Announcement

Collapse
No announcement yet.

Magnavox console record player playing slow

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Magnavox console record player playing slow

    hey there,

    first post here. thought someone might be able to help me out. i recently inherited an old console record player, stats below:

    Magnavox Astrosonic
    40 watts, Run #2.

    Its has 16, 33, 45, and 72 speeds. when i play 33 1/2 records on the 33 setting, they play pretty fast, and so when i play them on 16 speed, they play slow. it seems like it should play somewhere in between. its direct drive, so is something wrong with the motor? maybe someone here has run into the same problem. also, the radio sounds great, crisp, lots of treble and bass, but when i play a record, its really muffled and bassey, even with the bass turned most of the way down. is this a needle issue? thanks in advance.
    "You can't fight in here, this is the war room!"

  • #2
    Yes, probably is a needle issue. Look close and see if ther is any buildup of dirt or small fibers on the needle tip.

    This thing is like 40 years old, right? Pull the platter off, clean off the old lube on the hub and apply fresh oil or very light grease. WHile the platter is off, look at the idler wheel. It bears against the motor shaft and the inside of the platter rim. Pull the idler mounting piece against its spring to pull it away from the motor shaft. SPin it. Does it spin freely? If not, take it off, clean the hub and shaft, drop of oil and put it back together.

    The motor probaby is mounted with three or four rubber grommets. THat way the motor vibration is not transmitted into the turntable chassis. If those grommets break down - with age, rubber grommets can melt, turn to crumbles or otherwise break down - the motor will drop to a lower position than it should have. This makes the iddler wheel hit the wrong spots on the motor shaft. New grommets will fix that. Turntable grommets or turntable motor grommets maybe are specific types.

    ANd while holding the idler away from the shaft, grab the shaft with your fingers. Is it easy to stall or does the motor seem reasonably strong. It might need a couple drops of oil in the end bearings.
    Education is what you're left with after you have forgotten what you have learned.

    Comment


    • #3
      wow, thanks enzo. ill try all this tomorrow. sounds like a fun sunday project. yeah, its gotta be 40yrs old at least. its basically in near perfect condition except for what ive described before. ill post back to let you know if everything works. thanks again.
      "You can't fight in here, this is the war room!"

      Comment


      • #4
        so, ive got the platter off and lubed everything. one other thing i forgot to mention. whenever i turn the record player to the "on" position, it turns veeeeery slow for while. then it plays "normally" after it heats up a bit. any idea what this would be about? and when i do the "auto" setting, it wont play sometimes. its almost like it needs to warm up or something.

        edit: after letting it "warm up", i felt the main motor shaft, its pretty warm and it feels like its vibrating a bit, but not turning. could it be that the motor is burning out? the idle wheel spins freely and the rubber is basically perfect. the inside is really very clean.
        Last edited by mcjackson; 03-15-2009, 09:57 PM.
        "You can't fight in here, this is the war room!"

        Comment


        • #5
          Did you lube the motor shaft. SOunds like it is binding. Power off, turn the motor shaft with your fingers. Does it turn freely?

          If the motor bearings wear out enough, the play in the bearings can allow the armature of the motor to come in contact with the field coil pieces, and that will sieze up the motor. But that wouldn;t care about heat. I suspect the motor shaft bearings are dry.
          Education is what you're left with after you have forgotten what you have learned.

          Comment


          • #6
            that could be it. the shaft is really hard to turn, even when its on and supposedly "playing." ill take a look at that tonight. i dont want to take this apart too much, i'd be afraid to put it back together wrong. :-) thanks again.

            p.s. do any of you have any resources for schematics or manuals for these things? im having a hard time with google finding out what all this stuff is called. thanks.
            "You can't fight in here, this is the war room!"

            Comment


            • #7
              Originally posted by mcjackson View Post
              do any of you have any resources for schematics or manuals for these things? im having a hard time with google finding out what all this stuff is called. thanks.
              As I mentioned in another thread, there is a Yahoo group called "Magnavoxfriends" that may have some useful files. I'm not a member, so I don't really know what they have, but it might be worthwhile to sign up and find out.
              -tb

              "If you're the only person I irritate with my choice of words today I'll be surprised" Chuck H.

              Comment


              • #8
                I've fixed a few of these, i.e. the ones with a 15rpm setting and the "record size checking" tone arm action. Mostly, everything in there needs more lubrication, and the idler wheel needs to be carefully resurfaced. I let it run and hold a sharp knife just close enough to contact, hold it very steady. The grease they used to use hardens after a few decades.

                Comment


                • #9
                  ill try that.

                  the idler wheel and the other, bigger wheel, not sure what its called, are both in really good shape. the rubber on both is still nice and black and flexible. but i see what you're saying. guess i just gotta take it apart more and just lube everything.

                  p.s. any specific lube i should be using? wd-40, mineral oil, etc....?
                  "You can't fight in here, this is the war room!"

                  Comment


                  • #10
                    Usually it helps to remove the old lube. WD40 will help dissolve old grease, but plain old light machine oil will as well. WHat they used to call sewing machine oil is great. I always never liked 3-IN-ONE oil, it seemed thick and gummy to me.

                    I don't like to rely on WD40 as the ultimate lube, I prefer oil. Oil the rotasting shaft points, th gears and cam followers would want some light grease. There is a product "Phonolube" made for the purpose. Or use "White Grease." No, not silicone heat sink compound, white grease is a lubricant.

                    Look at the motor. The mechanism around it is complex, but won;t the motor just drop out if hte mounting studs are freed? You really need to relube both end shaft bushings.
                    Education is what you're left with after you have forgotten what you have learned.

                    Comment


                    • #11
                      ok, cool. ill just have to take the motor off of the mounts i guess and really get in there.

                      p.s. if the whole unit has been turned off for a while, and then i turn it on (power to the radio part), the turntable doesnt work right away. but if i leave the power on for a while (hour or so), the turntable will work, although slow. i left it on for a good two hours or so, then tried a record. it seemed like it played almost at normal speed, still a bit slow, but almost there. not sure why it takes it so long to "warm up" since its solid state.
                      "You can't fight in here, this is the war room!"

                      Comment


                      • #12
                        The turntable mechanism isn't solid state. Perhaps the motor would want to turn but can't, so it sits there getting warmer and warmer until the old hard lube softens enough it can turn itself.
                        Education is what you're left with after you have forgotten what you have learned.

                        Comment


                        • #13
                          hey there,

                          took the motor apart. it was devoid of any lube, totally dry. lubed it up and now it spins very freely and smooth. and it starts up right away now. now all thats left is to get it to play at the correct speeds. i tested a 45 and it plays way fast on the 45 setting. i read earlier that the rubber motor mounts may have compressed over time and now the drive shaft doesnt line up right. i found a place on line that manufactures replacements of those. thanks for all your help guys.

                          edit: this is that website btw: http://www.oldradioparts.net/
                          Last edited by mcjackson; 03-18-2009, 04:12 PM.
                          "You can't fight in here, this is the war room!"

                          Comment


                          • #14
                            Originally posted by mcjackson View Post
                            hey there,

                            took the motor apart. it was devoid of any lube, totally dry. lubed it up and now it spins very freely and smooth. and it starts up right away now. now all thats left is to get it to play at the correct speeds. i tested a 45 and it plays way fast on the 45 setting. i read earlier that the rubber motor mounts may have compressed over time and now the drive shaft doesnt line up right. i found a place on line that manufactures replacements of those. thanks for all your help guys.
                            It is a good idea to replace the motor mounts but if the turntable is rotating too fast the idler wheel might be the wrong one for that model. (You mentioned there being two wheels- perhaps the larger one is for moving the tone arm...?)

                            Steve Ahola
                            The Blue Guitar
                            www.blueguitar.org
                            Some recordings:
                            https://soundcloud.com/sssteeve/sets...e-blue-guitar/
                            .

                            Comment


                            • #15
                              The motor shaft spins, the turntable spins, the idler wheel connects them. The diameter of the idler doesn;t matter, so long as it makes good contact with the shaft and platter.

                              Typically, the motor shaft has a stepped shaft - or more likely a brass turning mounted on the shaft. The idler bears against this shaft and the platter, and the mechanism moves the idler up and down so it bears against different diameter steps on the motor shaft. That is how it changes speeds. If the motor mount grommets collapse, the motor drops down from its proper position, so the idler hits the wrong part of the shaft. The lower on the shaft you go, the greater its diameter, hence the faster it will turn the platter.

                              Turntable motor grommets are a specific item. If you already found them,. great. www.tubesandmore.com sells them. Stock P-R407 $4.50 for a pack of 9.




                              Usually the platter has a gear on it that turns a larger gear, and that is what drives the changer mechanism.
                              Education is what you're left with after you have forgotten what you have learned.

                              Comment

                              Working...
                              X