How To Ariston Q Deck Speed Adjustment - Solved

[fpdoc]

Hello all,

I've had some issues with the speed of my Ariston Q Deck and have solved the issue, so thought I'd post here if anyone has the same issue in the future.

The turntable was spinning at 43.7rpm for 45rpm and 32.9 for 33.3rpm. Before you flip the turntable over, remember to remove the metal platter!

There are three things you need to check. Firstly download a free RPM app on your phone that uses the gyroscope for rotation speed measurement and get a baseline.
- Check one - new official belt (£5 on ebay). This brought my speed up slightly.
- Check two - lubricate motor spindle and main bearing (lift off cap from main bearing from underneath the turntable cover, remove the cover with a few phillips screws). The loation can be seen in my image below, the white cap to the right on the main circuit board. A few drops will do, I used sewing machine oil. This raised my speed significantly, it is likely it hadn't been lubricated in 30 years!
- Check three - for fine tuning, the turntable has two 'speed pot' adjustments on the main circuit board for both 33.3 and 45rpm. This step is pretty fiddly and will take plenty of trial and error to get exactly right. Be patient and you will get there! You may have two screws for adjusting the speed, which I did not. I have linked two forum articles below with additional information on adjusting these

https://www.vinylengine.com/turntable_forum/viewtopic.php?t=72353

https://www.vinylengine.com/turntable_forum/viewtopic.php?t=58062

HOWEVER, there are multiple types of Q Deck. If your circuitry looks different than those forums, as mine did, you might have the same setup as me. See the tree images attahed of mine. You will see the small holes on the back cover showing the speed pot location. Remove the cover and the you will see two variable resistors on the circuit board to adjust speed. VR1 is for 33.3rpm and VR2 for 45rpm. I did find adjusting one has a slight effect of the other. So to increase speed, rotate the metal cap on the resistor to the left (anticlockwise) with a flat head screwdriver. This decreases resistance as to increase speed. It's the opposite of what might seem logical as you are adjusting resistance. Repeat the process on both resistors and test the speed until you reach the correct 33.3 and 45. Within 0.2rpm is usually ok.

Hope this helps, reply if you any more info. Enjoy

 

[nopiano]

A couple of cautions:-

1. I believe that some of these phone apps aren’t especially accurate. It’s using a mechanism not designed for the purpose, so personally I’d check with an old fashioned strobe disc under an incandescent bulb. (Or buy a special kit designed for the purpose)

2. The ‘errors’ you quote wouldn’t be unacceptable for a brand new turntable. While you might feel better about it, I believe only the acutest ears will perceive any difference.

3. I also 100% recommend new belt and oil change on any old deck as a minimum. Speed tweaks I’d leave well alone unless significantly adrift.

Ok, well that’s three for the price of two!

 

[fpdoc]

A couple of cautions:-

1. I believe that some of these phone apps aren’t especially accurate. It’s using a mechanism not designed the purpose, so personally I’d check with an old fashioned strobe disc under an incandescent bulb. (Or buy a special kit designed for the purpose)

2. The ‘errors’ you quote wouldn’t be unacceptable for a brand new turntable. While you might feel better about it, I believe only the acutest ears will perceive any difference.

3. I also 100% recommend new belt and oil change on any old deck as a minimum. Speed tweaks I’d leave well alone unless significantly adrift.

Ok, well that’s three for the price of two!

Yes, I read that about those apps as well. However, it seemed to do the job as at 43.7rpm it was very audibly 'out'. Got it up to 44.8rpm and now it sounds pretty spot on. Anything over 0.5rpm I could very easily notice as the pitch of the song changed. Another test I did was to play a record alongside the same song on spotify, and within 30 seconds the turntable was lagging behind the spotify track.