Doepfer A-134-2 VC Crossfader

Here's a quick look at - and a rather longer listen to - Doepfer's voltage controlled crossfader. This is my favorite sort of module: small, versatile and inspiring. The two VCAs accept either audio or CVs and can be configured via jumper to cross-fade either asymmetrically or symmetrically. A simple modification turns the A-134-2 into a 4-in 1-out two-dimensional x-fader.

Before I bought the A-134-2, I tried to patch my own crossfader using a Cwejman VCA-2P. While this worked to an extent, purpose-built modules tend to cut down the time spent cabling and yield quicker results. Within a couple of minutes with the Doepfer, I was up and running.

AUDIO EXAMPLES

Doepfer A-134-2 VC Crossfader Demo by navs

1) Audio fade/ symmetrical. Two VCO sequences. LFO as modulator.
2) Audio fade/ asymmetrical. Ducking effect with envelope follower.
3) FM modulator fade/ asymmetrical.
4) FM modulator fade/ asymmetrical.
5) FM modulator fade/ asymmetrical.
6) CV fade/ symmetrical.

IN USE

Provided you don't overload the VCA by applying too high a CF CV, the audio quality is good. I did notice a slight imbalance in one VCA when used asymmetrically (input one was not at unity at 0V, but rather needed about -0.5V), but I'm sure this can be calibrated. When used symmetrically and with 0V applied, inputs 1 & 2 are balanced at 50/50 rather than at full level. This might bother some users. I personally would prefer the option. Due to the nature of fading, I found the A-134-2 more useful for audio rather than CV sources, where I felt a sequential switch might be more appropriate.

Fading between audio sequences or FM sources are two obvious uses of the A-134-2. In conjunction with an envelope follower, it's also capable of sidechain/ ducking duties (the A-119's sluggish response adding to the severity of the effect!). I don't have a Wiard Boogie, but I could also imagine that, paired with a joystick, a modified A-134-2 would be great for dynamic vector-filtering.

Navs live @ SIN Bar Berlin. Thursday, 21:00.

I'll be playing live this Thursday at Stranded in Neverland, Kreuzberg.

Decidedly old school and modular-free, I hope to have some fun jamming with a P3 sequencer, Korg ES-1 & EX800 and a Novation Bassstation.

Fingers crossed the old tech doesn't crap out on me!

First on the bill is one of my oldest friends, Mat, playing a selection of his songs.

If you're in town, come along.

The address is Schönleinstr. 6 10967 Berlin, U-Bhf Schönleinstrasse on the U8.

More Hazarai! EHX SMMH Modification

Rechner7's modded EHX Stereo Memory Man with more Hazarai!

Following this thread at sequencer.de where ACA describes how he modded his Akai Headrush, I asked Rechner7 how he'd modified his SMMH and he kindly sent me these pictures, sound clips and details.





MOD DETAILS:

smmh-mod by rechner7.

inputs:
trigger/gate A
trigger/gate B
trigger C

switches:
REC ON-OFF
SELECT A-OFF-B
HP A/B ON-OFF

input C is always active and high-pass filtered to avoid a unintentional activation of the loop-mode. the high-pass is just a passive 1-pole high-pass with a cuttoff frequency at about 1-3Hz. a selective remoted looping can be done with A or B.
using the REC switch is equivalent to an enduring press of the tap button. this function is handy for long and pitchable delays in the loop-mode.

the function SELECT activates the additional trigger input A or B.
switching HP A/B to ON enables a high-pass filter. if the high-pass is active, A or B cannot release the loop function. bypassing the high-pass (HP A/B OFF) will activate the loop-mode if the gate length exceeds the threshold.

http://www.doepfer.de/faq/gen_faq.htm
paragraph: Converting Gate to Switched Trigger (S-Trigger)

http://www.doepfer.de/DIY/a100_diy.htm
paragraph: 2. Basic circuits

You can download a zipped folder with more pictures, the text and audio examples here (6MB).

Thanks to Rechner7 for sharing this! If you want to attempt this simple but Hazarai-enhancing mod, beware: apparently the hardest part is freeing the PCB from the enclosure without breaking it. Neither I nor Rechner7 take any responsibility for your SMMH. Just so that's clear, OK? Happy Modding!

Doepfer A-156 Dual Quantizer Demo

It's one of Doepfer's oldest modules and not something I really thought I needed. But, having spent a weekend playing with the A-156, I've got to ask myself 'Why the hell didn't I get one of these years ago?'.

Doepfer A-156 Quantizer Demo by navs

Patch Notes:

1) SEQUENCE FROM ENVELOPE. Plan B Model 10 loops, envelope to A-156, End Out to Wogglebug clock. A-156 Trigger to VCS. Wogglebug stepped output to A-156 transpose, M10 VC-Timebase and VCS VC Fall.

2) GLISSANDO 1. Pitch CV slewed by VCS, then to A-156. Trigger out to A-143-1.

3) GLISSANDO 2. Kenton Pro 2000 II provides auto-portamento. CV to A-156.

4) RANDOM. Wogglebug woggle out to A-156, trigger to Borg filter in LPG mode.

5) KINETIC GATES. Pitch bend via MIDI joystick to A-156 (chromatic mode) and VCO. Trigger to Borg (LPG).

6) SEQUENCE. LFO to A-152 Voltage Addressed T&H/ Switch. Digital outs to mixer, four stage sequence to A-156. Trigger out multed to main envelope and A-160/ 1clock divider/ sequencer to fire kick, high hat & bass.

7) DUAL Q. LFO clock to Q1 & Q2 trigger inputs and A-160/ 1 CLK DIV/ SEQ. /2 > EG1, /16 > EG2.

All patches feature manual toggling of the A-156's mode switches and, maybe a bit too much, EHX SMMH delay.

While not as stable or versatile as my Kenton Pro 2000 II/ Sequentix P3 combo, the A-156's ability to generate sequences from LFOs, envelopes, joystick sweeps and random sources, coupled with the fact that it outputs a trigger on each quantization, makes this a very useful and musically inspiring module.

Tiptop Audio Z2040 vs. Doepfer A-105

I've been a fan of SSM 24dB low pass filters since first playing with a mate's Korg MonoPoly in Brighton the late eighties. Years later in Berlin, I bought a second hand PolySix for 300 Deutsch Marks (around €150!) and this further cemented my affection for the SSM sound.

So, naturally, when it came to choosing a filter for my first modular system, Doepfer's A-105 was top of the list. As users of SSM - and indeed most 24dB - filters will tell you, the biggest drawback is the loss of volume and bass at high resonance levels. So when Tiptop Audio's Z2040 was announced, I was keen to hear how this problem had been addressed.

The following test showcases the Z2040, based on the SSM2040 filter chip, using Doepfer’s A-105 as a comparison. While the sound is similar, the Doepfer uses an SSM2044, which is not the same filter topology.

At medium gain and with no resonance, the filters are virtually indistinguishable. The real difference becomes apparent at higher resonance and gain settings, so that is what I have focussed on.

You can download the full test (12.4MB) here.

Here are a few tasters:

High Resonance, A-105, then Z2040 at 0dB, then at full resonance

While the resonance response of the two filters is similar at low gain levels, settings around 0dB and above have a marked effect on the Z2040. See the full test for more details.

Saturation, Z2040, then A-105

Three VCOs, medium resonance, high gain. The Z2040 displays real grunt while accenting harmonics, the A-105 sounds flat and distorted. Again, please see the full test for more details.



The Z2040 is well built and has a classy, creamy and warm sound. The gain stage saturates beautifully, adding rich harmonics without nasty clipping. Will it replace the A-105 in my system? No. I'd miss the 'squared-up', metallic, acid sound that the Doepfer filter is capable of. I guess they'll have to get used to being neighbours in my rack.

Thanks to SchneidersBuero for the loan of the Z2040 and Gur at Tiptop for taking the time to answer my questions.

Navs Live @ 48 Stunden Neukölln

I'll be performing live as part of the 48 Stunden Neukölln arts festival in Berlin tomorrow. Here's a taste of what you can expect:

Patch of the Day - Undergrowth by navs

Weather permitting, I'll start patching at around 16:00 at Parzelle 20 in the 'Hand in Hand' Kleingarten Kolonie in the Rütli Strasse. Full address and details are here. Scroll down to the bottom of the page: I'll be on after the scary-looking bloke with the megaphone!

Look forward to seeing you!

EHX Stereo Memory Man w/ Hazarai Demo

A live patch showcasing the EHX SMMH's multi-tap mode:

Repeater - EHX Stereo Memory Man w/ Hazarai Demo by navs

This box is lots of fun and very easy to tweak on the fly. Ironically, probably better suited to modular musicians than guitarists: it's not the sort of device that you should just set and forget.

Sadly, it doesn't 'pitch' the delays when the time is adjusted and the tap-tempo function is a PITA (viz Loop Mode), but if you just go with the flow and twiddle the knobs, it's capable of some great sounds.