Feedback hum on my turntable, no ground post

I picked up a Crosley turntable, and as soon as I plugged it in I noticed a hum which sounds like feedback noise. I also noticed no ground post anywhere on the unit like my vintage turntables had. This is a modern turntable that allows you to also use it with powered speakers, so switched with preamp or line out, the hum persists. It plays fine, drowning out the feedback noise between tracks, but it’s still there. I’ve tried different outlets perhaps wondering if it was a ground loop in my house, even the power out jacks in the back of my old receiver, no change. Before I rig in a ground lead from the bottom of the chassis, wondered if anyone else had experience and comments to help me here? Thanks.

I don’t have that problem, but I also don’t have a Crosley TT either. I’m curious though, which model do you have?

Rig a ground wire from the chassis back to phono preamp only and nowhere else. Avoid ground loops. Does your Preamp or receiver have a ground connection? Some turntables have the tonearm and chassis ground tied into one of the channels negative ( ground) wires to the RCA jack. My 2020 relatively high end Rega Planar 6 features this stupid setup and I had to move and reduce ground connections to eliminate hum I was getting. I’ve never had this trouble with any of my other tables. Play a records and start messing with the grounding until the hum dissapears. A properly set up turntable does not hum at all. Good luck…

Crosley DJ100A-SI Direct Drive DJ Turntable.

Yes, the receiver has a “GND” just under the phono RCA jacks, the turntable has nothing. I can remove one of the feet that has a steel screw holding it on, wrap a wire around the screw, and that ought to be a sufficient ground location. I’ll see what happens, thanks.

Hi,
If the steel screw is only threaded into MDF wood (which I assume it is) grounding it there will do nothing most likely as it’s a dead end so to speak. You need to get a ground wire from that grounding terminal on your receiver over to the base of your tonearm metal. The platter bearing base plate is another option but the hum usually originates in the tonearm area. The screw on the rubber feet would have to connect to tonearm or metal chassis material. I could fix it but I’m here and it’s there. Good luck…
Sometimes people put a 2 prong non- grounded adapter AC plug between the wall outlet and the grounded plug on the power cord. This lifts the ground connection from the wall which sometimes works but makes the equipment less safe overall, imho.

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I had put the brand and model # in my last comment - so here is the link on Amazon showing this turntable - https://www.amazon.com/gp/product/B07CJ4YB75/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=recordology-20&creative=9325&linkCode=as2&creativeASIN=B07CJ4YB75&linkId=eac2641bdb9053d6fb647910c8c2f6f9

No MDF materials. There is also a review of this model on Youtube that’s thorough.

I get it, chassis ground works if the arm is wired to it. Perhaps that’s the problem here? There is no ground plug on this power cord by the way. This also has a switch, that allows you to use the internal preamp. Using it, as I put in my opening post, doesn’t stop the hum either. I’ll investigate the tone arm, perhaps the stylus was installed incorrectly, or another issue exists with wires that run through it.

I see it now. Is it a molded plastic chassis ?
Maybe the built in preamp is causing the hum.
Most ( but not all) tonearm wiring looms have 5 wires internally inside the tonearm. 4 for L& R positive and negative and a internal separate black wired that grounds the tonearm. Like I mentioned my Rega Planar 6 doesn’t have this and the chassis ground is combined with one of the signal grounds. Some people modify this and run the tonearm/ chassis ground separate which has been the normal config. I will likely do that to mine once it’s out of warranty. If that foot screw is tied into chassis or tonearm metal then try your planned fix. If the hum is coming from the internal preamp that’s another issue. I’ve refurbished over 20 vintage turntables, it’s fun but sometimes challenging…
Any electro- mechanical audio equipment has unique quirks.

Yup, plastic, 13 lbs of it. I thought when switched to line out, it bypasses the preamp? Both ways it hums. I’ll dig into the arm tomorrow, thanks again. I would opt for the traditional ground myself. I do have a warranty in effect, and free shipping, just didn’t want the down time.
What’s your thoughts on the Fluance turntables? Clearly this budget stuff (Chinese) has its quality control issues.

Fluance are supposed to be pretty good. A used quality table is a good choice with an IFI phono preamp. Depends on how much vinyl music you play. Rega are good quality, Technics direct drive are also good. Hook up a ground wire to your receiver and just simply touch the other end to the metal base of the tonearm while playin a record, hopefully the hum will go away and you’ll know the fix.
I don’t know anything about Crosley turntables, so I can’t comment on your machine. Like everything else, you usually get what you pay for. Sorry I couldn’t pinpoint the exact issues. Ground loop hum is an evasive monster sometimes…

After agonizing for the last couple of years with the hum of the Crosley portable turntable, I read and followed this tip and voila. Problem solved. Thanks!

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