View Full Version : Pioneer speed issues.
for a while now the pioneer has been having speed issues,once adjusted it will either slow down or speed up a little and you have to keep adjusting the pitch controls.its not extreme although you can hear it when it does it, after an hour or so it seems to stabilize.
i've been off work today with a cold and got bored so i decided to investigate :grin:
https://s26.postimg.org/r97y7iedl/IMG_1179.jpg
here's a shot with the secondary metal plinth removed.
https://s26.postimg.org/psrubmm2x/IMG_1176.jpg
the ply plinth removed,i like the fact that its all contained in one unit.
https://s26.postimg.org/albur9u89/IMG_1177.jpg
here's one with the motor cover removed.
https://s26.postimg.org/d5c2z4761/IMG_1180.jpg
https://s26.postimg.org/yvkwweb7t/IMG_1185.jpg
https://s26.postimg.org/cid69laa1/IMG_1183.jpg
now ive done the obvious thing and given the pitch adjusters a good spray of contact cleaner and its still the same,im worried that some of the capacitors are too old and that might lead to something terminal failing so should i replace the capacitors as a preventative measure??
Audio Al
23-01-2017, 15:19
Have you looked at the bearing ?
Usual culprits are the 2 youve mentioned.. a resistor could too
Bearing will be fine, the two culprits are the speed pots needing to be replaced (more than just a spray), as well as old caps coming up to temperature over time & altering the parameters i.e. the speed changes. Resistors will be fine.
cheers,can the speed pots be bought new or is it a second hand jobby?
Beobloke
23-01-2017, 15:44
No, DO NOT go replacing capacitors at random. There's a chance it will make no difference and you could make things worse. There is a current thread on another forum where a poster re-capped his perfectly working Technics direct drive because he read on the internet that it's the 'thing to do', and now it doesn't run properly!
Checking and cleaning the pots is a good idea but if that doesn't work then take it to someone who can check it out properly. I can give you a name for this if you need it.
cheers adam,dont worry i wont go changing caps.
ive taken the backs off the speed pots and given them a good spray with cleaner,it appears to have done the trick,all im getting now is very slight fluctuation,not having owned a DD before i dont know if this normal or if it should be total stationary??
https://s26.postimg.org/97ot9pkcp/IMG_1187_1.jpg
https://c1.staticflickr.com/1/772/32483983525_01486b65ea_z.jpg (https://flic.kr/p/RuuUzt)IMG_1189[1] (https://flic.kr/p/RuuUzt) by , on Flickr
Had problems with speed control on my Pioneer Pl630,doing similar to the complaint on your's.Cleaned the pots as you have ,turned out it was the speed change switch which needed a good spray of Servisol.Exellent articles on same problem by a very experienced engineer on Audiokarma site[recommends spraying then working the switch 100 times or so] Hope this is of some help Mick
Beobloke
24-01-2017, 01:01
They really don't need spraying 100 times!
Jamie, as well as the two pots that you use to set the speed from the top of the deck, there will be two more internal speed adjustment pots on the actual PCB inside - you can see them on your first picture. You should also give these a squirt of Servisol or similar and turn them across their full adjustment range a few times to work it in. Do remember, of course, to note their original positions and put them back there afterwards!
And to answer your question, there should be no fluctuation - if should be steady. If it's not a quartz lock, you might find the speed will alter slightly after half an hour or so's running (they usually speed up slightly) but if you then correct it at this point, it should not change again.
Thanks I will do the others tonight after work, its already much better so hopefully the other 2 pots will sort it :)
They really don't need spraying 100 times!
Jamie, as well as the two pots that you use to set the speed from the top of the deck, there will be two more internal speed adjustment pots on the actual PCB inside - you can see them on your first picture. You should also give these a squirt of Servisol or similar and turn them across their full adjustment range a few times to work it in. Do remember, of course, to note their original positions and put them back there afterwards!
And to answer your question, there should be no fluctuation - if should be steady. If it's not a quartz lock, you might find the speed will alter slightly after half an hour or so's running (they usually speed up slightly) but if you then correct it at this point, it should not change again.
Read my post again, the idea is to squirt the switch contacts THEN work the switch 100 times or so.the article on Audiokarma is very comprehensive.
Beobloke
24-01-2017, 15:51
Sorry, point taken. However, there's a good chance working an old pot 100 times will probably wear it out! Half a dozen times is more than enough.
My '630 has a push button speed change-applied contact cleaner and worked it repeatedly as advised,didn't need as many as advised in article.Don't know the 'table in question ,if it's the same type of speed change-if it was the OP could benefit from my experience.
Needs as many as it needs. It it aint cured before 100 then its goosed
My '630 has a push button speed change-applied contact cleaner and worked it repeatedly as advised,didn't need as many as advised in article.Don't know the 'table in question ,if it's the same type of speed change-if it was the OP could benefit from my experience.
yes mine is push button too,cheers :)
Before I was rudely put down for being confusing elsewhere, I looked at the vid posted and saw that the strobe on the platter appeared to 'kick back' slightly every revolution. If this is audible, there's a problem somewhere, but I tried to make the point that it may just be the way the strobe markings were engraved into the platter edge. Without hearing what happens to a test tone or sustained piano note, it's difficult to locate from a distance.
Is the visual thing audible? I appreciate switches and pots on these things DO need cleaning and equivalent age pre-quartz Technics decks are also prone to this as both my SL150/1500's suffered from this until both pairs of adjustment pots and the main switches were cleaned (I used Servisol).
If it does turn out to be the speed change switch ,then spraying with a good contact cleaner and working it will do it no harm.The fault is caused exactly because the switches and pots have not been used over the 'tables lifetime of 30yrs plus
ok so ive cleaned the main speed pots on the pcb,cleaned as best i can the micro on/off/33/45 switches and its still the same.
its like you just cant dial the last pitch adjustment in to make it solid,another vid here
https://www.flickr.com/photos/145822004@N02/32126800030/in/dateposted-public/
so whats the next plan of attack or should i settle for this?
cheers for the input so far by the way :)
Beobloke
25-01-2017, 02:14
That could possibly just be machining on the platter. Can you borrow another strobe disc to compare?
cheers,yeah a few people on the site that cant be named have suggested that too.
just to rule them out ive tested the speed pots with a muti meter and the reading goes up and down smoothly,ive also ordered 2 new micro switches.
http://www.ebay.co.uk/itm/331569818978? ... EBIDX%3AIT
just a little update on the speed fluctuation problem,i had a call from the guy whos looking at it and he's found a few problems which he's fixed :dance: ,i got so excited that he's fixed it ive forgotten what one of them was but the other was one of the hall motor pick ups wasn't working .he's got it for another week to see how it goes,all being well i can pick it up saturday week :)
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