Restoring a LAB-1100 Turntable

Restoring a LAB-1100 Turntable

March 28, 2020

Working turntable next to mixer

I wanted to jump on the vinyl resurgence bandwagon – but in a more meaningful way than buying Wirecutter’s recommendation. Here’s how I restored my grandfather’s LAB-1100.

If you’re interested, this is a great entry-level turntable: it’s semiautomatic with a built-in phono stage (and RIAA equalization). That’s everything you need to get started playing records – you can pick one up on eBay and renew it for cheap.

Process

I used a USB mixer to record audio samples at each stage of the renewal, the RPM iOS app to track changes in spin speed (these apps use your phone’s accelerometer as a modern alternative to stroboscopes), and Madeon’s Adventure as my sample album.

Here’s the starting point - the needle scratches all the way into the 11th track, Pixel Empire, and plays with significant distortion and skipping:

34.95 RPM measurement RPM app reports spinning 4.85% faster than desired and 1.5% wavering

There’s two main components that need replaced over time (~1000 hours playing): the stylus and, for belt-driven turntables, the belt.

Replacing the Stylus

The manufacturer recommended stylus replacement is the Audio-Technica ATN3600L (found in online manual).

Picture of Audio-Technica stylus

There’s many great guides available on how to swap a stylus. The LAB-1100 manual has instructions on page 12:

Instructions to replace stylus

Replacing the Belt

Turntable belts stretch over time, affecting the revolution speed and motor responsiveness:

Picture of loose turntable belt This over-stretched belt loosely hangs off the platter

You can determine what kind of belt you need to by measuring the underside of the platter:

Measuring tape measuring 206mm platter size In this instance we’d search for a ~206mm belt

You may also be able to find a model-specific belt, like in the case of the LAB-1100:

Close-up of player Wrap the belt around the platter and then loop it around the motor

Fine-tuning the speed

After changing the belt and stylus, it’s sounding much better:

But a familiar ear will notice the song still sounds a bit faster than usual:

34.80 RPM app measurement

Turntables usually allow speed adjustment through knobs / potentiometers. I couldn’t find them on the LAB-1100 until I found this super helpful comment from Randy on YouTube:

Comment about adjustment holes behind stickers Thanks Randy!

Close up of adjustment holes on bottom The speed adjusters hidden under black stickers

Using a screw driver to adjust the potentiometer through the “33” hole (33 1/3 RPM) will make the motor spin faster or slower.

Past the stickers, there’s also a foam barrier you must slip a screwdriver through in order to be able to turn the potentiometer. It feels strange to blindly jam a screwdriver in an electrical appliance; double check that it’s unplugged and use care when fishing around.

After several rounds of trial and error, I was happy to land within a half percent of 33 1/3 RPM:

33.21 RPM measurement

At last, here’s how it sounds:


Dalton Flanagan is a software engineer & creator based in NYC.

© 2023 Dalton Flanagan