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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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19th Sep 2017, 2:29 pm | #1 |
Pentode
Join Date: Oct 2014
Location: Selsey, West Sussex, UK.
Posts: 204
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Toshiba SM-3350 Running Slow
Hello everyone.
I've got a Toshiba SM-3350 music centre with a turntable that seems to be running slightly slow on both 45 and 33 RPM, just enough to be audible and shows up on a strobe test. My first course of action is to lubricate the motor since there seems to be quite a lot of hum when the needle is on the record (not electrical hum). Can anyone recommend the best oil to use for this task and perhaps what else to check if oiling doesn't work? It appears to be a single speed motor since the 33/45 speed is changed by a plastic arm that moves the belt to the lower section of the motor shaft. Probably a cost saving move(?) Other than that, the system seems to be working fine (aside from a broken rewind function on the tape deck which I dont think i'll bother fixing since I hardly use it). |
19th Sep 2017, 2:44 pm | #2 |
Heptode
Join Date: Nov 2009
Location: London, Ontario, Canada
Posts: 673
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Re: Toshiba SM-3350 Running Slow
Looks like hifiengine.com has a service manual for the "big brother" of this music center, the SM-3750:
https://www.hifiengine.com/manual_li.../sm-3750.shtml There are probably lots of similarities, including the record player. Good luck, Peter |
19th Sep 2017, 2:46 pm | #3 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Toshiba SM-3350 Running Slow
A nice unit. The cheapest in Toshiba's range of quality music centres at the time, I believe, but still a cut above what most people were buying. It has a belt-drive turntable with magnetic cartridge, decent cassette deck with Dolby B NR, and a tuner with presets. Power amp is the STK461 module ISTR.
The motor is an AC synchronous type and is fitted with a dual-diameter pulley for the two speeds as you describe. This was a very common arrangement at the time, and was used for very expensive turntables too, so you can't really describe it as a cost saving measure. As you've guessed, I would clean and lubricate the motor bearings and the main/platter bearing too. N. |
19th Sep 2017, 2:48 pm | #4 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Toshiba SM-3350 Running Slow
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19th Sep 2017, 4:19 pm | #5 | ||
Pentode
Join Date: Oct 2014
Location: Selsey, West Sussex, UK.
Posts: 204
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Re: Toshiba SM-3350 Running Slow
Quote:
Quote:
Cheers. |
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19th Sep 2017, 4:40 pm | #6 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
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Re: Toshiba SM-3350 Running Slow
Yes, for the motor. But something a bit thicker for the main bearing might be better, e.g. a drop or two of engine oil.
N. |