Experiencing interference from my phono set up and would very much need your thoughts.

My setup:

Beolab 18, 19 front and sub - wireless via Transmitter 1

Center speaker - Definitive Technology - hardwired

Rear speakers - Beolab 15 - in ceiling with B&O Amp. - wireless via Transmitter 1

Transmitter 1

Marantz SR 6013 - pre amp outs to Transmitter 1

EAR Phonobox phono pre amp - into Marantz 

Clearaudio Concept Turntable - into phono pre-amp - 

TT grounded to phono stage. phono stage grounded to amp.

Transmitter 1, phono and Marantz are located inside a cabinet.

TT on top of cabinet.

 

The issue:

When playing records I select setting on the Marantz which activate only true stereo - front speakers only.

When stopping TT to change records there is a rhythmic buzzing coming out of the front speakers.

I have experimented with various placements and how I have them now creates the least "feedback"

I was very convinced that the Transmitter 1's proximity to the phono stage was the issue.

So, I took the phono stage out of the cabinet and placed it on top of the cabinet which is located between the 2 wall mounted Beolab 18's. The opposite of what I expected happened and the interference was 20 times as much. 

There is no doubt that the phono stage is involved because the moment I turn it off the interference stops. 

So, now my thinking is that somehow the speakers are directly picking up the interference. 

 

Any thoughts of what I could try to solve this problem?

 

 

 

Tifoso48:

There is no doubt that the phono stage is involved because the moment I turn it off the interference stops.  So, now my thinking is that somehow the speakers are directly picking up the interference. 

Wouldn't the next step be to determine if the phono stage was merely the cause or actually the source -- not the same thing?  Here's how you would test: Disconnect the output cables of the EAR Phonobox, and then turn it off and on to see if the noise comes and goes?  That will tell you if the speakers are directly picking up the interference (I doubt it), or if the interference is present on its own phono cables (more likely).  

Personally, I would bet on the separate ground wire between the turntable and the Phonobox being disconnected -- all the time -- from a tiny break in it somewhere, and you only hear the (ever-present) noise when no music is playing.  Even if that isn't the cause, and the Phonobox really is broken, it's still more likely to produce noise on its attached cables, than to be so noisy that other equipment is picking it up, through its full metal shell.  Good luck, and don't forget to post when you finally figure it out!

Hi Trackbeo,

 

Thank you for your sage recommendations.

 

So, I have disconnected the "out" from the phono to the amp and the interference on the speakers stoppedl

Then I disconnected the "in" from the TT and the interference also stopped.

What do you think I should conclude?

If I follow your thinking one has to think that somehow the TT is at the root.

If you are right and you suspect the ground wire - how would one go about proving that and remedy the situation?

Again, thank you for your help on the detective work.

 

 

[duplicate]

Check the ground wire later.  First, use the "inverse square law" of radiation strength: Try placing the WiSA transmitters at the end of their fully-extended input cables, as far away from all the other equipment as possible.  If that doesn't help, pull your turntable out of "the stack" of equipment as far away as you can, especially from things that are *supposed* to create radio waves.  The best way to do that is to extend the Phonobox input and output cables to their full lengths, a nice straight line, and place the turntable on a spare table or whatever, at that farthest distance possible.  If that doesn't help, you might also rotate it or the cables by 90 degrees to any known source of transmissions, even including power cords.  If even that doesn't fix it, or at least lessen it a lot, *then* you have to start digging in more carefully to the grounding of the turntable and the input cables shield (==ground) and ultimately the wire path in the tonearm and the headshell connections.  Let's hope it doesn't come to that.

Hi there,

 

I understand and agree with what you are proposing by moving key pieces as far apart as possible. 

The dilemma is that for many of the pieces of equipment the provided cable lengths do not allow for much room to maneuver.

For example:

the cables from the amp to the transmitter 1 are  quite specialized RCA/RJ45 cables directly from Bang and Olufsen and are about 2 foot long

the cable from the TT to the phono is provided by Clearaudio and is attached to the TT and is also about 2 foot long.

I think I am a bit between a rock and a hard place.

Where I have the pieces positioned in the moment is the lowest level of interference I have been able to do given the limitations of cable length.

 

Understood: I chose moving the turntable mostly because it was trivial work.  At this juncture I would *still* probably buy a 5- or 6-meter set of RCA-plug stereo cables to run from the output of the phono amp to the Marantz -- then plug both the phono preamp and the turntable anywhere else, both at far remove from the stack.  Line level audio should be just fine on that cable run; you don't need any special cables.  But it is not guaranteed to be the cause, just likely, and besides "everybody should have" a long pair of RCA cables to string up random pieces of equipment you bring into the house temporarily, anyway!

Alternatively, do you actually have a Moving-Coil phono cartridge?  If it's a Moving-Magnet cartridge, you could plug the turntable straight into the Marantz preamp's phono input, and see if that helps.  I bet not, because the input is the same right up to the amplifier, and that Phonobox looks like a well-built piece of kit.  But hey, you never know... [Edit: Yeah, probably MC because of course that's the lowest-level phono signal possible, most likely to be interfered.  Bleagh.]

Another thing I would have suggested is hooking up a pair of headphones and powering off all the WiSA transmitters to the speakers and see if the problem goes away.  If so, it tells you that the lowest-level signals need to be kept away from those transmitters specifically -- see step #1 above!  But I don't know if the Marantz even has a headphone jack behind that front panel?  (Also I have heard that powering down the WiSA is fraught with networking issues so you might prefer to just leave them alone if they are working now.)

 

OR... ... ... You could instead start in on shielding the Clearaudio cables, checking the continuity of the ground wire between the phono preamp and the turntable, re-seating the cartridge pin connections to the headshell wires, etc, etc, etc.  At that point you're headed to a turntable forum website and not here, anyway...

 

Let me throw a just discovered new crinkle into this:

On my Marantz I have a number of choices:

Stereo - both speakers plus sub and the ability to adjust/filter/manipulate quite a few of the parameters

Direct/Pure Direct - speakers only and a plain and truthful passthrough of sound.

On a whim I tested Stereo and Direct/Pure Direct.

drumroll .... no feedback when selecting direct/pure direct.

 

How can this be?

Let me throw a just discovered new crinkle into this:

On my Marantz I have a number of choices:

Stereo - both speakers plus sub and the ability to adjust/filter/manipulate quite a few of the parameters

Direct/Pure Direct - speakers only and a plain and truthful passthrough of sound.

On a whim I tested Stereo and Direct/Pure Direct.

drumroll .... no feedback when selecting direct/pure direct.

 

How can this be?

Two WAGs: 1) Does no signal on the input of *just one* of the WiSA transmitters (i.e, sub) cause it to power down? (Maybe just one is the culprit, either too nearby or mis-manufactured?)  2) Doesn't "Pure Direct" on the Denon/Marantz line turn off the display as well as power down the Audyssey DSP, as well as the HDMI switcher & all video outputs?  (I have only used a 4310CI video/theater receiver, not sure about your model?  Maybe the display, or even just its backlight, is spewing RFI?  On a 4310ci, I would try switching video sources to an empty input socket if I needed the Audyssey to do bass room correction, thus didn't want to use PureDirect.  But why wouldn't you use it in PureDirect mode -- turntable purists bla bla bla.)

Sounds like, despite it still being a mystery, you have a pretty good handle on testing and an acceptable workaround if not a solution.  Sure, the Marantz really shouldn't affect the turntable.  But other than sliding a large oven baking sheet between the receiver and the turntable, I'm out of random debugging ideas.  Except to say, good, at least you proved that you don't need to dig into your turntable wiring now!