Doing a bit of work on my Kenwood KD-3070 turntable. Removed the old lamp wire AC cord and replaced it with a nice more robust 3 prong equivalent. Also used the opportunity to do a full cleaning and setup of the TT's internals/externals.
As of now I do not have the ground wire of the new AC cord connected, it is floating. I have read about ground loops being induced if the ground is used. All my equipment connects to a power strip. Am I ok to connect the ground?
Pics for reference
Inside, note stock power cord on far right
New power cord installed, note green ground wire floating in the middle
As of now I do not have the ground wire of the new AC cord connected, it is floating. I have read about ground loops being induced if the ground is used. All my equipment connects to a power strip. Am I ok to connect the ground?
Pics for reference
Inside, note stock power cord on far right
New power cord installed, note green ground wire floating in the middle
I would guess no. I bought a Teac R2R and its power cord had been replaced and it hummed no matter how I connected it till I removed the ground wire.
Doesn't the turntable have a ground wire? One that your suppose to hook up to the reciever?
If you have 2 grounds then you will definitely get a hum.
Doesn't the turntable have a ground wire? One that your suppose to hook up to the reciever?
If you have 2 grounds then you will definitely get a hum.
It depends.
If you have equipment before the amplifier that is earthed then you don't need a earth connected.
On the other hand if you are using a floating MP3 player or similar then the amplifier needs earthing.
That has been my experience.
If you have equipment before the amplifier that is earthed then you don't need a earth connected.
On the other hand if you are using a floating MP3 player or similar then the amplifier needs earthing.
That has been my experience.
Surely a turntable has two grounds? One is a safety ground, to the incoming supply ground (if available). If built to Class II spec then this ground is unnecessary and must be omitted; otherwise it must be present.
The other is a signal ground, to the phono preamp. These two grounds are not connected together at the turntable.
The other is a signal ground, to the phono preamp. These two grounds are not connected together at the turntable.
This is a 70’s turntable, originally used a 2 prong AC cord.
I am a guitar player and build/repair tube amps. So whenever I see a 2 prong AC cord I want to upgrade it to a modern 3 prong for safety reasons. I am just wondering if I can ground the AC cord for safety reasons and not have a impact on sound...
It appears all the PSU ground, headshell grounds, etc. Go to one common ground point in the turntable chassis.
If the Mains powered equipment meets ClassII (double insulated) standard then leave it as is.
If it is built to ClassI standard then it NEEDS a safety Earth.
The biggest metal component should be connected to the Mains PE wire.
All other conductive parts should be electrically connected to that protected part of the Chassis. Here is the problem !!!!!
Adding a connection from the Safety Earth to the metal arm will almost certainly LOOP into the signal ground/return of the output to the pre-amp.
If one is lucky, then there may be electrical isolation between the arm metal work and the signal return.
I would suspect that most mains powered turntables are built to ClassII standard to avoid the need to connect the arm into the Mains PE wire.
If it is built to ClassI standard then it NEEDS a safety Earth.
The biggest metal component should be connected to the Mains PE wire.
All other conductive parts should be electrically connected to that protected part of the Chassis. Here is the problem !!!!!
Adding a connection from the Safety Earth to the metal arm will almost certainly LOOP into the signal ground/return of the output to the pre-amp.
If one is lucky, then there may be electrical isolation between the arm metal work and the signal return.
I would suspect that most mains powered turntables are built to ClassII standard to avoid the need to connect the arm into the Mains PE wire.
In my opinion it is best to use Class II (double isolated) equipment throughout in the audio chain, or maximum one Class I. Or two Class I power amplifier mono blocks at the end. In this case all previous equipment should be Class II (as they normally are). Most frequent exceptions are tape decks and I wonder how is ground loop avoided at them?
http://www.diyaudio.com/forums/pass...nt-gr-grade-jfets-latfets-10.html#post4199694
If you ground it there will be no floating ground..
I must be more than a little bit slow.
Post9 has a quote, then a link, followed by a comment.
How does the link expand on the quote and what relevance does the link have to your comment?
Post9 has a quote, then a link, followed by a comment.
How does the link expand on the quote and what relevance does the link have to your comment?
Ground zero
My 35 year old PS-X 600 stopped working this morning, after never having any problems. It powers up, but wont spin, I'm hoping it's just a sensor light bulb.
So I'm using a new Pro-Ject Elemental, with a Ortofon 2M Red, feeding an old combo, a Sumo Athena preamp, and Sumo Ulysses. Neither were made with grounded power cords.
The turntable had an annoying 60 hertz hum, and using the supplied ground wire to the grounding terminal on the preamp barely made a difference.
I extended the turntable ground wire, terminated it to the return side of an RCA plug, and put it in the jack of a modern grounded component.
Problem solved, mostly.
Moving an isolation power transformer for the DAC further away finished off the last audible hum.
I did consider connecting the ground wire to the earth prong of a power plug, and plugging it into the power strip everything else is plugged into, but didn't know if that would be safe.
My 35 year old PS-X 600 stopped working this morning, after never having any problems. It powers up, but wont spin, I'm hoping it's just a sensor light bulb.
So I'm using a new Pro-Ject Elemental, with a Ortofon 2M Red, feeding an old combo, a Sumo Athena preamp, and Sumo Ulysses. Neither were made with grounded power cords.
The turntable had an annoying 60 hertz hum, and using the supplied ground wire to the grounding terminal on the preamp barely made a difference.
I extended the turntable ground wire, terminated it to the return side of an RCA plug, and put it in the jack of a modern grounded component.
Problem solved, mostly.
Moving an isolation power transformer for the DAC further away finished off the last audible hum.
I did consider connecting the ground wire to the earth prong of a power plug, and plugging it into the power strip everything else is plugged into, but didn't know if that would be safe.
You appear to be saying that grounding a turntable to something which is not grounded does nothing, but grounding it to a ground stops hum? So what is the point of a 'ground' terminal on an ungrounded preamp?
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