FV-1 Project - REVISITED

[Ice-9]

A lot of you will know that I posted a basic FV-1 project here quite some time ago. Recently I have been asked from a few members here if any PCB's are left over. None are left of the original but the project is on OSHpark.

So after a couple of PM's about these I thought it would be a good idea to start a new Fv-1 project but go right back to the beginning and start the project off trying to see which way everyone would want the circuit to develop.

I will start off a few ideas.
I'm thinking a larger enclosure to allow for more pots and other options ?
Fully analogue dry signal
Possibly stereo in/out ?
The option for 'tails' ?
On board Pots but off board jacks and footswitch(s) ? or off board everything ?
The one thing I am not really intending to get involved with though is the addition of a display and automation for editing and saving patches.

If anyone is interested in getting this project going then post anything you might think would be good to include here and we will see where it ends up.

[Ice-9]

Does anyone think that it is worth having the option to use the internal programs as well as the external eeprom programs ?

What other options would anyone like added ?

Once we have a design roadmap, it can begin.

[Digital Larry]

I think the internal programs can be useful if generic.   

[potul]

Access to the internal programs will be useful, and should not complicate that much.

Analog mix is welcome... and could save one pot of the FV1 for other uses...

I'm a complete ignorant about the FV1 possibilities, but from what I saw on the datasheet it does not have analog inputs other than the program select, right?  It would be nice to have a second stomp switch to trigger something, but as the FV1 cannot take it, maybe the only possiblity is to do some magic in the PIC. I was thinking on something like, if this second stompswitch is ON, then use program 1, if not, use whatever the POT has selected.
This would allow for a shortcut to program 1 that can be accessed with your foot.

Or even better, ... you could even "save" a different program, like having 2 presets. When switch is on, if you move the program POT you select preset 1. This gets saved and can be recalled.

[potul]

I realize you mentioned you are not interested in automating patches... and my proposal is somehow in this direction.

In this case, I would want to be able to program the PIC in circuit, to give the possibility to add similar things externally.

[cliffsp8]

Thanks Mick for starting this up.

My personal aim will be to achieve echo and reverb from a single box, so I am guessing this will need 2 FV-1s to get the necessary quality. In which case the pcb footprint would need to be no bigger than your first version so that two could be housed in a reasonable sized box. I am not bothered about pots directly connected to pcb as I won't be mass producing

An analogue mix circuit would be useful - I think a dry/wet control would be  most flexible as it would allow for insert mode and for using existing patches which have the mix performed digitally.

Cliff

[Ice-9]

@Potul , While I won't be working on any automation but I don't see any problems with anyone else adding micro control, this is why I have asked for input from others regarding specs and input.

@Cliff8, A 2 FV--1 chip circuit board is something I have considered and is feasible, although I can't see anyway it would fit into the same footprint of the original 1590b if that is what you mean or are you suggesting each FV-1 have it's own PCB but stick two PCB's in the same box.  I have suggested a 1590bb for this project which would allow 2 chips on the same PCB, this format may be easier.

Can you explain a little more what you mean by insert mode for existing patches ?

[cliffsp8]

I realised that a 2 FV-1 board would not fit in a 1590b, but if the new version was a single FV-1 board and was no bigger than the previous one, then 2 could be fitted side by side in a reasonable sized box. But a dual chip board would be my favourite solution   And if it fits in a  1590bb size so much the better.

Re the wet/dry control, I meant to say that would allow it to be used as a send device (as opposed to an insert in mixer terminology ie on its own parallel route) with the control set to 100% wet. As I understand it existing FV-1 patches do the mixing internally in the digital domain so if an additional analogue mix is employed it will need to allow 100% wet to be backward compatible. A wet/dry control would save a knob compared to separate dry and wet levels.

[Ice-9]

Regarding the wet/dry mix, I had been thinking along the lines of keeping the dry signal completely analogue and not being mixed within the FV-1 at all. For use in a parallel effects loop a dry cut switch would be included. With existing effects that have the dry mixed internally in the FV-1 it should be simple to edit the code to remove the dry signal.

[cliffsp8]

The dry cut is a good option. Re editing code I'm looking forward to getting started - this will my first dabbling with Fv-1 ...

[MetalGuy]

With existing effects that have the dry mixed internally in the FV-1 it should be simple to edit the code to remove the dry signal.

From what I can hear some of the FV-1 effects are "well" mixed with the dry signal but some need additional dry signal mixing.
Can you be more specific as which of the stock ones are mixed and to what degree? IMHO the dry/wet mixing should be done entirely out of the FV-1 to everyone's taste but maybe that will require at least one more digital pot. Why not even one more for solo level boost for example.

[Ice-9]

With existing effects that have the dry mixed internally in the FV-1 it should be simple to edit the code to remove the dry signal.

From what I can hear some of the FV-1 effects are "well" mixed with the dry signal but some need additional dry signal mixing.
Can you be more specific as which of the stock ones are mixed and to what degree? IMHO the dry/wet mixing should be done entirely out of the FV-1 to everyone's taste but maybe that will require at least one more digital pot. Why not even one more for solo level boost for example.

When I mentioned existing effects I was referring to anything available to put on the external Eeproms, not the effects that are internal to the FV-1. Some of the internal effects may have the mixing done internally in the FV-1 ( off the top of my head I have no recall of which one's do or don't) these obviously cannot be altered in any way. I am mainly thinking of options for external effects in the audio path design. The internal effects if the option is used will work just fine with the dry lift switch anyway.

There is no reason to use a digital pot with analogue external mixing, after all this is meant to be an update on the first FV-1 pedal project and not a fully automated digitally controlled pedal. Of course throwing ideas around may lead to some changes and additions but personally I would like a good workable improvement on the original without going overboard.

[SeanCostello]

A few things that would be cool:

- stereo (dual ganged) pot for stereo wet/dry mix. The Neunaber Immerse uses this, so that the mixing can happen in the analog domain.
- a microprocessor that can be flashed with the ROM code, that can load directly to the FV-1 without using an EEPROM
- variable clock rate? This allows for the "size" of the algorithms to be altered, which is otherwise very difficult to do on the FV-1. The clock rate variation is limited to a 3:1 range (16 kHz to 48 kHz), but this can make a BIG impact on the attack and decay characteristics of reverbs.

I'm considering an FV-1 for a closed-source pedal, but would gladly contribute to an open-source hardware design.

Sean Costello

[grenert]

- variable clock rate? This allows for the "size" of the algorithms to be altered, which is otherwise very difficult to do on the FV-1. The clock rate variation is limited to a 3:1 range (16 kHz to 48 kHz), but this can make a BIG impact on the attack and decay characteristics of reverbs.

I've built one of the original versions of Mick's pedal (awesome!) and intend to replace the crystal with one of these for this purpose:
http://www.circuitbenders.co.uk/forsale/LTC/LTC.html

[orbitbot]

Hello everyone! Complete DIY pedal noob here, about to build my first kit, but I have my sights set on a FV-1 project eventually (hopefully sooner rather than later)!  I've read through the whole previous message thread and looked at some of the other forums, but all in all it's quite a bit to take in. The ideas already mentioned sound really exciting!

Taking my inexperience into consideration (can't really evaluate if these are simple / difficult / feasible at all), a dream programmable stompbox would support

- an external expression pedal for one of the pots (implies or easier to implement with offboard pots?)
- some way of supporting tap tempo (for delays etc.)
- effects loop on the wet signal path (before [analogue?] wet/dry mixing), for creative uses (fe. this video of a delay pedal with reverb & tremolo on the wet signal https://www.youtube.com/watch?v=1Ts76xVi8c0 )
- the "slam" function in the video would be really cool also, if there's some meaningful way of feeding that into the FV-1 programs?

Some of the above might be much easier to handle some other way, if maybe the core design is extendable or leaves some parts offboard for a modular approach?

- Patrik

[stringsthings]

Any news on this?

[imaradiostar]

As a thought- make it stereo and integrate a teensy microcontroller as the means of controlling/programming the bugger via USB. Emulate the rom (or program it on the fly) on the teensy and allow it to select programs and drive a little OLED. Using the arduino IDE and Teensy would make it approachable for people to change how it's controlled and used. Oh yeah, and the teensy could control analog dry path/wet levels to allow the board to function in a multitude of ways.

I'm 100% on board for the above.

JT

[Ice-9]

As a thought- make it stereo and integrate a teensy microcontroller as the means of controlling/programming the bugger via USB. Emulate the rom (or program it on the fly) on the teensy and allow it to select programs and drive a little OLED. Using the arduino IDE and Teensy would make it approachable for people to change how it's controlled and used. Oh yeah, and the teensy could control analog dry path/wet levels to allow the board to function in a multitude of ways.

I'm 100% on board for the above.

JT

Probably not happening now with the new Experimental Noise DSP in the making. More likely to wait for the new DSP for a new project.

[SeanCostello]

Probably not happening now with the new Experimental Noise DSP in the making. More likely to wait for the new DSP for a new project.

What new Experimental Noise DSP are you talking about? Anything public about this?

[Ice-9]

Hi Sean ,

The chip isn't cast in gold yet and still may have changes, but form early indications 4in/4out with external 12S ADC/DAC 6 pots  plus switch controls interanl eeprom lots more , have a look at some of our questions over at Franks Experimatal Noize facebook pagein this thread https://www.facebook.com/ExperimentalNoize/?fref=nf
under visitor postd by Philip Hawthorne and myself. Quite exiting new tech.