Forum FV-1 project

[free electron]

First I have to track down this popping when switching the effect on from the footswitch. I will post an up to date schematic as soon as I can with the switching on if anyone can spot something I have overlooked that could be causing the popping I would appreciate that.

Check if there's a DC voltage on the inputs and outputs of the main pcb.

[Govmnt_Lacky]

First I have to track down this popping when switching the effect on from the footswitch. I will post an up to date schematic as soon as I can with the switching on if anyone can spot something I have overlooked that could be causing the popping I would appreciate that.

I believe that some of the pre-designed effects boards that OCT has developed used a LARGE resistor tied to ground at the input.  What size pull down resistor are you using in your circuit?
I built a circuit based on the OCT G01 board and used the recommended buffer in the pdf and I have NO POPPING.  It uses a 22Meg at the input.

Could you also provide a link to the Rotary switch that you used? I used 3 rotary pots with onboard DPDTs but they are $15 for 3.

[Ice-9]

Could you also provide a link to the Rotary switch that you used? I used 3 rotary pots with onboard DPDTs but they are $15 for 3.

Thanks for the ideas on popping, i will check out both when i get home tonight.

The rotary switch can be found here. My memory was wrong it was £2.69

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=655+3235#header

[auximines]

  I have an FV-1 lying around doing nothing, so I'm really interested in this project!  I don't have a local source for SMD parts though, so I'd prefer through-hole.  I was going to see if I could put together a first-pass PCB, but the schematic posted a few pages ago is very low res and I can't read anything on it!  Ice-9, could you post a higher res version please?  I was going to add in the mix circuit  that was mentioned if it hasn't been done already.

Thanks,
Rich.
---

[Ice-9]

  I have an FV-1 lying around doing nothing, so I'm really interested in this project!  I don't have a local source for SMD parts though, so I'd prefer through-hole.  I was going to see if I could put together a first-pass PCB, but the schematic posted a few pages ago is very low res and I can't read anything on it!  Ice-9, could you post a higher res version please?  I was going to add in the mix circuit  that was mentioned if it hasn't been done already.

Thanks,
Rich.
---

Yes Rich, I will post a schematic as soon as i update it, I appreciate the interest and would be glad if you wanted to do the through hole PCB. Stay tuned.

[free electron]

Looking at your schematic:

i'd have a few suggestions:
- Inputs: the Left (or right) In could be rewired to work as Left/Mono


- i was wondering why did you choose an inverting output stages.. then i realised, they could be easily adapted to work as dry/wet mixing stages, an example:

This idea could be included on the pcb. If the mixing stages are not needed, a simple inverting stage is always there (do not install the R3, R4, R12, R13, R2, jumpers in place of R1 and R14), output gain would be determined by the ratios R2/R5 and R10/R11.

[Thomeeque]

then i realised, they could be easily adapted to work as dry/wet mixing stages, an example:

Some volume pot will be necessary than yet probably.. T.

Btw. output buffers at original schema IMO do not handle DC in signals well (GND vs. V_CC/2), but it's a bit hard to read at this resolution (and maybe already obsolete)..

[free electron]

Some volume pot will be necessary than yet probably.. T.

A stereo 100k lin pot in series with some 470R-1k resistor to avoid stability problems could be used in place of the R2 and R10. It's not a typical "volume" control pot application, but it will provide an usable range of gain.

Btw. output buffers at original schema IMO do not handle DC in signals well (GND vs. V_CC/2), but it's a bit hard to read at this resolution (and maybe already obsolete)..

Yes! You're right. There are two resistors to GND after the DAC coupling caps, they should be removed. I see them on the pcb, both are 10k.

[Ice-9]

Thanks for all the suggestions there everyone, Indeed that schematic is an older one, the newer one has only one input. The info on the output buffers is great, I did use inverting op-amp buffers ready for adding in mix controls and a newer schematic with these  will be posted tonight as I am not at home at the moment. (better res )

As for those 10k resistors to ground on the outputs of the FV-1 just after the caps these are also removed now, they were there as when I read the datasheet for the FV-1 it was suggested they be there to remove any unwanted out of band noise but they seem unnecessary.

Again thanks for all the input
Mick

[Govmnt_Lacky]

Mick,

Did you solve the popping issue? Did you try ther 22Meg input resistor to ground?

[Ice-9]

Mick,

Did you solve the popping issue? Did you try ther 22Meg input resistor to ground?

I haven't had any time this weekend to do any work on the circuit, hopefully I will get a chance sunday.

[jkokura]

By the way, I have been following and still have interest in this.

Second off, this is one of the things that makes me very interested in this: http://www.zcatpedals.com/?dir=view&id=20101015121326uDaa

That link to zcatpedals was super encouraging. I think this is totally worth pursuing.

Jacob

[Ice-9]

By the way, I have been following and still have interest in this.

Second off, this is one of the things that makes me very interested in this: http://www.zcatpedals.com/?dir=view&id=20101015121326uDaa

That link to zcatpedals was super encouraging. I think this is totally worth pursuing.

Jacob

These look interesting , there is no mention on the website that they are all FV-1 controlled. Does anyone know for sure if they use the FV-1 chip.

[Ice-9]

I am trying to decide which way would be the best to use for the mix control, there are two ways to do it. One is like in the example "free electron" has suggested where a pot controls the mix between dry/effect, where turning the effect level up also turns down the dry signal. The other way would be to have the pot only affect the wet signal so that the effect signal is mixed in with the dry.

What does everyone think is the best way to do it ?

[slacker]

Using the method free electron posted you can do both if you want just by wiring it up differently. If you just disconnect the top lug of the pot from the dry side and replace R3 and R4 with a single 51k resistor, then the dry will be on full all the time and the pot will just control the wet level.
You could even wire it to have separate volume controls for the wet and dry if you wanted using the same PCB pads as you'd have for that arrangement.

[Fuzz Aldryn]

By the way, I have been following and still have interest in this.

Second off, this is one of the things that makes me very interested in this: http://www.zcatpedals.com/?dir=view&id=20101015121326uDaa

That link to zcatpedals was super encouraging. I think this is totally worth pursuing.

Jacob

These look interesting , there is no mention on the website that they are all FV-1 controlled. Does anyone know for sure if they use the FV-1 chip.

Yes Sir, I do.
Voilà: (lying on my desk)



This is the Q-Mod Pedal of Z.Cat.

Helge

[Skruffyhound]

I'd prefer the mix CCW full dry CW full wet idea, or probably even better two volume pots for wet and dry.

[jkokura]

By the way, I have been following and still have interest in this.

Second off, this is one of the things that makes me very interested in this: http://www.zcatpedals.com/?dir=view&id=20101015121326uDaa

That link to zcatpedals was super encouraging. I think this is totally worth pursuing.

Jacob

These look interesting , there is no mention on the website that they are all FV-1 controlled. Does anyone know for sure if they use the FV-1 chip.

Yes Sir, I do.
Voilà: (lying on my desk)



This is the Q-Mod Pedal of Z.Cat.

Helge

Wow Helge! Boy I'm sure you could add a lot to this discussion, seeing as you're actively implementing this in your own product. I don't want to detract from your business to simply ask you to give us one of your products, but the only place I've seen that 'Hold' function is on the EHX Cathedral. It was my favourite function of the pedal actually, i didn't really like the way the pedal operated though. Would you be willing to share a little bit about how the 'hold' function could be built into a DIY FV-1 project? If it could be implemented into this project, I would do it. If it's your trade secret though, I fully, and totally understand you wanting to keep that to yourself.

Great pedals by the way.

Jacob

[jkokura]

I'd prefer the mix CCW full dry CW full wet idea.

Seconded.

Jacob

[Fuzz Aldryn]

By the way, I have been following and still have interest in this.

Second off, this is one of the things that makes me very interested in this: http://www.zcatpedals.com/?dir=view&id=20101015121326uDaa

That link to zcatpedals was super encouraging. I think this is totally worth pursuing.

Jacob

These look interesting , there is no mention on the website that they are all FV-1 controlled. Does anyone know for sure if they use the FV-1 chip.

Yes Sir, I do.
Voilà: (lying on my desk)



This is the Q-Mod Pedal of Z.Cat.

Helge

Wow Helge! Boy I'm sure you could add a lot to this discussion, seeing as you're actively implementing this in your own product. I don't want to detract from your business to simply ask you to give us one of your products, but the only place I've seen that 'Hold' function is on the EHX Cathedral. It was my favourite function of the pedal actually, i didn't really like the way the pedal operated though. Would you be willing to share a little bit about how the 'hold' function could be built into a DIY FV-1 project? If it could be implemented into this project, I would do it. If it's your trade secret though, I fully, and totally understand you wanting to keep that to yourself.

Great pedals by the way.

Jacob

Sorry, but I'm not Mr. Z.Cat. Its even not my pedal but one of a friend of mine. I do sell pedals from time to time but only to refinance my pedal built addiction. Constructionwise not that for of Mr. Z.Cat:

This is a ROG 22/7 btw. Best Muff I've ever tried.

Helge