Speaker noise when tapping turntable??

[robbie010 551]

I spent a couple of hours earlier finishing the setup of my new turntable and SME 3009 arm, its looking great and sounds stunning. However, when switching records with the motor off and the arm in its rest I could hear a horrible noise coming from the speakers when nocking or tapping the deck....

It sounded like the stylus was being dragged across a record that wasn’t spinning 🥴, could this be an earthing problem??

[radiant red 5,402]

Firstly, a turntable is one big resonator if not properly supported or isolated... any tapping of the deck will feedback to the arm and inevitably the cartridge. This worsens when the volume is higher of course.. 

what deck is it and how do you isolate it and how far from the speakers is it?

[robbie010 551]

Turntable is Audio Linear TD 4001, it has spring mounted feet and sits on the top (glass) shelf of my rack which in turn is sat on 3 large sorbothane domes and the rack is on spikes. 

Nearest speaker is about a meter away. 

[radiant red 5,402]

Sounds like that you have done the best you can there 👍🏻

Other than what I said above, it’s difficult to know what to suggest without hearing the noise... 

phonostage? Gain set too high? If you have one...

[tuga 2,036]

Just now, radiant red said:

Gain set too high?

This is what I was thinking.

[robbie010 551]

5 minutes ago, tuga said:

This is what I was thinking.

Thanks, I’ll check that as the phono stage is new and I’ve not looked at the dip switches yet. 

👍🏻

[Shadders 250]

1 hour ago, robbie010 said:

I spent a couple of hours earlier finishing the setup of my new turntable and SME 3009 arm, its looking great and sounds stunning. However, when switching records with the motor off and the arm in its rest I could hear a horrible noise coming from the speakers when nocking or tapping the deck....

It sounded like the stylus was being dragged across a record that wasn’t spinning 🥴, could this be an earthing problem??

Hi,

So, when you tap or knock the turntable, you get a noise through the speakers like a tap or knock to the turntable.

The solution is, don't knock or tap the turntable.

Which reminds me of the Etch a Sketch joke :

Q: My Etch-A-Sketch has all of these funny little lines all over the screen.
A: Pick it up and shake it.

Q: How do I turn my Etch-A-Sketch off?
A: Pick it up and shake it.

Q: What's the shortcut for Undo?
A: Pick it up and shake it.

Q: How do I create a New Document window?
A: Pick it up and shake it.

Q: How do I set the background and foreground to the same color?
A: Pick it up and shake it.

Q: What is the proper procedure for rebooting my Etch-A-Sketch?
A: Pick it up and shake it.

Q: How do I delete a document on my Etch-A-Sketch?
A: Pick it up and shake it.

Q: How do I save my Etch-A-Sketch document?
A: Don't shake it.

Regards,

Shadders.

[Beobloke 968]

As I recall, the TD4001 wasn’t particularly well liked when it came out, and one of the chief complaints was its poor isolation. As people have mentioned, your best bet may be just to be careful not to clout it!

[divedeepdog 131]

I had this argument with another audiofool friend,  when I tap the deck it comes through the speakers,  answer,  stop tapping the deck. It’s not part of the reproductive circuit. 

If you were getting feedback while playing very loud,  they’d be a problem that’d need a solution 😜

[StingRay 1,831]

It is common on turntables, some are worse than others, the Technics I had was quite bad, the AR was much better, it depends on the design and plinth material. Answer is stop tapping it. If it is causing a problem when playing music then you could look at forms of dampening, I know some TTs like the Technics ones have been modified by adding dampening materials inside the plinth. It will be nothing to do with earthing.

[bigfool1956 6,486]

I'm curious, because the sound described by Robbie isn't anywhere near what I would think of as the sound of a TT being tapped with the arm in its rest. I would expect 'thunk thunk' or if the arm stay is a bit loose, then some after-thunks as it rattled against the stay. Definitely not the sound of a stylus being dragged across a stationary record.

P.S.

@Shadders

[StingRay 1,831]

Try holding the cartridge/arm off the rest and see if the noise is the same when you tap the deck.

[robbie010 551]

Thanks all, it was indeed the gain setting on my new phono stage..... all is now well in the world!

[f1eng 80]

7 hours ago, divedeepdog said:

I had this argument with another audiofool friend,  when I tap the deck it comes through the speakers,  answer,  stop tapping the deck. It’s not part of the reproductive circuit. 

If you were getting feedback while playing very loud,  they’d be a problem that’d need a solution 😜

If there is sound when tapping the deck there will definitely be feedback while playing music, I remember 8dB down on the signal being measured at Garrard for one deck. It isn't enough to cause a horrible noise, in fact it is rather a nice addition of bass with a little delay, like reverb.

I actually prefer the sound of my deck picking up a bit of mechanical and acoustic reverb. I once moved it and the electronics to a different room with just speakers in the listening room and the sound was much more flat and uninteresting than with the deck in the room adding a bit of reverb.

But that is just me.

[uzzy 2,445]

3 hours ago, robbie010 said:

Thanks all, it was indeed the gain setting on my new phono stage..... all is now well in the world!

Good stuff - however, as you now know the deck will transmit vibrations through the stylus to the loudspeaker.  You can get a siesmic app for your phone and leave it on the turntable platter whilst playing music from another source to determine how much vibration is getting through (Max Townsend used it, I seem to recall at a show,  to demonstrate his stand isolators).

This interested me in as far as we hear so many views on which is better; this suspension, or that suspension, or no suspension, or idler drive, or belt, or direct drive?  That got me thinking, if a turntable is turning at the precise speed how can one type of turntable drive have an affect on PRAT and the claim of direct drive users that their is more "drive to the music".  I have nothing to prove it but I have a strong suspicion that all of those things may well be down to the added vibration noise (or lack of it)  especially when taking into account f1eng comment above, namely, 

2 hours ago, f1eng said:

If there is sound when tapping the deck there will definitely be feedback while playing music, I remember 8dB down on the signal being measured at Garrard for one deck. It isn't enough to cause a horrible noise, in fact it is rather a nice addition of bass with a little delay, like reverb.

I actually prefer the sound of my deck picking up a bit of mechanical and acoustic reverb. I once moved it and the electronics to a different room with just speakers in the listening room and the sound was much more flat and uninteresting than with the deck in the room adding a bit of reverb.

That should get some raging debate going perhaps lol.   However, at the end of the day it is what sounds best to you that matters innit  (as Linn users might say it is all in the bounce)