Mad Bean Pedals VFE Switching Board V.2, Quick Start Manual

Page 1: ...VFE Switching Board v 2 2017 madbeanpedals 2 15 W x 1 33 H ...

Page 2: ... Secondary momentary function The switching scheme utilizes a pre programmed micro controller to actuate a DPDT relay This relay handles I O functions for the separate audio effects boards Therefore the Switching Board must be wired to an audio board to complete the bypass switching for the effects VFE has also gotten very clever in addition to the components necessary to operate the switching oth...

Page 3: ...d DC is connected to the 7662 at pin8 Pin1 is shorted to pin8 to utilize the on board frequency booster This keeps the internal oscillator of the 7662 out of the audio range Pin5 outputs a negative voltage 9v and is decoupled with a 47uF cap C6 It supplies the audio PCB via the V pad at the top of the board The second 47uF cap C5 is used to charge up the voltage inversion within the 7662 In the Ch...

Page 4: ... as a switch IOW the nominal state for the LED is on and the mosfet interrupts grounds the power to the LED on bypass The 20k trimmer is for the user to control their preferred LED brightness 2 Q2 is used as a variable resistor In effect mode pin7 grounds the gate of Q2 and the resistance between the drain and source is on the order of 120 Ohm This acts as a small series resistance for the audio o...

Page 5: ...have the foot switch pressed To activate momentary mode do not press the switch for 5 seconds Then tap it twice quickly Now press and hold for a few seconds until the LED starts to blink You are not in momentary mode To de activate momentary mode and go back to latching mode do the same process again Wait 5 seconds tap tap hold If you encounter problems switching back disconnect reconnect the DC p...

Page 6: ...hes some a serrated others are link doesn t matter and solder a wire to it Solder the other end to the G pad next to the inductor on the Switching Board So when your foot switch is locked down the washer contacts the chassis and makes the ground connection Either method is fine it s up to your personal preference Lock washer soldered for chassis grounding Shown on previous version of the switching...

Page 7: ...horal Reef Dark Horse Fiery Red Horse Focus Mobius Strip Old School Pale Horse Springboard The Triplet Triumvirate Tractor Beam White Horse Value QTY Type Rating 1k 2 Metal Carbon Film 1 4W 8k2 1 Metal Carbon Film 1 4W 10k 1 Metal Carbon Film 1 4W 100k 2 Metal Carbon Film 1 4W 10M 1 Metal Carbon Film 1 4W 100n 2 MLCC 16v min 4u7 1 Low Profile Electrolytic 16v min 47uF 2 Low Profile Electrolytic LO...

Page 8: ...m 1 4 stereo insulated switched socket jack pcb html Wired Jacks When using wired jacks I recommend the Lumberg style http www smallbear electronics mybigcommerce com lumberg 1 4 compact shrouded mono jack Metal frame jacks should fit fine I just don t use these in most of my pedal building http www smallbear electronics mybigcommerce com 1 4 in mono nys229 http www smallbear electronics mybigcomm...

Page 9: ...entary switch when boxing it up This ensures the enclosure gets grounded to the circuit and DC power since all the jacks are isolated in this example The J1 ALT and J2 ALT pads are left empty Additionally you can see several other pads on the Tractor Beam A FET etc which are also left empty These extra pads are present in most of the VFE PCBs and should be ignored unless otherwise indicated in the...

Page 10: ...t there is no wire connecting the V pads on the two boards since it doesn t need 9v This example also shows how to wire non pcb mounted jacks if that is your preference Since these jacks are typically not isolated from the enclosure we also don t need the little grounded lock washer on the momentary switch Lastly the battery hook up was left off in this example ...

Page 11: ...11 Drill Template 1 For use only with the v 2 Switching Board Use this template for board mounted jacks and battery ...

Page 12: ...12 Drill Template 2 For use only with the v 2 Switching Board Use this template for wired jacks and no battery ...

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Page 14: ...y load almost everything and solder in one go You can do it however you like if you prefer to do one components at a time or a small batch that s fine TIP when soldering the ICs and relay do not solder all the pins at once Do a couple of pins move on to another component then come back This prevents the parts from getting too hot All the installed parts soldered up I went ahead and put on the 150u...

Page 15: ...ogether when things are boxed up and having the wires out of the way will help a lot For the grounding solder a wire to a lock washer like so I bought my momentary switches from BLMS and the do not come with lock washers Luckily I have some extras which I bought from smallbear The BLMS switches do have a flat washer which you can use instead You only need to do this when using PCB mounted jacks ...

Page 16: ...16 Lock washer temporarily put on the switch to keep it out of the way while the build is completed All the wires are installed and the whole thing is ready for testing ...

Page 17: ... hooked the effect input and output wires on the breadboard so I could test that signal was passing in both states bypass and effect Voltages off the V and V pads Everything checks out There is no load on the supply rails now so these values will go down once it is used to power an audio board Once the board is installed the three transistors should be pushed down on their sides a bit This ensures...

Page 18: ... previous Switching Board so the DC jack is drilled for the wrong spot No worries the Drill Guide in this doc works just fine for this board Here is a quick video of the board being tested and a demo of how to switch between latching and momentary modes https www youtube com watch v WvKMa8v0OvE ...