I like how at the end of the article, in big bold letters, it says “This Article Is Copyrighted”! I guess I should have put those same words on my article, since that guy stole that article and my pictures from my original article which can be found here: Quartz Mod | New Line THose are my pictures that I took of my turntable, which I still have. Now back to the mod. The best way to describe the mod is to turn on your turntable, look at the red strobe, now press on the platter with your finger. As you apply pressure, look at the red strobe and you will see the platter starts jerking trying to get back up to speed. It doesn’t slow down smoothly. What the quartz lock mod does is, it eliminates that jerking action. With the quartz lock mod, when you apply pressure to the platter, the platter will slow down smoothly and not jerk. It will slow down and maintain a constant speed as you keep pressure on the platter without the platter jerking, just like if you slowed it down with the pitch control. As you release the pressure, the platter will speed back up smoothly. Why would you want to do this? I’ll explain.
The 1200mkII came out in 1978, before that, most DJ’s that beatmixed used the Technics SL-1100A. Keep in mind that back in 1978, it was the Disco era, and that means that the music was made with a live drummer. Which means that the beat was very inconsistent. To keep the live drummer beats in sync, we would ride the platter by applying pressure to the SL-1100A platter to slow it down and speed it up, that is how we rode the pitch. The 1100A also had the pitch control right next to the platter, so you could press on the platter and adjust the pitch with one hand at the same time. When the 1200mkII came out, you couldn’t ride the platter because it would jerk like I mention earlier. Now I don’t know who came up with the quartz lock mod in the first place. The story I got was that a lot of DJ’s complained to Technics about the jerking action, and Technics released the mod as service bulletin to get rid of the jerking action. The mod doesn’t get rid of the quartz either, that was what we called the mod back then and the name just stuck.
So basically what the mod does it makes the 1200mkII behave like the old SL-1100A as far as pressing on the platter is concerned. All the torque is still there, the quartz still maintains a constant speed, it just makes it easier to beat mix. With todays music, you don’t need to do the quartz lock mod, since most of todays music is recorded with a drum machine and you don’t have to constantly ride the pitch like you do with live drummer tracks. I do the quartz lock mod to all my 1200’s, because that is the way I learned how to mix. The only problem with learning how to mix with a quartz lock modded turntable is if you go mix on somebody else’s 1200 that is not modded, you are going to have to ride the pitch control instead of pressing on the platter.
All 1200s can be modified except for the 1200 m5g. The m5g has a digital pitch control and as far as I know, there is no way to do the quartz lock mod to it. The quartz lock mod is easy to do and undo. Just cut one wire, and one resistor, and adjust the blue pot. To undo it, just solder the resistor back together and the wire, and readjust the pot.
