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I have a Project low-end belt-drive turntable that I had no problem with in UK. It requires AC 16V, and a UK power adaptor with 230V/50Hz/Output AC 16V 500mA worked fine.

Last year, I moved to South Korea, where the AC wall power is 220V, 60Hz. When I used the UK power adapter with a plug converter, the turntable spun faster than 33rpm. I suspected the difference frequency, so I got a new power adaptor which takes 220V/60Hz and outputs AC 16V, 1.1A. But it still spins faster.

I don't think it is the belt (cannot imagine a belt failure that will make it spin faster)... Can anyone suggest a feasible point of failure in this case please?

ntrolls
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  • I'm voting to close this question as off-topic because this has got nothing to do with music, it is a question about electronics. – BCdotWEB May 25 '16 at 08:33
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    @BCdotWEB To my own defence, I did skim through the list of StackExchange sites, and this not only was the closest one in my view (I mean, who else would know better than music fans) but it also already contained a few other turntable related questions, hence the posting.... – ntrolls May 25 '16 at 13:17
  • @BCdotWEB I have opened a new meta post to address the question of exactly what is and isn't on topic here. Please stop by to add your answers: http://meta.musicfans.stackexchange.com/questions/287/what-is-currently-on-topic-as-of-5-16 – Chris Sunami May 25 '16 at 16:31
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    @ntrolls All of those questions are appropriate, yours isn't. If you had the same problem with a mixer, you wouldn't ask this in a cooking SE. Etc. And if there isn't an appropriate SE, you can petition for one in Area 51. That you have this issue with your turntable is a coincidence, the issue is the differences WRT the electric network in both places. – BCdotWEB May 25 '16 at 18:03

1 Answers1

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The 'problem' is that the turntable uses an AC adapter rather than a DC one. The motor speed is based on the supplied AC frequency rather than anything the PSU/transformer is doing to it.
Simply put, your power supply has a 20% higher frequency, so your motor is running 20% faster than it would on 50Hz.

This would imply that the motor is an AC motor rather than DC, but it still may be possible to tweak.

You have only two options, one is free, the other is expensive.

  1. You hope the turntable has a manual speed adjustment. Unless the manufacturer designed the turntable with specific components for different world markets, this is quite likely to be feasible. Some have a variable resistor in or near the motor. DJ turntables have these on the outside, easily-accessible. Domestic turntables may not be in such easy reach.

    You can check the speed quite simply by printing out a downloadable strobe disc, available from many sites. This is one example - http://www.vinylengine.com/strobe-discs.shtml

  2. Get a frequency converter to take your power supply from 60Hz down to 50Hz. These tend not to be domestic devices & are not cheap. A quick Google is throwing up prices starting at around $1000. Unless you have an extremely serious turntable I'd guess this would be a less than ideal solution.

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Tetsujin
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    Of course, how silly of me! I initially thought matching the wall power frequency of 60Hz would solve the problem, but obviously the frequency applies to the output AC 16V as well... duh. Thank you for making me see the (blindingly obvious) light. – ntrolls May 25 '16 at 13:15