The problem occurs on both decks. At mid to high volume when the needle is on the record if i touch or tap anywhere on the deck u hear the tap thru the speakers . At high volume im getting a rumbling noise which comes and goes. It is not my cartridges, Have just replaced rca cables and ground wire and am pretty sure done it properly.
It would seem that the cabinets on your turntables are not isolated from your ground. When you touch the cabinet your body acts as a ground and changes the overal ground for the entire turntable.
Also, have you tried disconnecting one TT to see if it still does it then disconnecting the other?
Also does it happen with a very light touch that would not create an actual sound or does it have to be a hard tap?
Did you say you soldered your earth wires yourself? If you did is there a chance that there is bare wire touching a surface that should not be grounded like the cabinet or something? If so when you touch the tt your body is causing an impedance change and could cause your noise. Check your ground wires and maybe use wire that has more insulation.
Have you managed to check your ground wires for contact with something they shouldn't be touching yet?
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There are a number of possibilities here, but none explain why two players are behaving the same. I am assuming here that the tables are free to move and are not locked down to the frame as they should be during transport. Touching the table should make it bounce a little, but you should not hear anything. If the platter is tied to the frame, it will still spin and play OK, but will pick up all kinds of noise etc. If the cartridges are of the same age, it is possible that they have become microphonic. This is unlikely but possible.
Keep us posted.
Dan
Hi,
A couple of ideas:
1. placement of speaker(s) affects the performance of the turntables;
2. wear and tear on the needles/cartridge; have you tried replacing both or at least one to verify;
3. are there any other mechanical adjustments such as anti-skid or counter weight that can be fiddled with to eliminate/reduce the issue?
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.
Good luck and kind regards.
Thank you for using FixYa.
Hi
It is most likely you have an acoutsic coupling to the decks from the work surface, mixer, or a roadcase. If any part of the body of the deck is touching anything else, then you will get rumble and acoustic feedback problems. the deck should rest evenly on its own 4 legs, clear of anthing else. Technics sl1200 series decks are the best in the world for acoustic isolation. There will always be some feedback from your decks to speakers. However, only with a really high powered system should give you problems, DJ booths are sometimes suspended from the roof just to eliminate this rumble.
A 1/3 octave EQ (31band) can also be effective at reducing feedback.
regards
robotek
oh and a heavy worksurface, like slate, or even double 33mm mdf board makes a good solid non resonant work surface. You may be getting too much resonance from your wooden work surface.
OK sideyross. I can solve this for you as I have extensive experience in this sort of thing. A few more questions for you. How big is the room are you rippin tunz out in.
Is it techno or hip hop you are playing?
How many watts are you using
What sort of cartridge are you using
how does the setup on the needles LOOK is the cartridge dragging on the record?
You can use the 31 band equiliser to remove the feedback that you are experiencing.
The resonant frquency of the SL1210 tone arm with stylus on the platter is 6 hz. So unless your feedback is subaudible(you cant actaully hear is as much as feel it), you can rule out the tonearms/headshell/cartridge/stylus being the source of the problem, unless they have been setup poorly.
You could try to EQ the room to solve the feedback issues. To do this, you will need the 31 band EQ that I mentioned earlier. There is some wisdom on why written in a great article here
If you have an EQ I can give you step by step instructions on how to tune up your room and minimise feedback problems with your rig.
I await your response to my questions :)
robotek
This guy gives a good shoq on how to tune a room :) I have some extra tips on how to do it with a mic.
It wont be an electrical grounding/earthing problem either. Only if it is mains hum that you are worried about. Poor earth wont produce feedback... just mains hum
the room is kinda small, but you dont have alot of power there. You say 4 channels..Where are the rear speakers? If they are close or acoustically coupled to the bench top you are using for the decks, or mounted of the same wall as the speakers, you will have feedback problems.
I have run up full PA rigs with 6kw to double 15 +H and 18" subs in my band rehearsal rooms that measure only a little bigger than you have. You will get lots of feedback, that can be minimised with a 31 band EQ. Still used to get 140db c wieghted SPL!!
What tracking force do you use? The lighter it is the less wear on your vinyl, so try to set the tracking force to what the manufac reccomend
robotek
is it mains hum? like 60hz or 50 if you are down under. Can you post some youtube so i can hear the problem.
got any audio we can listen to :) Sorry for the impatience. Just want to solve this for you within 7 days or FixYa close this down. Click "Accept" if you want me to keep working with you on this problem.
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Did this issue occur after replacing the RCA cables and ground wire or before? If this is happening after the replacement, it is probably faulty cables/connectors or a faulty grounding.
If it happened even before the replacement of cable/wire, ther could be an issue with the speakers perhaps. Try a different set of speakers if available, and let me know...
Looks more like an earthing problem then..
That was just to eliminate any issue with the speakers.Yes, it definitely seems to be an issue with the grounding. Do check the RCA connectors as well, to make sure they are secure.
Could be a faulty solder, or could be that the wire itself is faulty. How do you earth it ?
Here is a link to the service manual for an SL 1200 model. (Nearly the same as SL 1200:
http://www.eserviceinfo.com/downloadsm/9...
or http://www.backspin.org/sl1200mk2.pdf
There is a possiblity of a faulty capacitor/resistor on the board as well..
If your decks are under warranty, then I'd recommend contacting Technics directly, instead of trying to open the device and find faulty components..
A rumble is quite normal actually, at higher volumes. It could be a rumble cut into the record at the cutting stage, or a rumble on the playback turntable itself. A rumble is not generally caused by a faulty earthing. If the earthing was faulty, you'd get a buzz or humming sound. I just went through your 5th comment and noticed that the hum disappears when you attach the ground to the mixer, which means it is not likely a grounding issue. But check the wiring in any case...
One method to deal with the rumble is to try using a subsonic rumble filter. (Do a Google search for this...)
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Have you tried replacing the tonearm at all?
If it's not the cartridge it is probably the tone arm
Let me know how this works out.
This wire that goes into the deck may be broken or a part branching off of it may be loose. Since this problem recently came up, I'm thinking that either a part over heated and cracked from heating/cooling or something just became loose inside. Please open it up and take a look at everything basically from the needle to the speaker
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Do you have these turntables on an anti-static mat, or some other non-conductive surface?
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No, but I never have, and they worked fine before.
they are on a wooden surface
chances of both tone arms being faulty is surely pretty slim no? wot could be wrong with the tone arm that would cause this?
when i take the earth wire out of back of mixer i hear the hum you get from having no earth when i put it back in the hum is gone does this prove its not an earthing problem? or could it be a very slight bad earth on both decks? if it was only a very slight bad earth would this explain why problem is only evident at higher volumes
one of the decks was definately like this before replaced cables. what could the issue be with the speakers? worked fine with those speakers in the past, use 2 sets of speakers and does it on both
where else apart from in the tone arm or on the phono cord pcb could the earth be faulty? could it be faulty before the point where i solder it on to the pcb.
on the phono cord pcb there is a small grounding tab which already has a small earth wire attached to it, this wire goes further inside the deck, I solder my earth wire 2 this tab and this wire goes out of the deck to my mixer.
what is a 1/3 octave eq? and how would i use it?
have tried it on two different surfaces to no avail
dont see why i should need a rumble filter now when ive never needed one in the past, only get rumble at full volume, is more the touching of the deck being amplified thru the speakers that is bothering me as this happens any where above 1/3 volume, obviously getting worse the more u turn it up although i would imagine both symptoms are being caused by the same thing, if it was an earthing problem would it not be evident at all volumes?
deck is sitting evenly on four legs and touching nothing else apart from the wooden work surface tried on different surfaces and is just the same
The problem occurs on both decks. At mid to high volume when the needle is on the record if i touch or tap anywhere on the deck u hear the tap thru the speakers . At high volume im getting a rumbling noise which comes and goes. It is not my cartridges, Have just replaced rca cables and ground wire and am pretty sure done it properly.
Many thx for ur help.
The room is 13' by 10' by 9'. Is mostly techno im playing. 50 watts per channel on 4 channels amp, 4 100 watt speakers. have tried using stanton 500 and ortofon concorde and both display the symptoms, the ortofon is possibly marginally better but not much. have tried various needles and ones that sit higher keeping tha cart from dragging sound againg marginally better but im still getting the problem.
do not think the room is the problem as i never had this issue before and its still the same room!
it doesnt matter where i put the speakers i still have a problem, tracking forces i use are the same as when didnt have the problem. The tone arm is the only part of the deck that displays the symptoms at all times whether it is on the record or in the rest, when it is on the record the whole deck has this "touching or tapping the deck being amplified thru speakers problem" when the tone arm is in the rest it is only the tone arm itself that has the problem not the chassis of the deck.
no is not mains hum. there is actually no real hum (im pretty sure now thast its earthed properly).
It sounds fine up to about 1/3 volume on the amp after 1/3 volume u start getting the problem i have described , it gets worse the louder u put the amp and when u r at full volume or close to it this is when i get a rumble, (touching the deck seems to induce the rumble. will post some you tube later today
have tried disconnecting one tt to no avail, it happens with a light touch. to me ur initial statement is as close a description to what i think the problem is as ive heard so far.
Works fine on low volume but when I turn it up it makes a horrible noise and the needles jumps over the record
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