Harmon Kardon ST-8
Pjh60004
Posts: 1
I have a pristine ST-8 just pulled from storage and it seems the dreaded Hall Effect is Sensor might have gone bad.
Can anyone provide expected Voltages at the motor.
Thank You Peter
Can anyone provide expected Voltages at the motor.
Thank You Peter
Comments
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You might try asking that question at AudioKarma.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
The service manual is available at the vinylengine site, here is a tabulation of the voltages present at transistors:
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@SeleniumFalcon beat me to it.
https://www.vinylengine.com/library/harman-kardon/st8.shtml
EDIT: It's a really comprehensive and intelligible service manual, too!
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I repaired an ST-8 for a friend. The motor had a bad hall effect sensor. I used a motor out of a donor ST-7. In my copy and paste notes, a post from diyaudio said a Dual CS 701 or 721 might be able to donate a hall effect sensor. I have no idea if there are substitute sensors that could be used.
It's common for the base of the cueing air pot to deteriorate and crumble. I came up with a fix in the link below. Airpot would still made them at the time though it was a pricey replacement ($97 US in 2022).
https://forum.polkaudio.com/discussion/197116/harmon-kardon-st-8-turntable-on-the-benchSalk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 * -
The designer of the Hall effect motor:
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very effective.
