4 YEAR WARRANTY - BUY WITH CONFIDENCE - All vintage vacuum tubes sold by Riverstone Audio are backed by our no-nonsense 4-YEAR warranty. THE BEST WARRANTY AVAILABLE in the audio tube business. We have been testing and using vacuum tubes for many years and know what it takes to select the best vacuum tubes for long life low-noise audio applications. | TESTED and MATCHED Pair (2 tubes) of low-noise 7-Pin NIB/NOS GE JAN 5654W Vacuum Tubes. Considered one of the best of the 5654 / 6AK5 / EF95 family of tubes for audio use. These vintage US manufactured GE tubes are Mil. Spec. (JAN) Electron Tubes - Higher Durability and Life. The 5654W tubes are NOS and were obtained from factory-sealed military surplus boxes. | RIVERSTONE AUDIO utilizes the best available equipment (Amplitrex AT1000) to test and match audio tubes. THE VACUUM TUBES WE SELL ARE 100% TESTED WITH DOCUMENTED TEST RESULTS ATTACHED TO EACH TUBE BOX. Our experienced engineers match vacuum tubes for BOTH plate current and mutual conductance. All tubes we must also pass a specialized life test and an audio sound test. ***All vacuum tubes sold by Riverstone Audio will have the "Riverstone Audio" name, logo and QC label on the boxes*** | TEST RESULTS ARE PROVIDED WITH ALL TUBES SOLD BY RIVERSTONE AUDIO. We do not recommend purchasing vintage vacuum tubes unless actual test results are provided. We reject over 60% of the tubes we test. We guarantee that the GE 5654W tubes selected for these matched pairs test at NOS levels at or above 4400 micro-mho and a plate current of 6.2 mA or higher. | ***IMPORTANT*** AMPLIFIER DAMAGE CAN OCCUR IF YOU SUBSTITUTE THE WRONG TYPE OF TUBE. 5654W tubes should only be used to replace 7-Pin 6J1, 6J1P / 6J1P-EB / 6Zh1P-EV, 6AK5, 6AK5W and EF95 tubes. DO NOT SUBSTITUTE FOR ANY OTHER TYPE OF 7-pin tube.

A Professional digital tracking force gauge designed for vinyl record purist's interested in precise measurement of vertical tracking force (VTF) at the correct vertical tracking angle (VTA). When used with the detachable cantilevered extension arm, the gauge closely approximates the vertical position of the stylus on the surface of a vinyl record when it is playing on a turntable- providing accurate “record-level” measurements of tracking force. | For optimal accuracy, tracking force should be measured at the same vertical position as the record surface. With Riverstone's VTF gauge's patented design (US Patent D878232), tracking force is measured 2 mm - 3 mm from the surface of a turntable mat - the height of a stylus tip resting on an LP record (LP's have a thickness range of 1.9 - 2.9 mm). With less expensive gauges, the measurement distance is typically 6 mm to 9 mm. | Precision strain gauge sensor provides 0.005 g measurement resolution and accurate measurements over the entire calibration range of the VTF gauge. To ensure accurate VTF measurement, our VTF gauges undergo a rigorous multi-point calibration procedure to verify the linearity, repeatability and accuracy of the VTF measurement. We have confidence in our gauges and provide TWO calibration masses (5g and 20g) to verify the readings at any time and also allow for future re-calibration if needed. | Manufactured using non-magnetic materials to minimize interactions with MM and MC cartridges. The housing of the VTF gauge is manufactured from a durable plastic. The cantilevered extension arm is made from a non-ferromagnetic grade stainless steel and the locking screw of the extension arm is made from brass. A polymer pad protects the stylus tip and allows stylus centering on the measurement platform. | The gauge is designed with two levels of battery protection, including auto turnoff of the display and automatically powering off of the circuit after 60 to 120 seconds of inactivity. A detailed instruction manual (in English) is provided. Includes a tin storage box to protect the VTF gauge when not in use. ***Requires one AAA ALKALINE battery (sorry, battery NOT included)***. Riverstone Audio Tracking Force Gauges are now covered by a full THREE-YEAR WARRANTY.