Doepfer A-147-2 Voltage Controlled Delayed LFO Announced

Doepfer recently announced the A-147-2, the successor of the VCLFO A-147.

This module but offers more features than the predecessor and is made of the following sub-units:

VCLFO: voltage controlled low frequency oscillator
VCA: voltage controlled amplifier, switchable to voltage controlled polarizer
VC delay unit: voltage controlled linear attack envelope (only one parameter: attack) for delayed LFO operation in combination with the VCA (e.g. delayed vibrato/tremolo)

"LFO: The voltage controlled LFO has the waveforms Triangle, Sine, Sawtooth and Rectangle available and features a Reset/Sync input. Triangle/Sine and Rectangle are displayed by means of dual-color LEDs (probably red/green), Sawtooth has a unicolor LED available (probably blue). 

The output levels are about -4V...+4V for Triangle, Sine and Rectangle. 

The Sawtooth level is about 0...+8V.
The CV control can be switched to attenuator or polarizer ("CV Mode" switch). 

In polarizer mode the CV inputs affects the frequency in the reverse manner when the CV control is left from the center position. In the center position CV has no effect and right from the center the control works like a normal attenuator. 

The frequency range (without external CV) is from about 0,005 Hz (i.e. about 3 minutes per periode) to 200 Hz. In addition a ultra-low mode can be activated by means of an internal jumper. 

When the ultra-low jumper is set a fixed voltage is connected to the switching contact of the "LFO CV" socket. In polarizer mode of the CV control that way extremely low frequencies (up to one hour period and more) are possible.

VCA: This is a linear VCA that can be switched to "normal" VCA (i.e. kind of a voltage controlled attenuator) or voltage controlled polarizer ("VCA Mode" switch). 

In the "normal" VCA mode amplification +1 is achieved with about +5V control voltage. 

In polarizer mode the amplification ranges from about -0.5 (i.e. inverted signal with about 50% level) with 0V CV to +0.5 (i.e. non-inverted signal with about 50% level) with +5V CV. With about +2.5V CV the signal is suppressed.

Details about the functioning of a voltage controlled polarizer can be found in the description of the module A-133. In this mode the VCA can be treated also a DC coupled ring modulator (similar to A-114).
The VCA of the A-147-2 has three sockets available: "In" (signal input), "Out" (signal output) and "CV" (control voltage input).
The Triangle Output of the LFO is normalled to the VCA signal input by means of the switching contact of the "VCA In" socket. If another LFO waveform (or any other signal) should be processed by the VCA the corresponding signal has to be patched to the "VCA In" socket. 

The VCA can be used also independently from the LFO and the Delay CV. 

In this case the VCA sockets In, Out and CV have to be patched accordingly. The VCA can be used also as waveshaper for the LFO signals (e.g. by patching VCA In and VCA CV to different LFO signals, if necessary via attenuator A-183-1 or offset generator/attenuator A-183-2).

A-147-2 block diagram

Attack/Delay: The third sub-unit of the module is a simple, voltage controlled envelope generator that has only the parameter "Delay" (or Attack) available. 

This unit generates a linear increasing voltage that starts from 0V after each Delay Reset until it reaches about +5V.
Then the voltage remains at +5V until the next Delay Reset occurs. 

The inclination or gradient is controlled by the manual Delay control and the Delay control voltage ("Delay CV" input). 

The waveform is linear, the control scale is exponential. The output voltage is displayed by a unicolor LED (probably orange) and available at the "Delay Out" socket.
The manual Delay control ranges - without external "Delay CV" - from about 5ms (fully CW) up to 2 minutes (fully CCW). By means of an external voltage applied to the "Delay CV" socket this range can be extended. A rising CV shortens the delay time (behaviour like a VCO) !
The Delay output voltage ranges from about 0V to +5V. The rising edge of the gate, clock or trigger signal applied to the "Delay Reset" sockets resets the Delay output voltage to 0 V.
"Delay Out" is normalled to the VCA CV input by means of the switching contact of the "VCA CV" socket and consequently controls the Triangle level provided that no other patch is made. 

A typical example is the usage of a Gate signal (e.g. from a USB/Midi-to-CV/Gate interface) as Delay Reset. 

That way a delayed vibrato or tremolo can be realized if the VCA output is patched to the frequency CV input of a VCO (or VCF), or the CV input of a VCA.
But the Delay sub-unit can be used also independently from the LFO and VCA, e.g. as a voltage controlled waveshaper or for other applications where a linear increasing signal with voltage controlled steepness is required."

The module is planned for early 2015, price ~ Euro 120.00, price and release date are still without obligation !

Source: http://www.doepfer.de/a1472.htm

Erica Fusion Series VCO and Analogue Delay/Chorus Tutorial Videos by @DivKid

DivKid presents his latest overview videos in the new Erica Synths Fusion Series.

The first overview is the VCO Mixer full of lovely tube goodness (as are the other 4 modules in the range).

Video 1: Erica Synths Fusion Series - VCO Mixer

" Here's the first in a series of overview videos for the Erica Synths Fusion Series. The Fusion series are all tube/valve modules and there's 5 units including the VCO Mixer, Delay/Chorus, VCA, Ring Modulator and Filter.
Check out www.ericasynths.lv for more information."

...or check out this post on MuffWiggler

The second one is all about the Analogue Delay/Chorus

Video 2: Erica Synths Fusion Series - Analogue Delay/Chorus

" Here's the second in a series of overview videos for the Erica Synths Fusion Series. The Fusion series are all tube/valve modules and there's 5 units including the VCO Mixer, Delay/Chorus, VCA, Ring Modulator and Filter.
Check out www.ericasynths.lv for more information."

Videos uploaded by DivKidMusic

Random Video: Automated Tape Delay/Reverse by Wouter van Veldhoven

Wouter van Veldhoven, a tape-addict and musician from the Netherlands, makes music using collected second hand materials including, cans, old tape recorders, cigarboxes, broken radios and toypianos.
He reworks them in experimental musical instruments and uses them as recording devices.
His music balances somewhere between dusty, lo-fi experimental ambient and jangly instrumentals, but recently he has also been delving into the realm of minimal techno.

His latest upload is made with a nice mix of Doepfer Eurorack and various tape-machines and sounds like it is influenced by the classic Dutch NatLab-engineers from  the early 60s.

Video: Automated tape delay/reverse

" I adjusted a tape recorder in such a way its playing direction can be controlled from my Doepfer system, this combined with an extra tape recorder that both records and plays back enables delayed tape reversing in a live setting. Quite nice for doing some minimal techno thingies"

Find more about this project on his Tumblr page at http://woutervanveldhoven.tumblr.com/

Uploaded by Wouter van Veldhoven

Follow Wouter on Twitter at https://twitter.com/WvVeldhoven

A-162 Dual Trigger Delay

The A-162 Dual Trigger Delay contains two separate delay circuits for trigger signals.
This module makes it possible to delay the onset of trigger pulses.
This is very useful in case you want the modulation to kick in a little after the initial start of a sound (modulation delay) or to create interesting echo-like effects.

Both trigger delays have two controls that can alter the onset time and duration of triggers, standard from 0 up to about ten seconds.
The time range of delay and/or length can be modified very easily by changing the value of a capacitor, e.g. 200 us...1 s or 20 us ... 100 ms or 2us ... 10ms.
That way the module can be used also for audio applications.

If you want to modify the module yourself please read this document: Timing capacitors of A-100 modules.

Locating the A-162 timing Capacitors C2 and C5

Timing capacitors:
C2 (delay time)
C5 (length)
Standard value: 10uF
Polarity: minus = left

Also check out THIS post from navs.modular.blog on how to modify a Doepfer A-162 Dual Trigger Delay for perfect filter pings.

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