1. Effective length,
2. Effective mass,
3. Moment of inertia,
4. Acoustical damping of armwand
5. Wiring impedance.
1. Effective length. Effective length of Reed can be from 9" to 12".
2. Effective mass. Effective mass of tonearm is very important when matching cartridge. Cartridge compatibility with tonearm is determined by Tonearm Resonant Frequency. It should be 10 Hz (-4 Hz + 6 Hz); it may vary from 8 Hz to 12 Hz. Tonearm Resonant Frequency can be calculated using following formula:
frez - resonant frequency of tonearm
mef - effective mass of tonearm
mc - weight of cartridge
ms - mass of the screws, nuts, spacers, washers, shims
c - compliance of the cartridge.
Since effective mass of different Reed models can be from 8 g to 25 g. Reed tonearm can be matched with almost any cartridge you have.
3. Moment of inertia. Tonearm moment of inertia It consists of two parts:
a) Cartridge moment of inertia Ic
b) Counterweight moment of inertia Iw.
Because Iw should be (and usually it is) at least 10 times less than Ic, we will use only for approximate calculation.
Cartridge moment of inertia Ic is calculated using the following formula:
(Ic)=(mc+(mef /2))*lef 2
mc - cartridge weight
mef - tonearm effective mass
lef - tonearm effective length
Best result is achieved when Ic is less than 20000 g*cm2.
If LP is perfectly flat, then Ic does not have any influence. Ic becomes important when LP is not brand new or is not flat for some other reason. In such cases cartridge and tonearm is moving up and down while playing a record. Even if swinging amplitude is around +/- 0.5 mm, tonearm with high Ic may not be able to catch up with LP swing. This causes instant VTF, VTA and SRA changes which lead to sound distortions. To reduce LP swinging, clamps are used.
4. Acoustical damping of armwand. Stylus, while moving in the vinyl’s groove, produces not just the musical signal, but also oscillates the cartridge. The oscillation can be transferred through the armwand, partially reflect from the counterweight, and through the tonearm bearings, tonearm support, chassis, platter bearings, platter, mat and vinyl return back to the stylus. On the other hand, stylus causes vinyl plate vibrations, which, through the mat, platter, platter bearings, chassis, tonearm support, tonearm bearings and armwand, return to the stylus again. The interference of these two acoustic vibrations can slightly impact the sound quality. Acoustical oscillation damping can be done in two ways:
a) vibrations transferring to the floor. This is the most widespread method. The most common solution is to build a tonearm that should carry away these vibrations as quickly as possible and via mechanical connection transfer them to the floor. Designers/manufactures/increasing the weight of a platter so that it can suppress vibrations and at the same time soft suspension allows much less vibrations to get to the stylus. It can be done quite easily in heavy decks but there are always some vibration that would come back to stylus eventually. The amplitude is not too big but considering the size of the groove they still might introduce some distortion.
b) choosing right armwand material. Reed tonearm armwands are made of different kinds of wood, so it’s sound damping characteristics are close to exponential function. This method was chosen after a lot of tests of different armtube materials and bearing setups. More about choosing armwand material can be found in our website's Research page.
5. Wiring impedance. It is very important to harmonize cartridge output impedance, wiring impedance and preamplifier input impedance. Cable (made by Stereo-Lux Musikanlagen) used in Reed tonearms has no soldering points and is harmonized perfectly.
After a lot of tests and listening to customer feedback we found out that tonearm adjustment is important not just for mounting tonearm for the first time, but also after changing cartridge or even LP.
That’s why we offer you Reed tonearm, whose sound performance can be compared to other well known world brands and have user friendly and precise adjusters (azimuth, VTA).
Tonearms.lt” is a small company with only 5 employees; however its history and development are quite interesting.
The designer and company owner, Vidmantas Triukas, is radio engineer, working in hi-fi audio equipment field since 1985. Some of his works, related to acoustic, were a rocket science, literally: he was working in scientific acoustic and ultrasound area, researching acoustical noise of plasma in long-range ballistic missiles, and has three patented inventions in this field.
In 1987, Vidmantas Triukas with a few friends built an “audio set”, consisting of turntable, speakers and an amplifier, and presented it in USSR’s largest technical achievement trade show in Moscow. For various innovations ( turntable motor automatic speed control, amp with very low linear distortions etc.) it was awarded a bronze medal in audio equipment category.
After 1990s Vidmantas started business in another area, however audio still was his passion all these years. In 2007 he decided to start business and offer something amazing to the market. After a year of continuous research, prototyping, design and testing he offered first Reed series tonearm. Since then, his company works for its valued customers and tries to bring something special to the audiophile community.
Despite that Vidmantas is an inventor and a technical designer, he is also very passionate art lover. He studied art history in Sankt Petersburg (formerly Leningrad) in 1980 - 1982.