Being a sucker for old technology, I recently acquired an old Technics SL-2000 turntable. It was introduced in 1977 but I have no idea how old mine is. Either way, it still runs well and cosmetically still 9/10.
My current setup. Playing Elton John’s greatest hits.
Unlike modern turntables, this turntable didn’t come with a built-in phono preamplifier. This means you cannot just connect it directly to a speaker. You will need a phono preamp stage to amplify the cartridge’s output to a higher voltage level that is suitable for the speaker input. Initially when I decided that I wanted a turntable, I had planned to build my own preamp (which I am still going to do) because turntables need a specialized preamp. This has something to do with the RIAA equalization curve. Basically it has something to do with how they cut the records. Read more about this here and here. Instructions on how to build your own phono preamp can be found here.
However, when I met up with the guy who was selling the turntable, we got into an engaging conversation on amplifiers, turntables and music. As we both had electrical backgrounds, there was plenty to talk about. He had tons of old stuff lying around his place, and 2 working tube amplifiers. When he asked me what amplifier I was going to be using, I told him I haven’t got one yet. So he told me I could have one that he had lying around. It needed a small simple repair to the electronics, but other than that it was working fine. It pays to be friendly!
The Sansui AU-101. According to this site, it was manufactured between 1973-75.
Mine is missing the top cover, 5 knobs and it has a broken “speakers” switch. I can source the knobs easily, but replacing the broken switch would probably require me to invent a time machine. The interesting thing about this amplifier is that it doesn’t use chips. Expected since it was designed in the 70s. But it works great and sounds good. I’m currently using it to amplify the signal from the turntable and feeding it to my Labtec 2.1 computer speakers. I haven’t been able to find affordable bookshelf speakers for this amplifier yet.
The white dots on the turntable platter is used to adjust the speed and to determine if the turntable is running at the correct RPM.
The orange light is a stroboscope. If the turntable is running at the correct speed, the dots should remain stationary. Home fluorescent lights work too since they flicker at line frequency too.
These are the two adjustments for the tone arm. The chrome cylinder object is a counterweight and is used to balance the arm while the anti-skating knob below is to prevent the needle from having too much tendency to move towards the center of the platter. The counterweight is now set to 1.75 which means that the force of the needle on the record is now 1.75 grams. This may not seem very high, but due to the small area of the needle, this can translate to 340 pounds per square inch on the record grooves!
It’s actually quite easy to adjust the counterweight and anti-skating control. With the arm free, adjust the counterweight until it balances the arm nicely. This means that the arm should maintain level when free. After that, turn the black dial so zero aligns with the mark on the top of the arm. You align it with zero because right now there is exactly zero grams of downforce on the needle (since the arm is balanced). Now you can turn the counterweight for the proper downforce. In the photo above, I had mine set to 1.75 grams.
According to the SL-2000 manual, the anti-skating knob is set to the same value as the needle downforce.
Next comes the alignment of the needle. There are actually lots of resources online teaching people on how to align their cartridge for the best result. You can read them up here, here, here, here, here, here and here.
Simply put, the needle must be perpendicular to the surface of the record and aligned with the grooves of the record.
I’m still trying to get used to skipping records, getting up every 25 minutes or so to flip the record, and not being able to put a song on repeat or album on random. I absolutely adore the convenience modern technology has brought us, but I’m constantly in awe of how previous generations get along without them. Hence my obsession with old stuff.
More to come!