I'll just throw this out there: Turn the TT on first.
Thorens TD 160 "pop" revisited
I realize that I may be late to this party, however I'm seeking some clarification and am hoping to get the final answer to this issue.
Just finished setting up new (to me) system with a beautiful TD 160, Rega 300 tonearm and Pete Riggles VTAF modification, along with his counterweight system. Connected to a restored Accuphase E-202, sending to a pair of Klipsch Forte IV.
To my ears, the sound is heavenly.
But: when I switch on the tt, there is a LOUD POP. I've seen discussions regarding snubbers and various capacitors placed within the tt, and yet others have said that failed to solve issue. Another post said he finally find the solution was adding a resistor somewhere unspecified.
Has anyone come up with a final reason why this happens and a proven solution?
A couple of snubber circuits to use. Both circuits are wired in parallel with the switch contacts First is to wire a capacitor and resistor in series and install the two across the switch contact terminals.
Second method is to install an MOV across the contact of the switch. Application Note: - Inductive Load Arc Suppression - Littelfuse
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As a rule turn on, (closure of the ON/OFF switch contacts), does not cause a high voltage transient. Opening the switch contact, (creating an arc), causes the voltage transient. To protect all the audio electronic equipment from the high voltage transient all equipment would have to be powered off. Not just the power amplifier.
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Here's some discussion of eliminating the startup pop. Having owned 5-6 TD160's I recall that the circuits can vary a bit (and I'm pretty certain that mine were all original/stock). https://www.vinylengine.com/turntable_forum/viewtopic.php?t=76532
DeKay |
A resistor should be wired in series with the capacitor.
“Snubber” Circuit
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Thank you all for very helpful and thought provoking advice. I'm going to ensure there is a proper snubber circuit including a capacitor and a resistor across the switch. Apparently, if left uncorrected it will eventually fry the contacts. After it's all done, I'll update with details for the benefit of the next poor soul. 😉 |
Or worse, damage electronic equipment.
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I wanted to provide an update on the solution to the pop which occurred on both opening and closing the power switch on my TD 160. This switch works in tandem with the speed control selector. As many have suggested, I had a snubber installed by a friend who knew just what was needed. ( Thank you Sanjib) A 0.1 microfarad/450 vdc capacitor was placed in series with a 100 ohm resistor across the switch. This served to prevent the arc across the air gap. Problem solved! The pop is gone completely. Thanks to everyone who contributed. I hope this information helps others who encounter this issue.
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