Phono Input on a 52

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My Rega P9 was sitting directly on top of my 52 which sits on the top shelf of my two tier stand. My CDS1 sits on the bottom shelf. My P9 supply sits on top of my CDSPS on the top shelf of my 4 tier stand then my Supercap, and 135's below. I started my taking my CDS right out leaving the P9 on the top self and the 52 on the bottom of the two tier.

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This should be an improvement over stacking the Planar 9 atop the 52's lid...in order to make a better comparison, you need an equipment stand with an appropriate number of shelves (or a dedicated stand for the 'table)--especially if vinyl is your primary source!!

Dave Dever, NANA

The equipment stand had no effect or it was so minimal I couldn't detect it. This is what I found interesting.

The P9 on the top shelf and the 52 on the bottom shelf of the two tier produced similar results as the P9 on top of the 52 on the top shelf and the CDS1 on the bottom with the CDS1 disconnected and plugged into a different socket. The connecting of the CDS1 to the 52 and plugging it into the wiremold powerbar (for my whole system) brought down the vinyl reproduction. There seemed to be very little effect having the P9 power supply directly on the top of my 4 tier or on top of my CDPS on the top shelf.

Am I explaining myself well??

John

both the CDS & the P9 are earthing the 52.

More than one earth will dramatically reduce performance of the system.

You need to find a way to break the earth of one of your sources without disconnecting the mains earth. Note, this is disconnecting the earth from before the point where is connects to the electronics or arm/cartridge. You must maintain the 0V line unbroken from the electronics/cart through to the preamp.

cheers, Martin

Thanks for the reply or attempted reply. I don't understand exactly what you are saying. Can you please try again. When I received the P9 I plugged it in my wiremold and discovered it pulled down my whole system. I then plugged it into a different socket and everything worked great. This latest discovery makes a huge difference. I need to find a solution or I will be stuck with having to power down to connect my CD player when I want to listen to it. The vinyl is absolutely amazing now.

Thanks
John

Alternatively, I believe that using a Prefix or Stagelne will also achieve this, and allow your two source components to co-exist without having to modify your deck.

Can you borrow a Stagelne to try this out?

cheers, Martin

I had the same problem as you with the ground on my P9 when I had it mated with a Grado "Reference" MM cartridge and an internal MM card. I still had some slight residual hum after disconnecting the CD player, but the Grados are apparently notorious for this problem.

I just unplugged the Din plug in the back of the CDS without powering down the player. Never had any problems doing it this way.

Now I have the P9 with a Lyra Lydian/Prefix "k" and powered by the 52. No hum. Not as much of a step up from the Grado Reference as I had hoped, but I did get rid of the bloaty bass of the Grado. I think it was the Prefix that got rid of the hum though.

Arthur Bye

This was posted before. I can't remember who provided it but it's a treat.

For all you never wanted to know about ground loops

"http://www.epanorama.net/documents/groundloop/index.html"

Arthur Bye

Thanks for the info. I will see what my options are regarding disconnecting the ground.

Arthur:

I currently have the CDS disconnected at the preamp and the CDS is powered up. Is there any problem plugging and unplugging the DINs when the system is running or should I be powering down first?

I am also interested in your thoughts on the Prefix. There have been many recents posts about the benefits but I suspect some people are moving away from a similar grounding problem. I can live with plugging and unplugging my CDS if I'm almost there but does the prefix provide significant gains?

BTW, my record collection has been climbing drastically. I am probably upto 1200 now. I bought an LP collection from someone local. Alot of the music I have never heard, like the Dixie Dreggs, but I am enjoying it very much.

Thanks
John

Seems like I might have a bit of catching up to do. 1,200 records in what? 6 months? The wife must think you're nuts. I've been buying about 20 records a month for the past two years and still only have about 800 records. My wife thinks I have WAY too many records.

I've been unplugging the Din connector on the back of my CDS1 for quite some time, at least a year, without powering down. Haven't had a problem yet. Probably not recommended by Naim though. I've also been swapping it, the CDS, over to a second Din connector that goes to a tube preamp/amp combo powered up without any negative results. YMMV. I suppose it's a pretty expensive mistake to make if you get it wrong. I've done the same thing with a Hicap powering a Prefix as well, swapping it over from one pre to another pre, hot. Nothing has blown yet.

The Prefix is definitely a step up from the internal cards. I consider it much more worthwhile than powering the Prefix with a HiCap. Using the 52Super to power the Prefix, from what I can tell, changes the sound a bit from the HiCap, but not making it any worse than using a HiCap. From what I understand the 52/Supercap has dedicated rails for the 52/Super connection. One of these days I'll get around to trying a solo Supercap on the Prefix and let you know how I make out.

Check out this months edition of Listener. Art Dudley goes completely off his nut about Mono records. He has a glowing review of the Lyra Helikon Mono cartridge, he also rants in the "Intro" about the benefits of mono records and then goes on giving a list of his "top 30" mono records. Definitely posing for FEP's. This is a must read for anyone with over 200 FEP's. Art's real big on anything that can be done on the cheap. He figures that most mono records can be had for 50 cents. Of course, this doesn't explain the $2,100 cartridge. I don't think you'd ever see and article like this in TAS/Stereophile. Lots of Flat Earth stuff.

I never got my Helikon SL to work with the P9, so I gave up and put a Lyra Lydian on my P9 and used the Helikon SL for my LP-12. The Lydian's OK on the P9, but just. I'll probably switch it for a Dyna XX2 when I get a chance. I heard an XX2 the other day on another P9 and I was impressed. The Helikon SL/Prefix/LP-12/Aro/Armageddon combo is incredible.

You also should do a serach for "M.A.G.I.C." This is audiophile grade device(made by Mondial I think) for correcting ground loop problems. I've never used one myself, but I've heard good reports about it. I've seen ads for them in Stereophile. Martin's suggestion of removing the ground from the P9 would require some minor surgery to it. More importantly you are possibly creating a shock hazard by eliminating the ground. It's a pretty remote possiblity, but you should be aware.

Arthur Bye

from what I understand the Prefix & Stageline isolate the earth from the preamp, so no surgery would be reqd if either of these were used.

Of course, this implies that running your vinyl with the CDS removed is operating your amps without an earth reference (electrically safe, but performance compromised).

Have you tried an A-B with/without the CDS recently?

cheers, Martin