Things we do to eliminate hum
jdjohn
Posts: 3,148
Thought I would share this contraption which was needed to eliminate hum.
Red wire goes to a grounding point on the tonearm; blue wire goes to grounding lug on the phonostage; black wire goes to turntable chassis. In the end, the tonearm is not grounded to the chassis, so a workaround was needed...for the cartridge being used. The cartridge being used usually dictates what configuration is needed. In this case, it was a vintage Shure M91ED, creating a ground loop for no apparent reason. Honestly...I don't know why I even bother with Shure carts
Red wire goes to a grounding point on the tonearm; blue wire goes to grounding lug on the phonostage; black wire goes to turntable chassis. In the end, the tonearm is not grounded to the chassis, so a workaround was needed...for the cartridge being used. The cartridge being used usually dictates what configuration is needed. In this case, it was a vintage Shure M91ED, creating a ground loop for no apparent reason. Honestly...I don't know why I even bother with Shure carts
"This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon
Comments
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That's pretty fancy! What are you charging for that contraption? My TT has an obnoxious hum that I may have to try to eliminate soon. With no ground it sounds like an arc welder. With TT ground to PP it's there but seems to diminish when playing vinyl but with nothing spinning I can hear it. Why oh why did I get into vinyl!!!
Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
Ha...trouble-shooting grounding issues are unique to every situation, so what works for me might not work for you. I didn't have any issues until trying a vintage Shure cartridge for testing beater records.
Does your tt have a muting switch? If so, it might have hum until the needle drops. If it doesn't have hum after the needle drops, then just let it ride.
Tell us the turntable, cartridge, and phonostage, and we *might* be able to help."This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon -
Harman Kardon T65c with a Grado Gold cart.Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
I've read that Grados can have hum when the cartridge is close to the tt motor. Your tt has the motor underneath the rear of the platter, so that should be safe.
Have you tried a second ground cable from the phono pre to the line-level pre, or even to the power amp?"This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon -
all righty then -- gonna get @jdjohn a big ol' bag of clipleads for The Holidays!
He is absolutely right -- ya gotta do what ya gotta do to deal with hum/ground loops.
When hum gremlins strike, start connecting things (chassis chasses chassises, umm, enclosures
) together... with clipleads. If nothing works, start isolating things. 
Yes, the Grado hum can be a thing -- the Grados are, or at least were, unshielded, and they can pick up induced hum from the motor on certain tts. There's a database, or at least a compendium, if memory serves, on vinylengine. I've never had the Grado hum nor the Grado dance problem on any of the tts/arms where I've used 'em, thankfully.
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Sorry for the slow reply. Been working a lot of hours. I'll give that a try tonight or tomorrowGustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
Well I removed one of the cover screws on my pre and stuck in a copper ground wire that I ran to the phono pre that I have. Hum has improved to the point that unless I stick my head to the speakers at listening levels, it's not really noticeable. If I crank the volume to max it's still there so the search continues. Thanks Jody!Have you tried a second ground cable from the phono pre to the line-level pre, or even to the power amp?
Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
There's nothing worse than a ground loop hum. They can be a bugger to troubleshoot. I think the 2 biggest causes are:
1. Integrating TV/Cable into your system (Use Toslink to kill video ground loops)
2. Intermixing 2-prong plugged equipment with 3-prong plugged equipment
I have been VERY fortunate to have no hum issues for a long time.Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2 -
Finally ended-up with this solution:
On the top of the headshell, though, had to search around for an exposed piece of metal - underneath the lacquer coating.
Interesting...I don't remember having a grounding issue with the MC cart
I'll eventually go back to one of those...just doing some MM needle drop recording tests. "This may not matter to you, but it does to me for various reasons, many of them illogical or irrational, but the vinyl hobby is not really logical or rational..." - member on Vinyl Engine
"Sometimes I do what I want to do. The rest of the time, I do what I have to." - Cicero, in Gladiator
Regarding collectibles: "It's not who gets it. It's who gets stuck with it." - Jimmy Fallon -
I recall Stanton and Pickering having ground straps to the head shell that could reduce or cause hum. My memory is foggy.....IIRC there was an add on clip you could get that would ground cartridge lead to head shell. I'd wager @mhardy6647 could tell if I were making that up or not...
Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 * -
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I had found a spreadsheet of Turntables and Grado cartridges, indicating if they hum or not. I'm not sure who compiled this but it could be useful.Stan
Main 2ch:
Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.
HT:
Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60
Other stuff:
Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601
