Turntable Hum


Any help appreciated!

Low pitched hum coming from TT input ...even when TT is not running . Hum is noticeable at about 1/4 volume & really bad at 50%

Manley Monoblock Snappers

VPI Scout w Hana MC cart right next to amp on table (moved TT away from amp to floor made 0 difference)

Allnic 1202 Phonostage grounded to VPI TT (on floor below JBL speakers & main speakers right to the left Tekton Encores)

Manley Jumbo Shrimp Preamp

Klark Teknik 32 band EQ

All cables (interconnects) recently replaced - Mogami

 

I tried ground lifting the TT motor - no change

unplugged tv & nearby laptop - no change

unplugged all lights nearby - no change

 

I suppose my next troubleshooting venture is to run a ground from phonostage to everywhere & start touching things? Phonostage seems to be the culprit....

😕

 

Thanks everyone!

128x128tommypenngotti

@discnik the phono pre uses 3 prong power cord . Ive already tried plugging it separately in a completely different outlet & ground lifted it as well...no change .

I should say that the hum happens slightly at about 1/4th volume & it is really noticeable at 50% up....thanks

Another thought....if the phono pre uses a wall wart and has a plug that is non-polarized, try turning the wart upside-down if possible to see if the noise gets better or worse, or doesn't change at all. In other words, invert the prongs into the outlet into which it is plugged.

If possible, I would unplug one of the power strips (obviously the one not being used to power the phono pre). But first, you may want to connect any component being used for vinyl listening to just one power strip. Does your phono pre use a wall-wart power supply or a regular power cord (is that power cord a 2 or 3 prong)?

 I cannot say exactly what the difference was in my system with TT/phono hum, but I was able to use 4 different phono stages. 2 of them had the hum trouble, 2 didn't. The 2 that didn't were both tube phono preamps. The 2 with hum were SS. Not that it makes any real sense to me. Might have been a coincidence. 

 It just leads me to believe that there is something in the matching of equipment. I bet that the 2 problem phono preamps sounded just fine with the 'right' system.

@browndt thanks for the tip , I tried some high end Mogami's on the TT to Phono stage , didn't do anything ...🤷🏻‍♂️

Had the same problem with a VPI Prime Signature and a Van den Hul

cartridge. I switched to Silnote highly shielded cables. Problem solved.

Believe me I tried everything list here without success.  VPI tone arms 

are known for hum problems. Top quality shielded and directional cables are a must.

Had a similar problem. Turns out it was the wifi router. Moved it and hum disappeared. Sometimes it's the simplest things hiding in plain sight.

I have a turntable in my computer room and had a weird kind of pulsing noise even with nothing playing.  It was the nearby wi-fi router.

I also had that problem with using Cyrus gear. The power inlet fitting on them only had a live and neutral and no earth. So when i changed  my amp to parasound that had an earth on the power supply fitting, the hum went away. So check the power inlets. 

Had a similar problem. Turns out it was the wifi router. Moved it and hum disappeared. Sometimes it's the simplest things hiding in plain sight.

@audio-union I will check the power with my multi meter ...thanks 

 

@cakyol no idea on tonearm grounding...it's a VPI Super Prime Scout w 10.5" tonearm....I know the headshell on Hana cart is grounded 🤷‍♂️

thanks 

I was reading the cartridge installation instructions for my tonearm last night- SME 3009 S2 improved. 
 

it said on some cartridges there’s s tab on the green lead which has to be disconnected from the headshell or it will cause a ground loop and hum on the RIGHT channel (white signal, green ground), IIRC.

 

FWIW

@tommypenngotti make it easy get a wall plug tester and make sure the power at the wall is correct. Check to make sure the power cords are ALL wired correctly.

I would also consider checking to make sure there is not some noise on your neutral or ground that should not be there. I once found the neutral at the power drop coming into the house was broken at the pole. This particular case will show up as a low voltage on the 110 circuits usually around 90 volts.

@millercarbon really appreciate your time on this matter , the hunt continues...I'll post soon...

 

@audio-union and of course I will go down the rabbit hole of what cart works best with my set up 😃  was investigating the AT ART-9 , have heard alot of positives . I'll try a different power cord on Phonostage...thanks 

I have had several issues with the noise coming from a Hana cartridge. It is due to the way they are internally wired. The Hana won't work well with all phonostages.

There does seem to be a power wiring issue for the phonostage based on the descriptions I see here. It may be in the power cord or inside the phonostage. It sounds a whole lot like the neutral and the hot wires are reversed somewhere.

Yes, inherently noisy, and this can vary a lot between cartridges and arms even on the same phono stage. Usually anything low level and uniform like you're talking would be within the norm. You can try and reduce if it matters to you but could spend an awful lot of time for very little to gain. Except when it is one channel like you said. In that case you should be able to get the noisy one down to the same level as the other- unless there is something wrong somewhere.

That is what we're trying to figure out. That is why you want to try the phono stage somewhere else. If you get the same noises, it's the Allnic. If not, keep looking. 

You picked up on the main idea, phono stages have a tremendous amount of gain. Things that would never be audible anywhere else can be unlivable with all the gain. Worth it in the end, even if it doesn't seem that way sometimes.

 

@millercarbon thanks..when I disconnected the RCAs from TT to Allnic & inputted 1 by 1 I noticed on the right input a slightly higher pitched buzzing , nothing major , just slight...electrical , emanating from speakers for sure..I'll try moveing the allnic to anotehr system & see if its noisy....Arent these Phonostages kinda inherently noisy because they are boosting the signal so much? 

@swanny76109 The Allnic 1202 Phonostage is almost brand new...I do notice when I tap on the cylindrcal tube cases I get a fair amount of feedback through the speakers ...noisy...thanks 

 

Building on Ralph’s diagnosis— you have tubes in the Manley. Have u checked the phonostage tubes?or tubes anywhere else in the signal path.   Perhaps microphonic?  

I'll try your suggestions, the only time the hum goes away is when the phonostage is out of the loop 🤷‍♂️

If nothing is connected to the input of the phono preamp, does it still hum? If yes, based on the statement above the problem is the phono section, which might have to be serviced.

Power cords themselves won't cause this except that they are the path to ground. So lifting the ground on one or both is another test. Use a cheater plug to test this. Then if that doesn't work I would try the Allnic somewhere else, another system, anything at all just to rule it out. 

Solving puzzles over the internet is a PITA because things that would be freaking obvious in person come in dribs and drabs online. Like I just noticed you said "high buzzing comes from the right side of the turntable." What are you talking about? Please be careful to discern between mechanical vibrations you hear emanating from the physical device itself and hum or other noise that is in the electrical signal and so is only heard coming from the speakers.

@millercarbon tried different outlet on phonostage & preamp , no change ...

could the power cables for any of my units be malfunctioning causing this? I could swap...

@rauliruegas Turntable & phonostage are grounded 

 

@aberyclark tried different RCAs from TT to Phonostage , no change...

Dear @tommypenngotti  :  As almos a " rule " any audio system needs to be grounded at only one place using a true system's dedicated  ground/earth conection. In my system that point is my phonolinepreamp.

If after that problem persist then one of the tube electronics power supply is out of specs .

 

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

I have a similar problem with my Mayajima cartridge, but not the Koetsu. Turns out that the Mayajima requires a step-up transformer for isolation as well as amplification.

May not work for you, but ...

Just throwing something out there. Could the phono cables not be shielded? Maybe try a different brand/model of cable and see if the noise changes any or goes away. 

Ground loop hum is typically about 60Hz, a low throbbing hum, and indicates a ground loop problem. Higher frequency buzzing sounds like your normal run of the mill phono cartridge/phono stage noise. Two similar and related but yet different things. As you can tell.

What I think happened was you disconnect the phono stage this eliminates the ground loop and cartridge completely and all is silent. Connecting the phono stage alone introduces the ground loop. Then connecting the phono adds that buzzing noise.

Now with phono RCA and ground disconnected try the phono stage. If you get hum from the phono stage alone check where everything is plugged in. Try plugging the phono stage into another outlet. Try plugging the preamp into another outlet. If you still get hum like this the last thing to check is disconnect the preamp from everything except the phono stage. If there are no outlets you can plug these into that doesn't result in hum then we have probably ruled out everything and are left with a bad phono stage. 

Otherwise, eventually, if the phono stage is okay then you are bound to find some way of connecting without hum. 

Then connect the phono ground to the phono stage. If this adds hum, well let us hope it does not! Then connect the RCA. Hopefully this only adds the noise. Eliminating this is another similar process. Set that aside for now. Start with the ground loop hum.

Tommy, I've going through this for a number of years.

I also Have some RF starting at  9 o'clock, it's a head scratcher.

For me dedicated lines to the fuse box and high end outlets may do the trick. 

It seems like matching the phono pre and the cart is most crucial, I'm thinking of going to the DS system with phono pre and optical cartridge to get the correct match, I've heard good things.

Your thoughts

@millercarbon 

when I disconnect the Phonostage all humming goes away . 

unplugging TT from phonostage completely the higher buzzing is gone , but a low end hum remains....the high buzzing comes from the right side of TT 

 

thoughts? 

@mr_m there is no power supply , just a cable into wall for motor 

I had a similar problem with hum like what the OP described. Tried all the usual grounding tricks. They helped somewhat,  but just couldn't eliminate the problem completely. 

Then I was given the suggestion to change turntable power supplies. Turns out my tt came with a cheap switching wallwort power supply.  All I had to do was order another wallwort power supply, only this time went to a linear type.

 Cost, 15 dollars. And voila!!! Hum totally  disappeared.  Not sure if it will work with what you have, but worth a try if your tt has a cheap switching power supply.

 

@noromance I did ground lift the TT motor & pulled everything in strips out 1 by 1 , no success

 

@millercarbon I'll try your suggestions, the only time the hum goes away is when the phonostage is out of the loop 🤷‍♂️

@femoore12 I did add a Marantz 2270 receiver recently but nothing inputted , just plugged in and I think I removed it to see , no change . 

@ei001h I moved TT to the floor , no change , I'll try the cable jiggling. thanks 

I had the same problem. try moving around the RCA cables around while TT is on. Do you hear a change? Try moving TT to a different position. Something inside my wall was causing interference with my TT and cables. 

Did you change anything in your system or room right before you noticed the hum? 

Try disconnecting things one at a time. Grounds can be funny. Normally you want to connect the turntable ground to the phono stage. But I went to a new arm where it was the other way around, going silent only with the ground disconnected. 

First I guess start with disconnecting phono stage from preamp. Then work your way back. Connect phono stage only- turntable disconnected from phono stage, phono stage not even plugged in. Then plug in phono stage. Then turn it on. One baby step at a time. Then connect turntable ground. Then R channel. Then L. 

I doubt it is internal arm wiring but if there is no hum until you connect a phono lead then it could be. But check the individual cartridge connections first. I doubt it will go that far. This is just to give you an idea how to track it down.

Ground lift everything except the phono amp using cheater plugs. 

Ensure no WiFi units are nearby.

@danmar123 I’ll check the headshell wire...thanks

@millercarbon Unfortunately everything is conected to the same outlet / 2 power strips