LP12 grunt

[audiopoor]

I bought this LP12 (serial no 066634) used about ten years ago and I've always wondered if this was the norm for this tt to give a bit of a grunt sound when you turn it on. I believe it's from the motor and it lasts just a second or two upon startup. I have always given the platter a helping hand, just a finger push from about 8 to 11 o clock to get it up to speed. This lessens the grunt sound by half. The valhalla power supply board was replaced by my local Linn dealer when the stock one quit working six years ago but the grunt continued. I pointed this out to him and he basically said not to worry about it. I've continued to be content with this issue and been mostly happy with the tt performance but now it's bugging me. I was at a fine audio store in Toronto last month and there sat an older LP12 with a raised red push start button, mine is the black rocker type. I turned it on and there it was again. So... is this really normal. Does anyone else hear the same?
Harv

[metaphacts]

Originally Posted by audiopoor

I bought this LP12 (serial no 066634) used about ten years ago and I've always wondered if this was the norm for this tt to give a bit of a grunt sound when you turn it on. I believe it's from the motor and it lasts just a second or two upon startup. I have always given the platter a helping hand, just a finger push from about 8 to 11 o clock to get it up to speed. This lessens the grunt sound by half. The valhalla power supply board was replaced by my local Linn dealer when the stock one quit working six years ago but the grunt continued. I pointed this out to him and he basically said not to worry about it. I've continued to be content with this issue and been mostly happy with the tt performance but now it's bugging me. I was at a fine audio store in Toronto last month and there sat an older LP12 with a raised red push start button, mine is the black rocker type. I turned it on and there it was again. So... is this really normal. Does anyone else hear the same?
Harv

Harv,

Does the table need help to get up to speed? Does the grunt come from the pulley area or from the bottom of the motor?

Take off the mat and flip over the platter. Put the inverted platter back on the table. Watch the belt and see what it does on start up. What do you see?

Bill

[audiopoor]

The platter does get up to speed and is stable. Nice idea to invert the platter

[metaphacts]

Originally Posted by audiopoor

The platter does get up to speed and is stable. Nice idea to invert the platter

Yes but what does the belt do when you hit the on switch?

[audiopoor]

I wasn't finished and I some how posted my last reply To continue, at start up the flat belt drops a bit on the pully but quickly rises back up to the middle of the pully. I got out my mechanic's stethoscope and touched the bottom of the motor at start up and there it was. I never tried this before but I tried to slow down the platter with my hand and there was the grunt, it's a motor strain noise. Anyone else getting this out of their Linn?

[metaphacts]

Originally Posted by audiopoor

I wasn't finished and I some how posted my last reply To continue, at start up the flat belt drops a bit on the pully but quickly rises back up to the middle of the pully. I got out my mechanic's stethoscope and touched the bottom of the motor at start up and there it was. I never tried this before but I tried to slow down the platter with my hand and there was the grunt, it's a motor strain noise. Anyone else getting this out of their Linn?

What does the bottom of the motor bearing look like? Does it have a cap on it?

[audiopoor]

It's a round solid steel shaft about 3/4" long.

[metaphacts]

Originally Posted by audiopoor

It's a round solid steel shaft about 3/4" long.

Steel? Sure it is not the color of steel and hollow?

If your table is the vintage I think it is, it should be a cup pressed over the bottom of the motor bearing.

[audiopoor]

You are so right. It is the colour of steel and when I gave it a quick push, to my surprise, it popped off. Inside there is a spring with a half sphere covered in white grease.

[metaphacts]

Originally Posted by audiopoor

It's a round solid steel shaft about 3/4" long.

Look like this?