I have a Technics SL-B200, and there is static sound in the signal while it's turning. The same sound is repeating every times. I found that it is a ground issue because when I touch the shaft with a grounded wire(with a lot of pressure), it stops.
I'm not quite sure which shaft you are talking about - is it the shaft the platter rotates on? Or is it the bearing shaft in the motor? You probably know what you're describing, but we don't!! However, if it is the platter shaft, or the motor shaft, then it certainly shouldn't have any static when it turns. Usually most turntables have a separate grounding wire to ground the tonearm. In most cases it's best to earth that to mains earth at the amplifier. However, some cartridges earth the body of the cartridge, and the headshell (and hence the tonearm) via the signal leads, in which case it's sometimes quieter not to connect the turntable earth wire, due to problems with earth loops. It's often a matter of experimentation to find the best result.
Anyway, after a bit of rambling, what I was getting to, is that if the tonearm is earthed, then you may be able to earth the shaft (whatever shaft it is!!) by running a wire from the tonearm earth, which is normally accessible at a tagstrip underneath the turntable, at the rear, where the signal and earth leads are terminated. Try it out with a crocodile clip leads to see if it reduces your static, then break out the soldering iron if it does. You may be able to make up a lead using a ring terminal to terminate to a screw, at the shaft?? end. I'll get back here in a few days to see if that has helped you, or if I've grabbed the wrong end of the stick, due to not knowing what you were asking!
The other thing is, does the static vary when the tonearm is moved towards the centre of the record? If it varies depending on the position of the tonearm, it may indicate that the static is being induced into your cartridge, from the motor, or something else. Anyway, try playing around with earths to see if you can cure it. It sounds like you are on the right track, if you can cure it with an earth wire. Usually the most common problem with turntables is hum, often caused by earthing problems, or induction into the cartridge from a transformer. Keep the turntable well away from things like amps is the cure for that.
Anyway, after a bit of rambling, what I was getting to, is that if the tonearm is earthed, then you may be able to earth the shaft (whatever shaft it is!!) by running a wire from the tonearm earth, which is normally accessible at a tagstrip underneath the turntable, at the rear, where the signal and earth leads are terminated. Try it out with a crocodile clip leads to see if it reduces your static, then break out the soldering iron if it does. You may be able to make up a lead using a ring terminal to terminate to a screw, at the shaft?? end. I'll get back here in a few days to see if that has helped you, or if I've grabbed the wrong end of the stick, due to not knowing what you were asking!
The other thing is, does the static vary when the tonearm is moved towards the centre of the record? If it varies depending on the position of the tonearm, it may indicate that the static is being induced into your cartridge, from the motor, or something else. Anyway, try playing around with earths to see if you can cure it. It sounds like you are on the right track, if you can cure it with an earth wire. Usually the most common problem with turntables is hum, often caused by earthing problems, or induction into the cartridge from a transformer. Keep the turntable well away from things like amps is the cure for that.
Yes, platter shaft.
The tonearm changes nothing and there is currently no cartridge.
Every shields are connected to the same separate earth cable in this TT. (Technics SL-B200)
I don't know if the grounding of the tonearm is on the same wire, but the shield around the output jacks is.
The static sound happens when the 3 (earth, L, R) cables are connected. If I push really hard on the platter shaft with an other cable connected also to earth, it stops. (But there's still hum)
It seems that there is a poor contact in the bearing...
The tonearm changes nothing and there is currently no cartridge.
Every shields are connected to the same separate earth cable in this TT. (Technics SL-B200)
I don't know if the grounding of the tonearm is on the same wire, but the shield around the output jacks is.
The static sound happens when the 3 (earth, L, R) cables are connected. If I push really hard on the platter shaft with an other cable connected also to earth, it stops. (But there's still hum)
It seems that there is a poor contact in the bearing...
You may need to try it out with a cartridge plugged in, to see if it is still there then. It may disappear when your phono preamp is correctly terminated in a cartridge. Tonearms in many turntables generally have a separate earth wire - you plug in the left and right RCA plugs (or sockets, if that's what is on the TT) into the phono preamp to connect to the cartridge, which is usually not earthed, and then to earth the tonearm a separate lead, usually with a bare wire end or a spade terminal, connects to an earth teminal, often a screw terminal next to the phono input, on the preamp. I managed to get a manual for the Technics SL-1200Mk5 from Panasonics' website, and it shows a separate earth lead. However, they didn't have any manuals for similar belt drive turntables to yours, so I couldn't check it. It's a pity that more manufacturers aren't as good as Yamaha, who have operating instructions for many of their hi-fi components available for download. Panasonic seem to only have very recent models available on their website.
The cartridge is generally floating, to avoid earth loops, as often the main amplifier earth is in the power amp. If the platter isn't being earthed properly, then it may be something that comes right with a bit of use, if it's caused by an oxide or dirt build up in the bearing. You could check the resistance between the platter and the tonearm. If the platter is floating above earth, then you may have to earth it with a wire from the tonearm base to the metal base at the bottom of the platter (whatever that's called). Having said that, the Japanese are great at producing equipment which technically should have the metal case grounded, but only has a two wire mains cord, without an earth wire, thus leaving everything floating! That should be OK if it's a double insulated appliance, but if it has a metal case, and the active wire shorts to the case, it becomes bloody dangerous, particularly for those of us with 220-240V AC mains.
The cartridge is generally floating, to avoid earth loops, as often the main amplifier earth is in the power amp. If the platter isn't being earthed properly, then it may be something that comes right with a bit of use, if it's caused by an oxide or dirt build up in the bearing. You could check the resistance between the platter and the tonearm. If the platter is floating above earth, then you may have to earth it with a wire from the tonearm base to the metal base at the bottom of the platter (whatever that's called). Having said that, the Japanese are great at producing equipment which technically should have the metal case grounded, but only has a two wire mains cord, without an earth wire, thus leaving everything floating! That should be OK if it's a double insulated appliance, but if it has a metal case, and the active wire shorts to the case, it becomes bloody dangerous, particularly for those of us with 220-240V AC mains.
Yes, I should try with my old cart. Do I need to also put the needle?
Try the SL-BD20D manual that you can find @ Vinyl Engine.
http://www.vinylengine.com/manuals_technics.shtml
There is a separate ground wire in my case, but all I know is that it's grounding the auto-stop mechanism and the RCA jacks PCB shield. I should look to see if the tonearm is grounded too.
In my case, the TT is in heavy gauge plastic so the chassis can't be completely grounded 🙁
All my HiFi components are made with 2-prong wires, but the chassis is never connected to the AC line. Sometimes it's left disconnected and sometimes it's connected thru a ferrite bead or a cap to the DC ground. Oh, an exception, all my EICO equpt. are using 3-prongs now. They were connected to one of the 2-prong wires thru a cap to the chassis before. If I plugged the plug on one side, and that the chassis was not grounded, I was getting 80v when it was on and 0 when it was off. If I plugged the plug the other side, I had 80v when it was off and 0v when it was on...
I decided to change the wires when a rca male-male adapter was under my knee and I touched the wallplate screw while I was plugging something in the plug... I measured the difference between both and it was 80v.
Yes, Yamaha is unbelievable when it comes to support, they told me the *specs* of an adapter for an old '70s PortaSound. They didn't tell me which one to buy, but the specs!
Try the SL-BD20D manual that you can find @ Vinyl Engine.
http://www.vinylengine.com/manuals_technics.shtml
There is a separate ground wire in my case, but all I know is that it's grounding the auto-stop mechanism and the RCA jacks PCB shield. I should look to see if the tonearm is grounded too.
In my case, the TT is in heavy gauge plastic so the chassis can't be completely grounded 🙁
All my HiFi components are made with 2-prong wires, but the chassis is never connected to the AC line. Sometimes it's left disconnected and sometimes it's connected thru a ferrite bead or a cap to the DC ground. Oh, an exception, all my EICO equpt. are using 3-prongs now. They were connected to one of the 2-prong wires thru a cap to the chassis before. If I plugged the plug on one side, and that the chassis was not grounded, I was getting 80v when it was on and 0 when it was off. If I plugged the plug the other side, I had 80v when it was off and 0v when it was on...
I decided to change the wires when a rca male-male adapter was under my knee and I touched the wallplate screw while I was plugging something in the plug... I measured the difference between both and it was 80v.
Yes, Yamaha is unbelievable when it comes to support, they told me the *specs* of an adapter for an old '70s PortaSound. They didn't tell me which one to buy, but the specs!
Just found that the shaft is grounded thru it's bearing. The bearing is full of graphite powder, which is oily. Should I clean the shaft and put new one? I feel scratches when turning it manually.
Yes, that may be a good idea. It may be worth having a look at either the operating manual, or probably more likely, the service manual. I had a brief look at the operating manual for the SL-B202 that I downloaded off the Vinyl Engine website, but it didn’t have any info on maintaining the bearings in it. It’s a pity that the Vinyl Engine website currently seems to have service manuals only for the Technics direct drive turntables, rather than the belt drive turntables. However, if you can find someone with a service workshop which was operating back in the 1970’s and 1980’s, they may let you have a quick look at the service manual if they have it – even photocopy it, if you treat them well! (Who said buy them a beer?!!)
Other than that, you may have to buy a service manual, from one of the sellers around. Make sure you deal with somebody who’s been around for a while, and with a good reputation, so you don’t get ripped off, if you buy one. A few years ago I bought a service manual off a company who had a very impressive website, but didn’t get anything in return, and no answer to emails. A few months later the website disappeared, leaver me slightly poorer and wiser for the experience! It has since been restarted, but I don’t know if it’s the same company or not – it’s the www.servicemanuals.net website. Personally, I’d now deal with other companies which have been around longer, and have a good reputation, like High Country Service Data here in Australia http://www.hcsd.com.au . A number of them sell on Ebay, which can give you an idea of how honest they are from the feedback they receive.
There is some discussion on slightly older Technics belt drive turntables at http://forum.ecoustics.com/bbs/messages/1/294.html . You may be able to find some info there that is helpful. I would say that if there is a course or gritty feel to the bearing, then it definitely needs to be cleaned and re-oiled. Probably something like WD-40 or CRC would be able to clean it out, although you’d need to drain it off and dry it out afterwards. There is some conjecture on what is the correct oil to use. I have heard light oil such as sewing machine oil is OK, but some sites sell the black, graphite-based oils, usually for slightly more. Elex Atelier (Lp Gear) sell their own brand of black oil – it’s available at http://www.lpgear.com/Merchant2/mer...=LG&Product_Code=LPGZBEAROIL&Category_Code=PE . J A Michell recommend using a synthetic oil, such as Mobil One 0W40 for their turntable bearings. And AJ Van den Hul, the excellent Dutch cartridge manufacturer and repairer, says on his FAQ page that he cleans and re-oils his turntable bearings every two years. He also says that you should make sure that you don’t get the oil anywhere a phono cartridge, as apparently it often causes them to fail.
Other than that, you may have to buy a service manual, from one of the sellers around. Make sure you deal with somebody who’s been around for a while, and with a good reputation, so you don’t get ripped off, if you buy one. A few years ago I bought a service manual off a company who had a very impressive website, but didn’t get anything in return, and no answer to emails. A few months later the website disappeared, leaver me slightly poorer and wiser for the experience! It has since been restarted, but I don’t know if it’s the same company or not – it’s the www.servicemanuals.net website. Personally, I’d now deal with other companies which have been around longer, and have a good reputation, like High Country Service Data here in Australia http://www.hcsd.com.au . A number of them sell on Ebay, which can give you an idea of how honest they are from the feedback they receive.
There is some discussion on slightly older Technics belt drive turntables at http://forum.ecoustics.com/bbs/messages/1/294.html . You may be able to find some info there that is helpful. I would say that if there is a course or gritty feel to the bearing, then it definitely needs to be cleaned and re-oiled. Probably something like WD-40 or CRC would be able to clean it out, although you’d need to drain it off and dry it out afterwards. There is some conjecture on what is the correct oil to use. I have heard light oil such as sewing machine oil is OK, but some sites sell the black, graphite-based oils, usually for slightly more. Elex Atelier (Lp Gear) sell their own brand of black oil – it’s available at http://www.lpgear.com/Merchant2/mer...=LG&Product_Code=LPGZBEAROIL&Category_Code=PE . J A Michell recommend using a synthetic oil, such as Mobil One 0W40 for their turntable bearings. And AJ Van den Hul, the excellent Dutch cartridge manufacturer and repairer, says on his FAQ page that he cleans and re-oils his turntable bearings every two years. He also says that you should make sure that you don’t get the oil anywhere a phono cartridge, as apparently it often causes them to fail.
Thanks, I'll have a look... Once I'll have a cart!
For the SMs I found this site:
http://www.arihantelectronics.com/
I doubt that it is a real site, but they are 5$ and you pay thru PayPal, so you have protection against fraud. This guy goes to the manufacturer's site in the authorised repair center's section that requires login and uploads it to a server and give you a temp. link.
For the SMs I found this site:
http://www.arihantelectronics.com/
I doubt that it is a real site, but they are 5$ and you pay thru PayPal, so you have protection against fraud. This guy goes to the manufacturer's site in the authorised repair center's section that requires login and uploads it to a server and give you a temp. link.
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