Liquid Mercury Phaser. Build doc V2.0

Transcription

1 Liquid Mercury Phaser Build doc V2.0 David Rolo / December 2014

2 The build consists of 2 boards that were designed to fit in a BB enclosure with top mounted open jacks. PCB1 holds the pcb mounted pots and rotary switch as well as the TAPLFO circuit. PCB2 holds the main phaser circuit. The 2 boards are physically connected together like this: (This is actually a picture of the Twin Peaks tremolo, but it s just to show how to connect the boards) These are the connections between the 2 boards:

3 Wiring Diagram: Ground +9V Rate indicator LED TAP Switch

4 Bypass LED Effect Input Effect Output

5 The pots best suited are Alpha 16mm Right-angle PCB mount Pots: And one mini rotary 2P4T switch like these: They can be ordered in batches from different places like: Band-Switch-2P4T-Rotary-Switch/ html Of course you can use other parts and not mount them on the PCB. Then you will probably need a bigger enclosure.

6 Partslist: Reference Quantity Value Description Capacitors C29,C u Capacitor Electrolytic C32,C7 2 10u Capacitor Electrolytic C2 1 1u Capacitor Electrolytic C n Capacitor C n Capacitor C1,C23,C24,C25,C26,C27,C28,C n Capacitor C10,C11,C12,C13,C14,C15,C8,C9 8 6n8 Capacitor C4 1 2n2 Capacitor C p Capacitor C p Capacitor C20,C p Capacitor Resistors R1,R3 2 1M Resistor R31,R32,R33,R34,R35,R36,R37,R k Resistor R k Resistor R k Resistor R10,R11,R8,R9 4 15k Resistor R k Resistor R15,R16,R17,R18,R19,R20,R21,R22,R23,R24,R25, R26,R27,R28,R29,R30,R40,R42,R53,R54,R55,R56,R62,R k Resistor R41,R7 2 8k2 Resistor R4,R5,R6 3 4k7 Resistor R51,R52 2 3k9 Resistor R2 1 3k3 Resistor R48 1 3k6 Resistor R49 1 2k Resistor R43,R44,R45,R46,R47 5 1k Resistor R R Resistor R57,R58,R R Resistor R60,R R Resistor Potentiometers / Trimmers Feedback 1 100k lin Resistor Potmeter Mix 1 10k lin Resistor Potmeter Rate 1 10k lin Resistor Potmeter Multiplier 1 10k lin Resistor Potmeter Depth 1 10k lin Resistor Potmeter Symmetry 1 10k lin Resistor Potmeter Vol (trimmer) 1 100k Trimmer Bias (trimmer) 1 5k Trimmer Transistors T1,T2,T3 3 2n3904 Transistor NPN

7 IC's U1, U2, U3 3 TL074 OpAmp U4 1 TAPLFO Microchip Diodes D1 1 1N4001 Diode TAP/LED4 1 LED Light Emitting Diode Other Xtal 1 20Mhz Oscillator Crystal TAP Switch 1 Momentary Switch single pole NO Wave Shape Rotary Switch 1 Rotary Switch 2 pole 4 pos. switch Dip Switch 1 4 Pin Dip with 2 switches 78L05 1 5V Regulator Fixed Voltage Reg. Opto1, Opto2, Opto3 3 VTL5C3/2 Optocoupler

8 Here are the steps I would recommend to assemble the boards: 1) Populate the boards with all parts, starting with the smallest to the tallest. Solder in the pots and rotary switch last. Notes: Use sockets for the IC s, at least for the TAPLFO Depending on the kind of caps you use, you may need to lay down your electrolytics flat on the board to gain space. I made sure to leave enough space on the board to accommodate the lying caps. Once soldered, cut the components leads as short as possible to minimize the space needed between the two boards 2) When you have finished populating the boards, solder all needed outboard wires (not the ones connecting the 2 boards together) already in place leaving enough length to connect to their destination later on. 3) Fit the 2 boards back to back with a piece of cardboard or other insulator between them. Don t use anything too thick but also not too thin that component leads could poke through and cause a short. There are 3 holes where you can fit screws (M2.5 or M3, preferably plastic) that will secure the boards together with spacers between them. If you use spacers, you might not need to use an insulation between the boards, but always double check that nothing is touching. 4) Now connect each opposing hole of the 2 PCB s together with some wire. I prefer solid core wire but twisted stranded wire will be OK too. Just watch out for loose strands that could cause a short. 5) Now you can fit the boards inside your enclosure and connect the outboard wires to their corresponding points, the bypass and Tap switches, LED s, jacks etc

9 Internal Controls: VOL: adjusts the overall volume of the effect BIAS: Adjusts the current going through the optocouplers. Set it to where you like the sweep best. Avoid setting it fully clockwise. I tried to size the limiting resistor to avoid exceeding the optocoupler s current but optocouplers vary so be careful. STAGES: lets you select between 2, 4 and 6 swept phaser stages. If you don t want to use a dip switch for this function, you can just bridge the 2 connections with jumpers: External Controls: Multiplier: allows to select the multiplier that will be applied to the tapped tempo Source: Rate: Sets the speed of the modulation Depth: Allows setting the depth of the modulation Feedback: Adjusts the amount of phased signal being fed back Mix: Adjusts the mix between phased and dry signal Symmetry: Allows changing the ratio between the upper and lower wave of the LFO signal For example, when using the square wave, you can set whether the off or the on periods are the longest.

10 This diagram shows the effect of the symmetry pot on some wave shapes: Source: Shape: Select between the 4 available LFO wave shapes: Square, Sine, Triangle, Random

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13 This is a drill template I have been using but take your own measurements to make sure everything fits (before committing to drilling your box ;-)