Technics SL-B2 slight strobe speed waver.. any clues??..
Harv
to, I don't have $500.00 right now so let's skip that part ;) ..
I have a Technics SL-B2 bought brand new in the late 1970s or early 1980s.
Semi-automatic, belt drive. It has developed a problem in that I cannot get
the pitch control to "lock" the strobe markings in either 33 or 45 to a
solid position. The table was used a lot for a few years when I first got
it. From about 1990 to three years ago, it was packed up in its original box
and not used at all. When I unpacked it, of course I found the original belt
had disintegrated, almost melted to gooey black crud, so I carefully cleaned
it all off the underside of the platter, sourced a new belt, and the
turntable worked perfectly. Strobe markings did not waver at all when
playing. Not at all.
I don't use it daily, mind you, but the strobe has always given me a solid
"lock" on the markings around the turntable. Lately, it is wavering a bit.
The markings will stay steady for a second, then waver to the next marking,
stay steady for a second, waver to the next one, and so on. It does this no
matter how I fiddle with the pitch control, or whether it's going at 33 or
45.
I have tried shooting some electronic contact cleaner down around the pitch
wheel and wheeling it back and forth 100 times, but no idea if it reached
the pot inside or not. I have not yet tackled taking the base cover off to
shoot cleaner directly into the pot or into the 33/45 switch..
I have let it run for hours with no record on the platter, just the arm
lifted so the motor engaged, thinking maybe a "burn in" would solve it. No
dice..
This turntable was never abused.. in fact, for a piece of hardware this old,
it looks absolutely brand new. There's a Shure M95ED/D mounted in the
headshell and set to track at 1.25 grams, the recommended pressure, but this
slight strobe waver happens whether there is a record on the platter or
not.. in other words, use the arm lift, move the arm in a bit so the table
spins, no record on the platter, and it still does it..
I found some archived posts on Google from a couple years ago with owners of
the same turntable describing exactly the same problem, as well as a friend
of mine who also bought one when they were new and his does it too.. none of
these three people ever found a solution..
So what would the group mind suggest the problem could be?
- The motor?
- Motor bearings?
- Dirty pitch wheel control pot or dirty 33/45 switch?
There is no crud left on the platter's underside from when I removed the old
belt and replaced it with a new one.. I carefully cleaned it all off first
so it's not like there's a lump there that the belt is traversing..
The turntable, which is a semi-automatic, operates totally silently. There
is no drag. if I move the 33/45 switch to a stop between the two speeds and
give the platter a push, it spins quite freely and takes a long time to
finally stop on its own. When powered on, there is absolutely NO noise when
I see the strobe waver this little tiny bit, but having been blessed (or
cursed) with perfect pitch, I notice it when playing various kinds of
music.. it's probably not even a 1/2% pitch waver.. it is very slight but it
is noticable, and annoying..
Any suggestions for a fix would be appreciated. Any suggestions from someone
who actually own(ed) an SL-B2, had this problem, and fixed it would be
appreciated even more..
Thanks,
Harv
Stephen W. Worth
<hla...@socal.rr.com> wrote:
> So what would the group mind suggest the problem could be?
Have you tried a strobe disk on it? The question is, is the speed
fluctuation real, or just a problem with your readout. If you don't
have a strobe disk, you can download one to print out at the bottom of
my page...
http://www.vintageip.com/records
See ya
Steve
--
#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*#*
CLASSIC MUSIC FROM ORIGINAL 78s, EXPERTLY TRANSFERRED TO CD!
VIP Records: Dance Bands - British Swing Bands - Opera
Check out the free MP3 downloads at http://www.vintageip.com/records
Harv
"Stephen W. Worth" <ne...@vintageip.com> wrote in message
news:250320032215223685%ne...@vintageip.com...
> In article <tpaga.21514$cj5.7...@twister.socal.rr.com>, Harv
> <hla...@socal.rr.com> wrote:
>
> > So what would the group mind suggest the problem could be?
>
> Have you tried a strobe disk on it? The question is, is the speed
> fluctuation real, or just a problem with your readout. If you don't
> have a strobe disk, you can download one to print out at the bottom of
> my page...
>
> http://www.vintageip.com/records
>
> See ya
> Steve
Actually I have one I printed out a few years ago when I bought an old KLH
Model 20, which has a Garrard changer on it
(http://www.amigazone.com/images/KLH20.jpg) and tried it with a fluorescent
desk lamp shining on it on that and the turntable speed/pitch is rock solid.
I also tried it on an even older KLH Model Eleven "suitcase" stereo which
has a similar Garrard changer, and it was rock solid on that too.. and those
are both old rim-drive automatic changer style turntables.. and they have no
pitch controls at all.. figures, eh??..
I'll try it on the Technics turntable and see what happens but like I said,
I can _hear_ a very slight waver on it..
Harv
Deke
turntable enought to where you can spray some cleaner directly into the
control. Trying to get the cleaner into the control from the top is
useless, wont work.
Deke
"Harv" <hla...@socal.rr.com> wrote in message
news:tpaga.21514$cj5.7...@twister.socal.rr.com...
Harv
"Deke" <den...@starbandmypants.con> wrote in message
news:1gjga.330$UV1.11...@twister1.starband.net...
> Bet you ten bucks its that pitch control. Bite the bullet and get into
the
> turntable enought to where you can spray some cleaner directly into the
> control. Trying to get the cleaner into the control from the top is
> useless, wont work.
> Deke
You're probably right.. I hate hardware (I'm one of those people who can
take something apart, fix something inside, put it back together and wonder
why I have some screws leftover ;) .. and just like things to work and am
all thumbs when it comes to repairs.. but I'll see if I can get inside the
turntable and get some contact cleaner into the pitch control.. since it's
right up front, it should be easy to get to.. I hope.. keep your fingers
crossed..
Thanks,
Harv
Monk
too tight?.news:R8kga.21633$cj5.7...@twister.socal.rr.com...
Harv
"Monk" <ph...@tann07.freeserve.co.uk> wrote in message
news:b5sjgs$b27$1...@news7.svr.pol.co.uk...
> Silly question but are you sure the belt is the correct length, it may be
> too tight?.
I am fairly sure it's the right belt. Point is, when I set up the turntable
and put the new belt on it about three years ago, the strobe "lock" was
perfect. Right on the money, didn't waver at all. I noticed a couple months
ago that it had started wavering a bit, so I'm trying to figure out why.
Next on the hit parade will be seeing about taking the bottom off the base
and shooting contact cleaner directly into the pitch control's pot and the
33/45 switch and hoping that solves the problem.. if it doesn't, I may or
may not try to get yet another new belt, or just give up, and buy a direct
drive model.. sometimes simple is better.. I'd almost prefer to have a
turntable that has no pitch control on it at all, as it seems like that's
just something else that can go wrong. Like I said, my circa 1967 KLH Model
20's Garrard Changer has no pitch wavering at all, when checked with a paper
printout strobe wheel on it and fluorescent light shining on the wheel.. and
it has no pitch control.
Thanks,
Harv
Monk
they always waver a little so you are forever adjusting them, what seems
like a big difference on the strobe is probably hardly noticeable speed
wise, you will probably be just as well of with a turntable without strobe,
apart from anything else there's less to go wrong & if you get a direct
drive it will run fairly quite & no more belts to stretch,news:rXmga.1$Mf...@twister.socal.rr.com...
Harv
> I've got 2 turntables with strobes & in a way they are a pain in the arse,
> they always waver a little so you are forever adjusting them, what seems
> like a big difference on the strobe is probably hardly noticeable speed
> wise, you will probably be just as well of with a turntable without
strobe,
> apart from anything else there's less to go wrong & if you get a direct
> drive it will run fairly quite & no more belts to stretch,
Do you remember the original AR turntable??.. Simplicity in itself. A
beautiful quiet design with one on/off switch on it and that was it. I'd
love to find one of those that is in perfect shape..
Back in college I had a professor who had an all AR system. This was about
1967 or so. Turntable, Amp, Tuner, and the big AR-3a speakers.. maybe
primitive by today's standards, but that was his pride and joy.. Where's
Henry Kloss when we need him.. sigh.. R.I.P. :( ..
Harv
Monk
attract you to something but it's always the simple, easy to use things that
just do the job well that you end up going back to.news:QDrga.33137$9G.84...@twister.socal.rr.com...
Brad Clarke
>>
>>"Monk" <ph...@tann07.freeserve.co.uk> wrote in message
>>news:b5sjgs$b27$1...@news7.svr.pol.co.uk...
>>> Silly question but are you sure the belt is the correct length, it may be
>>> too tight?.
>>
>>I am fairly sure it's the right belt. Point is, when I set up the turntable
>>and put the new belt on it about three years ago, the strobe "lock" was
>>perfect. Right on the money, didn't waver at all. I noticed a couple months
>>ago that it had started wavering a bit, so I'm trying to figure out why.
The SL-B2 takes a 23.6 inch flat large belt (1/4 inch/6.35 mm wide)
Brad
Deke
> what I usually find is that lots of knobs & gadgets etc might originally
> attract you to something but it's always the simple, easy to use things
that
> just do the job well that you end up going back to.
Simple is always better, but I'm not giving up my direct drive linear
tracking turntable for anyone!
Deke
Mark D. Zacharias
thinner.
Obviously the pitch and speed controls should be cleaned.
Regards the OP's problem, many of these tables are now coming up with motor
problems, and no replacements available from Panasonic.
If it is the motor, at least the top bearing should be lubricated. Possibly
a good tech could disassemble and "overhaul" the motor.
Mark Z.
"Brad Clarke" <bgcla...@hotmail.com> wrote in message
news:c6o48vc4gimaairgt...@4ax.com...
Monk
SL-DL1 fully automatic linear tracking turntable, but in general I still
think the simpler the better, also if something has lots of extra controls
chances are that quality is sacrificed for silly gadgets.
"Deke" <den...@starbandmypants.con> wrote in message
Harv
had developed and here is how I did it. This may or may not work
for you, but it worked like a charm for me, and cost me 99 cents
and about ten minutes of time..
I did not take the turntable apart to clean the pitch wheel pot
or the 33/45 switch. An electronics computer guy friend opined that
pot or switch dirt would cause random noise, and the strobe wheel
markings would waver randomly.. well the
wavering I was getting was not random.. it was a steady, repeating
pattern that the pitch wheel simply could not make stay solid..
He suggested that it was probably the belt and that the first thing
to try, before giving The Needledoctor.com or someone like that
$20.00 for a new belt (I cannot believe they charge $7.00 to ship
what is basically a big rubberband by UPS ground).. was to remove the
belt, clean it off with rubbing alcohol, and also clean the big
whatever the Hell you call it under the platter that the belt rides
on, plus the little brass pulley that sticks out of the motor that
the belt goes over.
I went to the store and bought a 99c bottle of rubbing alcohol.
Took off the turntable mat, released the belt from the brass pulley,
took it off the bottom of the platter, and proceded to give all
three a good cleaning with a washcloth soaked in alcohol.
There were black residue spots on both pulleys, which I cleaned
until shiny then dried, and I ran the belt by hand through the
washcloth as well. Went around it a half dozen times.
That left some more black residue on the cloth..
Then I went over everything with a dry part of the cloth..
When I reassembled everything, I turned the belt inside out (it's flat)
I figured why not, kind of like having your tires rotated so they'd
wear evenly,
put it all back together, lifted the tonearm with its lever and pushed
it in so the turntable would turn on and then crossed my fingers,
waved a Crucifix, said a few Hail Marys, tossed the I-Ching, and
held my breath..
Well guess what.. the strobe when adjusted with the pitch wheel is
now rock steady again. It wasn't the motor, the bearings, the pitch
wheel pot, the 33/45 switch.. it was simply some belt residue. I
should probably buy a new belt anyway, which I might do, but at least
now the turntable plays at a rock solid steady speed, the strobe
does not waver at all. Problem solved. Saved $200.00 to $300.00 for
a new turntable, with a couple cents worth of rubbing alcohol, a rag,
and ten minutes of time..
Harv
Brad Clarke
<mzach...@yis.us> wrote:
>>Actually 1/4" wide is too wide for the B2's pulley. The original type is
>>thinner.
Interesting....I got the info off of a web site that sells belts for
Panasonic/Technics turntables, and that's the info they give for the
SL-B2.
Brad
Harv
1/4" wide and 23.6" long is the correct belt size for this turntable.. or is
it 26.3".. one of those ;) ..
That was then, this is now, my SL-B2 is fixed, running perfectly now, rock
solid strobe markings, all it was was some bits of belt crud on the
pulleys.. gonna buy a new belt since this one is obviously going to keep
shedding rubber bits and the problem will come back again eventually.. but
$13.00 for a new belt plus the ridiculous rip-off shipping charge of $7.00
from Needledoctor.com is the best price I can find anywhere.. seven freakin
dollars to ship me a rubberband.. I could put it in a bubble mailer and mail
it anywhere in the country with two 37c stamps on it.. how do they sleep at
night!?..
Harv
Mark D. Zacharias
you'll find it's a bit thinner than 1/4", and if you observe a 1/4" belt in
place on the Technics motor pulley, the edges of the belt rub the flanges of
the pulley. Not a big deal, perhaps, but correct belts are available.
The PRB line FRZ 23.6 for example.
Mark Z.
"Brad Clarke" <bgcla...@hotmail.com> wrote in message
news:a2j78vs7v51pebp0d...@4ax.com...
Rivergoat
electrolytic caps on the older boards, that helped another user's
Technics, though not sure which model.
I had an SL-1400 direct drive. After many years of fine use the speed
would start fluctuating, especially at 45. I opened it and tried
spraying onto the pitch control pot, that didn't seem to help. I
contacted a Technics' parts supplier who said the pots were no longer
available from Technics. I suppose I could have disassembled and tried
to figure out what value the pots were (they can't be much more than
fairly standard variable resistors, can they?). Then, however, the
auto return mechanism went haywire on the unit, too. I gave up on it
and ended up donating it. The happier ending is that I just recently
found a perfectly operational SL-1400 elsewhere. I prefer having
direct drive, and the auto return was always a nice plus. (If this one
gives any trouble I'll work harder at service before I abandon it!).
Harv
"Rivergoat" <go...@goathead.com> wrote in message
news:3e924a80...@news.netgate.net...
Maybe you missed it when I posted the solution to the wavering problem I was
having on my Technics SL-B2.. it was built up belt crud on the pulleys. A
rag, some rubbing alcohol, and cleaning both pulleys and the belt itself
solved the problem, and the strobe, and thus the speed, is rock solid now. I
was on the verge of tearing into it to try to get contact cleaner into the
pitch wheel pot and the 33/45 switch.. I was even on the verge of boxing it
up and throwing it in the closet and spending $200.00 or more for a new
turntable.
Luckily, a friend of mine suggested that a dirty pitch wheel pot would cause
random noise, (electronic noise, not audible noise).. and the pitch would
waver randomly, not in a repeating pattern as it was, so the cause was most
likely a little blip or two of shedded belt crud on the pulleys than it was
the electronics. I took off the mat, flipped the belt off the brass motor
pulley, took off the platter and sure enough, there were a few little black
dots on both pulleys.. belt crud.. about a dime's worth of alcohol, a rag,
and ten minutes of time fixed it, instead of a big wad of cash..
Of course if a Direct Drive model is wavering, the problem is elsewhere as
it has no belt, but I was happy to find such a cheap solution to an
aggravating problem, as I really like the turntable, and have had it since
probably the late 1970s or early 1980s.. it still looks brand new.. unlike
Diamonds, Rubber is not forever.. I should probably buy a new belt anyway if
this one has started to shed but for now, it's running perfectly..
Harv
Mark D. Zacharias
enough that the belt crud you found would not induce an audible variation in
speed. If it were audible, it would definitely be a high frequency type of
flutter. Just my .02 from a repair tech.
Mark Z.
"Harv" <hla...@socal.rr.com> wrote in message
news:MmCka.154664$9G.21...@twister.socal.rr.com...
Harv
"Mark D. Zacharias" <mzach...@yis.us> wrote in message
news:b70vvt$9utqk$1...@ID-180484.news.dfncis.de...
> With respect, I would expect your problem to recur. The pulley turns fast
> enough that the belt crud you found would not induce an audible variation
in
> speed. If it were audible, it would definitely be a high frequency type of
> flutter. Just my .02 from a repair tech.
>
> Mark Z.
I'll try to explain this graphically.. pretend you are staring at one of the
strobe markings as the turntable spins at 33 and 1/3..
Before I cleaned off the belt and pulleys, the markings looked like this..
(obviously I'm trying to do in ASCII a representation of something that
really should be animated..)..
|||| |||| |||| |||| |||| |||| |||| |||| ||||
In other words, steady for a second, then a jump ahead one mark, then steady
for a second and a jump ahead one mark, and so on, in an exactly repeating
pattern, timed to the rotation of the turntable's platter, and I could HEAR
the waver in musical passages with extended notes..
After cleaning off the belt and pulleys, the markngs look like this..
|||||||||||||||||||||||||||||||||||||||||
In other words, no steady/jump/steady/jump, but just constantly steady with
no wavering at all..
Just imagine you're looking at one of the marks directly under the orange
light that lights up the strobe markings.. that mark stays in one place now
and does not waver back and forth and does not jump ahead in a constantly
repeating, repetitive, timed pattern as it did before I cleaned off the
crud..
Harv
Mark D. Zacharias
revolutions. Doesn't quite add up in my mind, though I'm glad it seems to
have fixed your problem.
Mark Z.
"Harv" <hla...@socal.rr.com> wrote in message
news:tCUka.158412$9G.22...@twister.socal.rr.com...
Bruce L. Bergman
D. Zacharias" <mzach...@yis.us> wrote:
>I understand, but in the space of a second, the motor has turned many
>revolutions. Doesn't quite add up in my mind, though I'm glad it seems to
>have fixed your problem.
>
>Mark Z.
The most basic belt-drive turntable motor is running at 1800 or 3600
RPM synchronous (on 60Hz power) turning a small drive pulley, so it
wouldn't make low-speed gross rhythmic variations like that. (And the
motor is under electronic control for the more common variable pitch
adjusting systems, but the motor speed is still in that range.)
But at 33 1/3 RPM it takes the platter a little under two seconds to
make one complete revolution. Large deposits of 'misc. crud' on the
platter belt tracking surface (at the outside edge of the platter) can
make large variations in the platter speed that are quite noticeable.
--<< Bruce >>--
--
Bruce L. Bergman, POB 394, Woodland Hills CA 91365, USA
Electrician, Westend Electric (#726700) Agoura, CA
WARNING: UCE Spam E-mail is not welcome here. I report violators.
SpamBlock In Use - Remove the "Python" with a "net" to E-Mail.
Mark D. Zacharias
mz
"Bruce L. Bergman" <blpytho...@earthlink.invalid> wrote in message
news:ne7b9vg0t2tqharc6...@4ax.com...
Harv
"Mark D. Zacharias" <mzach...@yis.us> wrote in message
news:b7573f$aucnu$1...@ID-180484.news.dfncis.de...
> On the turntable platter, yes. But the motor pulley?
>
> mz
There was one little black dot of belt crud on the brass motor pulley, there
were many little dots of black belt crud and a line of black on the flange
on the underside of the platter where the belt rides and transfers the
rotation of the motor pulley to the platter.. the belt itself also had some
excess crud on it. Cleaning all three of these solved the problem. As I've
explained, the waver in the markings on the edge of the platter under the
orange strobe was an exactly repeating pattern which seemed to directly
correspond to the rotation of the platter.. so I suspect the brass motor
pulley had very little to do with it as it was almost clean, and that the
crud on the flange under the platter where the belt rides had the most to do
with it..
At any rate, when I get a round to it, I'll buy another belt anyway.. but
for now, the cleaning solved the problem, which I still believe had
absolutely nothing to do with the turntable's electronics since it runs
flawlessly now, consistantly, and the strobe markings simply do not quiver
or waver at all when it's running..
I don't use the turntable every day. Sometimes I don't use it for weeks.
Belts deteriorate over time since they're just a big rubber band.. albeit a
higher quality of rubber band than you'd buy in a $1.00 pack of 100 at an
office supply store.. they're not forever. This one is obviously past its
prime, although visually it looks okay.. a replacement is in order..
Harv
Billy Blastov
speed was wavering even with a new belt. Electrical contact cleaner on the VR's and pot... good scrub of the platter and spindle...
steady as she can be... my teenagers are about to experience vinyl for the first time in their lives...