|
New member Username: TodguyPost Number: 1 Registered: Jan-11 | I recently bought a used dual turntable on Ebay, I'm not sure if it needs repaired or junked or I just dont know how to adjust it. Problem: It will play a record for a minute or so then the tone arm doesnt seem to want to advance on the record and it starts to skip in the same groove. Also I am not getting much volume thru the receiver. Dual CS 508 |
|
Platinum Member Username: PlymouthCanada Post Number: 15865 Registered: Jan-08 | Welcome to eCoustics Tod! First be sure that your stylus is good then you can adjust the weight on your stylus and also the anti-skating! I don't have the correct weight but you can try 1 gramme then put the anti-skating to 0 then see if it work fine! For the volume output, I presume that you know you need a phono input on your receiver or you can buy one there: http://www.guitarcenter.com/ART-DeeJayPre-II-Phono-Preamp-180641-i1125078.gc?sou rce=4WNTWXX |
|
Gold Member Username: SuperjazzyjamesPost Number: 1241 Registered: Oct-10 | The tone arm probably needs service unless someone else can tell you how to DIY a repair. For volume, I'm guessing that the turntable is not connected to a phono stage. A moving magnetic cartridge, which you most likely have requires a preamp often called a phono stage. Traditionally, this preamp/phono stage was in the receiver. Around the late 80s/early 90s, turntables were being made with built in phono stages, usually they were switchable (could be turned on or off depending on whether it was needed). You should see if there is preamp switch somewhere on your turntable (front or back most likely). You should also make sure the turntable is connected to a proper phono input on your receiver. Is it labeled moving magnetic cartridge or mm? |
|
Gold Member Username: SuperjazzyjamesPost Number: 1242 Registered: Oct-10 | Check out Plymouth's advice too! |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15741 Registered: May-04 | . http://www.dual-reference.com/Troubles/operation.htm To start you can probably find information regarding your table by reading the archives of this section of the forum. Questions regarding Dual tables are quite common and most have common solutions. I certainly wouldn't scrap a Dual table as they did represent a high value design that was built to last for decades when given some degree of maintenance. Did you install the cartridge on the table yourself or did the table come set up by a professional? If you did the installation and set up yourself, the problem is very likely to be in the installation or damage that has occurred since. All Dual tables require a cartridge set up protractor/guage in order to place the stylus (needle) tip at the precise location relative to the pivot point of the arm. If this isn't done properly - which is all but impossible without the proper guage - you'll have problems tracking the disc. Next you need to make sure you still have a stylus in the cartridge. You can do a visual inspection under some magnification to find whether a diamond still exists but you need to make certain you are looking at the stylus and not the cantilever's bonding pipe; http://search.yahoo.com/search?ei=utf-8&fr=slv8-hptb5&p=bonded%20vs%20nude%20sty lus&type= and http://en.wikipedia.org/wiki/Magnetic_cartridge#Cantilevers If the stylus has broken away from its bonding pipe, you will not track records well and the output of the cartridge will be excedingly low. Check that the cantilever (the pipe which exits from the center bottom of the cartridge) is not bent as this will inhibit tracking. Since you say the arm tracks a portion of the disc and then sticks, this would tend to narrow the probems down more to improper set up or need of maintenance. Proceed with set up only if you feel confident you can accomplish the task after reading through all the instructions at least twice and after you've determined the cartridge has been installed in the correct location in the headshell according to the stylus protractor. There's no point in setting up an arm that has a mislocated cartidge. It's very easy to screw up a set up from someone who knows how to work with a Dual and poor set up is one of the most common causes of complaints about Dual tables. If you're not certain how to do these tasks, turn the table over to someone who does. Make sure you have the cartridge/arm balanced properly; http://www.audiophilia.com/features/cartridge_setup.htm In short, you need to "zero out" the arm balance until the arm floats just slightly above the disc surface. You accomplish this by first setting the tracking force control to "0" and then turning the couterweight at the back of the arm until it has achieved a neutral balance point. Be very careful as any random motion of the arm can easily snap off the stylus and you'll need to replace the assembly at a (not so) reasonable cost. Hold the arm firmly in its rest as you turn the counterweight only letting it go to check for balance. If you have a stylus guard on the cartridge, use it during the adjustment procedure but remember to have the arm in balance without the guard in place. Return the arm to its rest and lock it down while you turn the main body of the counterweight until the arm neither rasies nor falls under its own weight. Return the arm to its rest and lock it down while you turn the dial which indicates tracking force to the correct downforce for your cartridge; http://www.dual-reference.com/Troubles/setup.htm Set this towards the upper end of the range provided in the cartridge specs, usually 1 3/4 to 2 1/4 grams of pressure is good for most cartidges that would fit in a Dual 508. The anti-skating is set on a Dual table by the guage at the base of the arm shown in the illustration and its measurement should match the downforce you've applied to the arm setting. Don't forget to adjust the anti-skating. After the set up has been properly performed the arm should track the disc from start to finish. If you're still having problems, re-do the set up just to make sure you've followed instructions accurately. Setting up a cartridge is an old time skill that requires experience to do well. If problems still presist, it's quite possible the grease in the automatic functions of the arm has harden with time and will need to be replaced. It's also possibe the automatic functions have been fouled and parts will neeed repair or replacement. Neither task is something a novice should attempt and at this point, if the table still isn't tracking the disc, you should have the table serviced by a qualified Dual technician. First try checking the stylus/cantilever and performing a good set up. If you have other questions, come back. As I said, read through the archives of this site as many Dual questions and answers already exist here. If the arm tracks the disc properly and you have low output from the table, you probably need a phono pre amp. That too is covered in the archives with suggestions for where to purchase the units. . |
|
Gold Member Username: MagfanUSA Post Number: 1995 Registered: Oct-07 | Good summary, Jan. The only thing I'd add is that my Dual came with a jig into which the tone arm end fit. A v-groove was cut at the exact location the stylus tip was supposed to fit. Adjusting the cart with spacers and fore/aft to fit the tip and you were pretty good to go. With the tone arm floating 'level'....you could 'eyeball' the cantilever for say....15 degrees to the records surface. It would be somewhere close to a miracle if that jig still was with the table! |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15747 Registered: May-04 | . That "jig" is the protractor/gauge I referred to in my post. It's not impossible to align a cartridge in a Dual headshell with a more conventional cardboard protractor but it's very difficult, tedious and highly aggravating as you have to disassemble the headshell for every tiny adjustment. The Dual guages are available, however, Dual was not consistent with the guage style and each series of table had a distinct protractor. Buy the wrong guage and you might as well have used your eyeballs. However, without proper cartridge set up, mistracking and distortion will remain an issue and, even if the the arm tracks the disc to the end, higher than normal reacord wear will result. Doing it right pays off. . |
|
New member Username: TodguyPost Number: 2 Registered: Jan-11 | Thanks for the advice guys... Looks like this may be going back on Ebay with a BIG disclaimer that I didnt have..... |
|
Gold Member Username: MagfanUSA Post Number: 2000 Registered: Oct-07 | That's what that thing was called? Somehow I expected a stylus protractor to be something more...complicated. I also now remember a setup disc I had. In the middle was a bare ring with no grooves. It was about 3/4" wide. It was supposed to be for adjusting the anti-skate. Stylus floats in middle without heading for the edge was the proper adjustment. |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15748 Registered: May-04 | . Anti-skate is guess work at best. Many arm/cartridge/table designers provide no skating adjustment. The Vilchur designed AR's in the '50's instructed the user to apply about 1/4-1/2 gram higher VTF and forget trying to do any more about skating. Kind of the putting snow tires on your stylus and tossing a few bags of sand in the trunk approach. Lots of designers have agreed including VPI on their unipivot arms though they seem to have bowed to pressure from clients with enough cash to buy those $1000 near mint copies of Mercury Living Presence discs from the time of Vilchur's original designs. VPI has now decided to include skating compensation in their latest revisions of the arms. Which device is best for anti-skating is just as "controversial". Hanging weights are consistent while springs loose their tension over time. Hanging weights have no compensation for the varying amount of skating required from the outer to the inner groove area where modulations are dramatically higher than at the lead in. Here a simple spring succeeds. What it comes down to though is skating is not consistent from disc to disc due to groove modulation and skating itself is never correct - just at times less wrong. . |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15749 Registered: May-04 | . Tod, why send the table back? The Dual's are good designs that need set up just like any other table. I would be more concerned about any table that arrived at my doorstep from the shipper supposedly in "correct" set up. Tables need adjustment and they need to be adjusted when you get them. Have you checked the items I suggested? If you can't perform the adjustment, you might try finding an audio shop or pro sound shop in your area that can make the adjustments for you. Shouldn't cost more than a few bucks and most shops would do this for free. If, however, the table needs actual repair, that's a different situation. . |
|
Gold Member Username: SuperjazzyjamesPost Number: 1256 Registered: Oct-10 | I had a turntable adjusted and some minor repairs done for a grand total of $50 once. This was a Sony, so chances are, a dual with actual repairs, even minor ones could be a lttle more. Perhaps you should get an estimate. That can't hurt. |
|
Gold Member Username: MagfanUSA Post Number: 2005 Registered: Oct-07 | I've seen a hanging weight anti-skate device with the weight attached by a wire loop to a horizontal rod which was parallel to, and below the tonearm. The horizontal rod was notched to accept the looped end of the wire attached to the anti-skate weight. Moving the connection toward the tonearm pivot lowered the leverage and the anti-skate correction. Moving the connection to the end of the rod nearest the stylus increased the force. the connection rod was maybe 30mm in length. tops. sheer guesswork. When a TT is shipped, shouldn't the counterweight be removed from the tonearm and the tonearm itself somehow secured? I wouldn't want that extra beating on the tonearm bearings during shipment. |