marcmorin
RIP 1953-2020
sounds like an issue. poor contact, cold solder joints, etc, have a major affect on signal. Sometimes becoming diodic in nature.
AR-XA tonearm ground wire?
- Thread starter jleon92f
- Start date
sounds like an issue. poor contact, cold solder joints, etc, have a major affect on signal. Sometimes becoming diodic in nature.
Still no progress with eliminating the buzzing.
I tried cleaning the buss strip as well as the spade connectors on the RCA lead that connect to it using fine sand paper and a file. I also made sure the spades were a tight fit. I have cleaned the RCA connectors at the amp end on several occasions already but had another go.
Following this I tried swapping the RCA leads with those from an XB that I have acquired just a couple of days ago. No change with these either which should rule out the RCA leads as the problem unless I have been unlucky and both have the same issue.
I have had another go at the ground wire connection to the tonearm base using a screw with a Philips head that I can get real tight. Next time I disassemble the arm I will probably solder direct to the inside of the arm tube to try to rule that out as well.
The buzz is in both channels but very mild which would suggest the issue lies with the main grounding rather than cartridge ground connectors. However to be sure I have tried several different cartridges with no difference. The problem also appeared when I used a bayonet headshell arrangement with prewired connectors. I have now eliminated the headshell as an issue completely with cardas wires direct from the cartridge tags through to the buss in a fixed headshell setup.
I have resoldered the tonearm wires to the buss strip on numerous occasions. The ground wires that connect to the t bar and to the chassis screw are both screwed in tight. There is a small amount of fraying on the ground wire that connects to the t bar but not on the one I swapped from the XB deck so I don't think the fraying is an issue.
The issue I mentioned when continuity testing also applies to the XB. Though I am still suspicious it may well be this is normal.
At the moment I am out of ideas. Anyway I now have an XB to work on so unless someone has further ideas I will park this issue for a while.
I tried cleaning the buss strip as well as the spade connectors on the RCA lead that connect to it using fine sand paper and a file. I also made sure the spades were a tight fit. I have cleaned the RCA connectors at the amp end on several occasions already but had another go.
Following this I tried swapping the RCA leads with those from an XB that I have acquired just a couple of days ago. No change with these either which should rule out the RCA leads as the problem unless I have been unlucky and both have the same issue.
I have had another go at the ground wire connection to the tonearm base using a screw with a Philips head that I can get real tight. Next time I disassemble the arm I will probably solder direct to the inside of the arm tube to try to rule that out as well.
The buzz is in both channels but very mild which would suggest the issue lies with the main grounding rather than cartridge ground connectors. However to be sure I have tried several different cartridges with no difference. The problem also appeared when I used a bayonet headshell arrangement with prewired connectors. I have now eliminated the headshell as an issue completely with cardas wires direct from the cartridge tags through to the buss in a fixed headshell setup.
I have resoldered the tonearm wires to the buss strip on numerous occasions. The ground wires that connect to the t bar and to the chassis screw are both screwed in tight. There is a small amount of fraying on the ground wire that connects to the t bar but not on the one I swapped from the XB deck so I don't think the fraying is an issue.
The issue I mentioned when continuity testing also applies to the XB. Though I am still suspicious it may well be this is normal.
At the moment I am out of ideas. Anyway I now have an XB to work on so unless someone has further ideas I will park this issue for a while.
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Come across a grounding issue with my XB which seems worth describing here.
The deck appears to be in original condition re tonearm wires and phono RCA leads and my preference is to keep this deck original for reference purposes.
When I first tried it on my main system the deck played with sound from both channels but with a definite hum that is audible during playback on quiet passages. I also noticed crackling if I touched the collar that holds the headshell in place. I have two headshells I can use and the crackling was the same with both.
I then carried out some cleaning of the various connectors from the headshell tags to the buss strip through to the RCA plugs. I also tried to ensure all connections were tight and secure. The hum remained.
After a further round of cleaning I then decided to try the deck on a second simple setup using a Furatech ADL GT40 as combined phono stage and pre amp into an old Rotel power amp. There was no hum (not even the faint buzzing I get from my XA) but I still get the crackling from the headshell collar.
From this I can conclude that I have a ground loop issue between the XB and my main system. The XB is the only one of my decks with this ground loop issue. The cracking at the headshell is probably a separate issue to the hum and at this stage less of a concern to me.
On examining the wires inside the XB I do notice that one of the ground leads from the RCA cable terminates at the base of the arm rest which is different to the XA.
There is also another blue lead terminating at the base of the arm rest that appears to be linked to the green/yellow earth wire in the power lead. The link between blue wire and yellow/green is covered by masking tape. This lead concerns me because there is no equivalent on my XA which has no earth wire in the power lead. I understand that no earth is standard for the XA decks.
Will Marc or any other XB owner who knows about these things please advise if the arrangement on my XB is standard or non standard.
Thanks
The deck appears to be in original condition re tonearm wires and phono RCA leads and my preference is to keep this deck original for reference purposes.
When I first tried it on my main system the deck played with sound from both channels but with a definite hum that is audible during playback on quiet passages. I also noticed crackling if I touched the collar that holds the headshell in place. I have two headshells I can use and the crackling was the same with both.
I then carried out some cleaning of the various connectors from the headshell tags to the buss strip through to the RCA plugs. I also tried to ensure all connections were tight and secure. The hum remained.
After a further round of cleaning I then decided to try the deck on a second simple setup using a Furatech ADL GT40 as combined phono stage and pre amp into an old Rotel power amp. There was no hum (not even the faint buzzing I get from my XA) but I still get the crackling from the headshell collar.
From this I can conclude that I have a ground loop issue between the XB and my main system. The XB is the only one of my decks with this ground loop issue. The cracking at the headshell is probably a separate issue to the hum and at this stage less of a concern to me.
On examining the wires inside the XB I do notice that one of the ground leads from the RCA cable terminates at the base of the arm rest which is different to the XA.
There is also another blue lead terminating at the base of the arm rest that appears to be linked to the green/yellow earth wire in the power lead. The link between blue wire and yellow/green is covered by masking tape. This lead concerns me because there is no equivalent on my XA which has no earth wire in the power lead. I understand that no earth is standard for the XA decks.
Will Marc or any other XB owner who knows about these things please advise if the arrangement on my XB is standard or non standard.
Thanks
marcmorin
RIP 1953-2020
there should be no connection to your wall ground. I have no idea why there would be other wires attached to where the top plate grounds at arm post.
Marc - is it normal for the XB power leads to have 3 wires including earth or are they usually the same as the XA with 2 wires and no earth?
I am wondering if someone at some time in the past has tried to incorporate a earth wire into a replacement power lead for the deck and used this configuration.
Thanks
I am wondering if someone at some time in the past has tried to incorporate a earth wire into a replacement power lead for the deck and used this configuration.
Thanks
woodj - definitely have a three wire power lead on mine. Don't know the origin or history of the deck. I am no expert but am wondering if it has passed through a dealer who felt a rewire was needed for H&S. I know with my XA that I had to do corrective action on a lead that was getting badly frayed.
Mixed indications from the state of the deck concerning how well it was looked after. It came with a lid in quite good condition and original manual suggesting not too many prior owners plus spare belt that suggests someone tried to keep the deck going.
However there are various marks on the inner platter which is quite tatty plus rubber detritus on the pully from belt wear as well as on the inner platter where the belt runs so not much recent maintenance. Not much oil in the bearings which I have topped up.
Mixed indications from the state of the deck concerning how well it was looked after. It came with a lid in quite good condition and original manual suggesting not too many prior owners plus spare belt that suggests someone tried to keep the deck going.
However there are various marks on the inner platter which is quite tatty plus rubber detritus on the pully from belt wear as well as on the inner platter where the belt runs so not much recent maintenance. Not much oil in the bearings which I have topped up.
marcmorin
RIP 1953-2020
should be two, and only two wires from the table to the wall socket. No ground circuit to the wall socket. The hot side of mains power is attached to the summed top white motor wire and green motor wire. The red motor wire goes to one side of the phase cap. the bottom white wire attaches to the other side of the phase cap and yellow wire from ON/OFF switch. Black wire from ON/OFF switch attaches to mains neutral side.
Hopefully attached is an image of the wires where the taped end of the blue wire is visible joined to the green/yellow wire that is part of the power lead.
If I remove the blue wire and terminate /insulate the green/yellow wire would that be a viable way of verifying if the additional grounding is the cause of the ground loop.
If I remove the blue wire and terminate /insulate the green/yellow wire would that be a viable way of verifying if the additional grounding is the cause of the ground loop.
Attachments
marcmorin
RIP 1953-2020
if the green/ yellow wire runs to the mains ground, you don't have to insulate it. That heavy blue wire will affect the suspension if left attached to the subchassis.
if you still get hum after that, you need to get a DVOM and start checking your "correct" grounds to see where the problem is. Somthing is open or high resistance to ground at the preamp
Marc - some progress
I attach a photo of the blue wire as attached to the base of the arm rest. I think there is enough slack in the thing that it should not interfere with the suspension. Anyway I removed it and no ground loop hum on my main system so the wire was clearly contributing to the problem.
However I am now detecting the same low level buzzing as with the XA. Perhaps a bit milder than the XA. It is not at a level on either deck that it interferes with listening but I would prefer to get the grounding sorted so that it is gone.
As I did not recall hearing the buzzing yesterday on the simple system I reconnected the blue wire and retried it on that system. There is no buzzing though I now hear a very very mild hum with volume at max that I did not notice yesterday.
Not sure if this gets me any closer to resolving the buzzing but for the moment I will continue my maintenance work on the XB with the blue wire gone.
Thank you for your advice.
I attach a photo of the blue wire as attached to the base of the arm rest. I think there is enough slack in the thing that it should not interfere with the suspension. Anyway I removed it and no ground loop hum on my main system so the wire was clearly contributing to the problem.
However I am now detecting the same low level buzzing as with the XA. Perhaps a bit milder than the XA. It is not at a level on either deck that it interferes with listening but I would prefer to get the grounding sorted so that it is gone.
As I did not recall hearing the buzzing yesterday on the simple system I reconnected the blue wire and retried it on that system. There is no buzzing though I now hear a very very mild hum with volume at max that I did not notice yesterday.
Not sure if this gets me any closer to resolving the buzzing but for the moment I will continue my maintenance work on the XB with the blue wire gone.
Thank you for your advice.
Attachments
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Marc - the blue wire is off the deck.
woodj - at the moment I am still using the 3 wire cord because that is how the deck arrived but if it is better to go to a 2 wire cord then I will look to do it. Electrics and in particular mains leads is not a subject I have experience so I need to take care.
woodj - at the moment I am still using the 3 wire cord because that is how the deck arrived but if it is better to go to a 2 wire cord then I will look to do it. Electrics and in particular mains leads is not a subject I have experience so I need to take care.
marcmorin
RIP 1953-2020
it doesn't matter if the cord you are using is 2 or 3 prong......as long as the ground on the cord is not attached to anything metal on the table