FV-1 projects?

[Rodgre]

I have to admit that I'm completely clueless when it comes to DSP circuits, but Small Bear's post about having FV-1 chips available has my interest piqued.

I'll snoop around, but if anyone has any direct links to information on what would go into making a simple FV-1 based effect (super-tremolo/vibrato?) to build into a stompbox?

Roger

[MetalGuy]

Spinsemi have couple of projects along with some free programs on their web page. IMHO using this chip only as a single effect is a shame.
I'm in process of drawing a non-SMD  PCB and when I'm ready I'll let you know.

[Rodgre]

Thanks for the reply.

You're right that it would be a shame to only use it for simple/single projects.

I rarely even venture into the digital/dsp section of this forum, and I've been building pedals for over 20 years!

I've always been curious about EPROM-based circuits and DSP-based effects that could do things impossible or at least difficult with analog circuitry. I've just never looked into it. Time to start looking!

Roger

[SeanCostello]

I am very very interested in a circuit board design for this chip, if anyone is still working on this. Ideally, it would have space for an EEPROM, as I am writing my own algorithms.

Sean Costello

[MetalGuy]

We're working on it but it will be a fully programmable /parameters adjustable/ design ready to be built in into a guitar amp. Of course there will be an EPROM.
The more simple one layer PCB project is not canceled but I still don't have time to finish it.

[SeanCostello]

When you say "fully programmable," do you mean that you will use the 3 pot inputs as part of the design? Or wil these be controlled by a uC?

I am wondering what the DV-1 will be. Even if it is a FV-1 with the ability to load program code on the fly, it will be useful, as massaging the pot values to create usable parameters takes up a fair number of cycles, and the operations that use the derived pot values are more expensive than if you have the coefficients as constants in the code.  For example, I think you can create a low shelving filter in 2 cycles, but if you want to control this from a pot, it takes 5 cycles.  Having the ability to load program code would also allow for random values to be generated from a uC, and sent to registers or code locations in the chip, which would be useful for a bunch of things.

Sean Costello

[MetalGuy]

When you say "fully programmable," do you mean that you will use the 3 pot inputs as part of the design? Or wil these be controlled by a uC?

It will be controlled by a PIC and will use the pots inputs to create your own 100 presets and to memorize them. Its based around those free programs that allow full control of effect's parameters and several combined with reverb - that's what I need. There will be 4 selectable inputs enabling you to connect it to a 4 channel amp/preamp where you'll be able to memorize presets for each channel. One set of presets for all the channels is a program, so if you're playing the song A you dial into program 1 for example and it will load the presets for all channels. If you're playing song B you go to program 2 etc.
The other purpose of this project will be to be used in one of my future all tube programmable preamp projects.
This is what I have in mind for this project right now but if you have any other ideas I'll be glad to hear them as well.

[SeanCostello]

I am just looking for a simple stompbox circuit that uses the FV-1, with added pots for input/output mix, an analog tone control, and op amp buffers for the input. A one-layer PCB project would be perfect.

Sean Costello

[MetalGuy]

I am just looking for a simple stompbox circuit that uses the FV-1, with added pots for input/output mix, an analog tone control, and op amp buffers for the input. A one-layer PCB project would be perfect.

That's the other one I'm working on. It will include In/Out buffers, Mix and Level control. It will use the pot inputs as well. I got the encoders already so there's nothing on the way except the lack of time.

[Fp-www.Tonepad.com]

http://www.tonepad.com/project.asp?id=68

comments welcome.
Fp

[TELEFUNKON]

http://www.tonepad.com/project.asp?id=68

comments welcome.
Fp

not much copper on that pcb.

[Fp-www.Tonepad.com]

yeah, the layout required thinner traces than i normally use, but it should still be doable in pnp blue.

[puretube]

http://www.tonepad.com/project.asp?id=68

comments welcome.
Fp

not much copper on that pcb.

Groundplane/noise issues?

[Fp-www.Tonepad.com]

I tried to route all the grounds and power supply traces and provide filtering so that ground planes are not needed (in a stompbox environment anyways), my intention was to apply some well known tricks from tube amp layouts/wiring to the power/ground traces that have already solved  a few noise issues before.

[puretube]

The Spin is no tube amp,



but an A/D hybrid...



the eval-board pix show the groundplane on the flipside...

[Fp-www.Tonepad.com]

The eval board is meant to be operated outside an enclosure, i think part of the reason for that ground plane is shielding (like behringer pedals in plastic enclosures use one side of pcb as shield-ish), using a metal enclosure like all decent pedals should would take care of that, ground current isolation to avoid noise (crosstalk and the like) are handled in this case by the trace routing, which is what i meant when i talked about to tubeamps, where ground planes are not available to prevent noise, so smarter ground (and overall cables) routing.

[puretube]

Well, maybe page 6 should not be taken too seriously for DIY devices...

[Fp-www.Tonepad.com]

That's what I'm talking about!

[hgamal]

On tonepad Fraverb projet the voltage regulator specification is missing.
Does anybody know which regulator is that?
I was planning to use LM 3940IT, but its input voltage is up to 7.5 Volts.
Any suggestions?

[Fp-www.Tonepad.com]

LM78L33

LM7833

Fp