@puptent Thanks again!

My house was built in 1905, and two owners ago, had an Electrician in residence. As a result I am up to code, at least NEC from 20 years ago  Consult with your electrician,,, A single breaker panel with a clean neutral and an isolated ground will do wonders. You will then have an orange, isolated ground, outlet, dedicated to a single use. Especially in older houses circuits are expanded, lighting added, extra outlets, and so on. All too often the ground is omitted altogether, and the neutral is picked up and used as a "common" wire and has too many connections on a leg which can lead to potential (Voltage) on the neutral, which is my SWAG for your issue, You might want to have an electrician look over your service, panels, wires and outlets/switches. Hope you're sitting down when you get the report. Having things brought up to code, though, will give you peace of mind (safety), improve the performance of your system and computers, AND increase the value of your home.

Keep us updated, and good luck.

@puptent 

The plug is keyed. I do have an outlet tester. I live in a pre war building so the wiring is most certainly off. I was thinking of just getting my electrician to run a new line just for my system as the wall where the system is against has no outlet and I'm plugging it all into an extension cord and power strip. Before I do that I'm thinking I will purchase a new Technics SL-1500C Turntable as this one is used. It might be worth the money as this one could be faulty. I think this is the way to go (?)

I would try a different circuit breaker when you change the plug for the TT, not just another outlet. Is it possible to turn the plug in the wall socket, sometimes changing the polarity will help (I have older TT's, always the first thing I try)? If the plug is "keyed", one wide one narrow blade you will not be able to do so. At the hardware store you can buy an inexpensive outlet tester (everyone should have one), it will look like an extension cord end. It will have LEDs on the back and the combination of the lights will tell if the wiring is correct, polarity, ground, etc. You probably are hearing 60 cycle hum, which is the frequency of A-C power. One outlet or lamp wired incorrectly, motor loads, nearby un-shielded transformers, bad ground or voltage on the neutral.....BTW some MM cartridges are "sensitive" do you have another to try? good luck

Thanks @jayctoy 

Audioquest has a good ground wiire for tt and your Sony .its $29

Try  to put your tt to onother wall socket , try separating it from Sony.

@curiousjim I think its getting to that point for sure

thanks @ newbee I'll try that 

If you bought the tt new, I’d return it and try again with another new one. Everything else seems to check out.

I think I didn’t ask a clear question, so I’ll be a bit more specific by illustrating an experience I had. I had a wall wart (12v transformer) plugged into an extension cord lying on the floor behind my components. I had a cable from my pre-amp to my amp which was very close to the wall wart = hum. Moved the wart, end of problem. Components have internal transformers as well and if an RCA cable passes too close it can create a hum. It’s not just a matter of where your components are plugged into a wall. FWIW.

@newbee 

the system is about 5 ft from our cable box and 3 ft from our TV.

The turntable and receiver are plugged into a power strip that runs to a single outlet with nothing else plugged into it 

You haven't routed your RCA from TT to phono stage near a transformer or other power source have you? That will create hum everytime (almost anyway). 

I'll do that, I think I have some somewhere 

@defandum 

I think most, but not all,  rca cables are adequately shielded for use with a turntable.

I was more thinking you could "borrow" a set you already have from another component. 

@jetter Ah, so I'll order shielded rca cables. thanks!

@dill thanks, I'll try that now

@defandum 

Based on my own experience, I suggest you try a different set of interconnects.  The first pair I used resulted in a not inconsequential hum.  Then switched to a different pair and the hum was completely gone.

I was told by the cable manufacturer that the particular interconnect was not shielded for turntable use.

Check the 4 connections from the tonearm to the cartridge. They might not be tight or on the wrong pins. If it has a removeable stylus, make sure it is seated correctly. Also, if you can, reverse the A/C plug.

I'm thinking I might need to do that

If that’s the case if possible you should return that table and find something else!

....other than that system sounds pretty good

@yogiboy nope, same thing...this is so frustrating. I had a lesser quality turntable (audiotechnica lp60xusb) set up before this and didnt have this problem. I just dont get it

I'll try that. Thanks!

Try using the phono input on the Sony instead of the internal phono on the Technics. The speaker wires do not have to be bound together. BTW, you do not hook up the ground wire if you are using the internal phono on the Technics!

Note

• When you connect a turntable with a PHONO/

LINE switch, be sure to set the PHONO/LINE

switch to PHONO.

• This receiver equipped with Phono Equalizer

amplifier to meet MM type PHONO cartridges.

MM type cartridge used on turntable have a

variation of audio output level. In case MM type

cartridge output is small, you can use phono

volume offset to increase the level (page 28).

• To record the sound from the receiver, you must

connect your device to the AUDIO INPUT 4 OUT

jacks

When I set up the speaker wires I removed the outer casing that housed the red and black wire. So the red and black wires are not bound together....I'm wondering if that could be the issue

@yogiboy input #1 of 4

What input are you using on the Sony?

@grinnell I tried grounding the turntable with the ground wire they provided and  nothing

@dalims4 definitely a deep hum

hi, yes I'm using the SL1500 internal phono preamp. 

Does the Sony have a built in phono stage you are using or are you using the SL1500 internal phono preamp ?

Ground loop  check turntable grounding