New Doepfer High End VCOs A-111-2, A-111-3 and A-111-4 Thru-Zero Announced

Doepfer has announced two new High End VCO's at the Superbooth event in Berlin (March 31st - April 2nd, 2016)

The A-111-2 is based on the CEM3340 Rev G chip
There was a close cooperation between Doepfer and OnChip since 2015 regarding to the new re-issue of the CEM3340 and they received the first samples in January during NAMM for development.
The first production batch of the CEM3340 Rev G arrived 2 weeks ago and the production of the A-111-2 has started during the next few days (they are still waiting for the latest front panel and pcb samples). 
Doepfer expects the first modules to be finished around the end of July/August. 
The A-111-3 is also based on the CEM3340 Rev G ,and Doepfer is working on a Thru-Zero VCO based on the CEM3340 Rev G too (module A-111-4).

The Doepfer A-111-2High End Voltage Controlled Oscillator II is the successor of the obsolete High End VCO I A-111-1 and here are the most important features of the planned module:

Triangle core, min. 15 octaves pitch range (typ. 0.5Hz - 20kHz)
perfect 1V/octave tracking over min. 12 octaves (typ. 5Hz - 20kHz)

Exponential frequency controls and inputs:

Tune (~ 1 octave range)
Fine (~ 1 semitone range)

A-111-2 Prototype June 2016

Octave (range switch with 6 positions)
1V/octave CV input
XFM input with attenuator
access to bus CV (via jumper, optional)

Linear frequency controls:
LF (manual linear frequency control: fully CW = standard setting for usual VCO applications, fully CCW: close to 0Hz frequency)
LFM input with attenuator, DC coupled

Pulsewidth controls for rectangle output:
PW (manual pulsewidth control from 0%/output = fixed at "low" state up to 100% / output fixed at "high" state)
PWM input with attenuator
Hard Sync input
Soft Sync input
Waveform outputs:
Sawtooth
Rectangle (with PWM)
Triangle
Sine
Nearly "perfect" waveforms (no glitches)
High end triangle to sine converter with excellent sine waveshape (thanks to Tim Stinchcombe who recommended this circuit)

14 HP Width

Price: about Euro 250.00
Available: spring/early summer 2016

The other new High End VCO  is the A-111-3 High End Precision VCO with a panelwidth of just 4HP.
Essentially it's the same basic circuit as the A-111-2 but with reduced features:

A-111-3 High
End Precision
VCO

Triangle core, min. 15 octaves pitch range (typ. 0.5Hz - 20kHz with appropriate external CV)
Perfect 1V/octave tracking over min. 12 octaves (typ. 5Hz - 20kHz)
Exponential frequency controls and inputs:
Tune (~ 1 or ~ 10 octaves range, selectable via internal jumper, maybe different ranges in the final version)
1V/octave CV input
XM input with attenuator
access to bus CV (via jumper, optional)

Linear frequency controls:
LM input with attenuator, DC coupled

Pulsewidth controls for rectangle output:
PW (manual pulsewidth control from 0%/output = fixed at "low" state up to 100% / output fixed at "high" state)
PW input (without attenuator)
Sync input (selectable hard or soft sync via internal jumper)

Waveform outputs:
Sawtooth
Rectangle (with PWM)
Triangle
Nearly "perfect" waveforms (no glitches)
Only 4HP wide panel

Price: about Euro 150.00
Available: spring/early summer 2016

All features, specifications, prices, date of delivery are still without obligation
Source: http://www.doepfer.de/home_e.htm

Make Noise Sub Timbral Oscillator (STO)

Make Noise released their Make Noise Sub Timbral Oscillator (STO) and it looks quite interesting.

Make Noise
Sub Timbal Oscillator
(STO)

The STO is a "compact Voltage Controlled Oscillator designed for generating SINE waves, Variable wave-SHAPEs, SUB-Octaves, Oscillator SYNC and Linear FM in the analog domain. 

The Sub-Timbral Oscillator is the more subtle and melodic friend to the DPO's complex harmonic lattice.

It features:
- Triangle Core with outputs for SINE, SUB and Variable SHAPE
- Unique Variable SHAPE circuit ripples Even and Odd harmonics for subtle timbral shifts
- Linear FM input with Depth control
- EXPOnential input for deep FM, SYNC sweeps or Transposition of sequences
- SUB-Oscillator yields max bass
- S-Gate input for gating or sync of SUB-Osc. independent of other outputs
- Hard SYNC circuit which combined with Linear FM and Variable SHAPE yields harmonically rich sounds
- Pairs well with the MMG or Optomix"

Video: Make Noise Sub Timbral Oscillator (STO)

Uploaded by http://www.youtube.com/user/MAKEN0ISE

On Twitter: https://twitter.com/makenoisemusic

A-110 Tuning Knob Modification

Triggered by a photo by Scott Rogers that popped up on Flickr a few weeks ago, I decided to re-create the A-110 Oscillator modification that he made.
Scott simply added a resistor in parallel with R5 to increase the tune knob range to a bit more than an octave up and down.

Locating R5 on the A-110 VCO

On Scott's blog he writes:
" I’ve already made my first modification to my Doepfer A-110 Oscillators.

For some reason they have set the Tune knob range to only a single tone up or down. 

One thing I do a lot is offset the oscillators by a fifth so this wasn't going to do!

So I contacted Doepfer and they told me (more or less) what to do.
So what I did was this: located resister R5 on the circuit board and added a second resister in parallel with it to reduce it’s value.

Locating R5 on the A-110 VCO
on the other side

I added a 100K resister and this now gives me a range of an octave and a third up and a bit more than an octave down. 

So now it’s a bit more difficult to fine tune, but now I have a huge tuning range that lets me do a lot more! "

The modification is also described in the A-110 service manual on the Doepfer website:
" From the factory the range is about 2 semitones to enable a fine tuning of the VCO.
If you are a bit familiar with soldering you may modify the A-110: shorten R9 (this increase the range about by a factor 3) or reduce the value of R5 (1M).

You may solder e.g. a second resistor in parallel to the existing R5 (1M). The smaller the value of the resistor the higher the range."

A 100K, 5% resistor in paralel with R5

Re-creating this modification was not difficult, after locating the R5 resistor, soldering the 100K, 5% resistor in parallel to it was a piece of cake.

I don't have any test-equipment, but after listening to the result, it changed the range of the tune knob on my A-110 from around 3 or 4 semitones up/down to a little bit over 1 octave /around 15 semitones, so the results seem to vary a little bit per A-110... which probably has to do with different internal potmeter settings on the PCB.

Scott's blogpost: http://www.scottfromcanada.com/wordpress/?p=194

For more info, also read the discussion on Reddit:
http://www.reddit.com/r/modular/comments/1h6zj5/new_to_modular_how_do_i_tune_a_doepfer_a110/

Thanks to Nicholas Keller for additional support, info and links!

The mods described on this site will most likely void any warranty and, if not done carefully, can damage the circuit board, IC chips, and faceplates.

Oscillator Synchronizing

Interesting sound-effects can be obtained by the synchronising of (multiple) oscillators.
In a typical setup, one oscillator (master) restarts the cycle-period of the other one (slave) , what results in equal base frequencies on both oscillators. This is called Hard Sync.

The result is an irregular waveform with it's own harmonic spectrum, completely different from 'standard' waveforms

Soft Sync is a more general name for all kinds of oscillator synchronisation.
This form is very similar to Hard Sync, but here the slave oscillator is forced to reset to zero with every cycle of the master regardless of position or direction of the slave waveform, which often generates asymmetrical shapes.

In Soft Sync, rather than resetting to zero, the wave is inverted;  its direction is reversed.
Further variations to the sound can be made by comparing the sounds with different comparison tresholds. For more info see the Wikipedia page on Oscillator Synchronisation
Soft Sync sounds smoother  and distinctly different from hard-sync.
It is difficult to replicate this effect on digital synths, due to aliasing problems.

Soft Sync-like effects can also be created with other modules, for example a phaser or a Phase Locked Loop (PLL) Module.

Never Enough VCO's

The engines or hearts of all modular synthesizers are definetely the VCO's. As main sound source for your patches it seems you never have enough of them.

I own 5 VCO's at the moment, One A-111 High End VCO plus four A-110 Standard VCO's. Ideal for stacking layers of waveforms to make extra- fat sounds, and also very useable for multiple A-100 melodylines

The A-111 is the one i use most because of its extended possibilities. 

This VCO has an extended frequency range, improved waveforms, FM and Soft Sync inputs plus an extra fine-tune-controller. Ideal for controllerfreaks like me. 

It produces sine, triangle, pulse and sawtooth waveforms, which are all derived from the triangle oscillator, what does make it hard to produce perfect sine-waves ( but a little better as the A-110's sine wave )

One of the best things is that all 4 waveforms are all simultanously available at the outputs for your mixing pleasure.

The much cheaper A-110  has less controls and is based on a sawtooth oscillator. All outcoming waveforms of this module are derived from this sawtooth by internal waveform converters. This module also generates sinewaves that are not completely perfect, but to 'normal' ears this is hardly audible

I never noticed, and i guess most of us don't care and never noticed the imperfect-ness of the sinewaves of both modules.

Even on an oscilloscope it is hardly visible that the sinewaves are nothing more than rounded sawtooth-waves.

For a perfect sine wave Doepfer recommends the A-143-9 Quadrature LFO/VCO, another interesting module, that i will highlight in a future blogpost.

Note: As the special circuit CEM3340 used in the A-111 High End VCO module is no longer available the module has to be discontinued. Sales at Doepfer while stocks last !