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[Ryan]

Austin, you helped me learn a lot with that trem code you posted, it's a clear example of using registers to hold the info that you want to affect the audio signal.. masterclass, buddy! *smile*

I don't find this confusion stressful, I think it's fun and cool and I want to pay my dues with code anyway... the deep confusion will one day lead to deep understanding. Hopefully.

Plus it's comforting knowing that Frank would give a push if asked, set one on the right track. Killer support.

[aziltz]

Ryan, I got those FV-1 boards in I was telling you about. I'd be happy to send a few your way if you want to PM or share your shipping address.

[Forrrest]

this can only bring good things.

Thanks Kev! I'm going for it! Love that new avatar pic, what's that from?

Star Trek TNG S04E17: Deanna Troi flying in a dream

[Ryan]

Thanks Austin, PM incoming!

Kev, that's a friggin cool avatar pic.. and TNG will always be my favourite Star Trek, I watched it every week when it aired, loved it.

This week I got a code push from Frank and was able to finish my bitcrusher patch.. I'm gonna put up a skeleton version of it here with 4 different bit depths, just in case anybody reading this thread is into the programming like Austin and I.

This program goes through 4 different bitmask settings and you should experiment with them, there's more than one way to crush the bits, I like this way though, especially at the lowest settings, I love the weird sweep it gives when you palm mute and hold it. (sorry the formatting went funny, it's nice and straight in the assembler!)

NSFW: show

Code: Select all

;Bitcrusher with variable bit depth: POT1 = Bit Depth


;equate registers

equ   positive      reg0
equ   negative      reg1
equ   crushedpos   reg2
equ   crushedneg   reg3

;bitmask values

equ    crush1    %1111_1111_1111_1111_1111_11   ;define the bit mask = 22bit, DEPTH1
equ   crush2   %1111_1111_1111_1111_1111   ;define the bit mask = 20bit, DEPTH2
equ   crush3   %1111_1111_1111_1111_11   ;define the bit mask = 18bit, DEPTH3
equ   crush4   %1111_1111_1111_1111      ;define the bit mask = 16bit, DEPTH4


;read adc, save positive and negative samples to separate registers

clr                  ;clear the acc
rdax   adcl,1               ;read in left adc
skp   neg,1               ;skip next instruction if negative
wrax   positive,0            ;write positive samples to 'positive' register for crushing
wrax   negative,0            ;write negative samples to 'negative' register for crushing

;prepare POT1 for Bit Depth control

clr                  ;clear the acc
rdax   POT1,1               ;read in POT1
skp   zro,DEPTH1            ;if zero skip to DEPTH1
sof   1,-0.333               ;subtract a value, adjust for even spacing through rotation
skp   neg,DEPTH2            ;if neg skip to DEPTH2
sof   1,-0.333               ;subtract a value
skp   neg,DEPTH3            ;if neg skip to DEPTH3
sof   0,0               ;force to zero
skp   zro,DEPTH4            ;if zero skip to DEPTH4



;crush and save the positive samples, invert and crush and invert and save the negative samples

DEPTH1:                  ;first bit depth = 22bit
clr                  ;clear the acc
rdax   positive,1            ;read in 'positive' register
and   crush1               ;and with crush1
wrax   crushedpos,0            ;write to 'crushedpos' register and zero the acc
rdax   negative,1            ;read in 'negative' register
sof   -1,0               ;invert the sample
and   crush1               ;and with crush1
sof   -1,0               ;invert it back
wrax   crushedneg,0            ;write to 'crushedneg' register and zero the acc
skp   zro,OUTPUT            ;skip to OUTPUT

DEPTH2:                  ;second bit depth = 20bit
clr
rdax   positive,1
and   crush2
wrax   crushedpos,0
rdax   negative,1
sof   -1,0
and   crush2
sof   -1,0
wrax   crushedneg,0
skp   zro,OUTPUT

DEPTH3:                  ;third bit depth = 18bit
clr
rdax   positive,1
and   crush3   
wrax   crushedpos,0
rdax   negative,1
sof   -1,0
and   crush3
sof   -1,0
wrax   crushedneg,0
skp   zro,OUTPUT   

DEPTH4:                  ;fourth bit depth = 16bit
clr
rdax   positive,1
and   crush4
wrax   crushedpos,0
rdax   negative,1
sof   -1,0
and   crush4
sof   -1,0
wrax   crushedneg,0
skp   zro,OUTPUT         

;prepare crushed signal for output to dac

OUTPUT:
rdax   crushedpos,1            ;read in 'crushedpos' register
rdax   crushedneg,1            ;read in 'crushedneg' register
wrax    dacl,0               ;write output to left dac

I set up my bitcrusher patch with 1 pot for gain, 1 pot for bitcrushing through 6 masks, and the third pot controls Frank's aliaser... sounds awesome.

I'm thinking the patches will go like this, each with 3 digital controls used in combination with the analog mix, volume, treble:

1 - Digital Tube Screamer - low to medium gain, filters set at the TS hump of 720Hz, controls for gain, midrange, maybe gate. still working on it
2 - High gain - medium to high gain, controls for gain, filter, gate
3 - Very high gain - high to higher gain, controls for gain, filter, gate
4 - Bitcrusher with sample rate reduction - controls for gain, bitcrush depth, sample rate
5 - Distortion with delay - highish gain with simple delay, controls for gain, delay rate, feedback or delay level, still working on it
6 - Distortion with reverb - highish gain with long reverb, controls for gain, reverb decay, reverb level
7 - PItchshifter with gain - one octave up/down pitch shift, controls for gain, pitch, gate
8 - still pondering

I was thinking a couple other things.. one thing.. all the patches that have an effect combined with them will be able to be used with 0 gain. When you turn the gain knob all the way down it goes to your dry signal level, no gain at all, and you can use the mid boost, mid filter, sample rate reduction, delay, reverb, and pitch shift all clean. Cool hey!

Other thing.. I'm thinking I'm just going to do the memory chip as an 8DIP rather than a smd chip like most guys are doing. I'm thinking that over time, I'm going to make new patches and tweak and perfect the old patches and if the memory chip was in a socket I could just send people new ones. Say in a year I make a new patch for this pedal, if a person was interested in it (and losing one old patch) I could pop a new memory chip in the mail to them and they could update their pedal.

Now I just need a cool name... I keep thinking stuff like the D'n'D (Digitals and Distortions) or the Distortion Adventurer or the Binary Brute... I don't know yet.

[goroth]

Sounds great Ryan!

Name: maybe something to do with Fermi's paradox. Thinking about that can keep you up at night.

[Tristan]

Wow, that sounds really cool!
For the last patch maybe some heavy filtered distortion or sample rate reduction / bit crushing (if you haven't already covered that with patch 2, 3 and 4).
Any plans for an expression input (would be sick)?

[goroth]

Patch 8: PWM?

[Ryan]

Interesting name idea for sure, Greigy, very cool, I love that kind of stuff!

PWM is an awesome idea too... sooo.. er uh, do you know how to do that? Haha I have no idea how to implement that in code... so far all my patches are things I can understand and work with from previous examples.... so please think of easier things, ideally ones with examples in the source material. *big smile*

Tristan, I do have a mix expression control for it... I think my favourite sound so far with this pedal is mixing nice clean guitar with sample rate reduced bit crushed guitar, sounds great to my earballs. I've pondered making one of the control pots be foot controllable as well since they're B50k pots but I'm completely out of enclosure room for two... maybe I could make the choice switchable but I'd have to throw so many signals to pull it off I think I'd need a massive toggle with 6 throws, probably doesn't even exist.. so it'll be a battle between mix or a control pot, I'm not sure yet...

[Bartimaeus]

What about higher gain with a sort of fast-ish reverse delay? Then one could kill the dry signal and play like weird reverse riffing and things.

[Ryan]

Love it, Bart.. not smart enough to do it but love it! I've read from the designer/distributor that it isn't designed/intended to do reverse and I don't know how to design code past what the original guy knows, I'm a complete noob.

[Forrrest]

maybe just throw a musical demo into patch 8. stomp on the pedal and the Dr.Scientist theme song plays!

[goroth]

maybe just throw a musical demo into patch 8. stomp on the pedal and the Dr.Scientist theme song plays!

+1

Or a loop of you and Tanya re-enacting a scene from Dr Who. The controls can alter the playback speed and direction (and of course indirectly the pitch). If done correctly I'm pretty sure you could use it to redo the intro from Hell Awaits.

[youtube]http://www.youtube.com/watch?v=yew9L0Xjm_g[/youtube]

I really do like the idea of patch 8 being a non sequitur.

Another patch 8 idea, which totally doesn't gel with the above notions (and is clearly an inferior idea) is perhaps having some LFO controlled aspect of the distortion. Like a filter that gets swept by an LFO, or maybe a some odd function, like a flange with depth at zero so you get that filter matrixy sound. Then sweep the manual, so you get metal klonk klonks with your distortion.

Or make it a wah patch hahaha.

New pedal name: Ryanoceros.

[skullservant]

Wow, didn't check this thread for a while, looks like stuff is coming along, that sounds INCREDIBLE!!

[Ryan]

Haha patch 8 being a theme tune is hilarious!

I like the idea of using an LFO for patch 8, something modulated or auto-sweeping, that's a great suggestion as the pedal is missing something fun in that style. I really want this to be like a distortion adventure, each click of the rotary switch bringing a new fun sound to play with. Plus I want the first 3 patches to just be cool sounding distortion patches. So 3 distortion patches and 5 adventure patches.

[Bartimaeus]

The theme song idea actually sounds really cool! Put the pedal first in chain and mess with loopers and pitch shifters :O

Another crazy impossible idea, riffing on the LFO idea: Make the patch itself higher gain distortion. First knob changes the LFO depth, second the LFO speed, third knob(this is key) changes what LFO modulates. Have a set of value ranges each refer to different oscillation destinations. First quarter of the pot modulates the gain amount, second quarter puts the LFO in front, working as a tremolo, third modulates gain and volume and tone all at once.