opinions on what effect this is: square wave vibrato?

[crochambeau]

Could you guys give me some recommendations on what steps to include? So far I have:
-1 ocatve
-7 semitones
+7 semitones
+1 ocatve
+1 ocatve and 7 semitones

Also I have room for one additional parameter. Any suggestions ?

Are these fixed steps or ranges?

If they are fixed steps I would vote also for the bog standard musical 2nd, 3rd, 5th, and 6th (gotta have those tritones). I know this is birthed in a specific effect, but milder implementations would prove musical as well.

As for additional parameters, I don't know what limitations you are working with, so open sky dreaming:

Second pitch step
Alternating mode that flips direction of shift every other cycle
Envelope shape on pitch shift
Reversing the audio clip of the "dry" signal (sampled from last duty cycle) while simultaneously playing the pitched (real time pass)
Lag or slop generator that will (randomly) advance or delay the cycle rate more and more as the knob is turned up

[coldbrightsunlight]

^I like these.

Sequenced or random +1octave/+2octave pattern?

[Bartimaeus]

Sounds really cool!

+M2 and -m2 could both be really useful for subtle uses of the effect.

[Pete]

Sounds really cool!

+M2 and -m2 could both be really useful for subtle uses of the effect.

Was just thinking the same thing!

[Pladask]

Are these fixed steps or ranges?

As for additional parameters, I don't know what limitations you are working with, so open sky dreaming:

Second pitch step
Alternating mode that flips direction of shift every other cycle
Envelope shape on pitch shift
Reversing the audio clip of the "dry" signal (sampled from last duty cycle) while simultaneously playing the pitched (real time pass)
Lag or slop generator that will (randomly) advance or delay the cycle rate more and more as the knob is turned up

Fixed steps I think? Like you skip between the base pitch (unaltered) and a fixed amount of pitch shifting. I'm thinking something like 8 or 9 possible settings (positions) for the Pitch shift knob. Won't be able to add anything all too fancy on top of the Rate and Interval knobs. Think I'll try to add glissando.

I'm writing it for the SPIN platform so would be possible to run it on for instance your BitQuest.

[Pladask]

What does +/-M2 refer to?

[Gigahearts_FX]

get an Arcadiator, they do this sound

[zoooombiex]

If it's 9 pitch settings i'd vote for:

-1 octave
-M2
-m2
+m2
+M2
+5
+m7
+M7
+1 octave

And gliss would be a cool parameter. If it were possible, it'd be great to be able to adjust the sweep on the gliss. E.g., 0 on the sweep means no gliss, from 0 to halfway on the gliss controls the speed of the gliss (fast > slow), then from halfway to max the sweep would stay slow at the ends of the travel around the target pitch center, but speed up in the middle of the travel (so at max, it would be kind of a warp speed across the middle of the travel, but a slow arrival and destination from the target pitch).

[coldbrightsunlight]

What does +/-M2 refer to?

Major second (a tone) as opposed to m2 minor second (a semitone).

Not a particularly musically correct notation in this context because one could be playing any note in a scale and it would change it by a tone or a semitone!

It works as shorthand that fits on a pedal though

[D.o.S.]

fun fact: This thread triggered cbs to beyond the grave and back

[PeterBregman]

No one has mentioned the Thermae?

http://chaseblissaudio.com/product/thermae/

[D.o.S.]

The pedal that hadn't been announced when the dude asked the question?

Peculiar oversight indeed.

[Pladask]

So the result came out somewhat useful. I find that the effect is done too cleanly and end up sounding somewhat uncanny (not necessarily in a good way). Listening to the youtube clip I think the effect lends itself better to something like 8Bit audio than a guitar played through a relatively high resolution DSP. Anyway the code is included in the NSFW below. It features:
P0 : Pitch Shift Rate [0 to 10ish Hz]
P1 : Glissando Amount [Square wave <-> Triangle wave]
P2 : Pitch Interval [-12, -7, -5, 0, +7, +12, +19] , Could easily be extended/changed to include other intervals by anyone familiar with SpinASM

NSFW: show

; Pitch Tremolo effect for FORM2
mem pidel 4096 ; Pitch delay
mem temp 1 ; Temp location for partial calculations

equ jump reg0 ; Pitch shifting value
equ rate reg1 ; tremolo rate reg
equ square reg2 ; square wave 0 to 1
equ tria reg3 ; sinus wave 0 to 1
equ shape reg4 ; blended waveform
equ nRise reg6 ; -1 to 0 ramp


; Initialization ############## 2 inst

skp RUN, loop
wldr RMP0, 0, 4096 ; Ramp0 init
loop:

; Ramp Generator ############# 6 inst

or 5120 ; 20 Hz
mulx POT0 ; * rate ctrl
mulx POT0 ; square
rdax nRise, 1 ; add last counter
skp NEG, 1 ; if GEZ : reset
sof 0, -1 ; -1
wrax nRise, 0 ; store new counter value, clr

; Triangle Wave #################### inst

sof 0, -1 ; -1
rdax nRise, -2 ; -1 to 1
absa ; 1 to 0 to 1
wrax tria, 1 ; store, keep

sof 1, -0.5 ; 0.5 to -0.5 to 0.5
skp NEG, 2 ; if GEZ : make 1
sof 0, 0.999023 ; 1
skp GEZ, 1 ; uncond. skp
clr ; if NEG : make 0
wrax square, 0 ; store, clr

; POT1 Glissando ctrl ####################

ldax tria ; Read tria
rdax square, -1 ; add inverted square
mulx POT1 ; * crossmixer
rdax square, 1 ; add back square
wrax shape, 0 ; store, clr [Square <-> Tria]

; Pitch adjustment ############### 5 inst

ldax POT2
sof 1, -0.143 ; 0 to 1 - (1/7)
skp GEZ, next1 ; if GEZ : to go next
clr
or 2097152 ; 12
sof -1, 0 ; -12
skp NEG, setJump ; uncond skp

next1:
sof 1, -0.143 ; - (1/7)
skp GEZ, next2 ; if GEZ : to go next
clr
or 1394942 ; 7
sof -1, 0 ; -7
skp NEG, setJump ; uncond skp

next2:
sof 1, -0.143 ; -1/7
skp GEZ, next3 ; if GEZ : to go next
clr
or 1052126 ; 5
sof -1, 0 ; -5
skp NEG, setJump ; uncond

next3:
sof 1, -0.143 ; -1/7
skp GEZ, next4 ; if GEZ : to go next
clr ; 0
skp ZRO, setJump ; uncond

next4:
sof 1, -0.143 ; -1/7
skp GEZ, next5 ; if GEZ : to go next
clr
or 2090051 ; +7
skp GEZ, setJump ; uncond

next5:
sof 1, -0.143 ; -1/7
skp GEZ, next6 ; if GEZ : to go next
clr
or 4194304 ; +12
skp GEZ, setJump ; uncond

next6:
clr
or 8374407 ; +19
setJump:

wrax jump, 0 ; store, clr [-0.25 to 0.5]

; Write Pitch shift amount ###########

ldax jump ; waveshape
mulx shape ; * interval (amplitude)
wrax RMP0_RATE, 0 ; store new ramp1 rate, clr

; Audio Input ###################

ldax ADCL ;
wra pidel, 0 ; Write to pitch shift delay, clr

; Audio Output ##################

cho rda, RMP0, REG|COMPC, pidel
cho rda, RMP0,, pidel+1
wra temp, 0
cho rda, RMP0, RPTR2|COMPC, pidel
cho rda, RMP0, RPTR2, pidel+1
cho sof, RMP0, NA|COMPC, 0
cho rda, RMP0, NA, temp
wrax DACL, 0 ; Output, clr

[Bartimaeus]

Just had a chance to try this out, and it sounds awesome!!!

Haven't tried it with guitar yet, but I did give it a go with piano and rhodes sounds. Rhodes worked very well, while with piano it really only worked for sound effects.

The square/triangle knob was a really good idea, and gives a lot of different options. I really liked the square wave on fast settings when playing melodic lines, similar to the original post. However, on moderate speeds, something halfway between triangle and square gave a really cool synthy texture that could honestly serve as the backing for a track. You can just hold a couple of notes and the effect does the rest.


I had everything hooked up to try it out, so here's a tiny bit of audio showing how much it transformed a totally plain piano sound:

[coldbrightsunlight]

ha, brilliant!