Fixing crackle and hum on AR XA table

[DijonMaster]

I recently found an AR XA table at my local savlation army ($15!). I picked it up and it spun and even produced sound. I have it hooked up to a JVC RX-701v receiver.

It seems to crackle and pop consistently, regardless of what record I play. I've cleaned the record and got a new stylus for the included Grado Model B cartridge. The crackling and popping is still present. It's loud, too, so not easily ignorable.

There also seems to be a hum coming from the system. The hum stops whenever I touch the tonearm, but gets louder whenever I get near the headshell (loudest when I come in contact).

Any ideas? I'm not particularly good at wiring, so I'd hope to avoid that but I can figure it out.

 

[j_loop]

Sounds like it's either that cartridge or the tonearm wiring or both. Do you have another cartridge you could test with?

 

[ronaldw441]

Try cleaning the contacts on the back of the headshell & in the receptacle. If you have no contact cleaner use a pencil eraser back and forth on the contacts. Make sure you blow out the end of the receptacle when finished. When replacing the headshell don't over-tighten the retaining ring. Just barely snug is enough. Otherwise you'll scrape off the projections of the headshell bayonet. They're just plastic & won't take much stress.

 

[DijonMaster]

Sounds like it's either that cartridge or the tonearm wiring or both. Do you have another cartridge you could test with?

I sadly don't. This is my first turntable ever.

 

[DijonMaster]

Try cleaning the contacts on the back of the headshell & in the receptacle. If you have no contact cleaner use a pencil eraser back and forth on the contacts. Make sure you blow out the end of the receptacle when finished. When replacing the headshell don't over-tighten the retaining ring. Just barely snug is enough. Otherwise you'll scrape off the projections of the headshell bayonet. They're just plastic & won't take much stress.

I tried with a cotton swab and 100% Alcohol. I'll try again with an eraser

 

[jbrainey]

Clean your album, preferably with a good vacuum cleaning machine. I use a VPI HW-16.5 Record Cleaning Machine. Any other method and you're just moving the dirt around. You'll never eliminate all the pops and clicks because vinyl is a physical medium but, you can eliminate 90% of the "noise".

 

[GChief]

That Grado may be humming also, they do that. The Grado Black I use does but you need to put your ear to the speaker to hear it.

 

[timmy.timmy]

The 'crack & pop' might indeed be due dirty record's groove but if ever too because of the old cable's RCA jacks. They would benefit from a replacement for the better of it all anyway. Only requiring a spare pair of RCA jacks, a soldering gun and a minimum of practice. Child's play ;-)

Grado 'Prestige' series are not shielded and so easily pick-up frequencies if ever but here the issue seems more to do with a grounding issue of the cartridge/tonearm. As when the OP touches the tonearm his body acts as 'ground' but not when he touches the head shell.

Could it be that the OP creates a ground loop when he touches the head shell/cart ? But then why the hum stops when the OP touches the tonearm ? Are the AR XA tonearm's grounded at all ? It seems that not here. Some carts are also extra grounded. Is this the case here ?

Have a friend who had such an issue with his Grado on a Thorens turntable. Exactly the same thing. I'll ask him if he did anything about it or not and to what results if ever...And post it on here if it's still unsolved on this AR XA. Hopefully such annoying issue should be easily sorted.

 

[DijonMaster]

Clean your album, preferably with a good vacuum cleaning machine. I use a VPI HW-16.5 Record Cleaning Machine. Any other method and you're just moving the dirt around. You'll never eliminate all the pops and clicks because vinyl is a physical medium but, you can eliminate 90% of the "noise".

I've been using a cheap record cleaning set,

The 'crack & pop' might indeed be due dirty record's groove but if ever too because of the old cable's RCA jacks. They would benefit from a replacement for the better of it all anyway. Only requiring a spare pair of RCA jacks, a soldering gun and a minimum of practice. Child's play ;-)

Grado 'Prestige' series are not shielded and so easily pick-up frequencies if ever but here the issue seems more to do with a grounding issue of the cartridge/tonearm. As when the OP touches the tonearm his body acts as 'ground' but not when he touches the head shell.

Could it be that the OP creates a ground loop when he touches the head shell/cart ? But then why the hum stops when the OP touches the tonearm ? Are the AR XA tonearm's grounded at all ? It seems that not here. Some carts are also extra grounded. Is this the case here ?

Have a friend who had such an issue with his Grado on a Thorens turntable. Exactly the same thing. I'll ask him if he did anything about it or not and to what results if ever...And post it on here if it's still unsolved on this AR XA. Hopefully such annoying issue should be easily sorted.

I guess I'll learn basic soldering if need be. Could be a fun project. The hum increases when I approach the head shell, which is interesting. I don't even need to touch it. I added a ground and got rid of the hum, but the crackling is still there. It's like static. Maybe it's the cart

 

[sKiZo]

I'd also replace the RCA cables while you're at it. Not uncommon to have those stretched, stressed, and otherwise damaged over time. Grab hold of each cable and bend it here and there and see what happens. You can replace the cables using a cheap pencil iron and good lead solder. Use "composite" cables (TV video) as those tend to be low noise with lower capacitance than off the shelf patch cables.

What are you grounding to? Most receivers will have a ground stud for that, but you can add a spade terminal and hook up to any available screw. A common ground like that can work wonders.

 

[timmy.timmy]

I've been using a cheap record cleaning set,


I guess I'll learn basic soldering if need be. Could be a fun project. The hum increases when I approach the head shell, which is interesting. I don't even need to touch it. I added a ground and got rid of the hum, but the crackling is still there. It's like static. Maybe it's the cart

OK so the AR XA tonearms are not grounded and you just answer to that. Now the crackles could be due to bad contacts. But as you indicate here it seems to be amplified statics of some sort. I suggest the amplified theory as if it sound like static loud 'cracks' it would mean for the static to be amplified pretty loud.

Now that static if it's that could still be very well due to bad nor no grounding where it builds and is then picked up by the cartridge then amplified through the signal out from the speakers. Now is the chassis of the AR XA grounded ? If not try to run another wire from it to any ground post close by and hear if that works.

 

[DijonMaster]

OK so the AR XA tonearms are not grounded and you just answer to that. Now the crackles could be due to bad contacts. But as you indicate here it seems to be amplified statics of some sort. I suggest the amplified theory as if it sound like static loud 'cracks' it would mean for the static to be amplified pretty loud.

Now that static if it's that could still be very well due to bad nor no grounding where it builds and is then picked up by the cartridge then amplified through the signal out from the speakers. Now is the chassis of the AR XA grounded ? If not try to run another wire from it to any ground post close by and hear if that works.

So, the chassis itself seems to be grounded. The ground cable is still attached and I even tried making my own and connecting it to my receiver's grounding post. Is there an easy way to ground the tone arm? I don't mind taking it apart. Would I need to solder anything? I have a bunch of speaker wire I can strip

 

[gkimeng]

AR tonearms are grounded. The braided shield that surrounds the four magnet wire leads connects the arm to the terminal block and the ground wire that is molded into the signal leads.

There should also be a wire connecting the terminal block ground terminal to the subchassis.

Check to see if the braid is screwed down tight to the pivot block and soldered to the terminal block. Your arm isn't grounded if either of those connections is broken. Or if the arm has been rewired and whoever did it didn't run a fifth lead to replace the braid. Or if the audio cables have been replaced without adding a ground wire.

 

[DijonMaster]

AR tonearms are grounded. The braided shield that surrounds the four magnet wire leads connects the arm to the terminal block and the ground wire that is molded into the signal leads.

There should also be a wire connecting the terminal block ground terminal to the subchassis.

Check to see if the braid is screwed down tight to the pivot block and soldered to the terminal block. Your arm isn't grounded if either of those connections is broken. Or if the arm has been rewired and whoever did it didn't run a fifth lead to replace the braid. Or if the audio cables have been replaced without adding a ground wire.

Sorry for the late reply. I checked everything and the arm wires are totally fine. The ground is there and leads to the terminal block and subchassis. It might just be the old grado cartridge that's the issue.

Now to fix the dampening system...

 

[timmy.timmy]

Sorry for the late reply. I checked everything and the arm wires are totally fine. The ground is there and leads to the terminal block and subchassis. It might just be the old grado cartridge that's the issue.

Now to fix the dampening system...

OK, the Grado 'Prestiges' can be "over" sensitive to such issues especially in comparison with other shielded cartridges. But some love them and manage to work it out. If no special love for them, like for everything and everyone, just seek another one. One that you know you'll like.

Now the fact that adding an external 'ground' extension to the tonearm killed the 'hum' or 'buzz' occurring on the tonearm before seems to indicate that the OEM grounding through the cold right signal wiring path is/was 'faulty' somehow... Maybe check that further with a multimeter.

Such commonly factory mounted molded ground path on those turntables (like on my Thorens as well FWIW) to the signal path is something I never like as it makes it troublesome to troubleshoot separately either's path issues if ever. Fixed on mine with an outgoing extra ground wite.

 

[DijonMaster]

OK, the Grado 'Prestiges' can be "over" sensitive to such issues especially in comparison with other shielded cartridges. But some love them and manage to work it out. If no special love for them, like for everything and everyone, just seek another one. One that you know you'll like.

Now the fact that adding an external 'ground' extension to the tonearm killed the 'hum' or 'buzz' occurring on the tonearm before seems to indicate that the OEM grounding through the cold right signal wiring path is/was 'faulty' somehow... Maybe check that further with a multimeter.

Such commonly factory mounted molded ground path on those turntables (like on my Thorens as well FWIW) to the signal path is something I never like as it makes it troublesome to troubleshoot separately either's path issues if ever. Fixed on mine with an outgoing extra ground wite.

Funny enough, i thought adding an external ground killed the hum, but when I took it away, the hum was at the same level. The hum has been pretty good so far, unless I get close to the cart or I turn the volume up. I'm wondering if it's related to the large amount of crackling at all

 

[timmy.timmy]

Funny enough, i thought adding an external ground killed the hum, but when I took it away, the hum was at the same level. The hum has been pretty good so far, unless I get close to the cart or I turn the volume up. I'm wondering if it's related to the large amount of crackling at all

OK, so that ground thing for the tonearm is cleared out for the moment at least. The crackle you refer to are most likely due to bad contacts either at the cartridge pins (but you cleaned those) or the RCA jacks of the cables. A common issue with old corroded RCA jacks.

 

[DijonMaster]

OK, so that ground thing for the tonearm is cleared out for the moment at least. The crackle you refer to are most likely due to bad contacts either at the cartridge pins (but you cleaned those) or the RCA jacks of the cables. A common issue with old corroded RCA jacks.

I may have to rewire the RCA jacks. Been looking for a new hobby anyway.

I forgot to mention, but the grado cart seems to have some weird white residue inside of it. I was able to clean most of it off, but some is plastered on. Wondering if it could just be a dud cart

 

[rothwellaudio]

Having the turntable sitting directly on top of an amp is not a great idea. It could be picking up hum from the mains transformer in the amp. Simply taking the turntable off the amp and moving it away might cure the hum. Might, but it's quick and easy to try it.

 

[timmy.timmy]

Having the turntable sitting directly on top of an amp is not a great idea. It could be picking up hum from the mains transformer in the amp. Simply taking the turntable off the amp and moving it away might cure the hum. Might, but it's quick and easy to try it.

Good move there. Since I didn't open the picture I wondered how you'd have know that... But yes evidently ; take the turntable off the amp.