1.2 volt per octave input

Pictured is the 258v with the addition of a trimmed 1.2 volt/octave CV input (the grey banana jack on the left). I have decided to go with this system because it gives the trimmed CV in I want, but doesn't take away any other inputs or outputs. The fine tune control for the left most CV in, I believe only was useful when scaling that input for a keyboard.

I'm working on them, and still waiting on the Selco knobs...

Gentlemen, I give you the 258v

This is a clone of the Buchla 258 oscillator. Despite what some people might tell you, it is totally true to the original in sound and response. I made all the electronics fit between the panel controls on a single PCB, as opposed to wiring to it like the original. I replaced the obsolete heated transistor pair with a modern matched pair and a tempco. The CV inputs respond exactly the same as a 258c. This one has the CV input fine tune control on the left, but I will be doing them with a grey banana jack in place of that. It will be trimmed to 1.2v/octave, but the other CV inputs are unaltered. Now I just have to build the rest of these....

Verbos' little workshop

I have a full on production line going here. I <3 my new Swiss Assembly Jig!

"Hey Mark, why is the timbre always on?"

Sometimes analog switch chips will not respond to the front panel controls if the control pin is missing!!!! How did that happen? I don't know.

Holding Pattern

As I wait for my silkscreen guy to come back into town and the rest of the back-ordered parts to arrive, I give you a picture of a 258 clone with no front panel legend.

funny waveshapes

Some people think that a good waveshape is one that looks like what is printed in a textbook. A clean SAW wave is not always the best sounding one. Buchla 259s do not address the waves at the main output by the way they look, but rather by their harmonic content. Sure, there's a square and sine output, but the main output is a blend between even and odd harmonics, between hi and low order harmonics and between lo and high timbre. This always seemed, to me, like the better way for a musician to deal with oscillator output. The 258 claims to have a saw and square wave, but I feel that the spirit has always been about even or odd harmonics. They crossfade from sine to saw on the top oscillator and square on the bottom. The waves never look perfect, but they sound so good that the oscillator has a cult following. People clone it left and right. The above 'scope pics are from the prototype of my clone.

Here you will find some scope shots from an actual vintage Buchla 258C:

http://www.synthtech.com/pix/buchla/b258/b258_w1.jpg
http://www.synthtech.com/pix/buchla/b258/b258_w3.jpg
http://www.synthtech.com/pix/buchla/b258/b258_w4.jpg

Looking good. Sounding good. Feeling good.

Big Bag of Bananas

Have you ever wondered what a bag of 500 Johnson banana jacks would look like? Here it is. I have included my old (and useless) cell phone in the shot to give some reference for the scale.