Author Topic: Octave down schematic.  (Read 28142 times)

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fuzzo

Octave down schematic.
« on: June 08, 2009, 07:27:33 AM »
Hi,

I'm looking for an Octave down schematic , but a "clean octave down" like the Boss OC2 does (yes I saw the scheamtic in the layouts gallery) instead of Slacktave MK2 schematic (that produce more a synth octave down)

Thanks.

oldrocker

Re: Octave down schematic.
« Reply #1 on: June 08, 2009, 10:45:07 AM »
DIY analog octave down circuits are generally not clean. There will be a fuzzy distortion along with the octave down effect which is the nature of the beast.  My favorite analog octave down is the MXR Blue Box that I built about 4 months ago.  I modified it to have a 1 and 2 octave down selection.  If you want clean you need to go digital which I believe may be beyond the scope for DIYer's.

Taylor

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Re: Octave down schematic.
« Reply #2 on: June 08, 2009, 05:32:04 PM »
Hi,

I'm looking for an Octave down schematic , but a "clean octave down" like the Boss OC2 does (yes I saw the scheamtic in the layouts gallery)

So you're looking for a schematic for something like the OC-2, and you've seen the schematic for the OC-2...? Is my brain dissolving slowly?

El Heisenberg

Re: Octave down schematic.
« Reply #3 on: June 08, 2009, 06:06:23 PM »
Lol. Yea dude, if you want hommes, sound just get the boss.

Shocktave is a good one.

Why are people so meam on this forum?
"Your meth is good, Jesse. As good as mine."

El Heisenberg

Re: Octave down schematic.
« Reply #4 on: June 08, 2009, 06:07:51 PM »
I did read a thread here where people were trying to emulate the pog with analog stuff. Like a green ringer mixable into a shocktave. Wutever happened with those guys?
"Your meth is good, Jesse. As good as mine."

Br4d13y

Re: Octave down schematic.
« Reply #5 on: June 08, 2009, 06:11:08 PM »
the picture of his project is in the gallery.

i actually wanted to do that, but was then pleasently suprised that i could buy a pog,  so i did,                                     my life is forever changed
freedom is the freedom to say 2+2=4

El Heisenberg

Re: Octave down schematic.
« Reply #6 on: June 08, 2009, 06:20:36 PM »
the picture of his project is in the gallery.

i actually wanted to do that, but was then pleasently suprised that i could buy a pog,  so i did,                                     my life is forever changed

What project?
"Your meth is good, Jesse. As good as mine."

Taylor

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Re: Octave down schematic.
« Reply #7 on: June 08, 2009, 06:21:49 PM »
Why are people so mean on this forum?

I think that's what you were going for here.

I really didn't intend to be mean, I just don't get what the question is. He's looking for an analog octave schematic like the OC-2. He's seen the OC-2 schematic. I can't figure out what he could be looking for that he doesn't already have.

FWIW, with perhaps myself excluded, I think the people on this forum are way cooler and more helpful than any other forum I've ever seen.

Taylor

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Re: Octave down schematic.
« Reply #8 on: June 08, 2009, 06:22:46 PM »
the picture of his project is in the gallery.

i actually wanted to do that, but was then pleasently suprised that i could buy a pog,  so i did,                                     my life is forever changed

What project?

I did read a thread here where people were trying to emulate the pog with analog stuff. Like a green ringer mixable into a shocktave. Wutever happened with those guys?

El Heisenberg

Re: Octave down schematic.
« Reply #9 on: June 08, 2009, 09:02:59 PM »
Could you please point it out to me? I dunno which album. I might find it tonite, but just in case.
"Your meth is good, Jesse. As good as mine."

fuzzo

Re: Octave down schematic.
« Reply #10 on: June 09, 2009, 02:42:49 AM »
Hi

To answer to El Heisenberg, I saw the OC2 schematic but it's maybe, too complexe although I understand how it works. Beside I'm gonna buy one.  I'm looking for something simpler and easier to build. The OC2 isn't complicated but needs a lot of attention to make a layout or worst, a veroboard. But maybe there's any other ways to build an octaver down pedal.

I'd like to build an octave box that contains an octave up and octave down with a clean blend (similar to Foxrox Octron or a Pearl pedal). I've almost finished to design the octave up effect but I know nothing about the octave down and how this octave is produced. So maybe my question can be stupid.


For the Shocktave, I think I read that sounds more like a vintage synth, producing a kind of scare wave , a nintendo sound (but maybe because of the outuput drive gain stage)

For the pog isn't analog, it uses a DSP.


SISKO

Re: Octave down schematic.
« Reply #11 on: June 09, 2009, 05:08:38 AM »
http://hammer.ampage.org/files/SuperOctaver.ZIP

Check this out. It maybe of your interest
--Is there any body out there??--

MusicAudio

Re: Octave down schematic.
« Reply #12 on: June 09, 2009, 05:37:03 AM »
You could always build a Shocktave or Blue Box and lowpass the output to get rid of some of the square wave bite. It'd be worth trying since it only takes a couple minutes to rig a blue box up on the bread board.
I don't care much about music. What I like is sounds.
-Dizzy Gillespie

jacobyjd

Re: Octave down schematic.
« Reply #13 on: June 09, 2009, 05:39:20 AM »
You could always build a Shocktave or Blue Box and lowpass the output to get rid of some of the square wave bite. It'd be worth trying since it only takes a couple minutes to rig a blue box up on the bread board.

This is a great idea--I did this to my BB as an extra control, and it sounds great--however, you'll want a gain recovery after the LPF unless you dramatically raise the gain before going INTO the LPF.
Warsaw, Indiana's poetic love rock band: http://www.bellwethermusic.net

Thomeeque

Re: Octave down schematic.
« Reply #14 on: June 09, 2009, 06:01:37 AM »
 IMO Boss OC-2 circuit could by significantly simplified if you would go true-bypass and wanted only one octave:

- very input and output buffers could be removed (since all output signals are buffered by op-amps, pasive output mixing could be used)
- 4027+A+D branch could be removed

 I'm not saying, that what remains is simple, but maybe it's necessary for good analog octave-down (and OC-2 sounds really sweet).

 T.
« Last Edit: June 09, 2009, 06:09:39 AM by Thomeeque »
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R.G.

Re: Octave down schematic.
« Reply #15 on: June 09, 2009, 06:11:04 AM »
You could always build a Shocktave or Blue Box and lowpass the output to get rid of some of the square wave bite. It'd be worth trying since it only takes a couple minutes to rig a blue box up on the bread board./quote]
Or you could just look at Craig Anderton's Roctave Divider which does this and much more.
R.G.

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Thomeeque

Re: Octave down schematic.
« Reply #16 on: June 09, 2009, 06:30:12 AM »
Or you could just look at Craig Anderton's Roctave Divider which does this and much more.

 Are there any sound samples of Rocktave Divider? E.g. digitalized original "Roctave Divider Demo Tape" would be nice ;) I tried to find some, but did not succeed so far..

 Thanks, T.
Do you have a technical question? Please don't send private messages, use the FORUM!

fuzzo

Re: Octave down schematic.
« Reply #17 on: June 09, 2009, 07:15:49 AM »
Hi guys and thanks for all those answers !

So, I study a little bit the Octave divider working principle, and that no really so hard that I thought.

http://www.bossarea.com/forum/uploaded/ssanyee/Boss_oc2.jpg

The signal passes through a buffer that ,after, divides it into 3 parts :

one does the low pass filter for the Octave divider section.
Tow others creates low pass filter for both octaves coming from BA634 and µPD4013C. Octave signal going through these filters by the transistor linked to the "+" input of op-amp. But there's also the ouput of input buffer connected to this AOP input;  It mixes the dry signal with octave to remove a little bit the scare wave sound ?

So, for an Octave I've to keep the lowpass filter with IC creator of Octave, and a low passfiler to filtering the octave coming from it.


Processaurus

Re: Octave down schematic.
« Reply #18 on: June 09, 2009, 02:46:04 PM »
Hi, here is an abbreviated 2 knob version of the OC-2 schematic I put together for people looking for a simpler, cleanish (ie not a square wave) octave down. From the nature of the effect, it can't really get any simpler than this, boss's fundamental extractor (the bit on the bottom) is quite elegant and works better than most.



Some explanation of how the boss circuit works and whatnot:
http://www.diystompboxes.com/smfforum/index.php?topic=58609.0
« Last Edit: June 09, 2009, 02:57:03 PM by Processaurus »

Gus

Re: Octave down schematic.
« Reply #19 on: June 09, 2009, 03:06:30 PM »
A nice octave down is the EBS OctaBass.