Hi-Fi Turntable Feedback?

[SwingsitlikeHogan]

Out of the blue I seem to be getting a feedback howl from a speaker.

The tabletop speaker sits immediately beside my turntable and on the same console table as it. The turntable sits on top of my very heavy receiver. Other than the receiver I have made no attempt to add any isolation between turntable and speaker. The howling has only just recently started. What is very weird - though maybe coincidental - is that if I stand very close the table the feedback howl stops, yet as soon as I step back maybe just 1m it can start again - step back to table and it stops. Also I can tap the top of the speaker and that stops the howling…until I step back and it can (not always) start again.

Baffled.

 

[jim8flog]

Does your turntable have a grounding wire connected to the amp? if yes is it loose?

have you made you own theremin?

 

[GreiginFife]

It sounds like vibration is causing this. Yep, could be a loose wire but ground wires normally cause a constant buzzing rather than a howl, which is usually caused by vibration feedback causing a loop.

Tap the surface of the console table, if you can hear it through the speaker (a dull thumping) then your tonearm isn't isolated. Why this would suddenly happen I couldn't say (could be a floorboard has come loose, it doesn't take much for a stylus to pick up additional vibration) but it could be that you need to introduce a layer of isolation between the console table and the amp or the turntable and the amp.

I have my turntable on an isolation platform to prevent this as the wooden floors in the room are terrible for vibration (even with the speakers lifted up on isolation spikes).

Luckily the Technics have all the isolation built in to the turntable chassis.

 

[SwingsitlikeHogan]

Does your turntable have a grounding wire connected to the amp? if yes is it loose?

have you made you own theremin?

‘theremin’?

 

[SwingsitlikeHogan]

It sounds like vibration is causing this. Yep, could be a loose wire but ground wires normally cause a constant buzzing rather than a howl, which is usually caused by vibration feedback causing a loop.

Tap the surface of the console table, if you can hear it through the speaker (a dull thumping) then your tonearm isn't isolated. Why this would suddenly happen I couldn't say (could be a floorboard has come loose, it doesn't take much for a stylus to pick up additional vibration) but it could be that you need to introduce a layer of isolation between the console table and the amp or the turntable and the amp.

I have my turntable on an isolation platform to prevent this as the wooden floors in the room are terrible for vibration (even with the speakers lifted up on isolation spikes).

Luckily the Technics have all the isolation built in to the turntable chassis.

My Dunlop Systemdek has a jointly suspended platter and arm mount so always considered that to be more than ample isolation…even on an dodgy and wobbly console table…after all that's what is is designed for no?

Plus this weirdness that I can have no feedback and then I physically step back 1m and I get howl? And I can be in the middle of the room and it comes and goes.

I’ll check connections etc as I was moving it all about a bit and the feedback seems to be subsequent to that…

 

[GreiginFife]

My Dunlop Systemdek has a jointly suspended platter and arm mount so always considered that to be more than ample isolation…even on an dodgy and wobbly console table…after all that's what is is designed for no?

Plus this weirdness that I can have no feedback and then I physically step back 1m and I get howl? And I can be in the middle of the room and it comes and goes.

I’ll check connections etc as I was moving it all about a bit and the feedback seems to be subsequent to that…

Which is why I questioned vibration. If you stand close to something you lessen it's ability to vibrate. You are definitely getting vibration from somewhere, suspended platter or not, yes it is designed to reduce resonant feedback but not eliminate it as it has to be physically connected to something in order to work.

Technics use heavy bases and rubber dampening to reduce feedback rather than suspension. It may be that in moving it you have upset the balance that you had previously.

 

[SwingsitlikeHogan]

Which is why I questioned vibration. If you stand close to something you lessen it's ability to vibrate. You are definitely getting vibration from somewhere, suspended platter or not, yes it is designed to reduce resonant feedback but not eliminate it as it has to be physically connected to something in order to work.

Technics use heavy bases and rubber dampening to reduce feedback rather than suspension. It may be that in moving it you have upset the balance that you had previously.

This could be the case as it is not easy to get the deck level…I should probably do something about levelling the console table as it sits on an uneven suspended wooden floor as that would make levelling the turntable easier.

 

[SwingsitlikeHogan]

‘theremin’?

AKA tone arm?

 

[GreiginFife]

AKA tone arm?

 

[Ye Olde Boomer]

A couple of decades ago, I tried to buy a Linn Sondek LP12 at Harrod's, but my wife wouldn't let me.
So I've got a Japanese Technics 1200 like everybody else. It's fine. The beautiful Linn was a pipedream.

In any case, a loudspeaker has no business being on the same table as a speaker, or at least that's what they said back in the day.

I have JBL 2RX 225's here in my mancave. They're on the floor where they belong.
And I've listened to so little music lately, they're used almost exclusively for TV.

 

[SwingsitlikeHogan]

A couple of decades ago, I tried to buy a Linn Sondek LP12 at Harrod's, but my wife wouldn't let me.
So I've got a Japanese Technics 1200 like everybody else. It's fine. The beautiful Linn was a pipedream.

In any case, a loudspeaker has no business being on the same table as a speaker, or at least that's what they said back in the day.

I have JBL 2RX 225's here in my mancave. They're on the floor where they belong.
And I've listened to so little music lately, they're used almost exclusively for TV.

My speakers were on stands but my wife thinks the stands are untidy clutter and so I was ‘asked’ that I refrain from using them.

 

[SwingsitlikeHogan]

1) Quick date check…ok
2) Quick search of ‘theramin’…ok
3) Hmmm…I have two aerials attached to the receiver…

 

[SwingsitlikeHogan]

Done a bit of unplugging and re plugging of connections. Made sure console table is level and added felt pads to table legs to level. Checked turntable chassis and platter separately level, and swapped rubber platter mat out and using felt one. As I can’t move the speaker off the console table I’ve added felt pads to feet of the speaker. So far…but it’s only early King Crimson I’ve got on…let’s see when I put on some real bassy Soul II Soul shortly.

 

[jim8flog]

are you now 21st century paranoid man?

 

[SwingsitlikeHogan]

are you now 21st century paranoid man?

I can certainly be a bit schizoid from time to time.

 

[Ye Olde Boomer]

My speakers were on stands but my wife thinks the stands are untidy clutter and so I was ‘asked’ that I refrain from using them.

Wives can be like that on any continent.

 

[jim8flog]

My speakers were on stands but my wife thinks the stands are untidy clutter and so I was ‘asked’ that I refrain from using them.

there are times I am glad I have not remarried

 

[SwingsitlikeHogan]

there are times I am glad I have not remarried


View attachment 54568

My Mrs would go Aaaargh - Tidy up that mess. Mess? I see no mess…!

And do I spot a Marantz Special Edition CD player? Can’t recall which model I have…it’s currently banished to the loft - it wasn’t hugely expensive but was a huge selling Best Buy.

 

[cliveb]

there are times I am glad I have not remarried


View attachment 54568

You don't have to be a woman to think that's a bit untidy. I prefer the minimalist look:

 

[Beezerk]

You don't have to be a woman to think that's a bit untidy. I prefer the minimalist look:View attachment 54572

Needs a bigger tv