Author Topic: octagon FV-1  (Read 3621 times)

amcmann95

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Re: octagon FV-1
« Reply #15 on: April 13, 2018, 05:24:25 AM »
How is the decay/travel on the reverbs? Im looking for something to replace my hall of fame and just want to make sure that I can get the really looong reverb trails that I like. I usually use the "Big room with a view" toneprint and will sometimes bump up the time up to 7-10 seconds.

oip

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Re: octagon FV-1
« Reply #16 on: April 13, 2018, 07:00:50 AM »
you can definitely get long/big reverbs, that's also how i use it.  however the two reverbs on this eeprom are shimmer and modulated, so to use them as straight reverbs you have to discard most of the settings - if you wanted a straight up reverb effect i'd suggest one the other eeproms, pretty sure there are dedicated reverb projects.  unless you want to code your own chip.

Hexjibber

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Re: octagon FV-1
« Reply #17 on: April 20, 2018, 08:48:45 AM »
This looks great! Really like the artwork on it! Got an Octagon board on my list of stuff to build so seeing yours all finished is good motivation!


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oip

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Re: octagon FV-1
« Reply #18 on: April 20, 2018, 09:03:49 PM »
thanks!  yeah it's an easy build and so far a lot of fun.  got a bunch of ideas for different circuits around the FV-1 after playing around with this.

also as there are no onboard programming pads i made a little interface for the pickit 2 to program EEPROMs running off a 9v battery and some parts lying around.  have successfully copied and written a few EEPROMs.



now to, uh, learn spinASM
« Last Edit: April 20, 2018, 09:05:38 PM by oip »

micromegas

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Re: octagon FV-1
« Reply #19 on: April 23, 2018, 03:37:37 AM »
I personally approve any pedal with Stacey Rozich artwork on it.
'My favorite programming language is solder' - Bob Pease

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ryanisradd

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Re: octagon FV-1
« Reply #20 on: April 24, 2018, 08:07:45 AM »
...  have successfully copied and written a few EEPROMs.



now to, uh, learn spinASM

Did you happen to copy the Darkstar hex files? I'd be curious to know how that went!
I make some pedals with my wife from time to time, we're called EAR electronics.

amcmann95

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Re: octagon FV-1
« Reply #21 on: May 07, 2018, 03:15:38 PM »
Got this one soldered up, but the nothings getting past the fv-1 chip. The Analog mix and anything up until the fv1 sounds fine, but Im getting nothing out of the outputs of the fv1 when I probe pin 28. Any chance I could get some voltages from someone who has completed their build?  ;D

bsoncini

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Re: octagon FV-1
« Reply #22 on: May 07, 2018, 05:27:52 PM »
Got this one soldered up, but the nothings getting past the fv-1 chip. The Analog mix and anything up until the fv1 sounds fine, but Im getting nothing out of the outputs of the fv1 when I probe pin 28. Any chance I could get some voltages from someone who has completed their build?  ;D

The first thing I would do is test with continuity all the fv-1 pins to something they should be connected to by looking at the schematic

somnif

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Re: octagon FV-1
« Reply #23 on: May 07, 2018, 05:36:52 PM »
Got this one soldered up, but the nothings getting past the fv-1 chip. The Analog mix and anything up until the fv1 sounds fine, but Im getting nothing out of the outputs of the fv1 when I probe pin 28. Any chance I could get some voltages from someone who has completed their build?  ;D

The first thing I would do is test with continuity all the fv-1 pins to something they should be connected to by looking at the schematic

This would be my suggestion. I had a similar problem with my build, and it turned out I needed to re-flow 2 pins on the FV-1. They looked good with my hand lens, but in reality there was no continuity.

As such, make sure you're reading from the pin to some component, and not the pad the pin sits on.

oip

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Re: octagon FV-1
« Reply #24 on: May 07, 2018, 05:44:56 PM »
yeah i agree with bsoncini and somnif - very easy to lift or bridge a leg of the FV-1, they are so tiny.  then maybe the regulator and the crystal?

i can try and check the voltages next time i pop the pedal open.

implementing algorithms from other places and forums is interesting - although the analog circuitry is usually similar there are a number of important variables that aren't constant across different FV-1 builds.  summing the input, using one or both output pins, gain of the analog circuit, presence of analog mix, presence of feedback pot.  algorithms will all be designed to take these into account. 

i've played around quite a bit with spinCAD now and it's very interesting, trying to get my head around spinASM but that's a whole other ballgame.

also looking to design a PCB and nice analog preamp circuit but that's gonna take a while.  basic improvements would be onboard eeprom programming header and also rotary switch for program selection (pot works and is fine for set and forget but is moderately annoying to change on the fly).  also would maybe like to lose the volume pot for an internal trimpot.

oh i forgot: decided to try learning eagle too so made up a little PCB for the eeprom/pickit 2 adapter.  was fun and super fast/cheap to get fabricated.  unfortunately after the excitement of receiving and opening the package it didn't work and after a lot of head scratching and frustration i realised i had mixed up two header pins.  learning experience...
« Last Edit: May 07, 2018, 05:50:02 PM by oip »

amcmann95

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Re: octagon FV-1
« Reply #25 on: May 09, 2018, 06:38:06 PM »
Thanks for all the help guys! I got it working with the help of Robert from pedalpcb and a friend with a hot air station. Despite the fact that i had reflowed with my soldering iron, it still didnt work until we hit it with the air. Im getting sounds out of it, but a fair bit of white noise and some nasty clipping when I strum too hard. Gotta experiment more. Im gonna test out some different op amps and see what that does for me.

Im loving the sounds im getting out of this pedal. Dont think it will be able to kick my hall of fame off quite yet, but would be quite nice in the effects loop of a delay Im planning on building in the near future--if I can solve the current issues with it.

Cant recommend pedalpcb enough though! Robert was a huge help with his support.