A phono preamplifier is not a FM receiver !

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Guy 13

A phono preamplifier is not a FM receiver !
« on: 15 Apr 2014, 09:30 am »

Hi all.
On last Friday I got my re-tipped Rega Exact MM cartridge (Re-tipped by Soundsmith) and today I decided to install it on my Rega RB301 arm with my Rega P3 turntable.





I had to remove the arm from the table to have more finger room.
A third screw to the center of the cartridge is a brilliant invention from Rega, it makes the alignment of a cartridge a breeze or a child play.
However, they still have those microscopic nuts and bolts that are the size of a human hair, (Yes, I know, I exaggerate again or as usual) plus you almost need a microscope if you are old with a weak vision like me to see what you are doing.

I did the calibration of the weight with my No Name
Stylus Force Gauge (Made in Taiwan) for 70 USD.
Set at 1.75g as per Rega recommendation.





I check my set up with a vinyl from Adele
and I’ve got a terrible interference noise.
I can hear a FM radio station on both of my speakers
and it’s loud, very loud.
I would say it’s 40% of the loudness of the music.
I did not have that problem with my same set up on the ground floor of my previous house, now I am on the fourth floor.
I have a Rega P3 turntable which works on 230V.
A Rega Exact MM cartridge.
A Bellari VP-129 powered by a walwart 120V. in and 12VAC out.
A Decware SE84C+ SET amplifier on 120V.
All the above (Except the Rega P3) are connected on my 120V.
Majik Buss line filter/conditioner.
The Majik Buss is connected to an auto transformer on 230V, with stabilized 120V. output.
Everything is on a common ground going to the 230V. dedicated wall outlet.
The Rega P3 turntable does not have any ground except for the cartridge interconnects.
My problem is the following: I can hear from both of my speakers a radio station, probably FM and its loud enough that I can’t really hear the music from my vinyl.
I would say that 40% radio and 60% music and it proportional the the volume control position.
No hum, only the FM station on both speakers.
I’ve double check all my ground wires.
Any suggestions?

Guy 13


NIGHTFALL1970

Re: A phono preamplifier is not a FM receiver !
« Reply #1 on: 15 Apr 2014, 09:54 am »
Guy 13,
your wires look like they are in knots.  Could that be the problem?

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #2 on: 15 Apr 2014, 10:15 am »
Guy 13,
your wires look like they are in knots.  Could that be the problem?
Hi NIGHTFALL1970
They might look like that, but they are not.
Several times I've I've re-route them
and made sure they don't cross 120V wires.
Any other suggestions ?

Guy 13

Wayner

Re: A phono preamplifier is not a FM receiver !
« Reply #3 on: 15 Apr 2014, 11:45 am »
Nightfall is talking about the wires to your cartridge. You can see from your photo that they are all inter-woven and in a mess. While untangeling that mess may not eliminate your radio station, it may improve your channel separation.

I'd like to inquire what kind of RCA interconnects you are using from your phono preamp to your line preamp. I suspect that there is some poor shielding going on. Unshielded interconnects are a radio antenna, and would explain your reception of a local station.

Delacroix

Re: A phono preamplifier is not a FM receiver !
« Reply #4 on: 15 Apr 2014, 12:15 pm »
Hi Guy

I don't know that phono stage but I think it has a mute. Try that and see if the FM disappears. If so, then you've narrowed down the source. From there check the gain settings on the phono stage to see if that impacts 'reception'. If nothing else works, try moving the arm around like an antenna and you might at least pick up a channel you can enjoy (just kidding!).

Keep us posted

Patrick

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #5 on: 15 Apr 2014, 01:46 pm »
Nightfall is talking about the wires to your cartridge. You can see from your photo that they are all inter-woven and in a mess. While untangeling that mess may not eliminate your radio station, it may improve your channel separation.

I'd like to inquire what kind of RCA interconnects you are using from your phono preamp to your line preamp. I suspect that there is some poor shielding going on. Unshielded interconnects are a radio antenna, and would explain your reception of a local station.

Hi Wayner.
Yes, I know, the cartridge's wires look like a spaghetti junction.
I will fix that later, but I will fix it, promise.




The interconnects come out directly from the Rega arm shaft and they are Rega stock and they are shielded.
Then, they go to the Bellari VP-129 phono stage.





Then from the Bellari it goes directly to the input of the Decware SE84C+ SET amplifier via a pair of Interconnects from Signal Cable OFC shielded.
The red wire (Should be green) is the ground that goes directly to the wall’s ground.
That set up is exactly the same I had in my previous house and it worked fine, no interference what so ever.





Any ideas before I put the axe in that stuff ?

Guy 13

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #6 on: 15 Apr 2014, 01:56 pm »
Hi Guy

I don't know that phono stage but I think it has a mute. Try that and see if the FM disappears. If so, then you've narrowed down the source. From there check the gain settings on the phono stage to see if that impacts 'reception'. If nothing else works, try moving the arm around like an antenna and you might at least pick up a channel you can enjoy (just kidding!).

Keep us posted

Patrick

Hi Patrick.
Yes, if I push the mute button, it goes quiet, dead, nothing, zilt.
If I turn down the gain knob, the FM radio goes down,
but also the music from the turntable.
Even if I move the arm around to get another FM station,
I am always stuck with the same boring FM station.
I suspect that there is something going on in/within the arm,
because the arm is not grounded in any way.
I even tried a ground jumper wire with an alligator clip,
but nothing, zilt, rien, khong, nenine...
Draken double drak, come up with something, otherwise I will do something I might regret.
(The axe is not far or withing an arm length...)

Guy 13





Nick77

Re: A phono preamplifier is not a FM receiver !
« Reply #7 on: 15 Apr 2014, 02:10 pm »
Boy, correct me if im wrong but i always thought that ground lug was for the turntable not for the wall outlet.

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #8 on: 15 Apr 2014, 02:18 pm »
Boy, correct me if im wrong but i always thought that ground lug was for the turntable not for the wall outlet.
Hi Nick77
My Rega turntable has no ground lug what so ever.
All the ground wires from the phono, amplifier, CDPlayer, etc...
will all end up at the wall outlet ground.
Does that makes sense the way I put it ?

Guy 13

Davey

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Re: A phono preamplifier is not a FM receiver !
« Reply #9 on: 15 Apr 2014, 02:23 pm »
Boy, correct me if im wrong but i always thought that ground lug was for the turntable not for the wall outlet.

You're not wrong.  :)

Guy, I think you should change your grounding scheme and remove the red (earth) wire you have connected to your phono preamp and connect the ground wire from your RB301 arm interconnect cable to that lug.  If your RB301 cable doesn't have a ground lead then you should get a cable that does.

Your phono preamp should not have a direct earth ground connection to the wall outlet.

Dave.

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #10 on: 15 Apr 2014, 02:29 pm »
You're not wrong.  :)

Guy, I think you should change your grounding scheme and remove the red (earth) wire you have connected to your phono preamp and connect the ground wire from your RB301 arm interconnect cable to that lug.  If your RB301 cable doesn't have a ground lead then you should get a cable that does.

Your phono preamp should not have a direct earth ground connection to the wall outlet.

Dave.

Hi Dave.
I will check that tomorrow,
because my wife just called me to join her in the bed
and I don't think it's for sleeping,
it's too early for that.

Guy 13

What you said make sense...

jtwrace

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Re: A phono preamplifier is not a FM receiver !
« Reply #11 on: 15 Apr 2014, 02:31 pm »
 :o


TMI

rollo

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Re: A phono preamplifier is not a FM receiver !
« Reply #12 on: 15 Apr 2014, 02:48 pm »
You're not wrong.  :)

Guy, I think you should change your grounding scheme and remove the red (earth) wire you have connected to your phono preamp and connect the ground wire from your RB301 arm interconnect cable to that lug.  If your RB301 cable doesn't have a ground lead then you should get a cable that does.

Your phono preamp should not have a direct earth ground connection to the wall outlet.

Dave.
It appears the tonearm is not grounded.  You could also try some aluminum foil rapped around the phono ICs. An old recording studio trick when FM signals were heard.


charles

Hank

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Re: A phono preamplifier is not a FM receiver !
« Reply #13 on: 15 Apr 2014, 02:49 pm »
 :o


TMI

+10

Guy13 is quite a character

Wayner

Re: A phono preamplifier is not a FM receiver !
« Reply #14 on: 15 Apr 2014, 03:21 pm »
Agree with a couple of posters. Ground wire should not go to house-hold system ground, and tonearm/turntable ground should go to the Bellari ground. Problem should go away.

The shield of the RCA interconnect will carry the Ballarie ground to your line preamp.

neobop

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Re: A phono preamplifier is not a FM receiver !
« Reply #15 on: 15 Apr 2014, 04:00 pm »
Hi Guy,
Unshielded wires at the headshell can pick up noise or RF.  Braiding those wires tends to reject noise, but you don't want to stress the connections.  Probably nothing to worry about, but I can't tell how tight it is.

So, you hooked up an antenna ground wire from your phono stage ground to the AC outlet and now you're listening to the radio and a record at the same time?  I suspect the reason it wasn't a problem in the last house is due to chance.  You know what they say, "Location, Location, Location".

Chances are, if you get rid of that wire you'll be fine.  There is no easy way to connect a ground wire to your Rega arm AFAIK.  The ground is in one of the channel grounds and it, in turn should be connect to the ground inside your phono preamp.
neo

woodsyi

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Re: A phono preamplifier is not a FM receiver !
« Reply #16 on: 15 Apr 2014, 06:01 pm »
:o


TMI

+10

Guy13 is quite a character

TMI but implicitly.  I will let it slide.  I mean she may have called him because the TV remote was stuck.  :dunno:

Guy, we don't need to know anymore about what goes on in your bedroom.   :shh:

yeldarb

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Re: A phono preamplifier is not a FM receiver !
« Reply #17 on: 15 Apr 2014, 08:56 pm »
I hate to say this but I used to own a Soundcraftsman pre-amp that picked up radio signals through the phono section.  Tried several turntables and, always, in the background was the local Christian broadcasting station.  Faint but audible.  I moved 13 miles, and no difference.  Apparently Soundcraftsman didn't use blocking caps in the circuit.  Finally sold it to a guy at work.  He has three turntables and it still gets radio.  I has to come through the jacks, as there are no vents in the cabinet.  He also has a Bellari that is dead quiet.

Hope it is your ground arrangement causing the problem.

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #18 on: 16 Apr 2014, 09:24 am »
You're not wrong.  :)

Guy, I think you should change your grounding scheme and remove the red (earth) wire you have connected to your phono preamp and connect the ground wire from your RB301 arm interconnect cable to that lug.  If your RB301 cable doesn't have a ground lead then you should get a cable that does.

Your phono preamp should not have a direct earth ground connection to the wall outlet.

Dave.

Hi Dave.
I am back and I have removed the red/ground wire.
An Interconnect cable with a ground,
then the ground wire of the interconnect should be connected at both ends.
Correct ?
On the phono no problem, I can use the lug,
however, on the arm, where can I put it ? ? ? :scratch:
In addition, that means I have to go inside the arm or in the pivot and do some delicate soldering, which I am not to brave to do.

Guy 13

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #19 on: 16 Apr 2014, 09:27 am »
:o


TMI

Hi jtwrace.
You american guys with all your abbreviations.
What's the meaning of TMI ? ? ?  :scratch:

Guy 13
I hope it's a compliment.