Table of Contents HA-S Main features........................................................................2 Cautions Before Assembly.................................................5 NUTUBE HEADPHONE AMPLIFIER KIT Tools to prepare................................................................................... 5 Checking the parts............................................................................... 5 Assembly..............................................................................
Thank you for purchasing the Nu:Tekt HA-S. To help you get the most out of your new headphone amp, please read this manual carefully. Main features • The HA-S is a kit to assemble a hi-fi headphone amp that utilizes a Korg Nutube vacuum tube. • Although this headphone amp is powered with only two batteries, it can drive the Nutube with a line voltage of 26 V for an authentic vacuum tube sound. • The filament is powered by a DC to DC converter, which consumes less electric current.
Precautions Notice regarding disposal (EU only) If this symbol is shown on the product, manual, battery, or package, you must dispose of it in the correct manner to avoid harm to human health or damage to the environment. Contact your local administrative body for details on the correct disposal method. If the battery contains heavy metals in excess of the regulated amount, a chemical symbol is displayed below the symbol on the battery or battery package.
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Cautions Before Assembly Be careful of injury when handling parts Use caution not to injure yourself due to the protruding parts when handling the circuit board. Use cotton work gloves to protect your hands when working. Also, be sure to wash your hands thoroughly after working. Tighten screws and nuts at a perpendicular angle Tightening screws and nuts that are inserted diagonally may damage the threads, making it impossible to tighten them again.
Assembly 2. Preparing the main circuit board and Nutube circuit board CushionN2 (3) Parts List 1 Circuit board cushion 2 Cushion N1 3 Cushion N2 PORON 7t, 8x19 Sponge 1t, 5x40 Sponge 1t, 5x15 1 2 1 4 Harness 5 Hex spacers 6 Hex spacers 7 Internal tooth lock washers 8 Screws -- 4 M2, L=3mm M2, L=16mm M2 M2, L=5mm, Black 2 4 4 2 Building the Nutube circuit board unit 1. Attach the cushion onto the Nutube circuit board unit. Attach cushion N1 (2) onto the edge of the Nutube circuit board.
Attaching the hex spacers 1. Mount the hex spacers (5, 6) onto the circuit board. Use the screws (8) to affix the two hex spacers (6) and the internal tooth lock washers (7) for the volume and jack side. In the same way, tighten the hex spacers (6) on the Nutube circuit board side and the internal tooth lock washers (7) by tightening the screws for the lower hex spacers (5).
Install the main circuit board into the case Parts List 4 3 11 10 1 2 3 4 5 6 7 8 Case Pan head screws Cover Knurled screw Main circuit board Insulation sheet Volume nut Mint-tin size case M2, No.
Fix the main circuit board in place on the case 1. 3. Put the insulation sheet [6] into the case [1]. Peel off the release paper on the double-sided tape attached to the insulation sheet [6], and attach it to the case [1]. Attach the washer [8] to the volume, and then use the volume nut [7] to temporarily tighten the volume onto the case. Make sure that the stereo mini jack protrudes from the hole in the case. Double-sided tape (bottom side) [6] [1] 2.
Put the batteries and close the case 1. 3. Put the batteries [10] in. With the printed jack names facing the jack side, put the cover [3] on, and fasten the knurled screws [4] in four places. Take care not to pinch the harness or other parts when closing the cover. Tighten the knurled screws by hand. Overtightening the screws using a screwdriver or other tool may damage the screws or the main unit. [4] [4] [3] Batteries are not included.
Part Names and Functions Adjusting the main circuit board The main circuit board comes preadjusted at the factory. The main circuit board generally does not need to be adjusted, but if you notice a difference in volume between left and right, adjust VR 4, 5, 6, and 7 to balance the levels between left and right. The tonal character will also change when adjusting the sound. Adjust the settings to get the sound you like. 1 4 5 1 2 3 4 1. IN jack: Connect a portable music player or similar device here.
Troubleshooting Replacing the operational amplifier When you have successfully finished assembling the unit, test its operation while reading “Part Names and Functions” . If you have found any problems with assembly or operation, use the troubleshooting steps below. The operational amplifier can be replaced with a DIP8 type operational amplifier. The power supply for the OP amp is a 24–28 V single power supply system.
Mounting Diagram - 13 -
List of mounted parts Main circuit board 2 IC1S Operational amplifier socket 8pin DIP 1 3 C10, C14 Chip ceramic capacitor 10PF CH 2 4 C27, C28 Chip ceramic capacitor 0.0022μF B 2 5 C16, C17 Film capacitor 0.012μF FILM 2 6 C8, C11, C12, C15, C23 Electrolytic capacitor 10μF/25V 5 7 C9, C13 Non-polar capacitor 10μF/25V BP 2 18 19 20 R8, R9 R10, R12, R17, R18 BATT1 4.
Nutube circuit board Quantity Rating Part name Circuit number Part number 31 32 33 IC3 IC2 Q1, Q2 Voltage regulator Voltage regulator J-FET TLV61046A TPS62510 2SK209 1 1 2 34 C4 Chip ceramic capacitor 22PF CH 1 35 C5 Chip ceramic capacitor 0.001μF B 1 36 C3 Chip ceramic capacitor 0.1μF B 1 37 C6 Chip ceramic capacitor 4.7μF B 1 38 C7 Chip ceramic capacitor 4.7μF B 1 39 C1, C2 Chip ceramic capacitor 22μF B 2 40 C25 Chip Electrolytic capacitor 390μF/2.
CIRCUIT DIAGRAM 0 OPEN R2 R1 1 CN2 B12B-ZR 62K 2.2uH 26V VCC R16 R32 0 C18 1K VCC_2 3 10uF/25V R6 10K VCC_2 R8 22K 2 CW VR6 10K B R10 47K 3 GND 1 C21 C9 10uF/25V BP C11 10uF/25V SW2A 1 [ OFF ] 2 C16 R17 3 MK-22D10-G2 47K 0.012uF FILM [ ON ] C15 10uF/25V SW2B 4 [ OFF ] 5 C17 R18 6 MK-22D10-G2 47K 0.012uF FILM [ ON ] 2 R35 4.7K 3 2 C23 100K 10uF/25V GND - 16 - R36 4.7K VCC 8 R14 100K R15 10 1/4W NJM4580 IC1C NJM4580 GND C14 IC1B - 7 R30 10 1/4W BIAS NJM4580 C28 0.
