Audio Effects DSP Board

[markseel]

The KickStarter project is live!  I could use your support - please pass this link on to other folks :-)

https://www.kickstarter.com/projects/689850781/flexfxtm-programmable-digital-audio-effects-platfo

[vigilante397]

I've been following this thread too long to not get behind this. I'm in

[markseel]

Ha!! Yeah it’s been going on for a long time!

[audioartillery]

I so far haven’t been able to find a photo of the guitar interface. Is it on the Kickstarter somewhere?

[cliffsp8]

Great news Mark!

I'm in.

Can't wait

Cliff

[markseel]

I added a photo of the guitar interface.  This board is stackable with the module - or you can not stack them and just wire them up. 

I do have a design for a board that includes three pots and two (in, out) jacks.  I could add that to the KickStarter if folks are interested.  But note that the FlexFX module has to be directly soldered to this 'pedal board' and would render your module forever integrated with the larger board unless you're able to desolder them.

Here's that 'pedal board' I could add ... Thoughts?

[Ice-9]

Great start Mark ,

I've just checked out the kickstarter page and it looks good, I have a Q regarding the video, On my PC there is no sound for this video, Does the video actually have sound ? if not I think it would improve the chance of success if there is some sound demo's as well.


Good Luck with this great project.

EDIT... Never Mind Mark, I found the other two videos that have audio, it was just the main video that is silent.

[vigilante397]

Here's that 'pedal board' I could add ... Thoughts?

YES.

[audioartillery]

I do have a design for a board that includes three pots and two (in, out) jacks.

3 pots is fine, a couple 2 or 3 position switches would be useful.  Oh, and a footswitch, obviously.  Is this designed around fitting in a particular enclosure?

I see two main use cases for all of this.  One is basically "developer kit" usage for prototyping effects.  For that I personally need/want a lot of pots and switches and I'm fine with a very large enclosure. 

Once I've got a good effect I probably want to do some low volume production (say, 20 units).  It would be nice if there were a unit that could fit in a fairly small enclosure and not cost very much.   Or, better yet, a turnkey solution with an enclosure and all the parts that I can assemble, flash with my effect, and paint.  Obviously that would be higher cost, but for low volume it would be nice to just get some effects shipped easily.

[markseel]

That board is dimensioned for the milled aluminum cases I'm using.

(1) I could either offer those cases for sale (they're not cheap) or ...

(2) I could make the board below to put inside a standard stomp box case where you'd wire up your pots, jacks, switches, and 9V supply yourself (board below needs a 9V to 5V converter still - easy to add).

Any preferences?

[markseel]

Not sure the KickStarter is going to make it - doesn't seem to be enough interest 

But anyway here's the collection of PCB designs related to FlexFX.  These analog boards can be stacked above or below the USB/DSP board.  Not sure where this is all going but I'll build the analog boards to test and then release the Gerbers.

From left to right ...

1) The FlexFX USB/DSP board.

2) Guitar interface using AK4621 differential in/out stereo CODEC.  Should be a very quiet interface.

3) 8x8 analog interface using four AK4556 24-bit CODECs.  4 layer board packed really tight.  So given layout compromises it will have modest performance compared to the AK4621 guitar interface.  But with 8 ins and 8 outs all with DC coupling (CODECs are configured to disable the HPF so that low frequency or DC signals can be sensed) this could be used for synth projects or effects where you want the parameter controls to used in real time.

4) Headphone amplifier with all DC coupling (AK4482 DAC outputs to headphone jack).  Four low noise buffers (two per differential DAC output) driving 2nd order RLC low pass filters (to filter out DAC sigma-delta conversion noise) and two dual high current OPA's (one AD8397 per channel for virtual ground, DC shift, and headphone driver).  SPICE shows 1dB flatness out to 170kHz, less then 6 degrees or phase shift at 20kHz, -70dB attenuation at 6.144 Mhz (frequency of sigma-delta), ~0.0003% THD at 10kHz, ~0.00003 at 1kHz, while driving a 32 ohm simulated headphone load at 1 Vrms (2.8 volts pk-pk).

[EBK]

Great start Mark ,

I've just checked out the kickstarter page and it looks good, I have a Q regarding the video, On my PC there is no sound for this video, Does the video actually have sound ? if not I think it would improve the chance of success if there is some sound demo's as well.


Good Luck with this great project.

EDIT... Never Mind Mark, I found the other two videos that have audio, it was just the main video that is silent.

Where are the videos with sound?

[vigilante397]

Not sure the KickStarter is going to make it - doesn't seem to be enough interest 

I was worried that might happen What are you going to do if it doesn't get funded? Would you be willing to do a small run of boards for the people that were interested?

[markseel]

The videos with sound are in the 'gallery' portion of the KickStarter.

Yeah if it doesn't get funded I'll build some for folks :-)  Maybe build like 10 or 20 by hand.  Sucks but if that's the only way to get these out to people then that's what I'll do!

BTW the pedal prototype was sent out to Pedal of the Day for review. It has one of these boards in it of course.  I've been tuning up some of the effects and they're really pretty nice - you can do sooo much DSP on one of these boards. 

Also, I'm working out a deal with Celestion to put some of their speaker/cab IR's inside the pedal.   Still some details to work out.

[Ice-9]

BTW the pedal prototype was sent out to Pedal of the Day for review. It has one of these boards in it of course.  I've been tuning up some of the effects and they're really pretty nice - you can do sooo much DSP on one of these boards. 

Also, I'm working out a deal with Celestion to put some of their speaker/cab IR's inside the pedal.   Still some details to work out.

Maybe worth mentioning this in the Kickstarter info to get more interest.

[orbitbot]

Haven't looked at this forum for ages as real life engagements have taken up all my time, and what do I find?

Kickstarter projects are not an immediate panacea, and I'd assume that a lot of people might want to see something more like a traditional advertisement video on the project pages and copy that is written more to drive home the unique selling points and benefits of owning rather than the faithful representation of what it can do. I hope the project has been posted to other websites as well to keep banging the drums, I first saw this in an Axoloti forum summary email a moment ago!

I believe there might be some analytics on Kickstarter as well to see who's actually looking at the page.

Mark, any way to set up something on Kickstarter where I could get one of the FlexFX modules and FlexFX+Guitar interface but pay shipping only once? Doesn't seem to be immediately possible though clicking at the project there...

[markseel]

Yeah my video pretty much sucks.  Sure I'll combine shipping

[Ice-9]

Hi Mark,
Still 15 days to go, I think it could be successful if you added a main video of yourself talking about what you are making, most successful kickstarters have a face to the video as that is what makes it interesting and if dare say, trusting to those who see it.

If I did not know better from reading the thread of the development of your project, the video you have as the main intro just does nothing to make me understand what exactly the FlexFX does which is what others will see if they don't have any introduction to the boards you are making other than seeing the Kickstarter.

Please don't think I'm being mean with my comments above, I do think your project is amazing and given the correct push would succeed in the way it deserves. It really is all about presentation and constant updates on kickstarter to keep interest up. You have to be a salesman so to speak.

[markseel]

Thanks for the feedback - and do I appreciate the comments :-)  Just not sure if I can get to that video re-do or not.  And there really doesn't seem to be high demand for this board anyway.  I'll find a way to make enough for who's shown interest.  Maybe after other folks work with them and make stuff the word will get out.  And if not then it shows that the appeal of this just isn't as broad as I thought it was.  Not a total loss - I use them for my effects.

[audioartillery]

I think there's a fair amount of demand, but honestly the DIY DSP effect crowd isn't very cohesive. 

The old Line6 SDK kit gathered something close to critical mass at the Line6 forums back in the day.  It was greatly hampered by the platform though -- not too many people are brave enough to learn 56k assembly just to write a guitar effect.

The kickstarter wasn't approachable enough.  If I didn't already know who you are and what you're making I wouldn't have really been able to tell if it was something I wanted.  And lower-end users (people who are just starting out) need a picture of the whole kit buttoned up and working in a box.  I'm also a little fuzzy on exit strategy... if I come up with an effect I think I can sell, what's the next step?  Is there some volume pricing that can get me at least down to boutique pedal pricing?

Is there enough interest in this forum to justify doing a run of boards and just selling them on Tindie like BlackAddr is doing?