Lavry - grounding issues in a Naim CD system ?
Posted by: james n on 15 October 2008
I've just changed my preamp (to a 282) and whilst looking at power supplies and bigger hydras, started examining the grounding in my system.
In a Naim system the ground link between mains and signal earth is in the CD player (or Turntable) - either via a wired link or via a resistor (value of which seems to vary between CD players but in the 10's of Ohms range).
Speaking with Lavry, the DA10 does the same but with a 25 Ohm resistor. In a typical Naim system with a Naim CD player, adding a Lavry could add another ground path and degrade the sound - Connecting two Naim CD players to one pre-amp (ie during a demo) seems to be a definite no-no on sound quality grounds so adding the Lavry to a Naim CD system would do the same.
For those using the Lavry in a Naim system with a Naim CD player it may be worth pulling the CD interconnect out from the preamp and seeing if it makes a difference ?
Thoughts ?
James
In a Naim system the ground link between mains and signal earth is in the CD player (or Turntable) - either via a wired link or via a resistor (value of which seems to vary between CD players but in the 10's of Ohms range).
Speaking with Lavry, the DA10 does the same but with a 25 Ohm resistor. In a typical Naim system with a Naim CD player, adding a Lavry could add another ground path and degrade the sound - Connecting two Naim CD players to one pre-amp (ie during a demo) seems to be a definite no-no on sound quality grounds so adding the Lavry to a Naim CD system would do the same.
For those using the Lavry in a Naim system with a Naim CD player it may be worth pulling the CD interconnect out from the preamp and seeing if it makes a difference ?
Thoughts ?
James
Posted on: 15 October 2008 by DeltaSigma
Some time ago, I briefly compared the sound of the Lavry with and without my CDS3 connected to the preamp to see whether the loss of the signal-mains earth link in the CDP would affect sound quality but found no significant difference. My TT (which I believe does not have that connection) did not seem to be affected either.
Interesting to know that the Lavry also has that connection, however.
Michael
Interesting to know that the Lavry also has that connection, however.
Michael
Posted on: 15 October 2008 by pcstockton
James,
I dont have a Naim CDP, nor a turntable, at this time.
Do you mean that with a Lavry DAC, my kit would finally be earthed correctly?
Thanks in advance.
-Patrick
I dont have a Naim CDP, nor a turntable, at this time.
Do you mean that with a Lavry DAC, my kit would finally be earthed correctly?
Thanks in advance.
-Patrick
Posted on: 16 October 2008 by james n
Looks like it Patrick.
rgds
James
rgds
James
Posted on: 16 October 2008 by djftw
I seem to remember some people with Beresford DAC only systems complaining of issues because of the lack of a signal earth reference. Was that you Patrick?
Two earth references would create a loop, which has detrimental effects in practically any system that doesn't use balanced connections, this is part of the reason why balanced connections are such a God send in pro-audio environments where ground loop hum used to be a huge annoyance.
If you can't hear it, you can't hear it, but I am absolutely convinced it must make a difference, time to visit your GP for an ear syringing!
Two earth references would create a loop, which has detrimental effects in practically any system that doesn't use balanced connections, this is part of the reason why balanced connections are such a God send in pro-audio environments where ground loop hum used to be a huge annoyance.
If you can't hear it, you can't hear it, but I am absolutely convinced it must make a difference, time to visit your GP for an ear syringing!
Posted on: 16 October 2008 by paremus
DJTW / Anyone
So if my turntable is earthed (LP12) to my 52 and my CDS II is also an earth, would this result in a earth loop? Should I remove the turntable earth from the 52?
I assume NAT01 / 02 tuners are not earthing points.
Thanks.
Richard
So if my turntable is earthed (LP12) to my 52 and my CDS II is also an earth, would this result in a earth loop? Should I remove the turntable earth from the 52?
I assume NAT01 / 02 tuners are not earthing points.
Thanks.
Richard
Posted on: 16 October 2008 by djftw
Erm no, that is correct the Turntable should be earthing through the pre. I don't honestly know if the LP12 references the signal to the mains earth in standard form, but I suspect not, I have never seen this arrangement personally. I think we need a turntable expert here and we're in the wrong part of the forum!
Posted on: 16 October 2008 by james n
The Tuners are not earthing points - the turntable may well be. You could lift the earth wire from the back of the 52 and try it. Worth a search on the forum - Andrew Weekes provided some great info on this problem.
Cheers
James
Cheers
James
Posted on: 16 October 2008 by DeltaSigma
Based on a response I received in the Hi-Fi Corner forum about a month ago, the LP12 can be set up to link the signal and mains earths when used with an ARO and Armageddon. However, I am not sure whether this is possible with other TT configurations.
It would be interesting to know whether this configuration would not cause a ground loop if used in a system that also included a Naim CD player (which also forms the same connection).
Michael
It would be interesting to know whether this configuration would not cause a ground loop if used in a system that also included a Naim CD player (which also forms the same connection).
Michael
Posted on: 16 October 2008 by pcstockton
why is this earthing issue so confusing?
And why is there NEVER any response from the experts on this subject.
I have asked over and over, how to correctly "earth" my kit, and what it exactly means to do so.
It seems it is a taboo question.
You need either a tt (which one, what kind????) or a NAIM CDP to earth a Naim pre/power kit?
But having both isn't a problem because the TT doesn;t really do anything?
Are LP12 ONLY kits not earthed?
It seems some serious explanation is in order for us to be able to correctly use our kits.
What am i missing??? a degree in physics? I have enough pieces of paper from institutions of learning......
Ground loops, two grounds, no ground, floating ground, earth connections, star earthing, linking mains to signal....
what the hell does this all mean?
Can someone tell me how to use my kit correctly?
And why is there NEVER any response from the experts on this subject.
I have asked over and over, how to correctly "earth" my kit, and what it exactly means to do so.
It seems it is a taboo question.
You need either a tt (which one, what kind????) or a NAIM CDP to earth a Naim pre/power kit?
But having both isn't a problem because the TT doesn;t really do anything?
Are LP12 ONLY kits not earthed?
It seems some serious explanation is in order for us to be able to correctly use our kits.
What am i missing??? a degree in physics? I have enough pieces of paper from institutions of learning......
Ground loops, two grounds, no ground, floating ground, earth connections, star earthing, linking mains to signal....
what the hell does this all mean?
Can someone tell me how to use my kit correctly?
Posted on: 16 October 2008 by pcstockton
yes djtfw, it was me.
No one sas EVER answered my questions, blamed any ground issues on the Beresford and told me I needed a Naim CDP. When asked if ANY other products would earth or ground (whatever) me correctly, my question was either dodged or ignored.
Is there a resource anyone knows of to educate myself on such issues?
Until Naim, I had never even heard of such problems outside of pro gear.
No one sas EVER answered my questions, blamed any ground issues on the Beresford and told me I needed a Naim CDP. When asked if ANY other products would earth or ground (whatever) me correctly, my question was either dodged or ignored.
Is there a resource anyone knows of to educate myself on such issues?
Until Naim, I had never even heard of such problems outside of pro gear.
Posted on: 17 October 2008 by james n
Patrick do a search on the forum on Grounding - some good info there. I agree there should be more info available but perhaps that would add more confusion and Naim presume that most kit is installed by their dealers.
James
James
Posted on: 17 October 2008 by paremus
Patrick
I have a Phd in Physics and the rules aren't obvious to me either.
I have a Phd in Physics and the rules aren't obvious to me either.
Posted on: 17 October 2008 by djftw
Hi Patrick,
I must admit that my understanding of this is little to do with my knowledge of physics and far more to do with my work experience with "pro gear" where much longer cable lengths, higher gain and noisier electronics tend to mean that rather than a ground loops or earthing issues merely compromising performance in a way that might be difficult to pin down tend to cause a loud and very irritating hum!
In your position my inclination would be to take a cable from the ground pin on a rewireable plug to your 102s phono ground binding post, and see what the effect is. I can't tell you definitively that that will work, and it might even sound worse, but it is an easy thing to try and a good place to start. Drop me an e-mail and let me know how you get on, I don't venture into this part of the forum all that often. Follow my user name from here with [at] talk21 [dot] com.
Regards,
Dom
I must admit that my understanding of this is little to do with my knowledge of physics and far more to do with my work experience with "pro gear" where much longer cable lengths, higher gain and noisier electronics tend to mean that rather than a ground loops or earthing issues merely compromising performance in a way that might be difficult to pin down tend to cause a loud and very irritating hum!
In your position my inclination would be to take a cable from the ground pin on a rewireable plug to your 102s phono ground binding post, and see what the effect is. I can't tell you definitively that that will work, and it might even sound worse, but it is an easy thing to try and a good place to start. Drop me an e-mail and let me know how you get on, I don't venture into this part of the forum all that often. Follow my user name from here with [at] talk21 [dot] com.
Regards,
Dom
Posted on: 21 October 2008 by pcstockton
Dom,
I will take you up on that conversation via email. Best to keep it off this forum.
Thanks for the offer of help.
Real quick question though before I try anything...
Do I need to replace the phono boards in my 102 to test your method? Does my phono ground "do anything" now that there are no boards?
James,
So a dealer can answer these questions? I will ask mine, although I dont expect more expertise from them than yourselves... They dont even like or carry the Fraim!!!
Also, I have looked and looked with the Find function. I have spent hours actually.
All i know is that if I have a Naim pre, power and CDP, all is well. otherwise I am completely in the dark.
-thanks....P
I will take you up on that conversation via email. Best to keep it off this forum.
Thanks for the offer of help.
Real quick question though before I try anything...
Do I need to replace the phono boards in my 102 to test your method? Does my phono ground "do anything" now that there are no boards?
James,
So a dealer can answer these questions? I will ask mine, although I dont expect more expertise from them than yourselves... They dont even like or carry the Fraim!!!
Also, I have looked and looked with the Find function. I have spent hours actually.
All i know is that if I have a Naim pre, power and CDP, all is well. otherwise I am completely in the dark.
-thanks....P
Posted on: 22 October 2008 by DaveBk
As far as I can see you need to consider 2 things -
1 - the impedence of the path to real ground should be as low as possible.
2 - avoid creating loops or in other words multiple paths to real ground.
The rationale for this is whenever a current flows through a non zero impedence it will create a potential difference (voltage) between the points either side - ohm's law. So, given that all cables have some impedence, any loop currents will create spurious voltages at points which are supposed to be at ground potential. These may be tiny but it they are at the input stage they get amplified along with everything else and distort the result.
I think most hi-fi manufactures 'get away with it' as this effect is generally quite small in domestic circumstances, but in the case of Naim kit the quest for perfection overrides.
1 - the impedence of the path to real ground should be as low as possible.
2 - avoid creating loops or in other words multiple paths to real ground.
The rationale for this is whenever a current flows through a non zero impedence it will create a potential difference (voltage) between the points either side - ohm's law. So, given that all cables have some impedence, any loop currents will create spurious voltages at points which are supposed to be at ground potential. These may be tiny but it they are at the input stage they get amplified along with everything else and distort the result.
I think most hi-fi manufactures 'get away with it' as this effect is generally quite small in domestic circumstances, but in the case of Naim kit the quest for perfection overrides.