Saturday, 5 February 2022

Driscoll Synth - some old panels - panels 4 & 5

 In the "to do" box.
I thought I'd upload some pics of an old Driscoll synth which is in need of restoration.
 
I've already got 3 panels 
 
so Ive decided to call these panels 4 & 5.
 
Panel 4
 

These are fairly rare.
The Driscoll was designed & built in the 70s by Australian composer/designer/engineer Julian Driscoll.
 at La Trobe University (Melbourne, Australia) between 1977 and about 1982. 

 

Its good I think to document things before I start tinkering around.

D-slope module  closeup x 2

An envelope generator 
Very much like the Serge DSG
Can be used as an oscillator, EG, ... lots of things
Very flexible module.
























 This panel has 8 D-slope generators
 

 



 
The RVG (random voltage generator) module contains a comparator, sample and hold, white noise, pink noise, low frequency noise, and a glide circuit.  
 
The sample and hold ....
 
This one is a bit odd..  It seems to hold while the clock input is high, but lets the input signal pass when the clock is low.  
 
Great for modulating the PWM on the clock signal
 
 Also, I think the comparator hi/low state is inverted ... need to check this..
A comparator is like a switch.comes in handy for converting changing voltages into binary low/high states.
 
 
 
 
 
 
 
 This is the boat for the above panel.

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Panel 5
 

A VCO, 2 x envelope generators
and a mixer section





A close up of VCO 1


PSU is +/-15v, +5v
CV is 0-5v
Oscillators are +/- 2.5v































The VC Stereo Mixer/Panner



These dual mixers are cool.
Thanks to Phil - J for his questions regarding the mixers
 

They each have three inputs.

My guess is that Hi Out stands for high impedance

And that LO OUT is 
Low Impedance

UG in stands for Unity Gain in ??

Unity Gain suggests there might be an op-amp in the input with a gain of 1

























Links

Friday, 4 February 2022

Sydney Northern Beaches

 Some pics of the Northern Beaches of Sydney.
My friend Allinaire, recently composed some music which was inspired by this beautiful region.
 
 

 
 This is the entrance to the lagoon.



 











Got to have some synths in this post.





Wednesday, 2 February 2022

Happy 202 day

 Happy 202 day
 


Arguably, the worlds first groove box .. 
This came out in 1983
Its a evolved form of TB-303. Programming is just as cryptic.
(Apparently, the programming is like a MC-4)
 
The sync is like you will find on a Tb 303. It's DIN Sync (sync 24) not MIDI sync.
A cool feature of the 202 is that it has 2 sequencers... or rather, its sequencer can play back two separate sequences simultaneously. 
One of the sequencers controls the internal synth. The other can control external synths.
There are two corresponding sets of CV/Gate connectors on the rear of the unit. This allow for connecting the 2 sequences to external synthesizers.
 
 
It's controls are much like the SH 101. The VCO, VCF, VCA, LFO, envelope and mixer sections
are really similar. It does however lack noise, a choice of LFO waveshapes and the modulation/pitch bend controls. In it's favour, there is a delay on the LFO.
 
You can also control the synth with Roland's standard CV/gate  that happens to work well with Eurorack systems.
 
 There is a voltage-controlled oscillator with simultaneous saw and square/pulse-width waveforms.
The Sub-Oscillator is a square/pulse wave. This is always one or 2 octaves below the main VCO.
(a square wave one octave down, and narrow pulse‑widths one or two octaves down)
The filter is a 24db resonant low pass. 
 
All this may sound limited by today's standards, but less is more.
 
If you can be bothered to learn how to program it the old fashioned way, it can be lots of fun.
The sequencer has slide & accents just like a 303 so you can get 303ish patterns and basslines,  I find it easy to control with a Midi to CV converter. The sequencer can store 2600 notes but remember that batteries must be fitted to preserve the sequences!

The MC202 sounds very similar to the SH101, as the circuits are almost identical,
though I think the 101 sonically wins for me. The 202 (and 101) are really good for acid baselines.
... and a whole lot cheaper to buy. If you are trying to emulate a 303, remember to not use any control of the 202 that a 303 doesnt have. For example, don't use the LFO, sub oscillator, or pulse width. A 303 only has square or saw waves and never both at the same time.. The 202 can mix both ... so don't use this.
The 303's envelope is super simple. There is no sustain control.
So just keep sustain to zero on the 202 & keep modulation of  the envelope to a min. On the 303, there is only a decay control. So on the 202 make sure the release & decay times are the same.
 

New Album - Pursuit of harmony

 Bandcamp
 
 

Tuesday, 1 February 2022

Zagreb - pics -1a

 Some pics of Zargreb in Croatia

Museum Of Arts & Crafts, Zagreb.


Croatian National Theatre.



Petar Preradović was a Croatian poet, writer, and military general. He was one of the most important Croatian poets of the 19th century Illyrian movement and the main representative of romanticism in Croatia.

Statue of Josip Jelacic.( Ban Jelačić statue)

Josip is remembered for his military campaigns during the Revolutions of 1848 and for his abolition of serfdom in Croatia.