Variable Slope Filter / Phaser

jhaible

A mean little module from my JH-3 Modular.

6 filter poles, realzed with OTAs and combined FET / Bipolar buffer stages.

Variable Slope function for 6-pole VC LPF.
Voltage controlled Pole Spread for Phaser mode.
Zeroes switcahbel in pairs, i.e. a lot of combinations of all pass and low pass stages. Positive and negative feedback. Positive and negative wet/dry mix. Rather special overdrive behaviour (Dirty!), and (IMO) pleasant way of breaking into oscillation.

JH.

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jhaible · Posted: Sun Mar 15, 2009 11:53 am Post subject: Demo

Arpeggio from OB-8, with delay and reverb.

First few seconds dry - then playing with phaser.

JH.

variable_slope_phaser_arpegg.mp3

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b-funk · Joined: Jul 17, 2007 Posts: 183 Location: Berlin

Jürgen!

You are crazy!!! This sounds fantastic (and also reminds me that I still have a broken OB-8 standing around collecting dust Embarassed

)...

Go for it.

Best wishes,

Tobias.

jhaible · Posted: Sun Mar 15, 2009 2:18 pm Post subject: another demo

This is something I recorded a few years ago. I don't remember all the details. But it was a Split on the OB-8, bass sound on left hand and organ sound on right hand, and the whole thing was processed with the Variable Slope Phaser / Filter to get that "pulsating" sound.
(Lots of delay and reverb as well, obviously.)

JH.

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Luka · Joined: Jun 29, 2007 Posts: 890 Location: Melb.

hell yes
sounds awesome

Funky40 · Posted: Mon Mar 16, 2009 8:04 am Post subject:

The Demo sounds very good, but to be honest:

filters and phasers are the least i need for now,
and i might be not the only one.

what i like to see first:
__ very good VC ADSR
__ BBD
__ Vocoder

the accent is on the term "first".

mono-poly · Posted: Mon Mar 16, 2009 12:19 pm Post subject:

I wanna join.

krisp14u · Joined: Nov 11, 2006 Posts: 181 Location: uk

Hook line and sinker I will be taking 2 me thinks Very Happy

Norman Phay · Posted: Mon Mar 16, 2009 1:17 pm Post subject:

Wow, that sounds great. I emailed you to put me down for 2 boards, thanks.

vtl5c3 · Posted: Mon Mar 16, 2009 2:37 pm Post subject:

Sounds good Juergen! Is this related to the variable slope VCF in Electronotes? IIRC, that one was also 6 poles, but it did not have feedback.

Romeo

numbertalk · Posted: Mon Mar 16, 2009 3:03 pm Post subject:

I'd be in for a board!

jhaible · Posted: Mon Mar 16, 2009 11:42 pm Post subject:

Sound · Posted: Tue Mar 17, 2009 1:50 am Post subject:

Intrerested in one or two. Very Happy

pdub · Joined: Jun 08, 2007 Posts: 12 Location: california

Very cool! I am in for one or two.

Thanks, Charles.

Electronicant · Joined: Feb 23, 2006 Posts: 79 Location: North

Awesome sound.

But is yet another phaser, so why not use either the Tau phaser or the Schulte phaser as the phaser part in this project? Smile

jhaible · Posted: Wed Mar 18, 2009 2:15 pm Post subject:

jhaible · Posted: Sun Mar 22, 2009 3:41 pm Post subject:

This one is fun to layout!

Finished the audio part.
Lots of space left on the board.
I will include a Noise + Sample & Hold Circuit, so you get these clocked random modulations without any outboard modules. Also, an on-board power supply, so this can become a stmp box as well as a modular synth module.

JH.

Now playing: Kitaro, Silk Road

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jhaible · Posted: Sat Mar 28, 2009 5:12 am Post subject: More Features!

Just wanted to tell you my further plans for this.

The Variable Slope Filter / Phaser will get a very special on-board LFO that is derived from my JH-4 synthesizer.

Voltage controlled Rate and Depth, of course.

But there is is more:

You will be able to crossfade between waveforms with a potentiometer, or with another control voltage.

Starting from ccw end, the waveforms will be:

Triangle, fading into Sine, fading into Square, fading into Sample&Hold, fading into audio rate self-modulation.

Let me explain that choice:

Triangle fading into Sine means rounding the edges.

Square fading into S&H means rhythmic modulation with more or less randmness thrown in.

S&H fading into audio self modulation means mixing and fading two different flavors of madness. Especially with high resonance.

JH.

Funky40 · Posted: Sat Mar 28, 2009 5:33 am Post subject:

sounds very good,
please incloude a LFO Out too !!
Your LFOs are anyway great, but this one seems to be very special

TekniK · Joined: Aug 10, 2008 Posts: 803

numbertalk · Posted: Sat Mar 28, 2009 8:12 am Post subject:

Keeps sounding better and better!

vtl5c3 · Posted: Sat Mar 28, 2009 8:24 am Post subject:

That's great news about the LFO. Are you using some sort of interpolating scanner for the waveform xfading?

jhaible · Posted: Sat Mar 28, 2009 8:31 am Post subject:

bugfight · Joined: Aug 02, 2007 Posts: 185 Location: Arlington, TX USA

sheesh, you're too productive lately, i can't keep up!

2 for my infinite queue...

dig the c.s. lewis quotes, btw. one of my fave writers since i was a kid...

jhaible · Posted: Sun Mar 29, 2009 3:39 am Post subject: