KUZMA 4POINT TONEARM Instruction manual 2008-6 Serial Number: …..
KUZMA LTD INSTRUCTION MANUAL FOR 4POINT tonearm The 4POINT tonearm is a very precisely engineered piece of equipment, however, the construction is robust and requires minimal maintenance for optimal performance. headshell lock vertical paddle vert. paddle lock horizontal bearing assembly VTA tower VTA lock loop trough - vertical pin for cable main tube assembly horizontal paddle trough–horizontal horizontal trough lock main counterweights cable - play position counterweight tracking force Fig.
General description : This differs from other arms by incorporating several unique features. The zero play bearing is configured on 4 points. There is very precise VTA adjustment and, despite a longer effective length of 280 mm (11 inches), fits the standard mounting distance of 212mm ( for 9 inches arms). The heart of the new construction is a unique 4 point bearing. The first set of two points (similar to a double unipivot bearing) allows vertical movement.
azimuth lock VTA scale - fine bias horizontal bearing assembly azimuth adjustment vertical bearing point Fig. 2 Technical data: Mass: 1650 gr Effective length : 280 mm ( 11 inch) Mounting distance: 212 mm Offset angle: 19.
1. Unpacking Open the box carefully and remove top covers. The tube with vertical bearing points is packed separately (tube assembly) on the top of the box. Please do handle with care and when put aside, ensure that nothing is touching the bearing points. Bear in mind how you will handle the termination box and output cable. The horizontal bearing assembly is permanently mounted on the main VTA arm tower. This is blocked during transport. (Fig.
264 mm Fig.3 Protractor for pivot to spindle distance Remove the fixing foam on the horizontal bearing assembly. Check that the bias thread is fixed and gently rotate horizontal bearing assembly from one to another extreme. It is only possible to make approximately ¼ of a turn. It is normal to feel slack in the bearings.
vertical bearing point vertical bearing cup Fig.4 Assembling the tube onto the horizontal bearing tower. Cartridge mounting: Mount the cartridge with the appropriate set of 2.5 mm screws.When fixing cartridge pins be sure that you do not damage wires under insulation tubes! Headshell removal and fixing: This tonearm has a detachable headshell and fixing and positioning it has no negative effect on tonearm performance. The whole headshell is fixed with one Allen key 2 mm.
Fig.7 Removing headshell Balancing of the tonearm: Fix cartridge pins. Add counterweights to the lower threaded carrier, starting with the longest counterweight, then a plastic ring and another counterweight, until the tonearm is roughly balanced. Be sure to fit the plastic rings that separate counterweights and, at the same time, allow them to fit together. (See Fig.
4. Adjustment of tracking force Balance the tonearm with the tracking scale, which must be at record height. Rotate the smaller counterweight towards the tube. Rotation for one turn (observe red dots) will change tracking force for approximately 0.1g. If you are unable to obtain the correct tracking force, add or remove main counterweights. By rotating two counterweights along the thread you can obtain the desired balance. Then simply rotate them one against other and this will fix them. (Fig.
7. Adjustment of azimuth To make azimuth adjustments, release the two screws locking the mechanism at the centre top of the main tonearm tube, with Allen key 2mm. Under the main tube is a tiny rod with a hexagonal screw. Insert the Allen key 2 mm into the screw (it may feel loose), rotate it slightly and it will alter the azimuth. (Fig.2) Rotating it back will bring azimuth to its previous position. Changes can be seen by misalignment of the white lines on the top of the centre of the tube.
9. Damping This tone arm has two independent damping systems. The lower trough is for horizontal damping and the second trough on the arm tube assembly is for vertical damping. (Fig.1) Both troughs are removable. The horizontal holder with paddle is permanently fixed on the horizontal bearing assembly. Vertical& horizontal damping: The vertical paddle is inserted after the tube assembly. Fix holder in the hole with 1.5 mm Allen key. (Fig 10) The paddles long screws (1.
Fig.11 Removing vertical trough Fig.12 Removing horizontal trough Fig.13 Both troughs removed 10. Cueing device adjustment Should you find that in the ‘up’ position the cartridge is too high or too low above the record then the cueing device can be raised or lowered. This can be done simply by using Allen key 1.5 mm: Insert key into screw on side of arm rest. Release screw, raise or lower device and retighten. Rotation of cueing device can affect the drift of cartridge while travel vertically down.
11. Maintenance The bearing does not need maintenance. Clean dust from the tonearm with a dry cloth and use a soft cloth and alcohol to remove silicone oil. 12. Transport During transport the tube assembly must be removed from the horizontal bearing assembly. To do this you must remove the vertical paddle. Remove vertical trough and reposition cable on the tube assembly. If you transport a turntable with tonearm, ensure that hard vibration from the car does not transmit directly to the tonearm.
APPENDIX 1 Tangential Cartridge geometry adjustment Once the cartridge has been mounted, it is necessary to ensure that the cartridge is tangential to the record grooves in order to minimize tracking distortion during playing. As the cartridge moves in an arc across the record, tracking distortion occurs and is minimized by the tonearm geometry and the angle of the cartridge in the headshell.
To rotate or readjust cartridge: 4. Slightly loosen the screws which attach the cartridge to the headshell. 5. Holding headshell in one hand slightly rotate the body of the cartridge. 6. Recheck alignment at position A and continue adjustment until line described in point 3 is achieved. 7. Alignment at zero point 121 mm (B): Reposition protractor and check alignment at position B. Fig. 15 Alignment at B 8.
10. Now rotate protractor and again position stylus at zero point A as described in 5 and 6 above, ensuring that the position of the cartridge in the slots alongside is not changed but only rotated for alignment of the cantilever in zero point A. (Fig.17) Fig.17 Rotation at A 11. Recheck alignment of the cantilever at zero point B. If cantilever is not aligned here, rotate protractor to find where on line “x- y” the cantilever is aligned again. (Fig.18&15) Fig.
Appendix 2 Fine Azimuth Adjustment This can be done using an oscilloscope and a test record or by using good records in a good system and listening to the sound. Cartridges with fine profiles (VDH, Microline etc.) are more sensitive to this adjustment. On the other hand cheaper cartridges are not made so well, making fine adjustment more useful. With an oscilloscope we measure the differences in crosstalk between both channel. The idea is that on both channels this is equally small.
Appendix 3 Fine bias adjustment 1. Set bias and tracking force as previously described and listen to mistracking on highly Modulated tracking bands on test record. On higher modulated bands mistracking can be heard as impure tones and there will be more overtones. (See instructions on test record) 2. If mistracking is apparent, increase or decrease bias until minimum mistracking is found.
A X Y B X Y S Cartridge Protractor ( Not in correct scale) Tonearm mounting protractor 19
