I’ve done some audio demo of the Harvestman Hertz Donut as a “standalone unit”, the audio path is just Hertz Donut and A132-3 VCA , no filters, no efx!
The only modules used to control the vco and the vca are a MFB ADSR on the VCA and a Plan B Model 10 on some sounds to control fm amount and wave discontinuity on the hertz donut.
The Hertz Donut is a voltage controlled digital dual oscillator that can provide sine, saw, tri and square waves on both the generators and a ringmod for the square waves.
The oscillators can work synched together in some different modes :

• No Sync
• Bad
• Worse
• Stupid
• “strong” Sync

As you can imagine except for the No sync option the other sync options go from a classic perfect sync to a bad , worse or even “stupid” wich forces the second oscillator out of sync in random ways, shifting the sync point .

Harvestman Hertz Donut demo1 by francescopoggianti

The idea behind the Hertz Donut is to get a Zero-FM oscillator using a Primary (the first oscillator) and a MODULATION (second oscillator) with different kind of sync and modulation capabilities over Frequency , Wave Shape and AMP.
Frequency , Shape and AMP are the possible destinations of the modulation oscillator, the Hertz Donut is indeed a simple 2 operator FM & AM generator!

Harvestman Hertz Donut Demo 2 by francescopoggianti

Harvestman Hertz Donut Demo 3 by francescopoggianti

This is just a short demo of the Cwejman VCO2RM thru the STG Soundlabs “Post  lawsuit ” LPF filter.
The VCO2RM is set on the middle wave (the modulated TRI) modulated by the VULCAN MODULATOR by Livewire.
Each VCO has its indipendent modulation rate.
The 2 vco are mixed by an A138 and then pass thru the STG LPF.

An A145 modulate (sine) the filter frequency.

The filter has 75% resonance and the frequency is between 5-6.

Cwejman & STG LPF by francescopoggianti

The TB303 Diode Ladder Filter by OAKLEY.
This is a great sounding filter!

Oakley PCB

The 4 filters:

1. Doepfer A-120
2. STG Soundlabs Post-lawsuit LPF
3. Analog Systems RS-500 e
4. Analogue Solutions SY02 Multimode filter

The oscillator: MFB OSC02 Triple VCO

The two filters that can be directly compared are the A120 and the STG, they are both 4 pole, 24dB slope ladder filters.
Ladder filters copy the classic “moog filter” (electronically speaking) so they have a very definite cut , a really fast response to modulations and oscillates at full resonance generating a sine wave.

The DOEPFER A120 was concived as the classic moog emulator but it doesn’t sound moogish at all, it is very clear and have a minimal touch to the sound, it lacks the organic carachter of the ladder moog, but it’s perfect for other tasks as aggressive minimal sounds or percussions.

The STG LPF emulates the ARP 2600 filter “post lawsuit” (the one used after the legal problems with R.Moog). I tried this filter face to face with the original and it is quite similar but not the same, but it retains the warmth and power. The only downfall of this filter is a kind of bleed you can hear as the resonance increase, not very pleasant but all in all tolerable. This filter has 2 freq inputs and 2 signal inputs all without attenuators, 1 amount input and a audio output.

The Analogue Solutions SY02 was dsigned as a Korg MS 20 filters and vca clone. It consist of a highpass + lowpass filters both with resonance and amount and a vca. The sound is raw and the filter can distort easy, this module is used even in the Vostok and Black Coffee . The fourth filter is the Analog Systems RS500e, a diode filter with 18dB and 24dB slope  clone of the classic EMS VCS3 and AKS Synthi (pre and post 1974). This filter has the classic frequency, amount and response  (resonance) controls plus a level in and level out (to get a kind of overdrive sound) and a cv slew (fast or standard), a mod that was usually done on the original synthi.

The first set of demo is based on arpeggio and bass sounds as they show the behaviour of the filters in simple sounds.

TIPTOP AUDIO Z8000 – Resonating Percussion Poly-Rhythms – Part 3 from Richard Devine on Vimeo.

Jam by Richard Devine and Josh Kay on the TipTop Z8000, generating some resonating percussion poly-rhythms.

Just to keep you tuned about my eurorack modular system, this is my actual configuration:

• Cwejman VCO2RM
• MFB OSC 02 Triple VCO
• Doepfer A138 mixer
• Analogue Solutions SY02 Multimode filter
• Doepfer A120 lowpass filter
• STG Soundlabs “Post-lawsuit” LPF
• Doepfer A145 LFO
• Livewire Vulcan Modulator
• PlanB Model 10 Polyphonic Envelope
• MFB Dual ADSR
• Doepfer A132-3 dual VCA
• Analog Systems RS500E EMS Synthi filter

The kick is a relly important percussion sound in electronic compositions, let’s get a different way to make it.

Usually to synthetize a good kick we use a sine wave layered with a square, and balance the two if we want a softer kick or if we want more attack.
VCOs tends to be harmonically rich so it’s not simple to get a kick that sounds not clearly tuned.
To get a more “percussive & less harmonic” kick (but it is even useful to create percussions like toms or bongos) I use an LFO.
LFO sounds more clinic, not many harmonic content on the wave generated.
Using a simple SINE wave on the DOEPFER A-145 can lead to interesting kicks and percussion.
The path is really simple A145->A132-3 (vca) and an env to control the vca.
The A145 is interesting as a sound source because it can work very well into audio frequencies, the only downfal is the fact that it has no freq. modulation capabilities.

Using the LIVEWIRE VULCAN MODULATOR  we can go further into sound design as the vulcan has cv inputs for the frequency mod.
Using the same signal configuration we can notice that the vulcan sounds more organic, the wave is not a perfect sine, it has some fluctuation too.
The result is a percussion that is not rounded as the 145 but with more punch and more attack.

Bananalogue is reintroducing a new stock of their Serge VCS.
For now this is just how it looks, I’ll post soon any info I’ll get.

Really interesting video from intellijel youtube channel of the Livewire Vulcan modded with sync reset.

Description by intellijel :

Demo of a mod done to the Livewire Vulcan to allow independent reset of the two LFOs.
To the right of the Vulcan you can see a 4HP panel with the two jacks mounted, behind this is a circuit board designed to interface to the Vulcan and process incoming triggers.
Jack1 is normalled to Jack 2 so that one cable can trigger both resets. Modules used: MFB SEQ-01 (provides the triggers) Livewire AFG (single oscillator that is being modulated) QMMG (not doing anything until the later parts where I modulate its in LPG mode) Doepfer VCA (just being used as an attenuator) The SEQ-01 could be replaced by any source of rhythmic triggers including gates from your midi to cv converter.
The demo starts with no sync and simple modulation and then I start to patch more complex triggers and cross mod. Sorry for the poor quality! I forgot to turn on the camera light…. future videos will be better Also this mod is not for sale but I can provide instructions… it is not for beginners though. I plan to add switches for selecting mod sources and jacks to patch in external CV to the SUM/DIFF/MAX/MIN circuits

The PlanB model 10 is a multifunctional module, not only a simple envelope.
The name “polyphonic envelope” does not describe the functions of this great module, the reason why they called it “polyphonic” is because it can output 4 different type of voltage “envelope” at the same time.
In fact the M10 is way more versatile than an envelope, this is really similar to the Bananalogue VCS module, a multitask voltage controlled cv generator .

The main task is the ENVELOPE.
The envelope consist of an AD env with RISE (0.5 ms-5 min attack)and FALL (0.5 ms – 5 min decay/release) controlled not by gate signals but by Triggers.
The attack and decay time can stretched x8 times their duration with the TIMEBASE control knob (so the complete envelope can last from 0.5 milliseconds to 20 minutes).
You can stretch the time manually just turning the knob or controlling it with the VC TB (voltage control timebase).
The VC TB can act in positive or negative, so it can add or subtract.
Than there is the level of the env, which is bipolar too , so it can act as a positive or inverted envelope.
On the left there are the 5 connectors for the 4 different envelopes generated:

• EOC
• EOA
• RAMP
• 2x AD (with ad contour switch)

The AD acts as the classic “trig” envelope, with 3 different contour (log, lin, exp).
The RAMP is a ramp with rise time 2x the RISE control time.
The EOA is a sustained square which falls when receive a trig and performs the AD cycle  at the “End Of Attack”.
The EOC acts as the EOA but the AD starts at the End Of Contour.

LFO MODE

The rise-fall cycle can be looped and can also work as an lfo.
Using the rise and fall it can produce various waveform between the tri, square, saw, ramp…
The interesting thing is that the timebase knob can control the time of the lfo, so it a vc lfo, the other thing that can lead to creative results is the fact that the rate of the lfo is not controlled by the timebase only, but it ‘s a mix of the rise and fall time.
So the shorter is the R&F the faster will be the lfo rate.

VCO MODE

The third interesting mode is the vco function.
The module has a  triangle-core , so it can sound useful even as a vco.
To get the vco mode  you have to switch into LFO and use fast R&F time and “tune” the oscillator with the timebase function and VC TB to control it with a keyboard cv.
It does not reach very high frequencies but can be used on the low and mid range as an audio modulator or a audio source.

TIPS:
I noticed two useful tips:

• As the core is a TRI-core the envelope create a sort of clip when, reached the max value,start the fall.
  To avoid the clip it’s useful to use a lowpass filter post the VCA.
• In LFO mode don’t connect any source to the trig in because the summing of the two sources can damage the module , too high voltage!