# New to FV-1 builds



## soothsayer86 (Jun 6, 2020)

I am looking at building the Deflector reverb pedal, but haven't done any of the FV-1 builds yet. I have a couple questions:
1) Besides ordering the pre-soldered FV-1, is there anything else I need to order from pedalpcb to complete this build? Don't want to miss something and have to place a second order.
2)What is an EEPROM (I am assuming it is where the alogrithm is stored but I could be way off, I honestly have no clue)?
3)Any big changes to the usual work flow of a pedalpcb build?
4) Are there any tips/tricks I should know about?

Thanks everyone!


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## phi1 (Jun 7, 2020)

1) All the other parts are listed.  The 1uMLCC caps are available from pedalpcb, but also available from other sites.  The 1uMLCC caps are important because an electrolytic or film 1u cap won't fit the board.  Some fv-1 projects have a crystal, which is also sold at pedalpcb, or other shops, but the deflector doesn't (it has the CD4049UB chip instead for controlling the clock).  
2) you're right, the eeprom is a data chip that stores the algorithm.  Probably best to socket this.  The cool thing about the arachnid or pythagoras boards is that you can get a totally different set of patches by swapping out the eeprom.  In fact, the spatialist reverb, octagon, and module8 are IDENTICAL builds except for the eeprom (they all use the arachnid pcb).  The deflector has a bit different setup of the circuit so it probably wouldn't be useful to swap out eeproms on that board.  Pedalpcb will send you the eeprom chip with the algorithm already flashed on.
3) the workflow is similar, just take your time when soldering since they are larger builds that most.
4) if you're the curious type, check out the fv-1 datasheet online, and study the deflector schematic to see how the pins line up.  For your next fv-1 build, I recommend the arachnid, and check out the eeprom builder where you can customize the patches on your eeprom chip.  (Unfortunately there is a shortage of the 1P8T switch right now, hopefully more will come back in stock soon).  The Spatialist reverb is also pretty cool, so you could get a few chips including the spatialist and swap them around to see exactly what you like.


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## soothsayer86 (Jun 7, 2020)

phi1 said:


> 1) All the other parts are listed.  The 1uMLCC caps are available from pedalpcb, but also available from other sites.  The 1uMLCC caps are important because an electrolytic or film 1u cap won't fit the board.  Some fv-1 projects have a crystal, which is also sold at pedalpcb, or other shops, but the deflector doesn't (it has the CD4049UB chip instead for controlling the clock).
> 2) you're right, the eeprom is a data chip that stores the algorithm.  Probably best to socket this.  The cool thing about the arachnid or pythagoras boards is that you can get a totally different set of patches by swapping out the eeprom.  In fact, the spatialist reverb, octagon, and module8 are IDENTICAL builds except for the eeprom (they all use the arachnid pcb).  The deflector has a bit different setup of the circuit so it probably wouldn't be useful to swap out eeproms on that board.  Pedalpcb will send you the eeprom chip with the algorithm already flashed on.
> 3) the workflow is similar, just take your time when soldering since they are larger builds that most.
> 4) if you're the curious type, check out the fv-1 datasheet online, and study the deflector schematic to see how the pins line up.  For your next fv-1 build, I recommend the arachnid, and check out the eeprom builder where you can customize the patches on your eeprom chip.  (Unfortunately there is a shortage of the 1P8T switch right now, hopefully more will come back in stock soon).  The Spatialist reverb is also pretty cool, so you could get a few chips including the spatialist and swap them around to see exactly what you like.


Awesome, thanks for the in depth response!


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## Thewoodenone (Jun 12, 2020)

Can I sub 1N4148 for the 1N914 in these (what I have on hand) or will it make a difference?


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## phi1 (Jun 12, 2020)

Yep no difference in this case.


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## Thewoodenone (Jun 15, 2020)

I can't find a single SP8T rotary ANYWHERE.  It looks like Mouser is expecting them mid September. I really don't want to wait 3 months. Is there a work around anyone has found? Possibly utilizing toggles or a more available rotary.


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## phi1 (Jun 15, 2020)

You could easily use 3 toggles, I can give more details if you want to go that route. You’ll just have to find room to install them off the pcb.


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## Thewoodenone (Jun 15, 2020)

phi1 said:


> You could easily use 3 toggles, I can give more details if you want to go that route. You’ll just have to find room to install them off the pcb.


Yes please. I think there is room between the board and stomp on a 125B


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## phi1 (Jun 15, 2020)

Ok so basically what you'll do is, instead of the rotary sw you'll have 3 toggle switches (1PDT, ON-ON type).  They will work like three binary bits to make the 8 settings (up=1=3.3v), (down=0=0v).  So if you think of the settings as 0-7, the binary will be:
program 0 = 000 (down down down)
program 1= 001 (down down up)
program 2 = 010
program 3 = 011
etc
program 7 = 111

This is actually how the fv-1 thinks, pins 16, 17, 18 are the three binary digits.  (0v means 0, 3.3v means 1).  The diode network on the arachnid board allow the rotary switch to activate those pins in the correct order.

You don't need to use the 9 diodes below the rotary switch (they won't hurt anything if they're already there). You'll keep R7, R16, R17 (100k each).

So when the switch is down (unconnected), the corresponding pin will go to 0V (pulled down to gnd level through the 100k resistor).  When the switch is up (connected), the pin is connected to 3.3v.

Please use a multi-meter to check for continuity between the rotary switch pads in my drawing, and the actual pins on the fv-1.   I'm thinking I drew it correctly but I'd like you to double check before soldering any wires.  (or someone else who has the board handy could confirm).

If you do it the way I have drawn, where pin 16 is on the left inside the box, then pin 16 will be on the right in the finished product (least significant bit). 

Hopefully that made some sense, let me know if you have any questions.


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## Thewoodenone (Jun 15, 2020)

Thanks. I'll test later this week and report.


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## phi1 (Jun 16, 2020)

By the way, @PedalPCB  do you think the arachnid pcb is the cause of the 1p8t shortage haha? Or maybe a larger Pedal manufacturer Bought a bunch up, or Maybe it’s a totally unrelated industry...

Anyway, if there’s a chance that the shortage will be a long term issue, I’d say offer another pcb with the pot and attiny (like the old arachnid). I have The old arachnid and have built the new one for a friend, I like the detents of the rotary sw, but the pot version is not so bad since I made a decal with the Patch positions marked.  To that effect, you could maybe add a face plate to show the positions.  maybe even an optional led (controlled by the attiny) to indicate even or odd patch so there’s no doubt which patch you’re on.  (The mix control of the new arachnid seems much better than the old one to me, so I don’t think just bringing back the old version verbatim would be the way to go).


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## phi1 (Jun 16, 2020)

@PedalPCB or a daughterboard would be cool, to interface the attiny with the arachnid PCB’s holes for the rotary switch, with spots to run wires to the pot lugs.


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## p_wats (Jun 16, 2020)

Yeah, the lack of available 1p8t rotary switches is annoying. I keep missing the small blips of stock that do come up and am waiting for repair a broken arachnid. Alas.


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## Thewoodenone (Jun 16, 2020)

phi1 said:


> Ok so basically what you'll do is, instead of the rotary sw you'll have 3 toggle switches (1PDT, ON-ON type).  They will work like three binary bits to make the 8 settings (up=1=3.3v), (down=0=0v).  So if you think of the settings as 0-7, the binary will be:
> program 0 = 000 (down down down)
> program 1= 001 (down down up)
> program 2 = 010
> ...


I tested continuity and you were correct. Now to populate once the on-on toggles arrive. Thanks again.


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## Thewoodenone (Jun 22, 2020)

Thewoodenone said:


> I tested continuity and you were correct. Now to populate once the on-on toggles arrive. Thanks again.


Just finished closing it up and mapping the programs. It works perfectly!!!


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## phi1 (Jun 22, 2020)

Glad it worked out for ya! Post a build report when you get a chance so we can see how it looks and give others the idea.


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## Thewoodenone (Jun 28, 2020)

phi1 said:


> Glad it worked out for ya! Post a build report when you get a chance so we can see how it looks and give others the idea.


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## djathey (Nov 13, 2020)

Maybe this is common info, but found what appears to be the same 1P8T rotary switch here:

https://www.aliexpress.com/item/4000700243796.html


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