment potentiometer, and the current dropped to about 80 mA. Still not 50 but not 300 either. Regarding the motors – there are 2, one simpler, which engages via relays for volume or balance adjustment. Without the wired remote, it’s useless. The other motor is truly special; it’s a huge beast, probably weighing around 2 kg including the drive mechanism. It’s an AC motor that can operate both clockwise and counterclockwise. Plus, it has two operating speeds. It’s powered from a separate transformer and has a special AC circuit with a unique 6.8 µF capacitor for stability. And yes, it’s still stable after all these decades. Practically, during automatic tuning, the motor starts, and when it detects a signal above the sensitivity threshold, it stops, or rather, it’s stopped by a special circuit and “vibrates” – I have no other word – right at the station frequency, where the signal is strongest. And yes, there’s a hell of a complex mechanism and electronics behind it. What fascinates me the most is that it still works. PERFECTLY. Everything I did to this system, aside from cleaning, was to adjust the tuning filter for the center tuning in FM. Other than that... Germanium from the 60s... I have no words. The search for stations with the motor can be done both automatically at low speed and manually; pressing the search buttons all the way switches to high speed, and the motor moves the needle quickly to wherever the user desires, and upon releasing the button, it returns to automatic search until the next station, where it stops on the station. Remnants from the tube era – the scale wire is made of metal, the scale is metal, and the glass in front is real glass. In the FM section, the receiver has continuous adjustment of the decoder, from mono to regular stereo, and then wide stereo at maximum.