Turntable hum??

How much is normal? I guess by nature a cart is kinda like a microphone, right (re picking up sound)

Just noodling around today with my set up.

Question: If I have nothing playing, but I crank to volume all the way up (doing this with my x-can and phones), how much hum would be normal by doing that? And is it typical for the hum to be louder when the tonearm is at rest vs when the tonearm is towards the center of the LP (again, nothing playing)?

hum level appears to be the same with either my Slee pre or my Fono, and also is the same with my P9 or P25 plugged into either pre...

Curious...

 

It varies. A very well designed table with quiet electronics, well designed cartridge and cabling.. quite quiet. Hum only audible on headphones at full volume, probably all from the phono preamp even.

Bad cartridge, cable, earth, electronics, bad motor placement - intrusive at the end of side when playing at normal volumes.

If the hum changes as you move the arm, likely something is not earthed near the cables where they are inside the arm tube/bearing or you have electronics under the cartridge inside the base when it's by the rest, or even to the right hand side of the turntable.

 

p9
Exact
Graham Slee Era Gold

All well designed stuff

Both my rega P9 and P25 both have reduced hum when the arm is moved towards the center

 

How close are the phono preamps to the turntable?

 

I moved them quite a bit away...no difference

Of course, Rega tables have no ground...

 

Just a heads up. I discovered that an Airport Express plugged into my DAC added significant hum to my phono. The power cable was the culprit. I relocated it away from the system and used a long toslink cable instead. That solved the problem completely. Now what caused me issues may work just fine n another setup, but it is something to consider if you are using one.

 

.. and almost no metal to need it. The fact that the hum changes with arm movement suggests that it's being induced into the cartridge or wiring from some physical place or direction, though.

 

I have almost no hum when the turntable is moving and the tonearm is at rest. There can be some very very slight hum if the tonearm is rolling in the deadwax lead out area but at that position it is getting a bit closer to the motor. Different cartridges will induce more or less hum. Of course I run my turntable off of a VPI SDS AC regenerator so that helps. Do you have the turntable plugged into a different wall socket than the other components? That can induce a difference potential that can show up as hum or sometimes as background noise. If so then figure out a way to get everything on the same outlet. You can also try running another grounding wire to the phono or preamp chassis. Also Racetripper is correct about power cords. Make sure they are separated from signal cables or at least cross at right angles.

 

In my case, the hum gets less as the arm goes towards the center...

 

Flip the plug - 2 prong- if possible.
I ran a ground from my P3 to phono pre.
No hum.

 

Flipping he plug indicates a "Ground Loop" causing the hum.
I'm tracking one down on my own system right now that has nothing to do
with my turntable. A devilish problem sometimes.

 

no change in flipping plug...or plugging in somewhere else.

I might be overthinking this...mis-describing it... The sound is only when turned way up. It sounds a bit like an amp at a concert before the band starts.

I think this might be normal...

 

Turntable hum can be quite difficult to solve. Everyone says check for a ground loop and asks if you've tried disconnecting your cable TV...but I don't have cable and my TV is in another room.

After moving last year I had some really bad hum issues with a Clearaudio Maestro and Virtuoso. I tried different interconnects, isolating the turntable, running ground wires...not running ground wires, bought a new phono stage and with the higher gain the hum made it almost impossible to listen to vinyl...then I came across something on either Audio Asylum or Audiogon about VPI tables and wood bodied cartridges producing a hum...so I tried a Shelter 501 I picked up second hand and voila...NO HUM! I was afraid to try the Shelter since it was MC and I'd have to use the higher gain setting on the JC3. I suspect that the Clearaudios were picking up some RFI from the power cables which are above ground.

If all else fails you may want to try changing to a different cartridge to see if the problem goes away.

 

The hum you hear when nothing is playing and you crank up the volume to full is probably due to you phono stage. Your phono stage is the highest gain amp in you system. It takes signals that are on the order of 0.5 mV (millivolts = 1/1000 of a volt) and boast them up to around 2 volts. Thus anything that goes to the phono stage inputs get boasted by a 1000 or so and anything that is in the first stage of the phono stage also gets boasted by a large amount. How much hum do you hear when there is nothing playing and the volume is at your normal setting?

The cartridge itself is not a microphone. It is a transducer designed to convert the mechanical movement of the stylus in the record groove to and electrical signal. If you talk right at your cartridge you should not hear anything like you would if you talked into a microphone. The wires that run from the cartridge to the output jacks of the TT could pick up EMI (electromagnetic interference). If you tonearm is made of metal it is important that it is grounded to help it act as an electrical shield for the cartridge wires that run trough it.

 

i used a p75mk2 and the hum is horrible

and solved the hum issue with a P75mk3. the new improved P75mk3 reduces the humming / noise.

now i don't need to earth the casing or etc. Wonderful phono stage. i doubt i going to change it..



it is a pain when you buy a new phono stage that comes with the Hum

 

Don't hear much hum as normal volume...but I "know it's there" because I can hear it turned up.
I'll check when I get home, but what would it tell me if the hum goes away if I unplug the table from the preamp?
I also notice a different hum when I tought my (metal) tonarm. Goes away when I take my finger off. Normal?
All Rega arems are metal, but none of their tables have a ground wire..

 

I don't hear hum in my set-up, so whatever "normal" is is beside the point. As far as I'm concerned, if the turntable/phono stage is set up properly, there should be no hum.

Tony Plachy is correct in pointing out that a cartridge is a transducer, but one that [by itself] is not microphonic. However, a needle in a groove can easily be microphonic, up to and including audible feedback. Another characteristic of the cartridge as transducer is the susceptibility of the cartridge to electrical fields potentially producing "hum". In this regard the cabling for the tonearm/TT is crucial, not only in it's potential of rejecting adverse electrical fields but also in how it mechanically interacts with the 'tables suspension, if any.

There are cartridge/turntable combinations that simply not work, in my experience usually involving Grado cartridges. Sometimes the turntables have electrical fields they produce, this is the case with some of the Technics direct drive 'tables. Not to mention the common situation of a turntable on top of a receiver, where the transformer can leak hum and buzz into the 'table.

I'd look into the physical positioning of the 'table, find out where there's the least hum, then see if you can live with it. In my case, I've hard-wired Canare StarQuad to the SME III arm, ground shield goes to the 'table, I don't use the ground tap on the receiver—thus no ground-loop hum. The Turntable sits beside the receiver, there is nothing electrical beneath it. I would not want to run my set-up loud enough to hear any residual hum, I'd blow out my speakers or ears trying.

 

I think your touching experiment is telling you what's wrong. Does your phono stage have a ground lug on it? Do you have a multimeter? Let me on this and then I can tell you what I think will help.

 

the phono stage does have a ground lug
Don't have a multimeter...radio shack item? I can get one...
My pre is the Graham Slee V Era Gold
I also use the separate Slee power supply with my pre...not a wall wart

Although I get the same noise when I swap out the slee for a Rego Fono...

 

picture of back of unit:

http://www.gspaudio.co.uk/eragoldvphonostagepreamp.htm

 

At full volume, I'd expect this because Rega don't usually ground the arm separately - I read it's through the left channel signal ground.
Try connecting the left channel (outside of RCA plug) to the ground tag at the back of the phono pre. It's possible the internal ground connection on the arm is faulty. Only a check with a meter will tell you what's going on.

 

So, is the amount of noise I am describing normal for a rega?

How would I use a meter in this situation?

 

Why did the turntable hum ? Because it didn't no the words .

 

I don't have a rega, so I'm sort of guessing there, based on electrical knowledge and working with many other turntables and arms.

You have a setting on a multimeter called continuity. It reads 0 or infinity, or sometimes beeps, when there's a low resistance connection between the probes. You can find if the arm tube or arm is connected to one or both signal grounds by checking arm metal to rca shield continuity. Or not. All parts of the arm should be connected to ground for low noise. Remember the arm may be painted or epoxy powder finished. I've heard of users literally drilling a metal connection into the arm for a ground tag to quieten it down. It's all to do with current flow through the phono inputs and back to the cartridge, so it really varies setup to setup. Some expensive phono stages have bad noise in some setups because the designer has guessed some circuit parameters rather than tested to a specification. For example, multiple-mono units can offer good separation, but end up with hum when bad power design means the L and R grounds aren't the same actual potential in use.