• QuadraphonicQuad welcomes you and encourages your participation! Treat all members with respect. Please keep all discussions civil, even when you have a strong opinion on a particular topic.

    Do not offer for free, offer for sale, offer for trade, or request copies or files of copyrighted material - no matter how rare or unavailable to the public they might be. We do not condone the illegal sharing of music. There are many places on the internet where you can participate in such transactions, but QuadraphonicQuad is not one of them. We are here to encourage and support new multichannel releases from those companies that still provide them and as such the distribution of illegal copies of recordings is counter-productive to that effort. Any posts of this sort will be deleted without notification.

    Please try to avoid discussions that pit one format against another. Hint for new users: make liberal use of the search facilities here at QuadraphonicQuad. Our message base is an incredibly rich resource of detailed information on virtually all topics pertaining to surround-sound. You will be surprised at what you can find with a little digging!

HELP: Technics SL-QL1 Linear tracking TT behavior

Help Support QuadraphonicQuad:

kap'n krunch

2K Club - QQ Super Nova
Nov 25, 2008
nola, estados hundidos
Hello all out there!

Hopefully someone will be able to clear my doubts...
I know that linear tracking TTs are mostly for freaks like me and that since there are no good methods of taking care of the LINEAR tracking part, the industry has given up on them...except for Clear Audio´s really expensive arms...

I personally love the sound of my TT but it has always had this nagging defect:
you can see it in the waves when I rip any album, it seems it either goes towards the inside or it is dragged from the outside and it makes this low frequency noise/thump once every revolution which I have to EQ from quiet passages.

Now, I think that my TT´s arm is moved through a servo motor but that´s as far as I go.

I have 2 other exact TTs in Madrid, (I got 2 so I could use one for parts) so my question is:

is this a "manufacturing/impossible to solve problem" or would it go away if I change the belt that is used???

I had my other 2 TTs in Madrid serviced by Panasonic/Technics personnel when I got them originally but it somehow still made that noise (I guess in a way this MAY answer my question but I will never know if the folks ACTUALLY changed the belt)...

This is the Vinyl Engine page where anyone (OK, you have to sign up but it´s free) can look up the user guide and schematics for this TT in case someone is willing to give me a hand...granted, I know a lot of you are a bunch of wizards (I am NOT!) and in case anyone can actually help out I will gladly ship this and pay for the upgrade...

Thanks in advance!


600 Club - QQ All-Star
Apr 5, 2004
San Diego area
I had one of these TTs at one time, been quite a while. Never noticed the problem you are having.
Sounds like pages 9 and 10 of the service manual are the parts of interest here (figures 12 -16).

The Bushmaster

500 Club - QQ All-Star
Nov 24, 2012
Ava. MO
Love my Dual 721...It goes round and round and gives no problems at all. No belts and no idler wheel.


1K Club - QQ Shooting Star
Since 2002/2003
Jun 14, 2002
Sacramento, California
I've never had the thumping with a Technics, but I have had it with a Sony. One shop tried to fix it but couldn't. Another replaced a belt and, a mere $30 later, the problem was gone.


Well-known Member
Nov 3, 2019
It might be the platter bearing. If it occurs once a turn regardless of where the arm is located it almost certainly is.
Getting the platter off should be in the manual. You probably need to top up the lubricant.
Or maybe something under the platter that is rubbing once per turn.
Last edited: