How to fix turntable hum 

Will have to forgive him that's Old age for you

@@johnsweda2999 of course we do!

Yup, that's what I was thinking. If JC is a little handy with a soldering iron, another option is to bypass the internal preamp... there are vids on the subject for the LP120. The MC-1 is a high output MC (3.3 mV), so the Mani alone should have sufficient gain to amplify it.

Yep, plenty of videos on youtube on how to remove/bypass the built in pre-amp. I use a vintage Onkyo amp myself and you definately need a ground wire. Once you have bypassed the in-built amp make sure you switch your Onkyo to MC input.

​@@jtfoto1 The MC-1 is a high output MC (3.3 mV) so I would assume that the MM input would be sufficient, but I don't own a vintage Onkyo. Is the resistive loading the same for both the MM and MC inputs of the receiver? The tech spec of the MC-1 recommends 47kOhms.

Depending on the state of the "Phono / Line" switch.... this answer is not quite true, although it's _very close_ to the mark. The problem isn't due to doubled phono stages, assuming the user has placed the switch in the "Phono" mode. The problem with this turntable is due to another couple problems with the circuitry inside, which is slightly more complicated to explain. Yes, the LP120 (LP-120-USB) have a built-in phono preamp, and yes there is a problem with the bypass mode in that it's not a true 100% clean bypass. Supposedly, the newer LP-120-*X*-USB model has been redesigned, but I've not verified that these problems with the "Phono" bypass mode have been solved... I only know that a few improvements and also a few arguably detrimental cost-cutting measures were made (for example: No VTA adjustment on the new model, the cueing light is cheaper and removable now, but at least there are RCA jacks now instead of a non-removable "captive cable"). Assuming the original question was about the original LP-120(-USB) model, the details follow. When the switch is set to "Phono" mode the built-in preamp circuit is indeed bypassed. The problem lies within some surface-mount components built into the phono cartridge traces on the PCB, which cannot be bypassed. There are 2 problems: 1) An inductor and capacitor are placed as an "L-C circuit" (a.k.a. a filter) between the signal Hi (+) and Low (-) lines for both Right and Left. 2) An SMD jumper is placed between the cartridge & tonearm wired signal Low (-) lines (again, both Left & Right), tying both to the shield (a.k.a. Chassis ground), and therefore the Phono grounding lug. These do indeed affect the output signal of the phono cartridge in a few ways: 1) The L-C circuit acts as a filter, affecting the passed frequencies out of the RCA signal lines. In this case, from testing it appears this is a lowpass filter which slightly attenuates the higher frequencies in the signal. 2) The SMD jumper causes a built-in ground loop issue, adding the familiar 60Hz + odd-multiple harmonics hum. Both of these soldered-in components are not possible to bypass by the "Line / Phono" switch due to these connections being made inside on the PCB before the signal lines hit the switch terminals. So, while the phono pre-amp is indeed bypassed, these other PCB components are not. The original question seemed to hint at noise problems, which seemed to indicate a ground loop issue, caused by problem #2 mentioned above. To explain the problem with ground loops further is it's own complicated (and often very misunderstood) topic. I'd refer anyone interested in the electrical engineering details of ground loop & noise issues to refer to Bill Whitlock's talks presented to the Audio Engineering Society. The solution to this problem is either: - Modify the turntable to remove the jumper, or otherwise just pass the tonearm wires directly to the RCA cable's shield & pin. This could solve both problems #1 and #2 depending on the after-market modification chosen. OR: - Use a phono-level audio signal ground loop isolator (a.k.a. an audio input-transformer) to break the ground loop between the LP-120 and the external preamp, therefore solving the noise issue caused by problem #2. Problem #1 would still affect the very high frequencies, so the signal would be "colored" by the L-C filter still.

Rega here too. Not a suspension turntable. Like my old Thorens

If I’m not mistaken, Rega (and other tables) tab a ground to one of the cartridge outputs for ground. On my old Moth table (a Rega), I connected a ground wire to the tonearm. It was not an easy task but I no longer had a ground issue, irrespective of the cartridge or phono preamp I used, including the very nice sounding Schiit Mani.

I don't have that kind of electronic hum, well l have it in much lesser terms, no ground connection from me to my fab VTL 5 tube phono pre amp. Just RCA plugs are doing the trick. Mechanical ground l had yes.

Ian Yates ~ hahaha ... that turntable is a status symbol..!

IAN!! You're so very generous! Perhaps, if you can't wait for Paul to get bored, you may look at some garage sales on the w/end. There may be one there for you to get for a buck!.. just a thought! LOL!..

Janina Palmer yep but it would look better set up on my system as my status Symbol I wish 😂😂

VThanasis Manolopoulos yes I know I’m very generous and if I could bye one like that fore a buck i I would have a house full of beautiful hifi 😂😂😂👅

Ian Yates ~ no it wouldn't ..! I'd use it in a modelling shoot .. to show off my delicate dexterity moving the long pick up arm .. that would make some men feel very desirous .. lol 😂

Meh, they sound OK, but nothing exceptional. Not sure why everyone fawns over the Mani. I guess they represent a decent value for the dollar. At any rate, he needs to bypass the internal preamp on the TT in order to use it with Mani, otherwise he's amplifying the cartridge's output twice and applying two RIAA filers.

@@terrywho22 Well congratulations on having ears (audiophile ears) obviously superior to the vast numbers of reviewers. I own a few costly phono stages highly rated, but to my ears, and many of my friends the 'Mani' seems to have a depth of resolution and transient detail that's missing from the other more costly stages, though of course, the Mani is by no means the last word, it's just damn good. I'll agree it's not a phono stage for MC cartridges. Give the Mani high end MM and a different picture is apparent. I'm actually a high end digital guy, but I always keep a good analogue system because I have a collection of decent vinyl records which I enjoy - many of which I helped master in my younger years.

@@ProjectOverseer See, this is what I'm taking about... people drinking the Schiit Kool-aid. Make even a neutral comment on Schiit gear and fans will resort to sarcastic replies, tell you how their friends and mom say its the best thing at the price, AND make sure you know that they and their gear are great so it must be you that is at fault. I mean, it's fine equipment, but Stoddard and Moffat are building quite the religious following. More power to them, I guess.

@@terrywho22 I wasn't really being sarcastic ... More complimentary 😉 At the end of the day (love that saying) its all a matter of personal preference. I always spend way to much on audio & film related kit, so it's a pleasant surprise when performance excels a particular price. I'm very critical and first to shout BS or snake oil ... The Mani (especially with MM cartridges like the Nagaoka MP500) is 'audiophile' quality, but like I said, "it's not the last word" ... I respect your opinion, Terry.

@@ProjectOverseer "Complimentary"? Yeah right! 🤨 That said, I agree with a lot of this being personal preference and that Schiit does offer good bang for the buck. For just a few bucks more, I would suggest pairing your VERY nice MP500 with a Hagerman phono section (whichever one fits your budget.) I mean, that cart would work with pretty much any top notch phono pre (AR, Parasound JC3, etc.) but Hagerman Audio makes some great stuff for several budgets. Since we are on the subject, which of those LPs in your collection did you help master?

Maybe a balance turntable should fix that problem! Because a balance turntable doesn't used a RCA cable and doesn't need a ground.

You are correct sir !! Btw, what's a Poo Ninja ?? 😆🤣😂

poserwannabe it’s a phonetic pronouncement of an African language that roughly translates to “ can you hear what I say” 👌🏽 Basically a misheard lyric

@@PooNinja very cool !! I'm glad I asked 👍👍

Because the phono pre and headamp/SUT are matched to the cartridge, not the turntable.

terrywho22 ~ that's bullshit .. most high end RIAA equalisers incorporate selector switches for type of cartridge and sensitivity.. so why not have the SAME kind of thing built in to the turntable .. with minimum connection length .. sounds like sheer common sense to me

​@@janinapalmer8368 Many turntable fans prefer an SUT over a headamp for their MC cartridges. What, you're going to have a bank of transformers wound to accommodate every needed gain/load impedance? Ok, say you are a turntable manufacturer and you decide to include an onboard headamp, not only are you building (and charging for) equipment that a significant amount of your customers may never use, but you also have to compete with specialty electronics companies like AR and Lamm that spend their R&D on electronics only (including stellar phono components. ) You can design the best TT in the world, but if your electronics aren't world class, its going to end up costing you sales.

terrywho22 ~ I know that ! What I'm saying is that phono cartridges come in 2 types as you know MM and MC ... they both fall into similar loading characteristics.. I have many of each type ... and I know all about them. Why I much prefer a head equaliser amplifier mounted right up against the phono cartridge is that the long lengths of cable can be eliminated. Cable capacitor compensation is no longer required. One of the things that bugs me with high end audio is the overuse of 'wrongs ' to make a "right " situation .. servos on subs is one of them too.

@@janinapalmer8368 MC and MM carts often need very different loads. Some HOMC can sound fine with higher loading levels, but there are a lot of MCs that need 200 Ohms or less. Conversely, MMs need 47k Ohms (or higher for vintage MM carts!) Also, capacitive loading has to be considered for MM.

Cartridge setup/alignment. Which alignment are you using? Lofgren A? B? Stevenson? Which turntable?

Increase tracking force...

@@jonahyue4755 Yes, could be that as well...

Lol....... maybe more dynamic range on paper but not in the real world. Records played on a good system blow cds away, far more engaging! Btw I stream mostly for convenience.

@@catified2081 i guess you used to come across a cd player with a weak output or something.

@@catified2081 my friend has a vinyl set up cost him 12,000, my CD system destroys it.

What a d-grade that is CDs for £1 NEW no one wants anymore , not in demand . Yep , go cheep LOL

@@shaun9107 yeah cheap... and also better.

Nothing is more 21st century than assuming you know better than someone else, what they want. And then telling them to spend hundreds on fixing a problem that's as trivial as grounding a wire.

@@cristi724 - I know that DAC's don't hum, and not only do turntables hum, but with all of their unnecessary moving parts they are inherent to timing and other noise issues. Those are the facts regardless of what century it may be.

@@jamiemcneil9462 Doesn't matter. The man has a turntable, he wants a turntable. You telling him how bad a turntable is, is not fixing the problem.

@@cristi724 - Actually, my solution for fixing the problem is accurate and will work perfectly every time. He never said he wanted to keep his turn table. He wanted to know how to make the hum go away, right? And, everything I said about turn tables is true.

@@jamiemcneil9462 Yes.