Author Topic: Octave Distortion Build.  (Read 2242 times)

Mark Hammer

Re: Octave Distortion Build.
« Reply #20 on: January 27, 2021, 06:12:33 PM »
Can one tell the two channels of an FV-1 to do something different from the other?  I was unaware of this.

iainpunk

Re: Octave Distortion Build.
« Reply #21 on: January 27, 2021, 06:21:37 PM »
GuyCorbin2001; sorry for derailing the thread

totally forgot to mention its not a guitar solo, its on an electric kalimba!

is there a pedal that just does that plasticky quality without the pitch shift?
for a song we recorded but never published, i put my pitch fork through a band mate's whammy, one oct up and one oct down, just to get that 'broken/fake' feel, that was the worst solo ever recorded tho, i used 100% WET reverb before a super fuzz and in to both the pitch shifters. i'd like to recreate that sound with less pedal board real-estate...

That ought to be possible on an FV-1. You could use the left input/left out for one octave up, and the right side for one octave down, and then feed one into the other! Hey Presto! Hideously munged frankensignal bearing only a passing resemblance to a guitar!

i didn't know the VF-1 can do different things left and right?!?!
i just found a solution, the pitchfork has a thicc chorus setting, which is 17ct up or down, this is quite small, and with full wet mix, sounds quite fake/plastic.
still, i might want to get a VF-1 chip for that effect, since i don't want to change pedal settings during or between songs.

.... that was the worst solo ever recorded tho,
That sounds like a challenge to me!
i'll ask my drummer if his brother (the studio's owner) still has those files, if not, i might re-record the 'solo' directly in to my laptop's mic input jack, its a cool noise-scape, a wash of distorted noise going up and down a double-harmonic minor scale in A.

cheers, Iain

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #22 on: January 27, 2021, 07:58:06 PM »
Hi all, the octave effect I was looking for was just to be as realistic as possible and just as close to the original sound just an octave, preferably with polyphony potential.
Looking more and more likely that Iíll just have to buy a Digitech Drop and then Frankenstein it into the Rangemaster -> Rat Circuit, that will also give me the variety of pitch shifting capabilities.

iainpunk

Re: Octave Distortion Build.
« Reply #23 on: January 27, 2021, 09:01:48 PM »
why do you want it to be realistic? have you heard how the ''octave'' sounds on its own in the original unit? absolutely not realistic. that's also not the point of the octave generation, its to create the texture its associated with, like an ampeg scrambler (the stoges - i wanne be your dog intro and solo), super fuzz (Electric Wizard and Mud Honey) or Rodger Mayer Octavia (made famous by Hendrix)

the octave down is maybe better used clean, Parallel mixed with the distortion, instead of having a distorted bass sound!

cheers, Iain

Digital Larry

Re: Octave Distortion Build.
« Reply #24 on: January 28, 2021, 09:09:14 AM »
Can one tell the two channels of an FV-1 to do something different from the other?  I was unaware of this.
The FV-1 has two audio gozintaz.  They are called ADCL and ADCR.
The FV-1 has two audio gozouttaz.  They are called DACL and DACR.
These are treated exactly like the 32 internal registers of the FV-1 as far as reading, writing, and arithmetic.

C'est magnifique, non?

You use the ones you want to use.  When you get to the point in your code where you have the value you want to write to the left output in the accumulator, you perform:

WRAX DACL, 0

(typically).  If you wish to write the same value to both left and right and be mono, then:

WRAX DACL, 1
WRAX DACR, 0


Now there are some extra LPF anti-aliasing filtering considerations to be given if you run one out one channel digital back to the other channel analog because of Sigma-Delta conversion or some other fraternity.   Best to contact Frank at Experimental Noize (official FV-1 design support) for advice.

That ought to be possible on an FV-1. You could use the left input/left out for one octave up, and the right side for one octave down, and then feed one into the other! Hey Presto! Hideously munged frankensignal bearing only a passing resemblance to a guitar!

Unless you separately needed the intermediate signal you do not need to have it leave the chip only to come back in the other side.  A pitch shift IIRC is about 8 instructions including setup.  A pitch shift does use up a RAMP LFO so that's why you can only do two of them at once.

I apologize to any non native English speakers for this post.
« Last Edit: January 28, 2021, 09:57:53 AM by Digital Larry »

Mark Hammer

Re: Octave Distortion Build.
« Reply #25 on: January 28, 2021, 12:25:57 PM »
But the upshot is that this is not a characteristic one can employ with any of the simple projects using the default programs in the chip.  Rather it's something accessible via programming the chip.

For the moment, well above my pay-grade.

ElectricDruid

Re: Octave Distortion Build.
« Reply #26 on: January 28, 2021, 02:21:45 PM »
That ought to be possible on an FV-1. You could use the left input/left out for one octave up, and the right side for one octave down, and then feed one into the other! Hey Presto! Hideously munged frankensignal bearing only a passing resemblance to a guitar!

Unless you separately needed the intermediate signal you do not need to have it leave the chip only to come back in the other side.  A pitch shift IIRC is about 8 instructions including setup.  A pitch shift does use up a RAMP LFO so that's why you can only do two of them at once.

Ah, yes, of course! Makes no sense to go "outside" and then back "inside". And as you mentioned, doing both bits of processing inside the box will avoid any problems with aliasing or HF digital noise on the output going back into the ADC, without the need to stick a LP filter in between. Much more sensible. Thanks Larry.

Ok, sorry. Thread hijack done.
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craftyjam

Re: Octave Distortion Build.
« Reply #27 on: January 28, 2021, 07:40:24 PM »

11-90-an

Re: Octave Distortion Build.
« Reply #28 on: January 28, 2021, 08:54:14 PM »
https://www.parasitstudio.se/building-blog/cmos-workshop-part-3-octave-down

This is one way without any programming.

(just a note,) This is still monophonic, though...

I love the CMOS Workshop articles!

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #29 on: February 01, 2021, 04:24:35 AM »
https://www.musikding.de/The-Range-Germanium-Treblebooster-kit
https://buildyourownclone.com/products/mouse
I also have a Micro POG which I can use for the octave, do you think this would be doable?
can I run these all of a isolated 9v outlet simultaneously, if so how would I go about this?
do you guys have any recommendations for enclosures (in UK or EU preferably due to the deadline.)

Chillums

Re: Octave Distortion Build.
« Reply #30 on: February 01, 2021, 07:49:45 AM »
There is a cool octave down in this that I have breadboarded before and got to work pretty well with some minor tweaking. 
https://www.google.com/url?sa=t&source=web&rct=j&url=http://electro-music.com/forum/phpbb-files/synthax_100_219.pdf&ved=2ahUKEwiR3dv-28juAhUCO60KHRKpAewQFjAAegQIARAB&usg=AOvVaw3dAi3qX6qSglRXTqsazg_n
Cheers!!

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #31 on: February 01, 2021, 09:09:42 AM »
For the Octave I have decided to use the Micro POG, it's not my favourite but it will definitely do the job, I'll do a little research on Rangemaster and RAT kits to see what my options are, feel free to let me know which kits you recommend, I'll update this thread as I find various options and as troubleshooting arises.

iainpunk

Re: Octave Distortion Build.
« Reply #32 on: February 01, 2021, 09:27:15 AM »
i recommend getting some pref-board and do them on those, they are both simple circuits with few parts, so using perf board isn't hard at all here.

a good opamp for the RAT is the LM358, it has the same slew rate as the original LM308, that is in the original pedals, but are quite expensive.
the LM358 is a dual opamp, so you can also use it for the buffer, instead of the original transistor, saving both a few cents and PCB space.

cheers, Iain

Marcos - Munky

Re: Octave Distortion Build.
« Reply #33 on: February 01, 2021, 10:44:33 AM »
I just like to point out this one again:
any advice for a beginner in general?
Yes.  Start simple.

Polyphonic octaves used to be out of DIY reality some time ago, unless you use a hexaphonic pickup with one octaver per string, and that probably won't even sound good. Now it is more affordable with the FV-1. Will it sound awesome? Maybe. Will it require a complex circuit to make it sound as good as possible? Sure. Is it a beginner project? Probably not.

If you're gonna use a pedal just to take it apart and put it inside another box, it makes more sense to just use it as another extra stompbox or to fully remove it from your project. You already have plenty of stuff to cover with "just" the rangemaster and the rat, like how to pick a transistor and properly bias it for the rangemaster, the reason of the ic you chose for the rat, diode clippers, hard clip vs soft clip, circuit troubleshooting... and, if you want to make your own boards (which isn't a hard deal for those projects even for a complete beginner), you can also include perfboard vs veroboard vs pcb, pcb tone transfer and etching (if you use pcb), layout drawing, and even more. And 12 weeks may be a good deadline or a very short one, it depends on the skills/knowledge you already have, what you still need to learn, and you'll need time to build it, troubleshoot it if needed, and do the paperwork.

Imo, if you pick just one of those circuits, build it all by yourself and document it very well, you'll end with a very good project and way simpler than your first idea. Kits will surely make it easier, but making the board by yourself may add a few satisfaction points when you finish it. Or may add a bit angry points if the board doesn't work :icon_lol:

A nice document on the rangemaster:
http://www.geofex.com/article_folders/rangemaster/atboost.pdf
A nice document on the rat:
https://www.electrosmash.com/proco-rat
« Last Edit: February 01, 2021, 10:48:15 AM by Marcos - Munky »

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #34 on: February 01, 2021, 11:01:12 AM »
I ended up by a few kits to experiment with as well as some tools (soldering iron, wire strippers, helping hands, breadboard material, cutting pad.)
I ended up getting a Rangemaster and Rat Kit from Effect Pedal Kits, also bought a Sunn model T pedal kit from FuzzDog just to play around with.

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #35 on: February 06, 2021, 03:32:54 PM »
Hi Yall, got all my equipment and the Sunn Kit, made a start on it this evening, this is my first time soldering to a PCB other than some breadboard practice beforehand, by no means done and still needs another evening of work and then testing before I can give it the green light.










Marcos - Munky

Re: Octave Distortion Build.
« Reply #36 on: February 08, 2021, 09:31:09 AM »
Looking good so far. I think it's better to test the circuit before you add the switch board. So, if it doesn't work, you know the issue is on the main board and not on the switch.

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #37 on: February 08, 2021, 11:13:21 AM »
Whatís the best way to go about that?
Also does the footswitch need to be installed in any particular orientation or does it not matter.

11-90-an

Re: Octave Distortion Build.
« Reply #38 on: February 08, 2021, 07:57:10 PM »
Also does the footswitch need to be installed in any particular orientation or does it not matter.

Nope, it doesn't matter...

Unless you're using a 3pdt, there may be chances one might install it sideways accidentally and the effect won't work...

GuyCorbin2001

Re: Octave Distortion Build.
« Reply #39 on: February 09, 2021, 05:56:11 AM »
http://pedalparts.co.uk/docs/OptoPuss.pdf
This is the Footswitch and Daughterboard for this test run.