Vinyl Asylum

Welcome Licorice Pizza (LP) lovers! Setup guides and Vinyl FAQ.

Return to Vinyl Asylum

Message Sort: Post Order or Asylum Reverse Threaded

Phantom speed increase

73.240.202.23
Posted on May 26, 2016 at 17:56:25
TMol



Occasionally while listening to my newly acquired JVC QL-A2 the speed will suddenly increase from 33 RPM to 45 until I manually switch from 45 back to 33. This is a quartz-lock turntable with auto return. It also seems to have a random mind of its own when it comes to staying at one speed, though I think I can tame it with some contact cleaner. I already tried blowing "dust off" down the hole to no avail. Can I just spray some contact cleaner down there, or should I open up the cover to get at the switch contacts? Also what is the best spray to use?

 

Hide full thread outline!
    ...
RE: Phantom speed increase, posted on May 26, 2016 at 18:17:53
BCR
Audiophile

Posts: 2446
Location: connecticut
Joined: April 7, 2009
 I use this to clean contacts. Give it a shot around the whole area.

 

RE: Phantom speed increase, posted on May 27, 2016 at 06:55:08
MannyE
Audiophile

Posts: 2088
Location: Miami Beach
Joined: March 4, 2001
 Could it be that the electrolytic capacitors need replacing? It's not a crazy difficult task if you have basic soldering skills and a cheap fix by a tech if you don't.

 

RE: Phantom speed increase, posted on May 27, 2016 at 09:30:43
TMol
 Thank you for the recommendation. I like that it's also "safe for plastics" so it won't discolor the area around the opening. I assume it comes with a narrow straw for pinpoint application, right? I have a WD40 straw, but it might have some residue so I'll need another. I was going to use WD40 but your recommendation seems to be just the thing I might need, not a lubricant.

 

RE: Phantom speed increase, posted on May 27, 2016 at 09:36:21
TMol
 Because of a previous post, I learned of online access to the service manual. I can probably get at the capacitors you mention, so thank you for that thought. Would they look corroded? But first, I think I'll try the CRC recommendation.

 

RE: Phantom speed increase, posted on May 27, 2016 at 09:50:51
BCR
Audiophile

Posts: 2446
Location: connecticut
Joined: April 7, 2009
 Yes it comes with a straw. Give it a try,you have nothing to lose !

 

RE: Phantom switching, posted on May 27, 2016 at 11:33:58
Lew
Audiophile

Posts: 10912
Location: Bethesda, Maryland
Joined: December 11, 2000
 Do I understand you correctly? Are you saying that when the speed changes from 33 to 45, you find also that the rotary switch shown in your photo has re-set itself to 45? Does this turntable have any (other) automated features, such as lift-off at the end of an LP or automated start-up?

 

RE: Phantom speed increase, posted on May 27, 2016 at 11:44:30
Lew
Audiophile

Posts: 10912
Location: Bethesda, Maryland
Joined: December 11, 2000
 If the unit was in long term storage before you got it, especially, I would advise you to change the electrolytic capacitors, first of all. You can buy them all from Mouser or Digikey at a nominal cost, and then you can do it yourself if you have soldering skills. Pay careful attention to polarity when you do the install and substitute like with like, when it comes to voltage rating and capacitance value.

I seriously doubt that spraying any sort of contact enhancer into that little hole will accomplish anything good. But if you want to fiddle with the switch, perhaps you can remove the mechanism from the chassis and gain access to that switch from the rear, so you can see what you're doing. It might be sealed, in which case spritzing will do no good.

 

RE: Phantom switching, posted on May 27, 2016 at 12:52:06
TMol
 I'm sorry, I should have been more clear as to what's going on. When playing a record @33rpm it occasionally increases to 45rpm for no reason. The rotary switch indicates 33. I learned that manually switching to 45, then back to 33 re-sets the speed correctly, but after a few minutes it'll do the same. At this point I do not know if playing a 45rpm record might result in a random decrease in speed. The turntable features auto return but manual start up. The speed switch is manual...I think :)

 

RE: Phantom speed increase, posted on May 27, 2016 at 13:09:02
TMol
 This was a garage sale purchase, so my investment is quite low while the returns are mixed, so far. I'll be spending more for the new record and the CRC contact cleaner than I did for the turntable itself, but I find the tweaking (and problems) interesting. More than likely I'll be replacing some easily replaceable parts such as those you mention, but for now I'll try the contact cleaner--I have none and it's a useful thing to have around. In fact, I may remove the chassis to see the switch from the rear to see if it's a sealed mechanism; a good suggestion, thanks.

 

RE: I'm thinkin'..., posted on May 27, 2016 at 19:41:15
mr.bear
Audiophile

Posts: 4167
Joined: November 13, 2001
 ...maybe a circuit board solder point has come apart. You can't always see these by naked eye, but I say that b/c I'm old and squinty... Find the speed control board and resolder, once over lightly. Often works wonders and costs zero.

 

RE: Costs zero, posted on May 27, 2016 at 23:08:26
TMol
 If I already had a solderer, yes, but I don't own one. However, I'm game & know someone from whom I could borrow one for, say, a beer. With this vintage turntable it might be wise to buy a soldering kit, but I'll see if the contact cleaner works first.

 

Page processed in 0.022 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]