What Are the Advantages of the signal lp？

cr0wl3y said:

Actually I did try a couple of things: What gave the best result was connecting the tone-arm ground to the signal ground - total silence was achieved. I also know that another solution that works is connecting the tone-arm ground to both internal TT grounding point and pre-amp chassis ground - this was the original set up and the stock tonearm of the 1210 is similar to the Jelco, in the sense that both have separate arm ground to cartridge/signal.

More than anything I wanted to get people's feedback and thoughts to understand what is causing all this. Have always struggled to properly understand what causes ground loops and by implication I have always struggled with "best practices" for grounding, so would really appreciate any explanation based on this practical example.

See also:
What Rating Is an Explosion-Proof Light?
Understanding Radiation Measurement Instruments
How to choose the LCD splicing screen and LED splicing display screen?
Exploring Ebike Battery Connections: Unveiling the Power Link
Unveiling the Functionality of Tension Clamps: A Comprehensive Guide
Tips for Choosing Rack Enclosures: A Comprehensive Guide for Seamless Integration
What Is a Limit Switch? Click to expand...

I didn't have to do this because the green wire from my player connects to the metal tone arm only. The rest of it is plastic except for the motor. Being double insulated, it was sold with a two wire power cord, in 1979. So the safety ground was not involved with the turntable, only with the case of the mixer. I got to dead quiet "hum" by attaching the green wire to the mixer case, which was isolated from the RCA rings which were analog "ground". The mixer did hum with the RCA rings touching case, as the mixer was designed & sold. Polarity of player power cord doesn't matter, no hum either way. It is belt drive so no connection motor to platter (plastic) or to LP either.
Also my "obsolete" 1970 amp has no safety ground connection either , so no ground loop there either. Don't try this ground loop extermination method at home fans, you might shock your grand-child on an amp case. I don't have any, toddlers are kept out with a entryway lock. Too many choke hazards in here for toddlers, too.
Ground loops are common in bands, where the instrument analog ground is connected to the mixer ground, which is safety grounded, and the power amp is safety grounded, so instrument cable to wall plug through wall wiring to mixer to instrument shield is a big area ground loop. With all that beer being slung around, and performers touching analog ground on the mikes with their faces, safety grounding is important. Bands have to use transformer or differential op amp "DI" units to separate the instrument cables from the wall wiring, to break the ground loop.

I didn't have to do this because the green wire from my player connects to the metal tone arm only. The rest of it is plastic except for the motor. Being double insulated, it was sold with a two wire power cord, in 1979. So the safety ground was not involved with the turntable, only with the case of the mixer. I got to dead quiet "hum" by attaching the green wire to the mixer case, which was isolated from the RCA rings which were analog "ground". The mixer did hum with the RCA rings touching case, as the mixer was designed & sold. Polarity of player power cord doesn't matter, no hum either way. It is belt drive so no connection motor to platter (plastic) or to LP either.Also my "obsolete" 1970 amp has no safety ground connection either , so no ground loop there either. Don't try this ground loop extermination method at home fans, you might shock your grand-child on an amp case. I don't have any, toddlers are kept out with a entryway lock. Too many choke hazards in here for toddlers, too.Ground loops are common in bands, where the instrument analog ground is connected to the mixer ground, which is safety grounded, and the power amp is safety grounded, so instrument cable to wall plug through wall wiring to mixer to instrument shield is a big area ground loop. With all that beer being slung around, and performers touching analog ground on the mikes with their faces, safety grounding is important. Bands have to use transformer or differential op amp "DI" units to separate the instrument cables from the wall wiring, to break the ground loop.