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Octave up and down
Posted: Fri Mar 27, 2009 2:30 am
by jovesdies
Hi,
is it possible to obtain an octave up and down pedal ?
E.G. Pot0 = clean signal, pot1 = octave down, pot2 = octave up
like an electro harmonix micro pog.
Regards.
Posted: Fri Mar 27, 2009 9:09 am
by frank
Sure, just program it. There is enough delay memory in the FV-1 to do both at the same time.
Posted: Thu Apr 09, 2009 2:26 pm
by clarky2003
oh! i'm really interested by this topic!
I'm waiting for the program
Posted: Sat Apr 11, 2009 11:34 am
by frank
Not in the office right now so can't write/test code but look at the last examples in
http://www.spinsemi.com/Products/appnot ... N-0001.pdf where is shows how to do pitch shifting.
Posted: Wed Jul 22, 2009 11:08 pm
by jovesdies
Any news about up-down program?
Posted: Thu Jul 23, 2009 9:24 am
by frank
Sorry, forgot all about this thread... give this a try:
Code: Select all
delayd mem 4096 ; Down delay
temp mem 1 ; Temp location for partial calculations
;
skp run,START
;
wldr RMP0,16384,4096
wldr RMP1,-8192,4096
;
START: ldax ADCL
; Write it to left delay and clear ACC
wra delayd,0
; Read in left
ldax ADCL
;
wra delayd,0
;
cho rda,RMP0,REG|COMPC,delayd
cho rda,RMP0,,delayd+1
wra temp,0
cho rda,RMP0,RPTR2|COMPC,delayd
cho rda,RMP0,RPTR2,delayd+1
cho sof,RMP0,NA|COMPC,0
cho rda,RMP0,NA,temp
mulx POT1
wrax REG0,0
;
cho rda,RMP1,REG|COMPC,delayd
cho rda,RMP1,,delayd+1
wra temp,0
cho rda,RMP1,RPTR2|COMPC,delayd
cho rda,RMP1,RPTR2,delayd+1
cho sof,RMP1,NA|COMPC,0
cho rda,RMP1,NA,temp
MULX POT2
wrax REG1,0
;
ldax ADCL
mulx POT0
rdax REG0,1.0
rdax REG1,1.0
wrax DACL,1.0
wrax DACR,0
Posted: Fri Jul 24, 2009 6:04 am
by jovesdies
Great program Frank !!
Thanks for all.
You're number 1
Posted: Thu Aug 06, 2009 7:02 am
by jovesdies
Hi !
Is it possible to split the octave down sound only on the left output and the upper octave only on the right output ?
Thanks.
Posted: Thu Aug 06, 2009 9:04 am
by frank
Yes it is, just change the code at the end to mix dry and write to the desired DAC
Posted: Thu Oct 15, 2009 5:52 am
by Sweetalk
Is it possible to do 2 octaves up or down only?, not both at the same time.
Posted: Thu Oct 15, 2009 12:06 pm
by frank
Sweetalk wrote:Is it possible to do 2 octaves up or down only?, not both at the same time.
Up: Not possible, the max up is just over 1.5 octaves. Well, technically you could by doing it twice in series but it would sound terrible.
Down: Yes, in theory can do infinite down to the point that all frequencies are 0
Posted: Thu Oct 15, 2009 12:20 pm
by Sweetalk
frank wrote:Sweetalk wrote:Is it possible to do 2 octaves up or down only?, not both at the same time.
Up: Not possible, the max up is just over 1.5 octaves. Well, technically you could by doing it twice in series but it would sound terrible.
Down: Yes, in theory can do infinite down to the point that all frequencies are 0
I figured out that the up capability was limited up to 1,5 octaves and down not. Really putting them in series will be that terrible? and If you do that externally?
I've been testing the Pitch program that came with the chip, I noticed some kind of tremolo effect in the shifted signal. Is that normal?, there is a way to get rid of this? sounds so nice that it's a shame this little thing.
Posted: Thu Oct 15, 2009 1:28 pm
by frank
Yeah, the effect you are hearing is an artifact of real time pitch shifting, while settings can change how it sounds it will always be there. It will also depend on the source material as to how much you will notice it.
You could do the 2x in the chip rather than externally, probably better then you don't go through the ADC and DAC a second time.
Posted: Thu Oct 15, 2009 2:31 pm
by Sweetalk
There is a way to make it less noticeable?. While it's mixed with the dry signal it's fine, but alone it's very noticeable.
Posted: Thu Oct 15, 2009 2:53 pm
by frank
You could try a shorter delay line (don't recall how long the one in the built in program is) and that might help but it could cause low frequencies to not shift. But the artifact will always be there.