Tonearm for Teres turntable - approx $1000 - ??

here is a good start to working out cart/tonearm issues.

http://www.theanalogdept.com/cartridge___arm_matching.htm

aa also has many threads on this and other vinyl-related issues.

best,

Hi OakIris,

Cartridge compliance is the stiffness of the suspension donut that holds the cantilever assembly in the body of the cartridge. It is the thing that allows the coils to be moved inside the magnetic field inside the cartridge. The compliance of cartridges is rated in units of CU(compliance units), with low compliance being generally considered under 10cu, medium-low compliance typically from 10cu-12cu, medium compliance from 13cu to about 20cu, medium high compliance from 21cu to about 25cu, and high compliance anything over 25cu. These are general ranges and some people may quibble about details, but they are pretty close to being what is generally accepted. Low compliance cartridges have stiffer suspensions, and high compliance cartridges have very soft suspensions, and the spring force of these suspensions has an effect on the interface of the cartridge and the tonearm.

With regard to cartridge/tonearm matching, the rule-of-thumb is that as the compliance gets lower, the effective mass of the arm must increase, in order to have the ability to keep the cartridge stabilized over the groove, and also to make a happy mass/resonance frequency in the desired range of 8Hz-12Hz. Going lower than 8Hz in mass/resonance can cause the system to be excited by rumble frequencies which is not desireable, and going higher than 12Hz can cause the resonance of the arm/cartridge matchup to have an audible effect in the audio range above 20Hz. So, when we look for matching arms and cartridges, we strive to have the mass/resonance match within this range mentioned above. Sometimes the match can yield somewhat higher than desired results, and still sound quite good. But we want to get as close as possible to the desired range.

There are charts available on the web which have matching curves for choosing cartridges which match to certain effective masses of tonearms, but these are general, and don't include all of the information needed for complete matching criteria, but they are a good general guide. You can also use the HFN&RR test record to check the exact resonance in your system.

What they don't tell you is that there is significant energy fed back into the tonearm and bearings, which can cause the tonearm to move in unwanted ways, or make the bearings chatter or break down. This energy is most severe in low compliance cartridges, and this is why I use and recommend quality higher mass gimbal-bearing tonearms for low compliance cartridges. Unipivots can be used on low compliance if there is a specific method of stabilization present on a unipivot tonearm, and if they have the correct mass needed for it.

So, for high compliance cartridges, generally you look for a lower mass(less than 9grams) tonearm to match it. For medium compliance cartridges, you look for a medium mass(9g-11.5g) tonearm to match. And for low compliance cartridges, you look for a high mass arm of over 12grams(and sometimes much higher, depending on how low the compliance is). The high mass arms and low compliance cartridges seem to be the most difficult matches to make because there is so much energy being sent back into the arm to excite everything, that much more than just the mass/resonance issue comes into play. Generally, it is less risky for beginners to start out with something in the medium mass/medium compliance range, because they are less likely to make a big mistake there. But, there are great sonic rewards in the low compliance cartridges, if you make a good match for them.

Typically, I make my matches by the "seat of my pants" because I've had a lot of experiences with many different matchups. But, a beginner should learn the basics first, and then try to fly later.

You can do some Google searches on the key words I've used and you'll come up with a variety of articles with charts and graphs to help you.

And, if you are in a quandary, just email me and I'll help you out.

BTW, the HiFi mod makes the effective horizontal mass of the Rega arms and OL Silver arms high enought to stabilize the low compliance cartridges, even though the effective mass of the standard tonearm is marginally too low for the use of such cartridges. The result is that the shortcomings of the matchup are overcome by the use of the HiFi mod.

I hate math!! :-) Anyway, the Zyx R100H compliance is listed as 15 x 1.6 cm/dyne (horizontal)/12 x 10.6 cm/dyne (vertical) How do I plug that into the formula (rf = 159 / sqrt ((eff. mass + cart weight + fastener weight) * (compliance)) ???

I may email you for assistance, Twl!

Also, anyone know where the Morch DP6 tonearms can be purchased? Music Direct sells them for the $1500 price I spoke about above, though you have to call them as they don't sell it on line. Just wondering if it could be found a little bit cheaper elsewhere! (Wish Chris of Teres sold them, but he only sells the Tier 1 tonearms he recommends on his site; the Morch is listed as a Tier 2. :-( )

With an 11.5gram effective mass tonearm, I get around 10Hz as your calculated resonant frequency in the horizontal plane, and 11.2Hz in the vertical plane, using your listed formula. 10Hz horizontal and 11Hz vertical is just fine. The actual measured frequency on your turntable may vary some from the predicted, but it should be fairly close.

The OL Silver MkII is about 11.5 grams

You may note that the cm/dyne rating is also known as compliance units(cu).

As you can see, this is a combination of a medium-high tonearm effective mass(11.5g-the higher end of medium), and a medium-low cartridge compliance(with 12vert. being in the lower end of medium compliance, and 15horiz. being in the medium). It fits nicely into the general categories that I presented in my earlier post.

However, with the light cartridge mass of 4.2 grams, the counterweight may have trouble achieving counterbalance, so the the supplied ZYX headshell weight may need to be used, and this will change the calculation, but even a 4g headshell weight increase will still yield results in the similar area of mass/resonance, and certainly still be in the target frequency range.

With a cartridge like the ZYX, you may choose from either a quality gimbal-bearing arm like the OL, or a quality unipivot tonearm with sufficient mass(around 11g).

Both Morch arms, up4 and dp6, have replaceable arm wands. They also come in both 9" and 12" wand lengths. If you contact Morch or an authorized rep they should be able to provide you with a list of popular cartridges and the recommended wand. The DP6 would be my fist choice, too, as I just don't much like handling a unipivot; it makes me nervous when it twists around while I am lowering the thing onto the record.

They come with wiring is my understanding but there are several options for more money. Biggest problem I have with the Morch and any other unit with detachable wands is all of the wiring joints. There is a break from the cartridge to the wire and then another break where the wand joins the tonearm assembly and yet another break where the DIN plug attaches to the bottom of the tonearm mount.

An arm with a seamless wire is the best option for the cleanest sound. Incognito and Audio Note offer such wiring (others might, too) for the Rega RBxxx arms. Biggest problem with the one piece wire scheme is most of the phono cables are 1 metre. This means you have to have your table pretty close to your phono preamp or you must use RCA couplers and an extension cable (yet another set of connections).

The Audio Note arms based on the Rega RBxxx arms are the ARM1 and ARM2. The ARM1 is the rb250 with audio note pure copper wire and is seamless from cartridge clip to the RCA termination. The ARM2 is the rb300 with audio note pure silver wire and seamless, too. There is also an ARM3 which is also a RB300 with even better silver wire.

The ARM2 with a Michell Technoweight (or Kerry heavyweight; several good ones out there) is an excellent arm for under 800 inc the weight. I believe Audio Note retails the arm for 600.