More Turntable Issues- Help!

[dr8track]

Arrrrggghh! Turntables! Well, after finally tracking down a Stanton quadrahedral replacement stylus for my Stanton quad cartridge, I now have new problems.
Before replacing the stylus on my turntable it functioned fine. When I got the new stylus I did the following;
1. Unscrewed the ring on the tonearm and detached the cart shell. (I realized after actually replacing the stylus that I didn't need to actually remove the shell from the tonearm)
2. I unplugged the old stylus and plugged in the new one.
3. I cleaned the end of the cart shell that plugs into the tonearm with an electronic cleaner
4. I mounted the new cart and aligned it using an alignment jig.
5. I plugged it all back into the Marantz CD-400 and attempted to play a stereo record. I found there was no output out of the left channel. I then tried to play a quad album. Same problem, no output out of the left channel.
6. I unplugged the turntable from the Marantz and plugged it directly into the phono input on my amp. Same problem, but I did discover that if I turned the Right Channel volume off and turned the master volume waaaay up, there actually WAS sound coming out of the Left channel. It was just very faint.
So, there is audio coming out of the Left channel. It's just very faint in comparison to the Right. (It wasn't this way before I removed the shell and changed the stylus)
7.I wiggled the phono input connectors going into the amp to see if maybe there was a short in the cord. It didn't make any difference.
8.I then removed the cart shell, took the connector wires off the left channel of the shell, cleaned the contacts and firmly placed the connectors back on. I checked to make certain all the other connector wires were on firmly.
9.I put the shell back on the turntable and tried it again. Same problem. Low audio out of the Left channel.
10.I wondered if it could somehow be a problem with the new stylus. I took the new stylus out and placed the old stylus in the shell. Same problem. Weak audio on the left channel.

So now I'm stumped. I would appreciate any suggestions anyone might have. Everything worked fine until I removed the shell and replaced the stylus.

 

[Quadwreck]

Detatch the head shell and insert a small screwdriver against the right positive terminal inside the tonearm, and then against the left positive terminal. You should hear a loud deep hum/buzz in each (there are also two negative terminals that won't give you any signal). If one is not as loud as the other, than the problem lies in your internal wiring or in your cable. You then have to get inside the turntable and touch the terminals where the cable meets the internal wiring (have the headshell off). If the sound isn't equal, then it's your cable or the end plugs that need replacing. If you hear equal noise in the tonearm test, then your cartridge may be shorted and needs replacing. Before you do that, detatch the headshell wires from the cartridge and hold each positive wire in your fingers (with the headshell attatched). Equal sound? It's your cartridge. Actually, try this last recommendation first.

 

[dr8track]

Thanks for the suggestions. Before I proceed any further I'll tell you what I've found from your suggestions. When I touch the contacts on the tonearm with the shell removed the buzz is much louder on the right contact. Very quiet on the left.
With the shell on the tonearm with the positive wires disconnected the buzz is much louder when I hold the right positive wire than it is with the left positive wire.
So, if I'm understanding correctly I need to take the turntable apart and find where the RCA cables connect to the inside of the turntable? Checking those internal connections where my RCA cables meet the internal wiring should let me know if it's in that connection? I'm assuming if the sound is equal at that connection then you're saying that it is probably a short in the left cable where it plugs into the amp?
If I'm on the right track I'll proceed with seeing if I can tear my turntable apart.
Thanks for the advice.

 

[Quadwreck]

The next step is to check your internal connections where your RCA cable connects to the tonearm wires. The headshell should be disconnected, as well as the turntable's power cord. By touching the right (red) and left (white) positive wires without touching anything else, you should hear the hum/buzz (bah! humbuzz!) equally if everything is OK with your cable. If it's weaker on one side, then your cable or one of the end plugs needs replacing. When soldering in a new one, the connection scheme is right: red-positive, green-negative, left: white-positive, blue-negative (and black is the ground). My experience is that the plugs are usually the problem, and the most common break in a cable is right where it exits the turntable.

 

[dr8track]

That reminds me of another question I had about the turntable input cable with the RCA plugs and ground wire.
It seems that I remember reading that a CD-4 turntable requires a special type of connecting cable? My Technics SL-1200 was purchased during the 70's specifically for quad. The cables connecting to the RCA plugs are very heavy duty. I always thought it was just because it was a higher end turntable, but I'm now wondering if the size of those cables doesn't have something to do with quad playback. If so, are their any sources for purchasing new cables appropriate for CD-4 playback? I actually wouldn't mind putting a slightly longer cable on the turntable anyway. It just barely reaches my Marantz decoder and the setup controls on the Marantz are on the back. It would be much more convenient if I had enough cable to pull it out about a foot so I could have easier access to those controls.
So, my question is, does CD-4 playback require special cables to the RCA plugs? If so, what would I ask for when looking for them and where might I start my search?
Thanks again for all the assistance.

 

[radioheadrox]

I believe that the CD-4 specs called for low capacitance cabling (thats why the cables are heavy duty) in an effort to preserve the carrier signal. I'm not sure if this is absolutely required, but I would think keeping the cables as short as possible would be a good idea. I'm not sure where you could buy some low capacitance cables now; maybe someone else here would know.

James

 

[Cai Campbell]

I can't help but think that the cartridge may have been damaged when you were cleaning it. Do you think that is a possibility? I remember you mentioning you cleaned the part where the stylus connects to the cartridge body, right? That's probably something I wouldn't have done.

 

[Obbop]

If ya'll be needing new cables I posted a link within the last 2 weeks or so to the Panasonic parts site where you can input your TT model number and see what parts are avaiable. There were still quite a few for my SL-1300 so I betcha' they have at least that many for your model.

Forgot where I placed the link..... perhaps the off-topic or quad hardware area.

 

[Obbop]

Ahhhhh, here it is:

www.pasc.panasonic.com/ep...hoice.asp?

And here's the page for the SL-1300:

www.pasc.panasonic.com/ep...tsList.asp

If the page doesn't load go to the search page. Ensure you hit the button vice "enter" on your keyboard.

Lots of parts there!!!!

 

[AllAroundSurround]

I aredy check as I have an sl1360 series tt, and no go for the cables
I wanted to change the cables .I know they are out there but can'y find them or the site I saw them at?:| :x
0] Rob

 

[dr8track]

Thanks for the link for the cables. Regarding Cai's question about possibly damaging the cartridge, yes, that's the first thing I was concerned about since both channels worked before I removed the cartridge. However, I've done all the tests that quadwreck suggested and the source of the problem really seems to be before it reaches the cartridge.
1.If I remove the cartridge and touch the R & L terminals in the tonearm there is a louder buzz on the R side than the L side.
2. If I remove the RCA phono plugs from the amp and touch one to the R input then one to the L input there is a louder buzz on the R channel.

So, if I did some damage by using that electronic cleaner it seems like maybe the damage was done to the tonearm connections? I'm pretty electonically illiterate, so it's tough for me to be sure what the problem is.
Not sure if I should just go ahead and get another low capacitance cable or if there's more I can check out first to determine the source of the problem.

 

[The Quadfather]

I have had that very same problem. I wetted a Q-tip with alcohol and used it to clean the contacts in the tonearm tube. Also, clean the tips on the shell. It is possible that the wire inside the tonearm tube could have broken off. This is more likely if the shell has been removed often. An ohmeter will tell the story. It is doubtful you damaged the cart if you didn't try to force the stylus in beyond the normal force required. The cables on the outside as well as the ones in the arm itself are low capacitance type. It is advisable to keep the length of the cable between the turntable and the demodulator as short as possible.

The Quadfather

 

[dr8track]

I tried the Q-tip and alcohol suggestion, but still no luck. I did find another site that has parts for many turntables including my sl-1200. If any of you have been looking for parts you might give it a try.
<a href="http://www.partsolver.com" target="top">Part Solver</a>

 

[ranzy]

The wires from the tonearm can be checked with an ohm meter from the contact point where the cart. contacts are to the end of the RCA cables end. They do not go through any circuits in the turntable. Just another thing about the cables. I would use the best cables I could find to use for long term use only because you know they have to send a carrier signal to the decoder, but I bought a cheap old Technics SL-D20 at a pawn shop the other day for my computer for copying my old 45s and I hooked it up to the QX-747 just to see if it would work. To my surprise it played a CD-4 record. The radar light came on and their was no popping at all. Seperation was great. This unit had the cheapest piece of crap pair of RCA cables I have ever seen on a stereo, ever.

Also have you tried to just switch the left and right connectors at the amp just to make sure the problem moved to the right. This would tell you easily if your problem is in the turntable or the amp. If you ohm out the cable in the tonearm all the way through the end of the RCA Cables and they ohm out good then your problem has to be the cartridge, since you have put the old stylus back on and still have the problem.

Personally, I think the cartridge is bad.

Ranzy

 

[dr8track]

I removed the headshell and placed it on another cheap turntable I have. No problems. I get audio from the L and R channels just fine. So, that would tell me the cartridge and cartridge wiring are A-OK. That means my problem must be in the RCA cables. I don't have an ohm meter and I'm not sure I could figure out how to use one if I had it. So, now that I'm pretty sure I know what is wrong I just may take it in to get it repaired. The strobe light is very intermittent anyway. maybe I could get both problems fixed.
Thanks to everyone for all the help. If I get brave I may pick up an ohm meter and try to check things out myself.

 

[ranzy]

You can pick up a cheap ohm meter at Radio Shack and it's not a bad tool to have anyway. Just set it to ohms and check between the contact and the end of the RCA cables. The closer to 0 ohms you get the better. That's all your looking for anyway, close to 0 or an open circuit. If it is open then you might want to get it looked at but if all 4 wires ohm out then the wiring is not your problem.

 

[dr8track]

One more question before I just haul my Technics into the repair shop and let them deal with it. If I got an ohm meter and checked the RCA cables as outlined above and discovered there was a problem with the cable, is there any way of determining where the problem exists in the cable? I'm assuming it's either at the solder connection where the phono cables hook to the cartridge wiring or at the RCA plugs themselves. I'd hate to hack off the RCA plug, replace it and then discover the problem was elsewhere. Any way of isolating the location of the break or short in the cable?

 

[sspsandy]

The way I've always done it is to check the continuity at either end of the wire , then stick a straight pin in at key points along the wire, touching the probes to the pin and the end of the wire, working my way back until there's a connection. You set the meter switch to the ohms symbol, and when you touch the probes together the the indicator on the meter swings all the way across. If it doesn't move when you touch each end of the wire, there is a break somewhere. Chances are that it is at the RCA jack at the end of the wire, they are notorious for breaking there. The ones at Radio Shack that you solder the wires to work fine.

 

[Quadwreck]

If you have confidence in your own soldering skills you can save yourself at least $30 by chopping off the plugs and soldering on new ones (available at Radio Shack and elsewhere). My experience is that the plugs are the most likely culprits when a cable malfunctions. The next most likely point where the signal is interrupted is where the cable leaves the unit, right at the rubber grommet. Chop off the cable about two inches out and resolder inside if the plugs aren't the problem.

 

[dr8track]

Thanks for the info. I would have to say that I'm NOT confident in my soldering skills, but I just may give this a try anyway. I will make a stop at Radio Shack this evening on my way home and pick up what I need.