Dual 601 Belt-Drive Turntable Service

Dual 601 Belt-Drive Turntable Service

I’ve just had a classic Dual 601 belt-drive turntable on my bench, in for a major service and it’s almost as good as new.

This particular Dual 601 needed recommissioning after an extended period of more than ten years in storage. The automatic tonearm functions were not working correctly and the deck needed a comprehensive grease and lube, plus proper tonearm setup.

So, for this Dual 601 service, I added synthetic oil to the dry main bearing assembly and carefully greased and lubed the key parts of the automated start and stop assembly, plus arm movement actuator. The automated tonearm movements were still not working though and this required further diagnosis.

This symptom is very common on the Dual 601, and other Dual turntables featuring an automatic arm return mechanism. I serviced another Dual 601 and discussed the problem here.

The problem turned out to be a small rubber part that had decayed and fallen off its original point of installation. Without this part, the tonearm can not be ‘gripped’ by the return mechanism and therefore won’t move. I fashioned a replacement part and now the arm works exactly as it should. I have since used this repair methodology in several other Dual turntable repairs.

The owner was very pleased with the result of this major overhaul of his Dual 601 and a few images outlining some of the steps follow.

German, elegant, well–made, but they are complex and the automatic mechanisms need extensive cleaning and many different types of lubricant
At first, it’s hard to figure out what is going on. Many points to lubricate here…
Trouble typically occurs here, often causing the tonearm not to return properly, or at all. In this case, a small rubber nipple that causes the arm to return had dissolved into nothing over time. This is a frequent source of trouble with Dual turntables.
This master control cam needs to be carefully checked and lubricated

Liquid Mike

At 10 I was pulling apart electronics and by 13 I'd have Dad's hi-fi in pieces when my parents went out! Later, I started Liquid Audio, a specialist electronics repairer known for detail-focused service, repair and restoration of hi-fi electronics & turntables. Keeping classic hi-fi gear alive and well is what we do. Our mission: to deliver TLC for classic Japanese, American and European hi-fi stereo equipment. In my spare time, I ride motorcycles, travel, listen to music and research interesting topics.

This Post Has 3 Comments

  1. Ben

    I’ve just purchased a Dual 601, lovely equipment but does have a loud hum, like an earthing problem .

    1. Liquid Mike

      Hi Ben, thanks for commenting, hum problems have many causes so tracing the source is important. Cartridge issues, wiring problems in either the arm, connectors or lead-out cable, bad ground connections, ground loops between pre and power amp and so on. As I always suggest, if you are local, you could visit with the deck and I can do some troubleshooting for you. If you are not local, it becomes harder for me to help from a distance, unfortunately.

  2. Gary

    Hi mate , do you know we’re I can get a counter balance weight for a dual 521
    Regards Gary.

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