Related Manuals for Eminent ET-II
Summary of Contents for Eminent ET-II
- Page 1 FLUID DYNAMIC DAMPING FOR THE ET-II EMINENT TECHNOLOGY, INC. 225 EAST PALMER STREET TALLAHASSEE, FL 32301 (850) 575-5655...
- Page 2 INTRODUCTION This kit includes a properly engineered fluid dynamic trough for the ET-2 Tonearm, which will operate on any turntable without interfering with any feature or adjustment ability of the tonearm. Installation is simple and straightforward, and does not require tonearm removal from the turntable or any special tools.
- Page 3 If you accidentally SPILL silicone fluid on the air bearing, do not operate the tonearm until that part is thoroughly cleaned. First, clean the part with a household spray cleaner, (409, Fantastic, Windex, etc.) using paper towels. Then use alcohol and paper towels, bath tissue, or cotton balls rubbing the bearing thoroughly.
- Page 4 The silicone damping trough is carefully designed to and positioned so that it is unlikely that fluid will get on your hands or any part of the tonearm during normal use. The rigid semi circular trough is constructed of an anodized aluminum alloy. The shape always maintains a constant distance between the paddle and any surface of the trough over the full travel of the tonearm.
-
Page 5: Installation
INSTALLATION We recommend that the user not install the fluid damping trough until you become thoroughly familiar with the use and features of the ET-2, and feel completely comfortable using the tonearm. You should know how to level the tonearm and set the tracking force before installing the damping trough. - Page 6 During all of the installation procedures, put your cartridge stylus guard in place on the cartridge and leave the cuing lever in the up position. No adjustments will be made to the cuing assembly.
- Page 8 In order to install the kit you must first remove the counterweight assembly from the backside of the air bearing spindle. This is done by loosening the top screw on the counterweight clamp. Loosen this screw about one full turn and pull the clamp off of the end of the spindle. Do not overtorque these screws when re-assembling this part.
- Page 9 The I-beam should then be re-installed in the new supplied counterweight clamp/paddle assembly. Install the new clamp cover leaving the screw loose. Then slide the fork spring of the I-beam under the clamp cover and tighten the screw. Install the new counterweight clamp/I-beam assembly onto the spindle. Be careful with the wires to make sure that they are not being pinched on the underside of the counterweight clamp as it is being pushed onto the spindle.
- Page 10 A very rigid coupling occurs with only a small amount of torque on this screw because of the close tolerances. Overtorquing this screw can distort the air bearing spindle and crack the counterweight clamp. If the fork spring breaks off the I-beam during the above process it can be glued back into place using ordinary “super glue”...
- Page 11 DAMPING TROUGH WITH ADHESIVE PADDLE...
- Page 13 Study the drawings carefully and position the trough on the underside of the manifold housing as shown. If the tonearm is viewed from above, the trough should be positioned directly under the spindle and parallel to it. The inside fluid stop should be directly up against the manifold housing.
- Page 15 The paddle is threaded into the counterweight clamp and can be raised or lowered by rotation. Turn the paddle until it is positioned about 1/16” above the dry trough across the full travel of the tonearm. (It is OK to move the air bearing back and forth without the air pump operating.)
- Page 16 ADDING FLUID Enough fluid is supplied for several refills. Initially, about 1 cc of fluid should be uniformly spread along the trough. An additional ½ cc of fluid may be required to establish contact between the paddle and the fluid over the full travel of the spindle. SETTING THE TRACKING FORCE AND LEVELING THE TONEARM If the counterweights were not removed or repositioned along the I-beam, then the tracking force should be the same and no adjustment is necessary.
- Page 17 The additional mass of the damping trough adds about 18 grams to the mass of the tonearm. This additional mass may affect a lightly suspended turntable so it is recommended that the level be checked. Use the procedures described in the tonearm owner’s manual. Please note that the tonearm now responds much more slowly due to fluid damping.
-
Page 18: Technical Discussion
TECHNICAL DISCUSSION The compliance (spring stiffness) of a phono cartridge and the effective mass of a tonearm create a spring-mass system with a corresponding natural frequency. For a typical tonearm/cartridge combination, the resonant frequency of this spring/mass system generally falls below 20 Hz. -
Page 19: Phase Shift
PHASE SHIFT If a tonearm/cartridge system has a substantial rise in response below 20 Hz as most do, the phase response at the low end will be shifted and phase shift will occur beginning at 2 to 3 times the resonant frequency down to F . -
Page 20: Wow And Flutter
WOW AND FLUTTER Wow and flutter, FM distortion and surface irregularities in the LP should all be grouped together because, as we will see, they are all tied together. When you cut a pure tone (say 1kHz) onto an LP and then play it back on a turntable/tonearm/cartridge system, you would hopefully want 1kHz to come back. - Page 21 “Weighting” is applied to the measurement to reduce the measurement’s sensitivity to very low and very high rate of frequency shift. The actual amount of frequency shift is much greater than the number implies. The weighting network is supposed to create a number related to a subjective ability to hear wow and flutter.
- Page 22 The measured results are usually an order of magnitude better than the results using a tonearm and test record (conventional wow and flutter method). Further proof exists if you take two tonearms, one straight line and one pivoted and mount them both on the same turntable. The straight line tonearm will give a wow and flutter reading with the same cartridge/test record of about 2/3 to ½...
- Page 23 A damping track applied to a tonearm (straight line or pivoted), will reduce the measured wow and flutter usually 10-30% and sometimes as much as 50%. ET-2 wow and flutter readings with a typical cartridge and good turntable will usually measure (.02 to .04%) which is extremely low for an LP system.
- Page 24 You can see visually small ripples on the surface of an LP as it is turning. These continuously excite the tonearm resonance. TONEARM MEASUREMENTS A low frequency sweep was performed twice on the tonearm, once without the damping trough and once with the damping trough. The cartridge used was of very low compliance and the tonearm was set up so that a high amplitude high Q resonance existed.
- Page 26 PADDLE SHAPE The design of the paddle and its position mean that it will be much more effective for damping horizontal resonances than vertical. Vertically, it is not as effective because of the ration of vertical displacement of the stylus to paddle movement is about 7 to 1 (horizontally it is 1 to 1). If the paddle were made wider it would be more effective vertically, but in general this is not necessary because the vertical resonances are generally not of large amplitude.
Need help?
Do you have a question about the ET-II and is the answer not in the manual?
Questions and answers