Rega P2 .... Buzz that changes with volume

[brubacca]

I am looking for some help. I have a buzz in my P2 that I have been trying to work on for months. I have looked at many articles, videos and the like. I have tried 3 different integrated amps, two different outboard phone pre amps and even spoke with Rega. I have had two different P2 , plus a third tonearm/cartridge in the system (rega tested this third tonearm before they sent it to me and it was fine in Texas). I have tried cheater plugs and running an extra ground wire from the phono pre to my outlet ground. I have looked at how cabling was done, used 4 different power configurations (cmx-2, just a power strip, belkin pf60, just an expander on the outlet itself). Its more than a humm or system noise level, its a buzz....

Just this morning I tried unplugging the turntable completely from power and audio connectio . So just phone into integrated and its fine, no buzz. Then I only plugged the turntable into the phone with the attached phono cables and BUZZ. This is without the turntable power even plugged in.

I do have dimmers in the house and led lights in the room. I was thinking about trying a PS Audio Hum Elimator (or called something like that). Also been considering a Torus Tot Isolation transformer ( don't really have the funds for this right now).

Any other suggestions?

[tomincle]

The buzz is there before the motor is even turned on the P2 ? Is there any kind of tube gear near the turntable ?

[brubacca]

No tubes in the system right now. I have a tube integrated that I use sometimes.

The buzz is there with the motor power supply not even plugged into the power strip. (Pf60 now).

[audiobill]

The dimmers and leds need to go....

[tomincle]

Wish this arm had a removable headshell because it would really narrow things quite a bit and eliminate the theory you might have a ground loop issue.

Did this start when you changed carts or recently added a component in your system ?

[KeithL]

The signal delivered by a phono cartridge is about 100x smaller than the line level signal delivered by other analog components.

That means that it must be boosted 100x as much before you can listen to it.

The situation is actually even worse - because the frequencies are boosted unequally - and the bass frequencies receive even more boost.

This means that even the tiny amount of hum picked up by the wires in the tonearm, and even by the cartridge itself, is going to be an issue.

(Note that some cartridges are more sensitive than others... and MM cartridges may be more sensitive than MC cartridges.)

(MM cartridges operate at higher signal levels than MC cartridges, but MC cartridges operate at much lower impedance, which often makes them less sensitive to hum anyway.)

Light dimmers and LED bulbs are notorious for radiating hum into the air - where it can be picked up by sensitive circuitry.

(They may radiate hum into the air, or back through the power lines, where it may make its way into other equipment, or be radiated into the air.)

Beyond that, the air around us is simply saturated with low level magnetic fields, many of them generated by current flowing in power lines.

(This includes the power lines outside - and the power lines running through your walls.)

Large AC power transformers are especially prone to radiating hum.....

Toroidal transformers have less leakage field than other styles... but still experience some leakage.

- Try a different outlet - or a different room altogether.

- Try eliminating all dimmers, LED lights, and fluorescent bulbs.

- Try putting line filters on the turntable and the amplifier it's connected to (to keep noise from getting in).

- Try putting line filters on the LED and fluorescent lights (to keep noise from getting OUT).

   (If the noise changes when you turn a particular light up and down then that points out its being responsible - at least in part.)

- Make sure your turntable and the wires running to it are NOT near other power cables.

   (This is MUCH more important with phono wires than with others.)
   (Make especially sure that your turntable and its wires are nowhere near the cables running through the walls between lights and dimmers.)

- Make sure the turntable itself is not even NEAR any large transformers (especially large ones - like the transformers in amplifiers).

   (And, obviously, don't sit that turntable on top of an amplifier or other piece of large electrical equipment, or near an LED lamp, or a lamp with a dimmer.)

- Try moving the turntable around... and try rotating it.

   (There may be magnetic fields due to cables running in your walls or through the floor... and it may be near them.)

   (Magnetic fields are directional, so rotating the turntable 90 degrees, or some odd amount, may make a lot of difference.)

[brubacca]

Remove Dimmers/LEDs - From the room, individual circuit or whole house?
(The only dimmer close is a Dimmed/LED Kitchen table light that shares a 3 way switch in the same room as the audio system)

Cabling- Honestly I have done this. I spoke with a dealer about thid and when I described the lengths that I took to keep the audio cable from the TT separate from everythinh else, he was surprised at the amount of separation.

Different Room- I could try this.

Distance from the wall, I can pull out the stereo cabinet and try this.

I have the whole stereo plugged into a Belkin PF60 which has significant filtration built in. All digital components go to the digital filters. All analog components go to the analog filters. This used to be on my HT, but as a last ditch effort I moved it to my stereo.

This started with adding the Rega P2. I had a VPI traveler before, and don't recall having this issue, but that table is broken and not usable to test.

What kind of line filters if beyond the PF60?

I'll try removing the LED lights and see if that has an effect. I also have a PC in this room, but I'm certain I tried the whole thing with it disconnected.

[brubacca]

Would an isolation transformer work if led/dimmer is the problem?

[KeithL]

Maybe/possibly - but not necessarily.

An LED dimmer could be introducing noise into the power lines, or into the power ground, or into the air, or all of the above.

The first step is to find out exactly what's causing the problem.

Try turning off or even unplugging all lights - one at a time.

Try using a different outlet.

Try relocating the equipment.

Try a different circuit (use an extension cord from another room).

See if the problem is better or worse at certain times of day.

Note that, because hum is so common with phono inputs, there may well be multiple causes.

So you are looking for anything that has any effect at all - for better or worse.

Unfortunately, you may also find that you have a very specific combination of problems, acting together.

For example, your new cartridge may be especially sensitive to noise radiated through the air, and a certain lamp may be prone to producing that particular sort of noise.

Once you find out the exact cause or causes then you can start trying to work to mitigate them.

(For example, if the problem is a particular noisy lamp, putting a ferrite bead on its line cord might help.)

Also remember that it's going to be a process of elimination...

(For example, adding a separate ground to the turntable may improve matters, but it's also possible that REMOVING a ground may help.)

There isn't any specific answer, or one that's always true, so you're going to need to play detective...

(Now you know one of the down-sides of phono gear. )

At this point it's also worth noting that ALL electronic systems have a noise floor...

And that noise floor is generally either hum or hiss...

And, because of the massive amount of gain involved, a phono input is ALWAYS going to be noisier than a line level input.

In a given price range, and at a given quality level, expect a phono input to be about 20 dB noisier than a regular line level input.

Although they vary considerably, it is simply unrealistic to expect a phono input to ever be dead quiet....

(Compare the background noise of the phono input to the noise level on a record between songs... if your system is quieter than a typical record, then don't go crazy trying to improve it further.)

Sept 16, 2019 10:58:49 GMT -5 brubacca said:

Would an isolation transformer work if led/dimmer is the problem?

[brubacca]

Its definitely not just noise floor. I get that. It a Buzzing sound not humm or hiss. When I ubplug the analog cables from the phono pre I can hear a louder noise floor, plugging in the TT L/R cables introduces a high pitched buzzing sound in addition to the noise floor.

I'll see what I can come up with. I also have a 2M blue cartridge that I could swap onto the table.

I like the extension chord Idea.

I also have a CMX2 not in use right now. I could temporarily wire only the TT to that and see if it helps.

[brubacca]

I unplugged everything in the room except the stereo. I went to the breaker box and shut off the HVAC System, the refrodgerator, the lights in the kitchen (with the dimmed LEDs) and still have the buzz. I pulled the unit away from the wall 4inches and rotated the TT 90 so the tonearm is away from the wall. There is literally nothing on in this room except the stereo. No lights, nothing.

Still getting the buzz. When I turn the volume on the pre up full I hear a click every second (60Hz obviously) in yhe background.

I'm going to try the extension chord. CMX-2 for powering just the TT did nothing.

Not sure if any of the new info helps.

Also my power company transformer that feeds my house is at the end of my driveway. About 200ft away. Also feeds the neighbors. It humms loudly when driving past. Could this be the problem?

[brubacca]

Is it reasonable to switch the cartridge that I had on my old table (2m Blue)? Don't remember having a buzz with that one.

I've never changed a cartridge on a table before. All I have is the rega template and stylus force gauge.

[audiobill]

Google audio hum vs buzz- they are different, and caused by different things....hum is 60hz, and buzz is 120hz...

[metaldaze]

So I had this exact problem with my Rega P3 and Exact cart (from the P6). It makes sense because I believe your cart still puts out 6.8 - 7.2 mV, same as the Exact. They are hand wound and very prone to micro-phonic EMI. I mean very. I read some other reviews of this, but didn't believe it would have been as big of an issue as it was for me. I tried everything you did, It made the noise only being plugged into the phono pre-amp and then the preamp, and the TT not even plugged into the wall!

I realized it was rouge EMI from my placement, which was near other components like my pre-amp and two big emotiva amps. Then I looked out my window right next to where the TT was set up and noticed for the first time the step down transformer from the main power lines. Maybe 20 feet or so away from outside the building, so perhaps 30 feet total.

I moved the whole set up, Rega P3 and Rega phono pre with the same cables- to my second system in the other room. An Emotiva UMC-1, UPA-2 and Ohm Walsh 2 speakers. I could turn the volume on the pre-amp up to MAX and ear to speaker, it was dead silent!

So as Kieth mentioned and you might have already moved it, but placement for this deck if you keep with the Rega cart is paramount. Other carts like the Ortofon Blue you mentioned don't have this problem as far as I'm aware, but may require a shim for your tone arm to be the correct height.

Also with the dimmer LED's, I've eliminated some buzzing in my apartment by switching them to the off position so the dimmer isn't in the active circuit. They're on a different zone but still share the same incoming line voltage, and my system is downstream from it. I don't have the option to re-run wires or put in dedicated circuits, but this works for me while renting my unit.

Good Luck!

[brubacca]

Maybe I should take a nema 4x stainless steel electrical enclosure with the door up and place the TT in?

I would believe the EMI thing. There actually is a radio tower in the clearing next to out neighborhood. Thats past the house next to us. Its about 750ft - 1,000ft away from the TT, but its a broadcast AM radio tower. Could this be it? It looks like the Soundsmith cartridges are fully shielded, but compatibility with my table is in question (fixed antiskate, which cam be overcome with some work at it)

I ordered a pair of those PS Audio devices.

The P2 platter is 2mm less than the p3 a2d p6 to accommodate the Carbon cartridge. That puts it close enough to the 2m blue height to give it a shot.

[drtrey3]

I used some Mumetal to kill a hum when my Rega got too close to its motor. I wonder if that would help in your situation?

Trey

[brubacca]

I put on my 2m Blue and no changes. Will try to move the table and test elsewhere.

[brubacca]

I have a bit of resolution I believe. It took some trial and error, but currently I am buzz extremely attenuated. If I put my ear up against the tweeter I think I can hear it faintly. Also there is an audible click at 60hz, again very quiet.

At normal playing volume it sounds perfect in the room.

I ended up with:
2 PS Audio Noise Harvesters (not sure if these are doing much I may take them out to see).
1 Emotive CMX-2
1 Belkin PF60.

The magic sauce seemed to be putting the CMX-2 and PF60 in the chain Simultaneously.

I have the CMX-2 into the wall. The PF60 into the CMX-2 and the noise harvesters at the same outlet and one at my refridgerator.

Still think I'm a candidate for an isolation transformer, but finances are down so it will have to wait.

For now I can listen to some vinyl, although I neeed to put my Gumby back into the chain. Hopefully that doesn't throw my results. And I need to put that Rega Carbon Cartridge back on the table. The 2m blue is too sterile for my taste.

[brubacca]

Spoke too soon. Buzz is back. Kids are home now and have the TV on. Maybe that is the trigger. I'll have to experiment. (Tv at other end of house almost directly above the elctical box in the basement)

[KeithL]

It is worth remembering that, in virtually all homes, all of the "circuits" are connected to the same place.

Either your entire house is connected to a single lead coming in from the mains transformer...

Or the mains transformer is center tapped - with 220 VAC appliances connected across the outside, and the 110 VAC circuits divided in half, with half connected to each side to more or less balance out.

In terms of protection by circuit breakers, your home is divided into a bunch of separate circuits.

However, in terms of noise, they're all connected together in parallel.

Therefore, it's not at all surprising that a noise source at one end of the house may affect something plugged into an outlet at the other end.

In fact, depending on what sort of service you have, you may share that transformer with several of your neighbors as well.

(So the noise could be coming from your neighbor's central air conditioning as well as from yours.)

Noise radiating through the air will be attenuated by distance - for example noise picked up directly from that transformer outside the window...

However, noise that has found its way into the power lines will reach the entire house...

To make matters even more annoying, power lines can act like an antenna, and pick up noise radiated through the air, or help broadcast noise generate by appliances into the air.

The problem is that, due to the signal levels and impedances involved, a phono cartridge and preamp are about as close to something designed to pick up noise as you can get.

The key to solving this is to figure out which sort of noise sources you're dealing with... which may require some detailed observations over time.

Does it happen in daytime, or at night, when the lights are on?

Does it happen when it's cold, or when it's warm?

Does it ALWAYS coincide with the kids' TV?

Or perhaps with the light they always turn on in that room?

Does it only happen when your neighbor is home?

And, if you suspect the radio tower down the block, then hold a big steel sheet, like a cookie tin, cookie tin, up next to the turntable, move it around, and see if the noise changes.

(You want something ferrous like steel - because it will block airborne noise and magnetic fields better than aluminum.)

Sept 27, 2019 13:49:43 GMT -5 brubacca said:

Spoke too soon. Buzz is back. Kids are home now and have the TV on. Maybe that is the trigger. I'll have to experiment. (Tv at other end of house almost directly above the elctical box in the basement)