Identifying Cirkus Mod

Posted by: trickytree on 11 November 2003

Dear all.

How do you tell if your deck has the Cirkus fitted?

The subchasis seems to be bonded rather than spot welded but was this done before the Cirkus?

The main reason im asking is out of curiosity more than anything else. I've just got around to throwing the Trampolinn in the Binn

and this has realy let the deck sing, I cant believe how much it has been holding the sound back. Thing is i've never noticed any bass bloom to the sound, something the Cirkus is supossed to remove.

Also while your all scratching your heads, any thoughts on the corner bracing? I want to do the bolt mod but have to put the bracing in first. How are the latest decks done?

Thanking you in advance, Paul.

Posted on: 12 November 2003 by greeny

If I remember correctly,

If you remove the inner platter then the cirkus bearing has a black inner sleeve as opposed to white/grey? It also protrudes more fromthe plinth (of couse you need to know how much the none cirkus ones protrude to know this!).

I don't think the colour method is absolutely foolproof though as I think a small number of non cirkus bearings may also be black.

Posted on: 12 November 2003 by RichardHallman

Bolt mod
This may help
- couple of shots of the "proper" bracing as well as the way I did my bolt mod. Well worth while, by the way.

Posted on: 12 November 2003 by Energy

the following photos should help,

Alan

Posted on: 12 November 2003 by RichardHallman

Think it was a 50mm M5, but I cut it down a bit once I could determine the exact length needed for the bolt to thread into the flange nut without hitting the top plate. More discussion of this over on the "dark side" at PFM.

Posted on: 12 November 2003 by trickytree

Thank you all for your help.

Bearing colour and the photo's indicate that I am pre-cirkus. Can't say as i'm to bothered as since removing the Trampolinn (hoping to find an ebay sucker, er, I mean knowlegable buyer for that!) it's as if a (very thick) veil has been removed from the whole system. I've not stoped grining since the weekend as I re-discover album after album.

I'll do the corner bracing and the bolt mod this weekend.

Paul.

Posted on: 13 November 2003 by David Young

I would appreciate if anyone could tell me how to identify the serial no. of an old LP12 and whether the motor for 120V and 240V version is the same as I understand that the motor used in LP12 is AC motor and the frequency (50 vs 60 Hz) will have the effect on speed.

Thanks

Posted on: 14 November 2003 by trickytree

Hi David and welcome to the forum.

The serial No. should be on the back of the plinth. If its not there then your stuck, although very early decks had a groove in the top of the plinth to hold the lid up.

Not sure about the voltage but I think i'm correct in saying that it makes no difference what frequency the mains is, the speed being adjusted by a different size of motor pully.

Sorry I cant be of further help.

Paul.

Posted on: 15 November 2003 by jacques (JD12)

quote:
Originally posted by David Young:
I would appreciate if anyone could tell me how to identify the serial no. of an old LP12 and whether the motor for 120V and 240V version is the same as I understand that the motor used in LP12 is AC motor and the frequency (50 vs 60 Hz) will have the effect on speed.

Thanks

David,

The motor is the same, only the design of the power supply is different (mainly capacitors)
Hope it helps

Posted on: 15 November 2003 by trickytree

David.

Jacques is quite correct. While putting the corner bracing on the plinth I could clearly see that the Valhala board has conections for both 110 and 240 volts.

Paul.