DOBOZ - Touch Sensing Note Memory - Buchla format 4U --- part 1

These are my build notes for the DOBOZ TSNM module

 I like the compact format.

Its a sequencer +

 

Here are some pics of the raw PCBs

 

There are two versions of this module .

One uses a teensy 3.2, and a second uses a teensy 4.0

i bought this board many years ago when teensy's 3.2 were plentiful.

I recently received a NOS 3.2, so thought I'd finish this build.

My board is from 2017. rev 1.0

MPR121 breakout board.

Links

+ Official site

+ BOM 

+ official build notes

SEMICONDUCTORS first

Orientation of IC1-IC5 and IC7, Q1, D1 and D2 is clearly designated on the PCB. 

74HC595 2 IC3, IC4 - shift registers

mouser 595-SN74HC595DR

 

 

OPA171

IC5 

SOIC-8 operational amplifier 

mouser 595-OPA171AIDR

TL072

 IC1 

SOIC-8 dual operational amplifier 

mouser 595-TL072CDR

 

 

ADP150-3.3V 

IC7 TSOT-5 linear voltage regulator 

Mouser 584-ADP150AUJZ-3.3R7

 

"The trickiest part may be the DAC8560 (IC2), it’s a VSSOP-8 device. 

This is hand soldered

 

Use lots of flux , a fine soldering tip and fine solder.

... and a steady hand

--------------

MMBT3904 

Q1 SOT-23 NPN bipolar transistor 

Mouser ;512-MMBT3904

I didn't have this exact transistor.

I used this instead:

Encoder: ordered and arrived.

Mouser No:

858-EN11-HSM1BF20

Mfr. No:

EN11-HSM1BF20

Mfr.:

TT Electronics

 

 

Resistors..

Some of the resistors need to have 0.1% tolerance

2 x 100K, (R1 & R15)

1K x 1, 

27k, 

33k, 

teensy 3.2

mouser

coco.

NLC build notes 2 for a LPG

These are some build notes for a Nonlinear circuits LPG version 1.

Its actually a really old NLC design with through hole components.

The old silver panel version too. I first built one back in 2015. 

I bought 4 panels/ Pcbs with the intention of building a quad Low Pass Gate (LPG).

like a 292 and only got around to building one module.

These are the original notes:

Low Pass Gate - Filter/VCA - Buchla Style - Build Notes

And these are Andrews blog notes:

http://www.sdiy.org/pinky/data/WAMOD4%20lpg.pdf

I decided to finally finish off the remaining 3 PCBs

This came about when a friend recently asked me what was the best sounding 

LPG module in Eurorack.

He was particularly interested in DIY.

There are many low pass gates out there.... eg:

Makenoise QMMG (ridiculously expensive)

                    ... might as well buy a real Buchla 292e and be done with it.

MakeNoise MMG

MakeNoise LxD MakeNoise Optomix

NLC Dual & single LPG

Meng Qi - LPG (passive)

Erica Pico LPG

Synthrotek LPG

Endorphin.es Grand Terminal Pittsburgh Modular Lifeforms Dynamic Impulse Filter.

Ken Stone's LPG Mystic Circuits LPG

Malekko/Wiard Boogie & Borg filter RYO Aperture Takaab 2LPG Pittsburgh Modular LPG

The synthrotek, Ken stone & NLC ones are DIY.

Below is the rear of a NLC single LPG... half built.

Notice the headers for the vactrol ... hopefully will make it easier to swap vactrols.

All LPGs are based on the Buchla 292 which is expensive and hard to find... esp a original vintage one.

Part of the problem in attempting rebuilding from the original schematics are hard to find components.

Esp the vactrols.

Anyway, I think it's pointless trying to rebuild the past.

Like a dog chasing its tail. 

Better (in my humble opinion) to use the past as inspiration and build something that

is of this time and place.

Andrew also did a later version of a Dual LPG

which is well worth checking out.

66. Dual LPG - build notes

This version used headers to make the dual vactrol.

The pic below is of the single NLC LPG.

I'm adding headers for the pots & vactrol to allow some experimentation

Both versions are designed for a dual vactrol. 

Some of my earlier 4U builds (eg of a "cloned" 208) use dual vactrols like the VTL5C3/2, 

If you have a few spare use them. 

Dual vactrols are actually two photo-resistors and a LED in the one package ....

The VTL5C3/2 are hard to find and expensive

You could buy cheap Chinese copies but another way around this is to build your own. 

I kinda like this as DIY is fun, I don't want to make a 292 and DIY lets you experiment and 

find your own unique sound.

My friend wants the module to be flexible ... with the ability to swap components to adapt the sound.

The LPG version 1 is best for this as the vactrol is standard.

Version 2 uses a box to make the vactrol.

The other mod I'm making is with the pots.

Do I use log, linear, anti-log?

The BOM indicated 100k linear .. but it will be fun to experiment with this.

With the first build, I liked the sound of the module with a log 100K pot for the frequency.

So I'm adding some trimmed IC headers for the pots and vactrol.

The 33k can be varied up to 51K .... It sets the Cv level.
I left it at 33k.

The 10K sets the gain of the output signal.

I started with this at 10K

Decided to use surface mounted resistors to make changing them easier.

After playing around with the module I deciced to up the 10K resistor to 22K

Better !!

upped it again ... this time to 51K

Yes !!!

Who wants to die for art?

Divine as Dawn Davenport in John Waters' Female Trouble, 1974. ..... ???

DIY Vactrol time.

(Dual vactrol)

This was my first attempt ... not very successful

You can find a bit more info on vactrols here:

+ Vactrols - Optocoupliers

I started with a 5mm green LED and 

 two GL5549 LDRs

It was really hard to encase this in shrinkwrap.

so opted to try making two separate  vactrols

I used two GL5549 & two 3mm Red LEDs.

I joined the two LDR in series ......there are 3 connections on the LDR side.

The LEDs were connected in parallel ... just 2 connections on the LED side.

In the pic below, the LED side is on the left.

The LEDs are sitting on top of each other .... sharing the same anode & cathode sides.

Pretty messy I know.

The pic below is the vactrol looking at the   LDR side (3 terminals).

I'll make the next one cleaner. however, the vactrol works.

The buchla 292 I think used a VTL5c3/2 which had a dark resistance of 10M ohms

and a slow response time.

which is pretty similar to the GL5549 LDRs which has a dark resistance of 10M and a response time of about 20ms

... probably best to just experiment.

Second vactrol.

I used two GL5549 & two white 3mm LEDs

Sounds great. I think better than the red LED.

In this test I used B100K pots for both Freq & res.

102

Some pics of the LA67 102.... Dual Stereo Locator
It's not a Buchla Module.

It follows the same size, format & the circuits used are I understand based on Don's schematics.

I hope one day, Buchla will release an official 102.

I've only seen one real Buchla 102 in the flesh. These are as rare as hen's teeth.
The LA67 version is a pretty easy build, though trying to match the JFETS is tricky.
 (I'm still trying to get it perfect at the time of writing).
I'm not affiliated with the manufacturer in any way. I'm building this to learn how it works
and these notes are just my personal doodles to help trouble shoot any issues I may encounter during the build.

 If you are unfamiliar with JFETS check this link out.
 https://djjondent.blogspot.com/2019/05/transistor-families.html

Metro Modular also make a module inspired by the 102 which is worth exploring if this module interests you. (I would also love to see a Buchla USA version).

 Anyway, back to the LA67 module.

The virgin PCBs, etc.

This module has a 0v & +15 power supply. The original used an additional +24V rail.
The original op-amp was most likely a LM301 (which has a +V rating of +18V)
This module's BOM calls for a TL071.

The BOM calls for J201's
Mouser No 106-J201
My sources tell me that the original used  2N4339 JFETs

tHE Rotary switches are these

172 - Dual Signal Leveler

This is a build I'm doing for a friend.
I don't have (or ever have seen an original 172)  vintage one. They must be very rare.
Do contact me if you have a original you'd like to sell.

Until that time, or until Buchla USA decides to make one, this will have to do.

Anyway, back to the build.

These boards are from LA67 in Spain.
They are based from original schematics so I hope will be close to the original.

rESISTORS first

Looks like a really easy build.

The original Buchla 100 catalogue describes the module as:
"Two high-gain, constant-output amplifiers. Output signal levels are maintained at 0db (plus or minus 1 db) for input variations from -40db to +10 db. Time constants are variable from .05 to 5 seconds."

So it appears to be a basic compressor/limiter with a time constant knob for each side.
The time knob I guess sets the attack/release compressor speed ??
A slow time probably provides very gentle changes in loudness where as a very fast time produces an aggressively signal.
 You will usually find in most compressors that even if the peak levels are set the same, a compressed signal will sound louder if it has a faster recovery time.
Im not sure if this module works the same

 Anyway, the build is all descrete components, & through hole.
Nice.

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Buchla Index
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Model 155 - Dual Integrator

Some pics of a build I'm doing for a friend.

It's not a Buchla module.

It follows the same size, format & the circuits used are I understand based on Don's schematics.

This is the LA 67 version.

I hope one day I'll find a vintage original, or Buchla USA will release an official 155 module.

I am in no way affiliated with the manufacturer.
These are just my personal notes to help trouble shoot any problems I might encounter during the build.

.
A vintage Buchla 155 is super super rare. I have never seen a real one and can only imagine how it would function. My hope is that Buchla USA will reissue this module soon. (please Eric).
Or if you have one and wish to part with it, don't hesitate to contact me.

The module is described in some old 1992 docs as such:

"(The 155) produces continuous control voltage functions when used in conjunction with sources of discrete control voltages (e.g. keyboards, sequencers). Positive and negatives slopes may be individually varied from 15 volts in .0025 seconds to 15 volts in 10 seconds; either or both slopes may be voltage controlled. Particularly useful for generating complex voltage controlled envelopes, frequency glides, and repetitive control functions."

(from a catelog for the 1992 Ars Electronica exhibit Eigenwelt der Apparatewelt. Pioneers of Electronic Art, edited by David Dunn)

So it looks like it's an early form of function generator.

 The integrator is a very important electronic circuit. You will see this type of op-amp circuit again and again.

This is a common RC or resistor capacitor circuit.
It's also commonly known as a Op amp integrator circuit.

This module however doesn't use op-amps. 

Instead it uses transistors.
Google Miller integrator.