Thorens TP16 base tilted?

[p.robustini]

Hi guys!

I was experimenting with thinner mats than my 5 mm Funk Firm Achromat that got a little warped. So I noticed that even with the tonearm pivot all the way down and a 3 mm spacer over the cartridge, the tonearm is still sloping towards the headshell. To be honest, even with the Achromat the wand is still dipping.

Looking closer, I noticed the tonearm base is a bit tilted inward so the arm’s pivot is slightly leaning. That may result in the pivot being also too high…

I will open the deck as soon as I can but in the meantime I’d like to have any suggestion, since I’m not sure it might be a matter of regulating the springs: the platter is horizontal and the tonearm base is not, as you can see from the attached photo.
Maybe there is a way to better fix the tonearm’s base to the sub chassis?

Thanks!

 

[tnsilver]

I’m not sure it might be a matter of regulating the springs

It usually is. The TA mount base has a couple protruding plastic pins on the bottom that go in the matching sub-chassis holes for alignment. Unless the pins aren't in the holes, or something got caught between the base plate and sub-chassis, it's suspension spring tuning related.

 

[ddarch]

I agree with Tom is usually suspension related, but it never hurts to tighten those three screws that hold the armboard in place...it's also sometimes that someone removed the screws for whatever reason and cross threaded one or more. Lastly, and much less likely, it can sometimes be a bent subchassis...if it's not suspension related or screw related, put a short metal ruler against the subchassis underside...

 

[gadget73]

Confirm how level the platter really is relative to the rest of it. The arm mounts to the same plate that the platter bearing does, which is all supported by the springs. If the arm base is tilted because of a suspension issue, the platter will also be tilted. If one is tilted and the other is not, either the screws are loose or someone bent the sub-chassis.

its possible for the top plate to be bent and cause things to look wrong without actually being wrong. Might want to check things out with a level before doing anything else.

 

[Fishead]

Hello in Italy!

I have the same tonearm and did quite a bit of work when I first got my TD160 getting things set up correctly. As tnsilver and others suggest, all that will likely be required is for you to adjust the springs. This will enable you to get your VTA dialed in as well since it will raise, or lower, the tonearm itself in the mount. If your table (is it a TD160?) is like mine, look at it from underneath and you will see some holes in the base (assuming it is the original base) that will allow you to adjust the springs without actually having to remove the base. I don't remember as it's been a while, but seems like I used a 10mm socket with a short extension to get to the three nuts on the ends of the long screws that hold the springs in place.

Find something that you can place your turntable on so that you can see the underside of it. I have mine on a wall shelf that I can remove the board from so the table sits on the supports and nothing else, opening the view from beneath perfectly.....see here:



With the shelf, it looks like this:



You will have to look closely to determine which of the holes actually leads to the springs, but you will see them if you use a flashlight. I'm not certain why the base on mine has more than 3 holes, but we'd have to ask Thorens about that!

If you are not familiar with this website, it will provide you lots of great information to work on your Thorens, particularly how to adjust those springs to give you the right amount of "bounce" as it goes into great detail on the subject:

https://www.theanalogdept.com/thorens_dept_.htm

Just scroll down until you see your model and then look at the various links depending on what you are working on. Let us know how you do, amigo, and good luck with your efforts!

 

[p.robustini]

Thank you guys!
I’m familiar with the spring tuning procedure, I did it a few times on Td-160/5s. Not a real expert but good enough… ;-)
Last time I performed it on my Td-160, I leveled the platter and did not notice the tonearm base was tilted. The platter is level indeed. I really hope the screws are badly inserted. I can’t see why if the platter is level the tonearm base is not! Unless the su platter is bent! Wow…
Now I’m thinking our cats long ago jumped over the turntable while it was spinning. It happened twice and I was more worried about the record and the cantilever…. I did not notice anything wrong with the tonearm…
I’ll follow your advices and check all possible issues, hopefully in the weekend!

Thanks a lot again!
Pasquale

 

[p.robustini]

Hello in Italy!

I have the same tonearm and did quite a bit of work when I first got my TD160 getting things set up correctly. As tnsilver and others suggest, all that will likely be required is for you to adjust the springs. This will enable you to get your VTA dialed in as well since it will raise, or lower, the tonearm itself in the mount. If your table (is it a TD160?) is like mine, look at it from underneath and you will see some holes in the base (assuming it is the original base) that will allow you to adjust the springs without actually having to remove the base. I don't remember as it's been a while, but seems like I used a 10mm socket with a short extension to get to the three nuts on the ends of the long screws that hold the springs in place.

Find something that you can place your turntable on so that you can see the underside of it. I have mine on a wall shelf that I can remove the board from so the table sits on the supports and nothing else, opening the view from beneath perfectly.....see here:

View attachment 2575440

With the shelf, it looks like this:

View attachment 2575442

You will have to look closely to determine which of the holes actually leads to the springs, but you will see them if you use a flashlight. I'm not certain why the base on mine has more than 3 holes, but we'd have to ask Thorens about that!

If you are not familiar with this website, it will provide you lots of great information to work on your Thorens, particularly how to adjust those springs to give you the right amount of "bounce" as it goes into great detail on the subject:

https://www.theanalogdept.com/thorens_dept_.htm

Just scroll down until you see your model and then look at the various links depending on what you are working on. Let us know how you do, amigo, and good luck with your efforts!

Hey! Thanks! I learned much of what I know from that website…. And also a lot from the audio karma guys years ago!
Ciao from Italy!

 

[p.robustini]

This is why I was not originally thinking spring tuning…. (See attached photos).
Hopefully it’s not a bent subchassis, just misplaced screws…

 

[gadget73]

yeah something is going on there. Platter looks pretty OK so it won't be a spring issue. The arm is not in the same plane as the platter anymore.

 

[Fishead]

I'm looking at your first picture in post #1 and still scratching my head.....several things look wonky to me. The tonearm base is pretty high in the opening, which you should be able to lower and that should help with the VTA, i.e. getting the arm level with the record surface. If I am remembering correctly, isn't this accomplished at least in part with the springs? The tonearm base is not centered in the cutout as it should be, something else I seem to remember is adjusted with the springs. Here's mine:



From your picture in post #1, your tonearm base appears a bit higher than what you see here. Is that true or is it just optics with the angles in the pictures?


And here's my tonearm with the stylus resting on a record surface:



Really, really close to being parallel to the record surface. And, aren't there two allen screws (2 mm) on the tonearm pillar that can be loosened so the arm can be raised or lowered? Have you made this adjustment?

It sounds like you know your way around these tables pretty well so I'm not sure if this will be any help at all, but just thought I would cover some of the more obvious things.

 

[p.robustini]

Yes, Fished, you tonearm base is centered, horizontal and lower than mine. I see you also have the original rubber mat. I have a 5 mm Achromat. I have used the Allen screws to lower the tonearm almost completely and still I don’t have a horizontal tonearm (with a spacer on the cartridge). It’s too much but I’m not sure its just a matter of springs…
I’ll have to open and see from below.
Thanks to you too, much appreciated!

 

[Fishead]

I believe, when I was first setting it up and learning, that I had the tonearm base nearly level with the top of the deck using the springs. I could be remembering incorrectly, but if not, this positioning of the base results in the springs being compressed too much for a good "bounce" to be had, meaning the suspension is too tight and will not perform as intended. So, in looking at yours I believe you could come down a little and still have the right compression on the springs. Maybe that will help you get your tonearm a bit more level. At very least, you get to have some fun messing around with it, eh? Let us know what happens.

 

[p.robustini]

Subplatter slightly bent…. Ruler rocks slightly

 

[p.robustini]

Wait! But if I loosen the 3 screws I can rock the tonearm-base assembly!
I put a spacer under the inner screw and a thinner one under the front screw: it may be not perfect but it’s much better!
Still too high but at least flatter….

 

[p.robustini]

Actually, when I place the ruler under the subplatter after having removed the outer platter, the ruler rock a bit less.
with the turntable resting on its side, I can’t notice any bend.
So it seems to me that the subplatter yields under the weight of outer platter and counter platter! I would have never thought it possible….

 

[gadget73]

hm, the subchassis shouldn't be bending with the weight of the platter on it. Any chance there is a crack at the edge of the subchassis where it rolls down? That will provide a lot of strength but if the edge is cracked it will flex at that point.

 

[Fishead]

Good work, PR! Man, you should be able to drop that arm base a little more by manipulating the tension of the springs but like I said, it's been a while since I worked on mine so I'm not absolutely positively sure about that.....others may be able to confirm, or not. Also, from how it looks right now, you don't seem to be all that much higher than mine, maybe 2mm higher at most, so I'm not quite sure why you are not able to get the tonearm parallel? Maybe the cartridge body is just too short, which you said you already compensated for with spacers, so maybe just more spacers will do it but then I'm not sure how that will be affecting the overall characteristics/dynamics of the unit as a whole? What cartridge are you using? Guess you gotta just try and experiment until you get it to your satisfaction. Again, good call with the washers and getting the base level!

 

[p.robustini]

hm, the subchassis shouldn't be bending with the weight of the platter on it. Any chance there is a crack at the edge of the subchassis where it rolls down? That will provide a lot of strength but if the edge is cracked it will flex at that point.

I can’t see any cracks. It sounds strange to me too, but I can detect a bend only when the platter is on….

 

[p.robustini]

Good work, PR! Man, you should be able to drop that arm base a little more by manipulating the tension of the springs but like I said, it's been a while since I worked on mine so I'm not absolutely positively sure about that.....others may be able to confirm, or not. Also, from how it looks right now, you don't seem to be all that much higher than mine, maybe 2mm higher at most, so I'm not quite sure why you are not able to get the tonearm parallel? Maybe the cartridge body is just too short, which you said you already compensated for with spacers, so maybe just more spacers will do it but then I'm not sure how that will be affecting the overall characteristics/dynamics of the unit as a whole? What cartridge are you using? Guess you gotta just try and experiment until you get it to your satisfaction. Again, good call with the washers and getting the base level!

Thank you!
I’m using a Grado Prestige Blue 3 with a spacer and a Shure M97HE with Nagaoka ED stylus. Plus, I’m using a felt mat over the stock rubber one… so the tonearm is almost there. See the picture with the Shure on.
I don’t know, man, playing with the springs affects both platter and tonearm in the same way (anybody correct me if I’m wrong but they are both on the subchassis). I mean they would both drop….

 

[Fishead]

Yes, I believe you are correct in that.....so I was probably mistaken, sorry about that. So the only real adjustment you have are the two screws on the arm pillar that let you go up and down with it. Are you all the way down? It sure is looking pretty dang level, so you are might close. Can you measure, with a caliper perhaps, the distance of your platter off of the top of the deck?