Thorens Tweaks

This page documents modifications done to my TD-160 and reports how well they worked.

8/19/2003: Some time has passed since I first wrote this page. Back then I was looking for a project and so thought it might be fun to make improvements to a turntable. As it turned out, it is quite fun and nearly two years later, I'm still at it. What follows is the revised and continuing story of my test mule, a TD160 mk1 that sounds much better than any standard Thorens has a right to. Initially, I just wanted to see whether it was easy or hard to improve on one of these models. Now I can say that much of this work really is simple and, as a bonus, cheap to carry out.

You can't really start a project without a plan. Initially, I looked for a plan, a list of procedures to carry out. What I came up with was the list below. The Chadwick mods. These became my plan. Back in the latter days of the LP era, Chadwick used to advertise in the classified sections of audio magazines. He offered an upgrade service for Thorens turntables. I remember sending for and receiving his catalog. I never did send in my Thorens and, ultimately, lost track of the catalog. Then came CD's and years of idleness for the Thorens.....sigh.

I didn't completely forget the Chadwick mods and eventually, when renewed interest in vinyl came over me, I began looking for information on Chadwick and exactly what it was that he did for his customer's tables. The links below offer the best detail I could find. Chadwick died in 1999 and took the knowledge of his method with him. Otherwise I'd have called him up.

Link: http://www.audioasylum.com/audio/vinyl/messages/15633.html

The Thorens is a much discussed turntable on the internet at the audio-asylum, (vinyl-asylum) which can be found at the link below:

http://www.audioasylum.com/audio/vinyl/

Within the archives there I was able to dig up the following scraps of a recipe of Chadwick mods on a TD-125. Here is the link to the full post which refers to a magazine article in the Absolute Sound and an A/B comparison between the modified Thorens and a much pricier VPI table: http://www.audioasylum.com/audio/vinyl/messages/95257.html

Snip

9 mods were done:

baltic birch plywood 1/2 inch replacing the existing bottom plate with three spikes or cones underneath
isolation of the 3 suspension springs of the suspension using new gaskets and silicone
dampening the top of the motor plate and the underside of the top plate with 2 kinds of silicon damping material
readjustment of the bearings and selective damping of the arm tube
dampening of the platter hub with silicon and rebalancing
lining the underside of the arm board with cork for further isolation
replacing the rubber mat with a Chadwick "Corktone" mat
replacing the standard interconnect with a Sumiko PIP box and the interconnects of your choice
installing and aligning of the arm and cartridge of your choice

Snip

I have experimented with the above list and have the following thoughts about it.

The birch ply bottom plate really does work wonders for a TD160, but mdf should work fine too.
I do not use silicone on the rubber grommets at the susp. springs of a TD160...! Follow the Tim Bailey method instead.
Yes, damp the motor plate
Yes, adjust tonearm bearings, they probably need it especially if the arm is a TP16.
Yes damp the hub platter. The attached spindle shaft spins in bushings and noses down against a vertical thrust plate. Bearing vibes happen there. It helps to keep plenty of oil in the bearing housing, by the way.
Sure, damp the arm board. Why not. Just don't add a bunch of weight.
Yes, the standard platter mat can be improved. Cork works.
Nice idea. The Thorens phono outputs can be improved on.
Yes, naturally. A better arm and cart will work miracles.

Below are links to pages that detail the various work to be done.

Chassis Damping

Suspension Tuning tutorial by Tim Bailey

More suspension tuning notes.....with lots of pictures....and movies

Tonearm/cartridge alignment definition of terms use info here to align your tonearm.

Cartridge / Arm matching

Finding a proper replacement belt Testing replacement belts from various belt vendors.

TP16 MK I Tonearm, maintaining the cue mechanism Restoring the cue drop time.

plus Installing RCA jacks for the interconnect of your choice.

Rewiring a TP16mkII with silver wire. Wei Zhu sent in these photos of his experience.

Setting Overhang on a TP16 with a Clearaudio protractor. Only useful if you have this protractor.

Mounting a different Tonearm, SME 3009 Improved

Parking it on a wall shelf Suspended tables like it on the wall.

Results:

The result of all this work is well worth the time invested. The transformation is like having a completely different table. Background noise is way down. Signal to noise is way up. A sense of "in-the-room" presence is apparent. Soundstage, imaging. Notes hanging in air that didn't used to hang. Cymbals having more shimmer. Now it's making some music that draws you in.

Most Effective (Important) Tweaks:

1) Correct settings of suspension, tonearm and cartridge. If it were a car, you'd call it tune-up, lube and maintenance.

2) Damping.

	Make the heavy bottom plate
	Damp the motor plate
	Damp the inner platter (bearing hub)

3) Wall shelf. This eliminated the problem of structural born vibration disturbance that plagued this table when it was placed on a floor standing audio rack . The wall shelf allows the suspension to become stable and then it can react as it was designed to against the forces happening between stylus and groove. Also, life with the player is much better this way by allowing me the freedom to walk by without having to tip toe.

4) Drive belt, renew it with an original equipment replacement. Worn out belts lose grip during the more dynamic moments on a record and in the lower frequency notes. The result is lifeless music. A new belt brings back your dynamics and bass response.

5) Tonearm / arm board upgrade (replacement with SME 3009) The tonearm is important, but so is the arm board it mounts to. Different materials result in different sounds.

6) Phono Cartridge, get one that matches well to your tonearm. (Effective mass versus compliance of cantilever) Basic rule: More money in the cartridge = better sound. The question becomes "where do you draw the line...?" Consider the value of the table, quality of the tonearm. More info to come on cartridge/arm matching.

7) Platter mat. For a long time, I was not a believer in platter mat tweaks. That changed when I tested Malcolm Coulsen's Spotmat. This led to some experimentation of my own and, ultimately, mat #10. This mat allows a more solid lower frequency and a more alive and natural sounding midrange. More musical detail reaches my ears. Yes, mats can make a difference. Have some fun, make your own.

What is my reference.....? Teres 145, Thorens TD124

The SME 3009 S2 Improved is a lower mass version of their previous arm. It is also lighter and smaller and fits under the dustcover of the TD160 without interference. However.....

It might be best, when considering a tonearm swap to first choose the cartridge you wish to use. Following that, select a tonearm that will match well. Then, of course, you have the problem of determining if that arm will match well to your turntable. One thing leads to another, then another....etc. With the assortment of cartridges and arms available to choose from, your perfect match is entirely possible. More info about using this tonearm on a TD160.

Materials list:

Bottom Plate

1/2 inch birch plywood, Grade A. One piece at 12-15/16 x 16-1/2 (note, I had to buy an entire 4ft. x 8ft. sheet.)

4 - rubber feet, hole in center for wood screw mounting. (hardware store item)

4 - #8 x 1 inch brass wood screws

Damping

1 - 4 sq.ft. piece Dynamat (can be found at Car Stereo stores)

2 - 36 x 12 inch pieces of 1/8 inch automotive cork gasket material

1 - tube Blue RTV Silicone

1 - package of Blu-Tak (Bostik) available at audiophile vendors

4- packages of Elmer's Tac 'N Stik (Blu-Tak substitute, much cheaper commonly available)

Suspension Tuning

1 - can of talc (available at billiard supply shops)

Tonearm

Link to page for the tonearm details

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