Frank Schroeder has created some of the best tonearms in the modern analog world.
His designs are original if not extraordinary and some of the models even skip the use of horizontal and vertical bearing drive system.
These unusual designs suspend the arm hanging by one or two filaments, whilst stabilization is provided by the magnetic field of a magnetic system.
The paramount of his work is his linear tracking arm - a rotational tonearm with tangential drive magnetic system.
Here are some photos:
On another page I will give you more details about these arms.
The aim of this presentation is to introduce you to one of the first tonearms designed by Frank - CB.
CB was designed to work with the Artemis Lab SA-1 turntable, originally called TA-1.
It was available in 9 and 12 inch version, the 12 inch model was named TA-1L.
After Artemis Lab cease their activity, Frank continue to produce and offer this model , now under the name Schroeder CB.
This is what CB looks like:
The abbreviation CB stands for Captive Bearings - the type of bearings used.
Captive Bearings, are hybrid bearings that make use of steel shells and ceramic bals.
These bearings are famous for extreme low friction, thus the CB tonearm requires minimal force to move - 0.002 g vertically and 0.0035 g horizontally, making the model one of the most sensitive in this class.
The gap in the camp for horizontal rotation is minimized using a magnetic system and the magnetic field also damps the vibrations.
The tonearm offers all possible features: magnetic anti-skating, adjustable height (VTA), azimuth, rough and fine adjustment of the tracking force, interchangeable cartridge shells to accept a wide range of cartridges.
In order to reduce parasitic resonances, the tonearm uses tubes made of exotic hardwoods such as: Rosewood, Ebony, Grenada, Kokobolo, Indonesian teak, African wood and others.
The wood is aged (over 10 years), in order to avoid deformations and after tube is manufactured, it is externally oil treated.
In order to achieve maximum quality, the whole manufacturing process, assembly and tuning are carried out manually.
Due to the technology employed, this tonearm reproduces music with extreme accuracy that positions the model in the top segment of it's classl.
Thanx to Mr Rumen Artarski, president of Thrax Audio - Bulgaria I got the opportunity to meet Mr. Frank Schroeder.
Later on I was invited to join the Thrax Audio team and to deal mainly with the production of tonearms and turntables.
In this regard, several meetings took place with Mr. Schroeder in order to start production of the CB tonearm by Thrax Audio.
At the last meeting, a successful experiment of using carbon tube was carried out.
The idea was proposed by Rumen Artarski and was implemented by Frank and me at the Thrax Audio production facility.
I can share that the carbon pipe has a "sandwich" construction, with additional damping materials inside.
Resonant vibration test showed that the carbon tube produces by degree less vibrations compared to the wood.
Here are photos of the carbon tube tonearm:
Auditions were carried out in the Thrax Audio test room.
For this purpose, we mounted the tonearm on a Technics SP-10 direct drive turntable with veneered box made of birch plywood "sandwich".
The second tonearm used was the original Technics EPA-100.
Audition findings stated that carbon tube tonearm is of the same quality as the wooden one.
The opinions of most of those present are that the carbon tonearm reproduce musical material accurately, without coloration.
We were very pleasantly surprised by the quality of the playback I must admit that this tonearm plays music with exceptional realism.
Part of the musical material for the audition.
Schroeder and Artarski in conversation about the carbon fiber arm.
Video showed the exceptional sensitivity of the tonearm.
The use of carbon tube, does not mean we are not going to use the wooden one.
This experiment was held to test the suitability of the modern materials during the design and crafting of the shoulder.
The carbon tube showed excellent musical quality and will be included as an option in future production.
Of course, everyone will be able to listen and compare and will choose the right option depending on their own preferences.
Here is the technical data for the shoulder Schroeder-CB, which will be produced by Thrax Audio.
Tonearm Shroeder CB specifications:Armwand Type: Wood (glossy finish), or carbon tube.
Effective Length: 239,3mm (for 9 inches) or 282mm (for 12 inches)
Pivot To Spindle Distance: 222mm (for 9 inches) or 267,48 (for 12 inches)
Overhang: 17,3mm (for 9 inches) or 14,52 (for 12 inches)
Effective Mass with supplied
cartridge mounting plate: 14gr (for 9 inches) (19gr with optional heavy cartridge mounting plate, also supplied).
18gr (for 12 inches) (23gr with optional heavy cartridge mounting plate, also supplied).
Mounting Hole: 24-25mm with single M6 tapped hole.
Raised bearing technology: Ceramic hybrid bearings - less then 2mg vertically
- less then 3,5mg horizontally
Type: Neutral balance arm, no change in VTF when altering VTA or record thickness.
Internal magnetic damping for the horizontal movement.
All essential parameters
adjustable: VTF, VTA, Overhang, Offset angle, Azimuth, Anti-skating
Frictionless, resonance free magnetic antiskating (for up to 2.3gr. VTF) - higher tracking forces can be compensated
for by exchanging the antiskating screw (available upon request).
Wiring: High purity copper wiring, 1m from arm to RCAs (longer lengths upon request).
Double Counterweight: "Lower counterweight can be changed to an optional lighter or heavier cylinder, allowing for an increase or decrease
of total counterweight mass without altering the overall mass distribution of the arm This way, even ultra light,or
very heavy cartridges can be used as long as their weight/compliance yields a fundamental arm cartridge resonance
frequency of 8-12Hz."
Metal color: Black