INSTRUCTION MANUAL FOR KUZMA TONEARMS S T O G I S T O G I A ND R E F E R E N C E KAT d. o. o. Kuzma Audio Trade Hotemaže 17 a 4205 PREDDVOR SLOVENIA tel.
CONTENTS I. GENERAL DESCRIPTION 3 II. PACKING LIST 4 III. UNPACKING 4 IV. MOUNTING AND ADJUSTING A. Mounting Tonearm B. Mounting Cartridge C. Tracking Force Adjustment D. Height (VTA) Adjustment E. Tangentional Cartridge geometry adjustment F. Fine VTA Adjustment G. Azimuth Adjustment H. Bias Adjustment I.Fine azimuth Adjustment J. Cueing Device Adjustment 5 5 8 9 10 11 15 16 18 19 19 V. GENERAL MAINTENANCE 20 VI. MINOR PROBLEMS A. Pin Connector Breaks Off from Internal Wiring B.
I. GENERAL DESCRIPTION The main structure and headshell are both machined from solid aluminimum blocks while the tube is of specially treated aluminium which is internally damped. The tube also allows rotation for azimuth adjustment. Stogi reference tonearm has conical tube with different adjustment. The quality bearings are carefully selected and individually checked and tested before assembly. They can each support 20 Kg. and are mounted free of play with minimal friction in all planes.
II. PACKING LIST 1. Tonearm with fingerlift. 2.Counterweight. 3. Base. 4. In small bag: a) Three socket head screws M5 x 35 mm and three washers for fixing base. b) Allen keys: 5 mm for attaching base to armboard, 3 mm for height adjustment (VTA), 2,5 mm for fixing counterweight, bias and cueing device adjustment. c) Bag containing two headsocket screws M 2.5 x 12 mm and nuts for fixing cartridge plus Allen key 0.7 mm for removing fingerlift. 5.
IV. MOUNTING AND ADJUSTING A. Mounting Tonearm 1. Take tonearm mounting protractor and place on spindle of turntable. The cut-out is similar to standard Linn cut-out. (Fig. 1) 2. Mark position of holes as indicated on protractor on tonearm mounting board. Ensure that there is adequate space in front for tube and headshell and behind for counterweight, in order to avoid problems of lid closure. Check also that screw positions will be over cut-out on subchassis, unless screws are to be sunk.
5. To fix base to armboard you will need the three socket head screws, spring washers and Alley key 5 mm. Fit washers on screws and insert into underside of tonearm board and up into tonearm base. (Fig. 4). Position base so that height adjustment (VTA adjustment) screw is at top right position, i. e. 2 o’clock and tighten screws using Allen key. Remember that screws are of harder material than tonearm (steel and aluminium) so do not overtighten as this could damage base. (Fig. 5) 6.
_________________________________________________________________ STOGI/STOGI REFERENCE 7 KUZMA
B. Mounting Cartridge You will need Allen key 2.5 mm plus the two screws and nuts M 2.5. 1. Keeping stylus guard on cartridge, insert screws from undeneath cartridge through slots in headshell and screw on the two nuts manually. (Fig. 9) The tip of the cantilever should be level with the end of the headshell (viewed from side). 2. Fix by slightly tightening screws using Allen key. Ensure that nuts have fitted into ledge around slots.
C. Tracking Force Adjustment The instructions with your cartridge will recommend suitable tracking forces. We recommend you choose the highest force given and set arm to that amount. A higher tracking force causes less damage to the record as the stylus maintains more stable contact with the sides of the grooves. The counterweight is marked with five red dots. (Fig. 13) One full rotation of the counterweight increases tracking force by 0.5 grams, therefore distance from one dot to another corresponds to 0.
D. Height (VTA) Adjustment (Fig. 14) 1. Put record on platter. 2. Remove tube from armrest with cueing device still in ‘up’ position. 3. Put stylus guard on. 4. Position needle in normal playing position above record with lift still up, to ascertain how low or high the arm is. 5. If tonearm is too low, then the tonearm must be raised by releasing the screw in the base while holding the tonearm by the ‘C’ shape and lifting up. (Fig. 15) 6.Tighten screw when tonearm is in position though do not overtighten.
E. Tangentional Cartridge geometry adjustment Once the cartridge has been mounted, it is necessary to ensure that the cartridge is tangentional to the record grooves in order to minimise tracking distortion during playing. As the cartridge moves in an arc across the record, tracking distortion occurs and is minimised by the tonearm geometry and the angle of the cartridge in the headshell. With optimum tonearm geometry very low distortion levels (below 1 %) can be obtained across the entire playing surface.
1. Ensure bias is on minimum. 2. Place protractor over spindle on platter. (Fig. 16) 3. Alignment at zero point 66 mm (A) Place tip of stylus on point A (ie. zero point 66 mm). With a strong light observe cartridge from front. The cantilever and the line on protractor (Fig. 17) should be in perfect alignment. If the cantilever is not then the body of the cartridge will have to be turned slightly. (Fig. 18) Do not adjust cartridge by observing body of cartridge only.
Alignment at zero point 121 mm (B) Fig. 19) 7. Reposition protractor and check alignment at position B in the same vay as in position B. 8. If the cantilever is not in alignment then rotate protractor until it is in alignment somewhere along the line ‘x y’ though not necessarily at point B. (Fig. 20) Raise the cueing device. 9. If needle is in front of point B, pull the cartridge forward in the slots of the headshell for approximately the same distance.
13. Securing Cartridge The screws holding to the headshell must now be tightened and it is very important to avoid moving the position of the cartridge, so tighten in the following way: slowly, one screw at a time in extremely small stages. Before screws are completely tight check that cartridge is still in alignment at position B and then at position A.
F. Fine VTA Adjustment VTA describes the angle between the record surface and the stylus (Fig. 21). This angle changes as the height of the tonearm is altered. The standard angle is 15° but cartridge manufacturers work with degrees of anything between 10°- 30° so only by listening tests can one ascertain the correct angle for your particular cartridge. The VTA also varies according to the tracking force and thickness of records.
G. Azimuth Adjustment Normally this is obtained automatically when the tonearm is mounted, providing the lines (Fig. 22 a) are in alignment. Rough Adjustment (Fig. 22) Azimuth describes the angle between the record surface and the stylus, viewed from the front of the cartridge. This should be 90° and can be checked by observing if the cartridge body is square with its mirror image on the blank part of a record or by putting a mirror under the stylus (taking care that the stylus does not slide).
Fine Adjustment This can be done using an osciloscope (see p. 16) 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. Start listening with the tube in zero position, ie. with the marking lines aligned. Listen to the sound-stage, the focus and the stability of the instruments.
H. Bias Adjustment The bias should be adjusted according to the tracking force. Using cartridge protractor provided you will see marked distance ‘x’ in grams equivalent to the tracking force. Hold protractor as in Fig. 24. Using Allen key 1.5 mm, until in the position equivalent to your chosen tracking force. Lock screw when in position. For maximum trackability, it is advisable to set the bias by use of an appropriate test record, ie. those with tracking bands.
I.Fine azimuth Adjustment Using a Dual Trace Oscilloscope Even if the cartridge body is square there is no guarantee that the generator within the cartridge is at the correct angle to the cartridge body. With an oscilloscope and test record which has channel separation tracks, one can measure how much of the signal from one channel crosses over to the other. This is called crosstalk and is always present to some extent, but it should be equalised. Azimuth affects channel separation.
V. GENERAL MAINTENANCE 1. Dust only with a soft brush, do not blow away dust. 2. If the tonearm is mounted on a wooden armboard the base may need to be retightened to the board after a few weeks. Checking Tonearm Bearings for Play Holding the headshell, gently try to rotate tube of arm. There should be no movement or audible clicking. If there is, consult your dealer. NOTE: Ensure that Azimuth and height adjustment screws are fixed before attempting the above. Checking Tonearm Bearings for Friction (Fig.
VI. MINOR PROBLEMS If any problems occur with your tonearm please do not hesitate to contact your dealer. Many audiophiles do, however, find it convenient to try and solve small problems themselves and, therefore, the procedures outlined below may be followed if such difficulties should arise. A. Pin Connector Breaks Off from Internal Wiring To repair this you will need a small soldering iron, non acid solder, tweezers, sharp knife, uncut end of drill or nail about 1.3 mm dia.
B. Broken Bias Thread You will need about 100 mm of thin nylon fishing line, Allen key 2.5 mm and a sharp knife. 1. Remove counterweight. 2. With Allen key remove screw at point A (Fig. 28) NOTE: This does not in any way affect the bearings. 3. At the end of the thread is a small plastic tube to which the thread is attached. Cut away the broken thread and tie and knot new thread around tube. 4. Pull thread through screw as in Fig. 28 a and replace screw with Allen key. 5.
C. Hum and Buzz 1. Check to ensure that grounding wire has been connected. 2. If using an M. C. transformer, try connecting ground wire to this or to the preamplifier. 3. Alternatively, connect grounding wire to preamplifier and run another grounding wire from the M. C. transformer ground to the ground of the preamplifier. Hum This can be caused by the transformer in the power amplifier being situated too close to the cartridge or by the tonearm output cable being too close to the mains cable.
VII. TRANSPORT AND PACKING A. With tonearm on Turntable The tonearm can be left on the turntable when being transported short distance by. 1. Placing tonearm in armrest. 2. Securing arm to armrest with elastic band or tape. 3. By removing counterweight and 4. Securing movement of subchassis by insertion of wedges. Many turntables, however, cannot be properly packed for longer transport with the tonearm in position and the tonearm, therefore, must be removed and repacked in original packing. B.
CONTENTS Page I. GENERAL DESCRIPTION ..................................................... 2 II. PACKING LIST .......................................................................... 3 III. UNPACKING ............................................................................. 3 IV. MOUNTING AND ADJUSTING ......................................... 4 A. Mounting Tonearm .................................................................... 4 B. Mounting Cartridge .............................................
