4Point-9 with brass headshell shim
Recent experiments with the Kuzma Safir arm (60 g. effective mass) inspired us document some ongoing mass mass experiments we've been undertaking.
If you're not aware, we released a headshell shim kit last year for this purpose - a kit that also includes an angled shim to address SRA issues.
After posting this, a paper from Franc Kuzma was brought to our attention. While it primarily relates to the Safir-9 tonearm, it has some general comments on mass, as well as why many modern turntables can "tolerate" higher mass arms.
It's a good, short read. Click here to view it.
The Kuzma CAR 40 (as are all Kuzma cartridges) is quite the beast - weighing in at 17 grams.
It was an unlikely candidate for these experiments, but what better way to explore its limits?
Our heavy brass shim adds 8.25 grams to the 4Point-9's 13 grams, which in combination with this cartridge's hefty weight stretched the limits of the 4Point-9's counterweight.
We pressed a 4Point-11 accessory counterweight into service to balance out the arm.
We're going back and forth on this configuration, and we're leaning toward running without the shim. You'll note that this particular installation also has a 2 gram, angled shim which we've left in place.
All of this is to say, that experimentation will show you the way. In the case of this cartridge, Franc Kuzma did the work for us by adding so much mass to the cartridge body. A 17 gram cartridge is a rare animal indeed (as are all cartridges in Kuzma's lineup).
In the photo, you'll note the 4Point-11 accessory counterweight at the end of the arm stub.
This experiment inspired us to release a heavy rear counterweight section to mate with the 4Point-9's larger front half.
We'll be bundling this counterweight along with our brass headshell weight as a mass tuning package.
We encourage you to experiment, to the limits of the adjustment range of your arm.
The old college method of affixing a coin on your headshell will do. A nickel (or two) affixed with some Blu Tack will suffice.
Remember to reset your tracking force!
4Point-11 counterweight added
brass headshell shim + heavy carrier
Next up, was a Hana Umami Blue on our Schröder CB-9.
We had already employed the heavy brass cartridge carrier which brings the CB's mass to 19g.
Adding our brass shim brought the mass up to 27.25g.
The Schröder's arm stub/counterweight had enough adjustment range for the slightly lighter Umami Blue (10.8g).
Stay tuned for an "extra-heavy" Schröder carrier, using the same brass Frank uses.
This heavy carrier will add a 24 gram option to the CB-9's 14 & 19 gram selections (Certal and brass carriers).
If you have a suspended turntable, this 8-10 Hz target may be more significant, but this is an easy enough experiment to carry out.
If your bass quality muddies up (and "slows" down), then this is either stretching the mass compatibility range of your cartridge, or resonances are building with your suspension.
It's an easy enough experiment to back out of with some Blu Tack and a nickel or two. BTW, a nickel weighs 5 grams.
Related Posts
5-pin DIN ConnectorThat, is the question … For years, we bought into the common knowledge that tonearms wired with a straight run from the cartridge clips to the connectors (RCA or XLR) are superior to arms with plug-in cables employing a 5-pin DIN connector. Then, we put the theory to the test. The ExperimentWe compared two 4Point, 11″
Read MoreWind RiverCan we talk? Quite some time ago, we published photos of a well-maintained stylus, and followed up with a post describing various stylus cleaning methods. It’s time to have a serious conversation about our connectors …Audio HygieneMaintaining a high-performing audio system requires a minimal amount of work, and one chore involves periodically cleaning and re-treating our
Read MoreCompleted AssemblyOK, so you accept the premise that cables break in over time by just playing your hi-fi, and that a burn-in device is an unnecessary indulgence. Fair enough. Have you taken into consideration whether the millivolt level voltage output by a moving coil cartridge will ever break in a tonearm and its interconnect … in your
Read MoreShockingIt’s that time of year, when we’re fielding questions about static build-up on turntables … well, non-Galibier turntables that is. On our Galibiers, static is a non-problem as you’ll see below, but with other turntables the solution may not be “built in”. We have 2 approaches to solving this. In this post, we addressed a possible work-around to
Read MoreNever miss a good story!
Subscribe to our newsletter to receive a copy of a setup report we created for a customer.
Subscribers also receive discounts on all accessories, including Audiodesk, Feickert and AnalogMagik.
This report is in 3 sections:
15 pages packed with general setup information - tricks you may not have seen before
Documentation of the customer's setup
A tool guide - how to specify a USB microscope and build your own azimuth gauge
Click the photo below, to subscribe.