Mounting the cartridge

The needle should be at the correct distance from the tonearm’s bearing, the pivoting center. Thorens provided a headshell gauge as a guide for mounting the cartridge on the stock TP-60 mounting shell. Both the TP-16 and the TP-11 tonearms mounted on the TD-160 (the one I currently have) and the TD-165 (the one I owned before) turntables, respectively, have a TP-60 shell. I don’t have such a headshell gauge, so I calculated the key distances from the scale drawing on the TD-165 manual: from my calculations, the needle has to be at about 24-25 mm in vertical from the headshell’s outer edge and 7-8 mm (better lower it down to 4-5 mm – as better explained in the cartridge alignment page) horizontally from it (click on the picture at right for an enlarged drawing). With additional patience, it is quite easy to take those measurements after removing the headshell and placing it upside-down on a table. It is as simple as aligning the cartridge by sliding it back and forth until we measure the correct needle position.

The problem with most cartridges is that they are not “tall” enough for Thorens turntables and their needle will always be at less than 24 mm from the headshell’s “roof”. Shims must be used, spacers that were purposely provided by Thorens along with the headshell. Some are sold on the market but I couldn’t find any. So I solved the problem with a DIY solution: plastic badges holding cellular phone SIM cards are usually thrown away besides the fact they have vital PIN and PUK codes written on them; I found out their thickness is just half the one I needed to correctly position my cartridge’s needle. I cut two rectangular pieces and I placed them between my Grado cart and the Thorens headshell: the needle fell at 24 mm as required. Some Lego small bricks, those with a smooth face, possibly black, can also be used, being 3 mm thick. Even better, I’ve recently obtained them from thin PCV sheets (top left). I real pain in the back are the cartridge mounting screws, which aren’t usually long enough to secure the cartridge after the spacers have been installed. I had to find and buy the proper Thorens-compatible, non-magnetic screws and washers.

The use of shims is meant to achieve the correct VTA, the vertical tracking angle in this kind of Thorens turntables: it depends on the height of the tonearm, adjustable by releasing two allen screws at the bottom of the tonearm’s pivot. If you don’t use shims, the headshell and stylus tip will fall too low on the record surface with respect to the tonearms bearing. But adjusting the tonearm height for this reason, would possibly need also adjustment of the tonearm lift mechanism and compromise the functions of the automatic versions of the turntables – using spacers is sometimes simpler.

At this point, a protractor is not strictly necessary for tip positioning, but it is still advisable to use one for a final check and side alignment. It is very important the needle is at the correct position along the tonearm and that the cart body is aligned (well, the cantilever actually). There are several different theories about the correct alignment of a cartridge along a tonearm (see the alignment page).

A very useful upgrade everybody should do on all old Thorens headshells is replacing the 4 leads that connect the cartridge to the tonearm. The original ones are very thin and the contacts are dirty and rusty. As a first step, it is a good idea to remove them and polish all contacts – even the old leads’ – with de-oxi fluid and a small brush. But they should be replaced as soon as possible. Several types of substitute leads are available on the market. They are compatible with almost every headshell around. Some cost a fortune, but I managed to find good, gold plated terminals for just a few euros. I didn’t expect such a good result: it was as if the classical “veil” had been removed from the music. The leads are thicker than the originals, so they weigh more (0.18 g each); this affects the tonearm/cartridge assembly’s resonance frequency, since I have a heavy arm and a rather compliant stylus. In order to lighten the arm a bit, I removed the Thorens logo plate and a small piece of plastic form within the headshell. Remember that the TP-60 has a different wiring schematics than the standard. Follow the picture at left as a guidance if you choose to replace the headshell leads.

According to the usual mathematical formula, I didn’t obtain an optimal relationship, but I didn’t notice tracking problems or background noises. Then I purchased the very useful HiFi News Test Record.

It contains several tracks with different signals useful to verify the correct tonearm/cartridge interaction. A really useful track is that for verifying the resonance frequency of the arm/cart system. What really surprised me was that the frequency I obtain mathematically for my TP-16 tonearm and Grado Prestige Gold cartridge is around 7.5 Hz. The optimal range according to HiFi News is 8-15 Hz. The Test Record’s track gives a resonance frequency of around 13 Hz, far better than mathematical forecasts.

Another interesting track is the one considered to be a torture even for high-rated systems. To my great surprise, after having optimized the alignment thanks to the test record itself, my Grado Prestige Gold with 8MZ stylus passed even the terrible test: it stayed in the grooves. It seems that even the acclaimed tracker Shure V15 VxMR TNT-Audio’s Geoff Husband loves so much had been “spat off the record” on his very expensive SME IV tonearm. Not bad!

Actually, the Shure cartridges I tested with Thorens tables on this record didn’t perform as well as the Grados. As long as I had my system in a room at the ground floor, I had no problems with the Shures whatsoever. But when I moved on a suspended floor, my Shure Me97 started to bump at the slightly stronger step. I had to spend some more time to properly setup the TP16 with this Shure cart for best performance and limited bumping.

So my advice for Thorens TD160/165 type decks is installing a Grado Black 2 if you are on a budget or the rest of your system is low/medium level; if you can or your system allows for it, try to go as high as the Grado Red 2 (especially if you have a TD160). If the system is worth it, you may be able to hear the difference with a Silver 2 or even Gold 2. Remember the modern Gold 2 stylus is pretty similar to the 8MZ replacement stylus of today (although it doesn’t perform well on Signature bodies!). Probably, the Grado Prestige Gold 2 is the top choice for a TD160 installed in a worthy system. On the other hand, if money is scarce and the system is yet to be upgraded, just look for an old AT95e – no cart can beat its quality/price ratio, especially now that they are no longer produced. And it can be upgraded with higher performance styli (like my HE replacement), but for about the same price as a Grado replacement stylus. Worth a thought are certainly the modern evolution of the most famous AT cartridge line: the ATV95 is a step above the older AT95 series (the replacement styli are not compatible).

Shure cartridges, non longer produced today, were popular on these turntables and they perform really well (I love them), but need more attention during setup and fine tuning.