That 214 Booster Board

In my post about the Music Easel, I mentioned my clone of the 214 power booster board. Here's a picture of it.


Here is the original.


And, here is the reverse engineered schematic I made.


Since I traced this, I have seen another one that had most of the values changed, but you get the idea. Here it is inside Reed's 300 cabinet. Notice the red velvet trim on this bad boy.

The 266 project

The Audities Foundation got whatever parts were left in Don's archives during the garage sale about 6 years ago. Included in that lot were 2 unused 266 Source Of Uncertainty panels. I built this one and am working on the other.

Obviously, this is a very popular module and every Buchla user wants to have one, but without any circuit boards nobody was jumping at it. A couple "kits" for this module went out the door at the same time. So I was fortunate to track down some scans of the circuit boards without any parts installed. Then came the long process of cloning them. This module has 3 PCBs inside. The motherboard (with all the panel components on it), A and B.



I know, I know. "They're not blue!" Well, I didn't feel that it was necessary to make the PCBs the same color as the originals. The second cry is, "But there are no orange banana jacks on MY 266!" True, the original release of the 266 used red banana jacks for both pulse input and pulse output jacks, but since Don changed to orange for pulse inputs in the late 70s and is still using that standard today I went with the new standard. It turned out that I made several errors in my cloning of the PCBs, leaving short traces between pins on ICs off. It's ended up working after a little stress and now lives happily between a 265 and a 266e. Long live the Source of Uncertainty.

This is a Music Easel I had for repair. That's a suitcase type case with a 218 touchplate keyboard, a 208 stored programmable sound source and a 214/215 power supply. The power supply was not working on this unit. It was designed to be operable from 12 volts in batteries as well as from the wall AC. It takes the 117 VAC and sends it through a huge 12 volt transformer. This 12 volts is filtered with a GIANT capacitor. Then that unregulated 12 volts is plugged in where a battery would have also worked. There's a circuit that takes the 12 volts in and spits out +/-24 volts. That is then regulated down to +/-15 and +5 by the normal 215 power supply card. I have cloned that "voltage booster" card and I think I'll use it in my 203 cabinet if I ever need to power a 24 volt module. By the time Don made the 203 cabinets, he had stopped using 24 volts in his designs. Those cabs have Power One brand single output supplies accross the back. Mine is 8 spaces wide so it has doubles of the positive and negative 15 volt supplies. The top two boats get their own.

Why Buchla?

Since this is the first post, I'd like to start by explaining why I vote Buchla.

The Buchla 200 is the best modular electronic instrument ever made.

1. Don Buchla designed the front panel of his instruments first and the electronics second. A musician himself, this means that each module was an idea for a musician's tool rather than an engineer's.

2. Audio paths and control paths are totally divided. The control path uses unshielded stacking banana cables. The audio path uses 1/8" mini cables. On early modules the control paths and signal paths even used separate power rails! The audio signals are line level, just like all the signals in a recording studio, so patching in and out of the system is seamless. The stacking bananas are great for control signals, they mult simply. The EF Johnson banana jacks come in a variety of colors, which Don used to code what the jacks are used for.

3. Controls sweep within a musically useful range. This is in some ways related to #2. Because audio processing modules never have to concern themselves with CV signals and vice versa, the controls don't have half of their rotation representing useless values, like a Serge.

4. "Unencumbered by engineering expediency or presumed musical asthetics..." Taken from the 248 catalog page.

5. Circuit boards are all mounted parallel to the panel, making the system take up less space behind the panel than most modulars. This allows for the suitcase cabinets and folding 203 cabinets. I will never understand the MOTM/Moog/Blacet/whatever system of mounting PCBs sticking way out back.

6. Sound design emphesis taken away from "fat" and "juicy" 24dB/Oct. lopass type sounds and into more interesting textures. Sure, you can do FM, AM, whatever audio rate modulation on any modular, but Buchla really pushes the user that way. The 259 has a switch and VCA internally patched for FM. It has a dedicated modulation oscillator!

7. Analog address of sequencers. Most of the time a sequencer is simply going to be pulsed along linearly. But having the CV in to sweep through the range of steps allows the sequencer to be used in several new ways including as a quantizer, tracking generator and more.

8. Harmonic Generator. No other modular ever had an oscillator module with the first 10 harmonic sine waves available. Don updated his 148 module for the 200 series too, but only made 2 as far as I know.

9. Source of Uncertainty. These days, all modulars have noise and sample & hold modules, but nobody ever made so many specific and musical options available to make sounds randomly shift and evolve. All hail the 266!

10. Quadrature mode on the 281. After a while, the ADSR became de facto for the whole of the synth industry. The 281 module allows all of the modes on a 284 or a 280 to be achieved, with voltage control of each stage. It's the quad mode that allows a quadrature LFO to be created, for quad panning or whatever. However, this mode can also be used to creat ADSR and DASR envelopes. I like the ADSR that you get from this because it follows through the whole decay and release cycles, even when it only gets a short pulse.

11. "Timbre." No, I don't mean the sound of the machine, at least not in this case. I mean the "timbre" circuit that is inside the 208 and the 259. It involves wave folding similar to the Serge wave multiplier (totally different circuit) attached to the sine wave output from the oscillator. The 258 already had the ability to sweep from a sine wave to either a saw or square wave, which is a bit like lopass filtering. A sweep of the "timbre" sounds unlike any other synth and is amazing.

12. Voltage Controlled Panning. The 207 allows 2 channels to be sweeped around via a CV. The 227 and 204 allow quad panning from 2 CVs. Simple yet wonderful.

13. Tunable Touchplate Keyboards. Those users who have no interest in playing a piano keyboard can rig up a 217 to do lots of things that no other system has ever allowed.

14. VTL5C3. The vactrol used in the 292 lopass gate has a characteristic slew to it. It makes the attack of any note from a Buchla 200 a little round. The "woodiness" of the sound is a key reason that the Buchla's sound has been discribed as natural.


I'm sure there are more reasons that will come to me as soon as I post this, but it will do for now.