markus46

Impact of continuous tonearm cable on sondek suspension

Recommended Posts

Hello all.  My 1st post here ;-)
I am giving serious consideration to purchasing an Audio Origami PU7 tonearm for my Kore chassis Sondek.

I have the option of a hard-wired continuous run of phono cable OR a right-angled DIN connector with a separate phono cable.
Which option is best for the Sondek?

My understanding is that the phono cable (the way it exits the tonearm and connects to the inside of the plinth via the P-Clip) is considered part of the suspension system.  I am concerned that if a continuous run of cable is bent to connect to the P-Clip then it will be pulling on the sub-chassis and may make it difficult if not impossible to get the ideal "bounce".

On the other hand, the suspension is tune-able via adjustment of springs so perhaps the pulling of the tonearm cable can be compensated for by adjustment and I have nothing to worry about.  I would prefer to go with a continuous run of phono cable if possible.  One less physical connection.

Which way do you think I should go?  What have other PU7 users done?
Thanks in advance!

Edited by markus46

Share this post


Link to post
Share on other sites

The P-Clip design was implemented to minimize the effect of the arm cable on the suspension.  It works pretty well (with Linn arms).  The only PU7s I've seen had a vertical cable entry into the arm base which might produce more problems than a right angle entry cable. 

The problem with a completely separate RCA cable is just one more connection in the signal path, which can't be good.

Share this post


Link to post
Share on other sites

If you trust his version of the tonearm them I'm sure his advice about fitting it should come from previous experience.

B|

Share this post


Link to post
Share on other sites

I’d want to be able to setup the suspension with the arm cable unplugged.  I would also want to unplug and pull the arm off the deck when changing out cartridges.

  • Upvote 1

Share this post


Link to post
Share on other sites

I'd talk to Jonny Seven and see what he says.

Share this post


Link to post
Share on other sites

Thanks all for your replies.

I am in contact with John via his Australian distributor.  Despite having asked specifically about the suspension issue, all I have got back is that the arm is 100% compatible with any era of Sondek with any available sub-chassis.  I am sure this is quite true from a geometry and weight point of view.  Just not sure how the continuous run of phono cable impacts on the suspension :(
I'm being told it's my choice to go with either a continuous run of cable or a right-angled DIN connector and a separate phono cable.

I note the Ekos SE uses the DIN connector and a separate phono cable solution https://www.linn.co.uk/speakers-and-amps/accessories/tonearm-cables#t-kable-phono, so one part of me says if it's good enough for the Ekos SE it's good enough for the PU7.
Though I would prefer a continuous run if possible.

I have asked the Oz distributor to find out how the cable exits the bottom of the PU7.  Straight down or at a right angle?  If the latter then there is no issue.

Ta

Share this post


Link to post
Share on other sites

I don't think the continuous run of cable will impact the suspension if it is dressed properly. What does have an impact - as John76 pointed out - is that the connector allows you to release the cable to see if the cable is impacting the suspension. With a connector you would set up the suspension with arm in place but no cable and when optimally adjusted then connect the cable and verify the suspension still behaves the same. Have a look to the Peter Swain's set-up guide (linked below) as he covers both cases.

https://www.cymbiosis.com/download/setting-up-your-lp12-volume-iii/

I've no idea of the sonic difference of a hardwired cable vs a connector.

Share this post


Link to post
Share on other sites

Thanks for the link Duke.  My original thought to John76's suggestion was what's the point of getting the suspension adjusted just right without the cable plugged in?  The weight of the cable & connector once connected to the tonearm must pull to a certain degree (see pic attached) - and then you've got to do it all over again.
But that is just my intuition with zero basis in the reality of actually doing any of this stuff.

I've looked at the link and it's really good.  Thanks again.  So obviously the best tonearms (as far as the impact on suspension goes) are those that have a connector that exits at a right angle to the base of the arm in the direction of the P-Clip.  And in this case, the weight of the cable & connector will tend to pull straight down so the effect can be easily catered for.  So I can see the benefit of getting the suspension set up without the phono cable connected when dealing with a tonearm like this.

I can get a right-angle DIN connector for the PU7 - but what if it points diagonally away from the P-Clip?  That would have a massive impact on the suspension once the cable was plugged in because there would be a twisting motion applied.

I've reached out to J7 directly...

Cable.png

Edited by markus46
typo

Share this post


Link to post
Share on other sites

If you can make a single run of cable from the headshell all the way to the phono preamp work, then this is going to be your best option, SQ wise. 

Share this post


Link to post
Share on other sites

I reckon with the product support you've had being so poor I'd have no hesitation moving to a much lesser fussy arm and move away from resurrecting the past it's an old arm.:whistle:

Servicability and support is vital for long term peace of mind and enjoyment.:minikev:

  • Upvote 2

Share this post


Link to post
Share on other sites
15 hours ago, markus46 said:

I can get a right-angle DIN connector for the PU7 - but what if it points diagonally away from the P-Clip?  

I've reached out to J7 directly...

Yes, just ask Audio Origami if the cable exist parallel to the rear of the plinth - I would imagine it does.  

  • Upvote 1

Share this post


Link to post
Share on other sites

All sorted.  Johnnie7 got back to me straight away.  Excellent service which gives me confidence in purchasing.
This is the solution using a continuous run of cable. "The fixed cable can be bent up the arm pillar and secured with a cable tie.  Then the cable flows nicely to the P clip."

I acknowledge that only a separate cable DIN connector will allow the suspension to be adjusted prior to cable connection so this solution will make suspension setup more tricky.

Thanks to all for your responses.

UNADJUSTEDNONRAW_thumb_724.jpg

Edited by markus46

Share this post


Link to post
Share on other sites

Just note that getting that cable positioning correct will be very important.  As it is relatively thick, being sure the suspension is working right with it in place will be more difficult.  Also if the arm cable at the top of the bend hits the sub chassis and then pulls away from it when the suspension moves (as it looks like it might) that will harm performance.  Finally I don't see how that can possibly be a single run of cable all the way through.  Obviously that thick a cable can't go through the bearing and arm tube.  It looks more to me like what Rega does with a thin internal arm cable soldering to a thick one at the exit of the arm pillar.  That might reduce the number of connections but certainly not eliminate them.

Share this post


Link to post
Share on other sites

That was a common instruction from the LP12's early days  See for example:

https://www.russandrews.com/images/pdf/LP12booklet2a.pdf

I'm surprised that Audio Origami don't have an angled plug (or a much thinner cable).  

Share this post


Link to post
Share on other sites

>> I'm surprised that Audio Origami don't have an angled plug (or a much thinner cable) ;

They have a DIN connector and external cable as an option. 

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.