A-162 Trigger Delay Modification

An update to this post on how to modify a Doepfer A-162 Dual Trigger Delay for perfect filter pings.



Replacing the A-162's stock 10uF capacitor with a 0.1uF helped, but meant that most of the useful range for pinging filters (0.5 - 2ms) lay within the first 10% of the pot's throw i.e. settings between zero & 1.

An attempt to reduce the resistance of the pot failed to help, so I replaced the 0.1uF with a 0.01uF/ 10nF cap. This did the trick: a setting of 5 now yields a ca. 2ms long pulse.

Here's a clip of three filters being pinged with various pulse widths:


Cwejman MMF-1, RES-4 & Metasonix R54.

As you can hear, the tone and volume are affected by the length of the pulse. This is even more apparent when the filter additionally receives pitch CV. The R54 shows the most dramatic response to changes in pulse length, especially when an attenuated multiple of the trigger is used to apply some pitch bend or 'thwap'. The A-162 is also perfect for pinging low pass gates.



Above is a picture of the solder-side of the board. I've marked two possible connections, depending on the type of capacitor you want to use. The two holes marked in pink are connected by a trace to allow for 'extra leg room'. The cap should be connected between the green and one of the pink holes. Pay attention to the polarity if you're using an electrolytic cap.

Needless to say, this mod will void your warranty and is your own risk. It's not difficult, but if you don't want to do this yourself, Doepfer offer a modification service on most of their modules at very reasonable rates.

Thanks to the Wigglers who helped in this thread.

Rechner7's modded Deluxe Memory Boy

You might remember Rechner7's modded Stereo Memory Man w/ Hazarai from this post. Here are some sounds of his latest project, a Deluxe Memory Boy modded with trigger inputs for the tap clock, tap divide and expression mode:

Dmmb tapdiv by rechner7

The sound is lo-fi, but musical. The additional trigger inputs open-up many possibilities when used in conjunction with a modular. Click here for more examples.



Because the tap circuit is passive, it apparently needs a fairly hot trigger and it won't respond to very fast changes, but this shouldn't be an issue in most cases.

If you like the sound and possibilities of this mod but don't fancy the DIY involved, Rechner7 is selling his DMB. You can get in touch with him at Rechner7 (ät) directbox (döt) com.

Patch of the Day - Ping

Live patch featuring a modified Doepfer A-162 Trigger Delay to ping filters, including a Cwejman MMF-1, RES-4 and a Metasonix R-54.





I love the sound of a pinged filter and normally use Maths' EOA to convert a gate signal into the short pulse necessary to achieve this. Having only one Maths in my system, this can be an 'expensive' use of the module, so I wondered whether the A-162 could be a cheap alternative.

At 10V, the A-162's output is hot enough to push a filter into oscillation. Unfortunately, the stock module's minimum time is only just short enough to avoid a double-trigger. I first replaced the standard 10 uF timing capacitor with a 1 uF, but, despite shortening the range by a factor of 10, it didn't give the scope I wanted, so I settled on a 0.1 uF blocking cap!

At the beginning of the recording, you can hear the effect the pulse width has on the MMF-1's ring as I increase the length up to the point where it double-triggers and back. With a 0.1 uF cap, the pulse is so short it can also be used to FM the filter to add a percussive edge.

If you want to try this mod on your Trigger Delay, or other Doepfer module with a timing capacitor, there's more info here.

See an update to this post here.

Club Transmediale Reminder

A reminder of the Club Transmediale which opens this week and of my modular workshop & tour of Schneidersbuero on Wednesday.

Look forward to seeing you there - in the meantime, here are some moody shots from the buero:


Mini Teststation


Haken Horns


State Zero

You might remember the Mungo from this post. I've since had a chance to play with the Leploop and you can look forward to an overview with audio soon. The State Zero still eludes me, but as soon as I find a ruck-sack big enough ...

Shifter Shootout

A comparison of two frequency shifters: the Cwejman FSH-1 and Synthesis Technology E560 'Deflector Shield'.


Two 'Klangumwandler': one analogue, one digital. One is capable of wide shifts, the other of going thru-zero.

To kick things off, here's a multi-tracked recording featuring both: 


Download the album for €1 or more to access the examples.

Internal make-up aside, the key difference between the Cwejman and Synthesis Technology modules is the range of available shift. The FSH-1 is quoted as spanning 0.02Hz to 12kHz. The E560 concentrates on lower frequencies to take advantage of the stereo effects made possible by shifting thru-zero.

Take care of your ears and speakers with these recordings!
Here's a quick manual tweak of the frequency.
(range, MMF-1 sine. FSH-1, then E560).

While the Cwejman has a switch to toggle between LFO and audio rates and a fine tune dial, the SynthTech relies on a single frequency knob with a highly-exponential response. This makes it easier to dial-in slower rates, but, as you can hear, the jump in the last 10 degrees of the pot's rotation makes it harder to set higher frequencies.

Unlike the FSH-1, the E560 is capable of thru-zero shifts, offering enhanced stereo images. Modulated with a bi-polar CV, the up & down shifts swap sides; what's up, goes down and vice versa:
(e560_thruzero, MMF-1 sine. E560, manual tweak, carrier 8).

Due to it's highly exponential response and clamped range, the E560 seems happiest at slow rates, producing lush tremolo effects. Here's an example, isolated from the first recording:
(e560_slow, RES-4. E560 carrier wave changed near end).

By contrast, the FSH-1 will track higher changes:
(hitrack, MMF-1 sine, CV to FSH-1 then E560).

This opens up timbral possibilities which, given a suitable offset, can sound similar to linear FM:
(fsh-1_tone, MMF-1 sine, FSH-1. 50-50 mix. Eos reverb).

These last clips show what's possible when putting a FS in the feedback path of a delay:
(e560_fsdelay, EHX SMMH, E560 plus feedback).

Carrier bleed is the bane of the analogue FS. The E560 does not suffer from this. The FSH-1 quotes good carrier suppression, but I initially couldn't get the above patch to work. The more feedback I introduced, the louder the howl of the carrier. I asked Wowa Cwejman who suggested calibrating the FSH-1 to my system/ power supply. Two trim-pot tweaks later and the carrier was as good as gone:
(fsh-1_fsdelay, EHX SMMH, FSH-1).



The build quality of both modules is excellent. The Cwejman has attenuators for its inputs and a VC-able up/ down mix output. The SynthTech has a built-in feedback path and dry/ wet control. To my ears, the FSH-1 has the superior sound, but it is almost twice as expensive. The E560 offers thru-zero shifting but, in practical terms, is limited to low frequency shifts. Both modules have a ring-mod mode, offering out-of-phase outputs for extreme panning effects. The E560's phaser mode might not be as pronounced as a dedicated unit like the SPH-2, but it is a nice bonus. The FHS-1 can also be pressed into phaser-like duties by mixing dry and wet signals and introducing some single sideband feedback. The E560 alone offers morph-able carrier waveforms, a unique feature in a hardware FS.

Thanks to Paul Schreiber and Wowa Cwejman for taking the time to answer my questions and to Schneidersbuero for the loan of the modules.

Ultraschall Festival

A quick heads-up about the Ultraschall Festival for new music, which opens in Berlin today.



For details, check the programme at the Kultur Radio or Radialsystem sites.

Tickets are still available for tonight's TU-Studio concert, featuring a five-channel performance of Pierre Alexandre Tremblay's Ever Now Soon An End, a new piece by Ron Kuivila and a live performance by Alvin Curran.

Patch of the Day - Define Time

Thru-zero linear FM fun with the Cyndustries Zeroscillator and Toppobrillo Sport Modulator.





Today's PotD showcases some of the lovely linear FM timbres and stereo effects that the ZO is capable of. It's a single-pass recording of the 0 and 270 quadrature outs, panned hard left and right, with only a little plate reverb from Audio Damage's Eos added. I used a self-oscillating Cwejman MMF-1 filter as modulator, manually offsetting its pitch with four pre-set voltages from a Fonitronik mh01.

The Sport Modulator drives the patch, delivering both CVs and gates. The cycle/ sample times were nudged manually, with some cross-modulation and the stepped random signal of a Wogglebug. The latter's smooth out modulated the attack time and loop trigger of a Cwejman CTG-VC. At high speeds, the envelope amplitude modulates the VCA-2P used as the final gate, adding further sidebands to the mix.