Features of the Mørch Tonearms

The MOERCH tonearms consist of an arm base with its mounting facilities, bearing assembly, balancing rod and weights, and the arm tube for the cartridge. One appealing feauture of the MOERCH design is the arm tube, which can be separated from the arm base by removing a nut. Four standard 9” arm tubes, each one of different mass (from ultra light to extra heavy), are available for specific cartridge requirements.

Green dot: Effective mass 4 g. Red dot: Effective mass 6 g. Yellow dot: Effective mass 8 g. Blue dot: Effective mass 14 g.

Standard 9” armtubes

The fundamental tonearm resonance (present in all arms) is partly determined by the compliance and the weight of the cartridge that is to be used and partly by the weight of the arm, known as the “effective mass” of the arm. However, the frequency of the fundamental resonance can be moved up or down by altering the mass of the tonearm. Thus, by choosing the correct weight of arm tube out of 4 available, the fundamental resonance can be moved to a frequency where it does not interfere with the audio signal.

With the lightest of the arm tubes you achieve the lowest effective mass, and with this particular arm tube the MOERCH tonearm is the lightest available today. This arm tube is designed for cartridges using a low tracking force, since they have a high compliance. For cartridges requiring a high tracking force (usually low compliant) one of the heavy arm tubes should be chosen. Users that own more than one cartridge can mount each of them in its proper arm tube. Changing cartridges then becomes a simple swap between arm tubes. Thus the mass of the arm is always optimized for its cartridge.

To counteract resonances the arm tube and its mounting platform for the cartridge are made out of one piece of metal angled twice along its length, and internally damped with a foam-type material.

A cavity in the central body housing the bearings is off-centered in the forward direction, providing an asymmetric mass distribution for the prevention of symmetrical barrel resonances. Both the rod with its balancing weights and the arm tube are rigidly attached to the arm’s central body. The body itself is solid and very heavy. Thus vibrations originating in the cartridge are efficiently damped before they reach the bearings, their stability being assured.

In addition three counterweights of different size, and one tracking force weight contribute to the ideal concentration of the arm’s mass close to the fulcrum. The lateral balance is adjusted by way of the counterweights, which have the center of gravity eccentrically positioned as to the counterweight rod.

The bearing assembly in the above mentioned cavity is in height located as an extension of the horizontal plane of the record surface. Therefore with warped records the motion of the stylus will remain vertical when “bumps” are negotiated and warp wow will not be heard.

The antiskating force is applied by a watch spring. Its tension is adjustable for maximum accuracy even while a record is playing. The tension is transferred via a nylon string which is attached to the outside wall of the arm’s central body. As the arm tube moves over the record, the correct geometry between the spring/filament assembly and the central body’s rotation provide for the exact variation of skating compensation over the entire playing surface of a record.

The tonearms are adjustable for the vertical tracking angle as well as the azimuth.

A Special version of the 9” arm tube called PRECISION is supplied with a wide cartridge mounting platform having the underside precision ground for perfect contact with especially wide cartridges.

Also 12” armtubes are available. They are available only with the narrow headshell such as the one on the standard 9” armtubes.

PRECISION armtubes and 12” armtubes are available only with red and blue color codes.

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Model DP-8 Anisotropic

Model DP-8 Anisotropic has a unique combination of bearings: For the horizontal mode of motion a silicone damped, high precision ball-bearing assembly with large housing for substantial damping.

Two precision sapphire bearings are incorporated for the vertical mode of motion. This also may be damped, if desired, by injecting silicone fluid into a well for vertical damping. Vertical damping is rarely needed for this model. It is independent of the damping of the horizontal mode of motion, and further it can be adjusted to all intermediate levels of damping.

Model DP-8 Anisotropic has a device for adjusting the VTA while playing integrated. Markings for “getting back” to a special setting is provided.

The large effective mass for the horizontal mode of motion is stabilizing the the armtube horizontally, so that at very low frequencies it is only the cantilever of the cartridge, that is moving – not the tonearm. This means that the bass goes all the way down reproducing all the bass on the record with full amplitude and dynamics.

It is the two weights on each side of the heavy central body of the tonearm that provides for the majority of the effective mass (Inertial moment) for the horizontal mode of motion. The center of gravity of these weights are pointing backwards – either upwards or downwards, so that they contribute to the counterweighs at the same time as they provide for moving the center of gravity of the moveable part of the tonearm up or down.

The feature with different weights of armtubes to optimize the tonearm for any cartridge is maintained. Thus warps will not influence the tracking force, and there will be no vertical deflection of the cantilever.

In model DP-8 the azimuth adjustment for perfect channel separation is accomplished at the pivot of one of the sapphire bearings.

Supplied in CHROME- or 24 carat GOLD finish.

The armtube plating being made without the use of magnetic materials.

Model DP-6

Model DP-6 has a unique combination of bearings. A silicone-damped, high precision ball-bearing assembly is used for the horizontal mode of motion. Two precision sapphire bearings are incorporated for the vertical mode of motion, which may be damped also, if desired, by injecting silicone fluid into a well for vertical damping. The damping of the horizontal mode of motion is independent of the damping of vertical mode of motion, and the latter can further be adjusted to all intermediate levels of damping.

In model DP-6 the azimuth adjustment for perfect channel separation is accomplished at the pivot of one of the sapphire bearings.

Vertical cross section of model DP-6 through the center of the bearings.

Supplied in CHROME- or 24 carat GOLD finish and at special orders also in BLACK.

The armtube plating being made without the use of magnetic materials.

Model UP-4

Model UP-4 incorporates a special concept of the unipivot principle. The bearing consists of a hardened steel pivot resting in a concave, polished sapphire. The bearing is damped in all directions with silicone fluid.

The low positioning of the bearing provides for a greater stability compared to other unipivot arms. This is because a considerable part of the moveable mass of the arm is positioned above the pivot point, thus forming a physical pendulum together with the mass below the pivot point.

With the model UP-4 the azimuth adjustment is made by the way of the counterweights.

Vertical cross section of model UP-4 through pivot and sapphire.

Technical specifications: Moerch DP-6/DP-8/UP-4

The right to change specifications without notice is reserved by the Manufacturer.

Moerch Prices

SORAsound is the exclusive distributor for US, Canada and the rest of the Americas for Moerch tonearms.

We offer high quality phono cables (from Moerch, Nordost and ZYX) and phono cartridges as optional. Attractive package pricing when you purchase a Moerch tonearm, any phono cable and a phono cartridge of your choice.

Warning: We have seen some so called used/mint Moerch tonearms offered at low prices. You get what you pay for. In reality some of these tonearms are well over 10 or 15 years old; about 22 years old in two recent cases. The good news is that there are many Moerch tonearms that are this old and still used well by satisfied customers. The bad news is that some of these arms may have broken or missing parts. Give us a chance. We take care of you well and you will have a peace of mind.

Suggested retail prices are shown in the table below. As seen below, 12 inch and/or precision arm wands are also available as an option for an additional $400 over the retail price of standard Moerch tonearms and arm wands. 

Latest models of Moerch tonearm cable available as an option.