SOLVED Octagon little output: Voltage Request

[Mike52]

(I will post pictures tomorrow, but they aren't really necessary for the purposes of this post.)

I boxed up my Octagon last night and played through it. Each effect seems to be working but the output of the effect is really low. Like really low. Staring at it and reviewing pics of other troubleshooting threads it dawned on me that I'd screwed up and put a .22uf box cap at C14 where a 220p ceramic should have been. Out of time and patience to swap it out last night, but I will do it tonight if I get a chance.

In the meantime, does anyone have voltages for this project? A few of them are obvious, but not all.

(I normally use my Auditorium to test circuits before I box them, but in this case I was getting sporadic bypass signal and sporadic effects signal at low volume and was having a hard time getting the terminals to bite on the ground wire. I like that thing well enough, but it feels a little dainty sometimes. Not real rugged.)

 

[Mike52]

Here's some pics. As I said, it appears to be working as advertised, although the volume doesn't seem to have the travel to go higher than unity volume. That is weird.

I used 9mm pots because that's what I had onhand. The three control pots are B100k and the volume pot is A100k.

 

[Mike52]

Wow, 82 looks and no comments.

So this weekend I will remove the ICs and take some voltages just to get a baseline (and guess what looks right vs. what may be off). If all that seems to check out, I will try to increase the 15k resistor at R10 to see if it squeezes a little more volume out of it. I'd like to go up in small increments but I suspect that the next resistor up that I have is a 22k.

 

[zgrav]

If you want to test the change in output from swapping that resistor, go ahead and remove R10 and tack in a 50K to see how much difference that makes. If it is too much you can swap in a lower value.

 

[PJS]

I just pulled mine out for a listening test. It is waiting on a new stomp switch - the one in there is a bit intermittent. Unity volume or maybe just a hair more than unity with the volume on full seems to be about right to me.

 

[Mike52]

I just pulled mine out for a listening test. It is waiting on a new stomp switch - the one in there is a bit intermittent. Unity volume or maybe just a hair more than unity with the volume on full seems to be about right to me.

Good to hear, so it may be normal. I think I'd still like to try getting a little more volume.

 

[Mike52]

Ok, so I got this all sorted out over the weekend. I put a 22k resistor in place of the 15k at R10 and my volume is right about where I want it. Depending on the effect it's generally at unity gain right around 60 percent. I can goose it a bit when using the tremolo effect. I don't think I'd go much higher than 22k.

I had wired this wrong from the beginning, screwed up the LED (it was softly glowing all the time and getting brighter when effect was on), put in a cap at the wrong value and made several other mistakes that caused a signal spike when turning the effect on. With those mistakes, it sounded ok but very low-fi. Corrected, it sounds pretty good (although the bit crusher sounded better in the erroneous version). In general, I don't think I like FV-1 builds. Too many choices, too much of everything really. Everything is pretty good, nothing is great.

 

[zgrav]

The

..... Everything is pretty good, nothing is great.

The FV-1 has hardware that can do a number of things very well and sometimes gets used to do other things it cannot do very well (like real time pitch shifting). I think there are some great implementations of some delays and multiple delays that can get lost among lots of programs when you are spending a few minutes with each one. The challenge is to find the programs you like and will use.

 

[Mike52]

The

The FV-1 has hardware that can do a number of things very well and sometimes gets used to do other things it cannot do very well (like real time pitch shifting). I think there are some great implementations of some delays and multiple delays that can get lost among lots of programs when you are spending a few minutes with each one. The challenge is to find the programs you like and will use.

Good insight. As I think about it, while puttering around with it this weekend I found that everything that involved pitch shifting was disappointing.
There are really good sounds in this pedal, but you've really got to dig for them. I could see this pedal being used for maybe a couple of things only. All the rest of the settings would just gather dust. But that's sort of the story with most multi-effects pedals.

 

[JamieJ]

This is where the custom EEPROM service is perfect. You can try out new effects and really make a multi effect pedal that suits your needs.

 

[Mike52]

This is where the custom EEPROM service is perfect. You can try out new effects and really make a multi effect pedal that suits your needs.

I'm not that familiar with FV-1. Can you order an EEPROM with only three selected effects and then just put it on an On-On-On switch? Like I said earlier, I think this thing suffers from too many choices.

 

[PJS]

I bought a cheap eeprom burner and I am currently looking through this archive https://mstratman.github.io/fv1-programs/
I will probably end up filling all 8 slots with things I like, but if I can find a decent flange, decent chorus and octave down then I can replace 3 pedals on my board that I use, but not often and give myself more space. That's the goal

 

[JamieJ]

PedalPCB will do it for you -

EEPROM Builder - PedalPCB.com

Custom Programmed EEPROM

www.pedalpcb.com

You could order 3 effects on an EEPROM but then the other parts on the switch would be blank. You may as well find 8 you like.

 

[Mike52]

PedalPCB will do it for you -

EEPROM Builder - PedalPCB.com

Custom Programmed EEPROM

www.pedalpcb.com

You could order 3 effects on an EEPROM but then the other parts on the switch would be blank. You may as well find 8 you like.

I think that's my main criticism with FV-1; Too many choices. But it's just a personal preference thing, really. I am just looking for a pedal to do one thing really great, and maybe have a couple of useful things on tap to be used from time to time. Too many choices and I just get lost down the rabbit hole or it gets too difficult recalling "that one great thing" that I discovered previously.

 

[PJS]

I think there is a pedalpcb pcb that does have a toggle switch for 3 options, rather than the 8 position switch. There is also one that has a USB input so you can easily download code to it

FV-1 Development PCB - PedalPCB.com

FV-1 MultiFX with USB

www.pedalpcb.com

 

[JamieJ]

That one PJS is for developing your own effects in the FV-1 format. Pythagoras based boards are the ones with three effects only (radium spring, D3lay and three verb)

 

[music6000]

I have only built one FV-1 based pedal which is the VCR & the Reverb sucks (Volume drop & Reverb type) as designed.
I'm waiting for an EEPROM to be corrected so it is a usable pedal after all the extra work I did building it!!!!

 

[Mike52]

Very cool. Is that four stomp switches?

Mine was so complicated that I had to include a cheat sheet, ha. I think FV-1 just isn't for me. I'm a simple guy.