Help with TD-160 tuning/suspension (both subchassis and motor spindle).

T

Taketheflame

Super Member
Hey all,

So I need some help in finally getting my TD-160 Super up and running correctly, and I'm at the last steps in doing so - adjusting not only the suspension, but also the position of the motor spindle pulley. I've gone onto Analogdepot and watched a video from ddarch (Dave @ Vinyl Nirvana), but still have some questions.

First, the motor spindle adjusting questions - The motor started knocking (a ticking sound) on occasion at one point. I have a thrust support kit if it's being caused by internal wear, but I've read that sometimes it can be caused by the suspension/pulley position being off, and proper adjustments/belt break-in can often "fix" it (I am using a proper Thorens belt). I've also read that the spindle being off can cause speed issues (on mine, 33 RPM is a bit slow, and 45 RPM is slightly fast, but closer to accurate than 33 RPM mode).

I actually had to remove the motor at one point as well (the wires had to be tinned in order to successfully connect it to a PCB power supply upgrade), so the spindle may not be in the same position as before (as it knocks all the time now). It's my understanding I simply need to adjust the spring loaded screw closest to the platter to correct the spinde position? Do I just do so until the knocking goes away? (Is it ok to do so while running? Only with the belt and sub-platter on).

Secondly - it's obvious that the suspension is off, because there isn't enough "bounce", and the platter doesn't spin completely flat (there is a bit of "dip" towards the front of the table). Seems like the easiest way to adjust is to do so with the outer platter upside down to better see how it's spinning/how the belt travels along the subplatter/pulley.

I'm assuming I adjust until the platter spins completely level/as flat as possible with a mat/record on top of the upside down platter? But I also read conflicting reports of what the proper distance from the bottom of the platter to the top plate is...6mm? 7? 8?

Getting this thing finally dialed in is my plan for the afternoon/evening, so help is much appreciated :).
 
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My Thorens 160 also has a noisy motor, with the classic 'knock'. But speed and wow and flutter are still exceptionally good, so I am not sure if the knocking sound necessarily means it is the cause of speed and stability issues.

I had suspension issues, and it caused the pulley to touch the platter, which threw everything off of course. Any chance this is what is happening?

The other thing that could cause this is your pulley got bent somehow. This is apparently a common issue, and why later models have a pulley protector (indeed, my 145 has this).

Good luck! I would check the suspension first, and hopefully this will fix it.
 
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As far as I know, the pulley on mine is just fine, although I will inspect it again later. The bearing/bearing well and inner platter shaft are all in excellent condition as well.

When I originally heard a motor knock, it was seldom, and only with a full load (i.e - the outer platter and a record). I made sure to be exceptionally cafeful with the motor while it was removed for wire tinning. Going to see if motor spindle adjustment can get it to stop, as I may not have set it exactly how it was prior to removal. Most of the time, the motor was completely silent.

My table does have a pulley protector, and the platter has not hit it with the table running. If anything, the suspension is probably set too high/too stiff in the back half of the table, in the interest of extra caution w/the pulley while dialing the table in.
 
gadget73 said:
If you poke through the TD160 Super conversion instructions it tells you how to set the suspension initially

https://www.vinylengine.com/ve_downloads/index.php?thorens/thorens_td160_super_conversion_kit_en.pdf

basically level the plinth, put the platter on upside-down, adjust the left suspension nut for 10mm between the pulley and the inverted outer platter, adjust the other two springs to level the platter. After thats done you confirm the belt alignment.
Click to expand...
Unfortunately, the link doesn't work for me (I get an error message about links to VE content from an outside web site), but nice timing, as I'm in the middle of trying to get this beast dialed in.

For something that sounds relatively straight forward, it sure seems awfully tricky to get things quite right. I made a cardboard "level" about 6mm in thickness to check the distance from the bottom of the platter to the top plate. Seems like no matter how I adjust the suspension, the left-rear position of the platter (closest to the motor) always seems slightly higher than the other two points. I had to drop the the left screw position to a very low position (almost hitting the safety screw with the bounce test, but not quite) and raise the front and arm screws higher than seems ideal just to get it relatively level, but I can tell it's still not quite right.

I have at least managed to get some bounce in the setup (maybe 2-2.5 seconds worth?), but it seems videos of good bounce tests last for at least 5 seconds...

The upside down outer platter trick mostly seems to confirm what I'm finding - that adjustments must still be made. Problem is, it seems like I have to have the front screw adjusted too high to try and get the platter more level (i.e - I lose the bounce in the process).
 
Taketheflame said:
Unfortunately, the link doesn't work for me (I get an error message about links to VE content from an outside web site), but nice timing, as I'm in the middle of trying to get this beast dialed in.
Click to expand...

I have to turn my VPN off with a lot of websites, such as VE.
 
doctor fuse said:
I have to turn my VPN off with a lot of websites, such as VE.
Click to expand...
Seems to be a message about VE not allowing direct links to downloads from other websites...

Well, I can at least say my suspension tuning efforts, while not 100%, have improved the sound of the table quite a bit (sounds much more open and airy, was a bit congested with the springs too compressed), but unfortunately another electrical problem I've been having w/the table has returned (new thread coming!).
 
So I'm uploading a quick pic that shows the best I've been able to get it....(from the tonearm base)

20211019_214821_copy_1612x1209.jpg

Notice the slight lean forward of the suspension. If I push up a bit on the most forward spring (in front of the spring closest to the arm) it gets perfectly level, but if I tighten the bolt to raise it, it doesn't seem to rise enough to level out and it kills the bounce. But if I try to lower the other 2 springs to compensate, it doesn't really lower the back corner (motor area) enough to level it out yet becomes too loose (hits the pulley protection roe with the bounce test).

You can see a slight wobble with the platter spinning as well (not a lot, but noticeable). Using a test record and a few cheap records for playback tests, the tracking tests check out, but I detect the slightest of sibilance on the other records at times. They don't have the sibilance on my DD tables and it's a new stylus on the Thorens, so I suspect the less than perfect platter leveling is causing it by lowering the VTF at certain points.
 
gadget73 said:
try this one instead

https://www.vinylengine.com/library/thorens/td160.shtml

scroll down a bit to find the TD 160 Super conversion instructions
Click to expand...
Checked it out, but per the instructions, I can't seem to acheive 10mm of clearance between the bottom of the platter (when upside down) and the top of the motor pulley, maybe more around 7 or 8 mm?

I was able to get slightly more bounce playing around with it after raising the leftmost screw and tweaking the others a bit. Seems like a fair amount of trial and error (aka practice) is needed to get it dialed in spot on? I'm getting that there probably shouldn't be any extreme differences in how loose/tight each of the 3 nuts is adjusted?
 
the different points of the suspension have different amount of weight on them. The springs on mine aren't compressed evenly, but I won't swear its adjusted right either. I haven't gotten around to trying a re-tune using the Thorens instructions but its been on my list of stuff to tinker with when I have time to tinker.

something I probably ought to try and figure out is if the springs are tired or at least unevenly worn on mine. I suppose I could just take them out and check the free height, that may be enough to tell me if something is wrong.
 
This should help you.

Each spring has it's own vector , in other words they all lean slightly off vertical. Add to that the tension applied by the belt and you have a complex set of forces acting on the sub chassis.
In all likelyhood one of your spring rubbers is nudging the pillar therefore causing the lean.
Re your comments about adjustment height , the rear right spring needs to be higher because the mass of the tonearm compresses the spring more than the other two.
What you need to do is get the deck supported in some way that enables you to have access to the springs etc.
With the belt on start rotating the springs. I normally start with the tonearm spring. If the chassis is 'free' you will see that the chassis
will move around laterally. If you are new to this it will take you a while to sort this out. After you have done a couple of hundred it will come naturally..
Bit by bit you should get the feeling that things are falling into place.
You need to gently provoke a bounce with your finger more or less above the spring you are rotating.
Patience and all of a sudden it will be nearly right , then you go round again making small adjustments one way or the other on each spring.

Once you get the springs all freed up you can make the last small adjustments to the height.

Also check that the arm cable is not fouling anything and is free to flex.

Regarding your nuts , it's a good idea to use Nyloc nuts if the deck doesn't have them. 5mm from memory

M
 
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While I'm at at, I might as well post some updates on my suspension efforts...

I feel like I've gotten closer, but it's not quite there. I get about a 2-second bounce with a push test in near the spindle that is pretty vertical without excessive side movement or banging on the motor safety post.

The platter seems like it spins with a very slight vertical wavering effect (platter is not physically warped). I suspect it is effecting playback. I notice a bit of sibilance on more records than my other tables (non-suspended DDs), and I slight wow effect when playing a tracking test tone with a test record (otherwise, the tracking seems fine - it does not begin to audibly distort despite the wow effect). I suspect the platter variations may be causing a loss of VTF enough to cause the sibilance? (It seems more prone to outer grooves than inner grooves).

Here is where each spring is tuned to...(in order from right/tonearm spring, to front spring, to left spring).

20211106_131015_copy_1003x1209.jpg

20211106_125441_copy_1612x1209.jpg

20211106_130851_copy_1030x1013.jpg

The tonearm spring is around the 11th/12th thread of the shaft, front spring around the 8th, and side spring around the 9th.

The platter dip seems like it's in the front. If I adjust the front spring upwards to try to level it out, I lose a lot of bounce. If I lower the tonearm screw instead it does the same while becoming too loose in the back.

Hopefully someone can tell me if I'm too high/too low, or at least somewhat there. And I'm not sure if it's my imagination, but it seems the longer the bounce/the better the tuning, the better the sound from this thing.
 
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The tonearm lead in your first pic above looks rather too close to the sub chassis IMO.
Also the foams inside the springs will reduce the boing time.
I would suggest removing them.
I cant offer anytthing worthwhile re your platter without seeing it.
 
1. 10mm is a fallacy...it's in that ballpark, but depending on your platter weight (they varied by several ounces) and the tonearm used, it can vary by several mm.

2. Having tuned literally hundreds of these, sometimes you just have to settle. A two second bounce is ABSOLUTELY fine. Sometimes the plater weight and arm weight are perfect and you end up with a perfectly tuned suspension that bounces many seconds, and other times, after fighting with it, you just need to accept those factors (mentioned above) are never going to yield better results. (Given fresh or non-worn springs)

D
 
The number of bounces is irrelevant - the idea mostly stems from linnies misunderstanding the suspension of their LP12s. The point of the springs in the suspension is to isolate the inner chassis from external vibrations - nothing else. Too much of bounce will not add to that isolation, but will definitely add to speed instability, due to variations in the tension of the belt due to vibration of the inner chassis. Fewer bounces will give less flutter from the belt, which is far more important than the possible reduction of vibrations entering the inner chassis.

The audible improvement you have achieved so far is precisely what you are aiming for - an inner chassis that only has a vertical bounce, without any sideways wobble really makes the Thorenses sound better. That is what the Linn folks did get right about the suspension - the emphasis on eliminating the lateral movement of the inner chassis, instead of the Thorens manual method of only adjusting the height of the platter.

An off-centre spindle or pulley won't affect this, unless they are grotesquely off - those vibrations will be damped out in the belt before they can affect the suspension. (If someone is interested in those problems we are discussing them here)

The exact height of the platter isn't crucial - ideally, it should have the height that gives as much room as possible for the vertical movement from external disturbances - possibly with a little bit more margin for a downward movement, since that is more common than the opposite. As long as no normal use will make the springs to bottom out, you are OK.

As has been touched upon here, it is important that you do your adjustments with the belt in place, and make sure the tone arm cable has enough slack to not disturb the action of the springs. And of course, the entire inner chassis on Thorenses in unbalanced in itself, which makes the adjustment even more difficult. (Marc Morin had a wonderful solution for the same problems on the ARs he worked his magic on, by adding weights to the inner chassis to balance it).

Start by aiming for a consistent gap of about 5-6 mm under the platter. Then locate the point of balance of the inner chassis - somewhere along the line between the centre bearing and the tonearm - look for the spot where you can give the platter a light quick downward thrust, giving the least of sideways movement. After that, you keep on testing at that spot between your adjustments of the springs. Focus on the sideways movement, not on how it looks or measures.

There are two quirky things to look out for: Just rotating the springs without adjusting the height of them will affect the direction of the bounce, depending on the point at where the spring is in contact with the rubber grommets. Another complication is that you can't know if all of your three springs are evenly hard - after fourty years, they probably aren't. To minimise the sideways movement you may also need to compensate for that by adjusting the springs to unequal heights.
 
Ok, I'm back with a vey belated return to this thread...this table sat unused for awhile due to no time to work on it, but am back it it trying to get it running right/solving various issues.

So I started trying to tweak my suspension again, as I was never convinced it was actually "right", because of frontward platter dip. Was under the idea that twisting the springs can help alleviate this, but it doesn't seem to do anything. And no matter how high or low I go with the suspension, it's never quite right - and more telling, I cannot get the platter to spin perfectly level - there's always around 1-2mm of "wobble" while spinning.

I cannot find any visible issues with the motor shaft of inner platter, but I fear the problem might be the outer platter itself...I decided to dig through some old threads from people with similar issues of platter wobble (on both Thorens and AR tables), and in many cases, the platter is warped if suspension tuning doesn't fix it.

I also noticed that the outer platter does not sit perfectly flush with the perimeter of the inner platter - a small section of it seems flush, and the rest seems slightly raised...very fearful that I've had a bad platter the entire time here.. :mad:

FWIW, speed is not quite perfect using an RPM app (around 33.23 RPM for 33-1/3). I was thinking of doing a true W&F test w/a test record and software W&F meter to see what that might be too. I'm using a genuine Thorens belt..

I've uploaded a couple of videos of it in action...hoping that this is somehow normal, but worried that I'm SOL and that the platter is why I can't get the suspension/platter leveling quite right.

Platter on normal/with a record


Platter on upside-down -

 
Well, this is bad. And surprising - I've never seen a mismatch of those parts on a Thorens. Does the inner platter wobble in the same way? The wobble comes from one of the platters - a bent 10 mm hardened spindle would be a bit of a surprise. Since the platters don't have a perfect fit one of them must have been replaced somewhere along the way.

Start with checking the inner platter. It seems to be the metal one, so it should be original. Look for visible wobble, and try to feel for an uneven rotation with a finger nail. I expect that to be OK. Just to be sure, draw a marker line at the lowest dip of the outer platter where both platters meet, and and then rotate the outer platter one third of a turn or so, to see if the dip is still at the same place of the outer platter. If not, the inner one is at fault. If it is, it is the outer one, and you should start looking for a spare one. Luckily, those are the parts that normally survive even from the most banged-up machines, so it shouldn't be too difficult to find one. A good inner platter may be a bit more difficult to find, since the spindle may be worn from lack of oil in the bearing. If you need one, remember those were made in both 7 and 10 mm versions - a TD160 should have the 10 mm one, and preferably be of the metal variety.

No point what so ever to proceed with the platters in that shape. With a visible excentricity there is no point in measuring W&F - it is guaranteed to be off.
 
As our learned friend in Sweden says and as a one time dealer I have to say that Thorens QC was extremely good.
I am getting the feeling that at one time the deck may have been transported without removing the outer platter. Maybe it got a dunt or was dropped.
All is not lost however. The alloy casting material is relatively soft.
If you have a local engineering shop pay them a visit with your platter / hub / subchassis. Ask them to ' indicate ' the runout and which component the error is from . my bet is its the hub / spindle. It takes very little offset at the joint in the hub to produce the run out that you can see.
Engineers are used to this kind of thing and have solutions , specifically a couple of taps with an 'Engineers Hammer'
Then re measure. The pot metal casting will give.
In thirty years in the audio biz I have genuinely never seen a TD with an issue like this.

One more thing that springs to mind , if the deck was dropped in transit it may be that the main spindle bush ( in the sub chassis ) is not perpendicular to the sub chassis itself..
 
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Yes, damage from a drop would be the most probable explanation, which also could account for the mismatch. A dislocated spindle bush would tilt the platter at one fixed position. Hence the suspicion about the platters, primarily the outer one which is most prone to falling off.
 
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