MATRIXSYNTH: Patchell


Showing posts with label Patchell. Show all posts
Showing posts with label Patchell. Show all posts

Monday, June 16, 2008

Vocal Filter detail

flickr by fonik2000
full size "PCB for Jim Patchell's Vocal Filter" "The 100-1003 is now in the public domain. This filter was designed to simulate the vocal tract of a human. To do this, there are three resonant filters that will be tuned to different frequencies. To make it so that the phonems can be selected via voltage control, there are three CV shapers on the board. These will allow you to make a more or less arbitrary function to control the filter frequencies." More details on Jim Patchell's site.

Tuesday, March 04, 2008

Jim Patchell Patchtron

DIY modular built from scratch by Jim Patchell in 1978.

Note the filter in the Mattson Mini Modular bears his name.

You can find previous posts feature Jim Patchell including more of his modular DIY here.

You can find the Jim Patchell DIY Synthesizer Web Page here.

Tuesday, September 25, 2007

From the Syntar to the MMM Phoenix

In case you missed it, click here for a letter from George Mattson on the MMM Phoenix series analog modular synth. I thought I'd pull some highlights from the letter below, but please do read the full letter. You can also find a detailed spec list for each module available for the system here, and you can find more info on the Syntar here and here.


"My name is George Mattson.
30 years ago I developed and manufactured a performance oriented analog synthesizer I called a Syntar. The synthesizer was innovative at the time, met with limited success and has recently become a topic of conversation in a variety of synthesizer forums.

Due to the growing abundance of new, analog synthesizer enthusiasts, I have been asked to return to manufacturing.

I took the core circuits of the Syntar (thus, the Phoenix Series) and designed a new format; a portable, true analog modular synthesizer specifically budgeted for the new market."
[Matrix: note the analog of the Phoenix rising out of the ashes of the Syntar.]

Some highlights on some unique modules to the system.

"Signal distribution: I do have one major design philosophy quirk. I don’t like passive multiples-period. Using a passive multiple for signal distribution degrades the signal. Using a passive multiple as a “mixer” sums the signals together and can lead to overloading the input of the destination module. I designed two new modules to replace these functions:
The 4X-1X2 buffer: Sort of a buffered “splitter”. It can take 4 different input signals and split them into two output signals for each channel. Each signal is buffered so, the signal is rejuvenated and doesn’t degrade. I took the liberty of cascading the channel outputs into the input of the next channel. So, if a signal is patched into channel 1, it is available on all 8 outputs until the chain is broken with a subsequent channel input. Then, the original signal is available on the preceding outputs while the new signal is available on all of the remaining outputs. It sounds weird but, once you’ve used it, you wonder how you were able to get by without it.

The 4X Mixer: The “other function” replacement of a passive multiple. The mixer has four inputs and actually two outputs, an inverting and a non-inverting output. I designed the mixer to be used for either audio or control voltage signals. This allows for precise adjustment of an audio mix or, a real nifty way to build complex control voltages by using multiple CV sources. In order to add a bit of excitement, my audio mixing days came back to me and I added a “punch-in” pushbutton on each channel to allow for an abrupt addition or elimination of the channel signal into or out of the mix. This is usually a subliminal function but, makes a big difference in audio or CV real-time control.

Filter: The Syntar utilized the SSM 2040 filter. They’re not available anymore at any kind of reasonable price or in guaranteed quantity. Since I had plenty to do with the rest of the system, I was able to get a custom filter designed specifically for this system kindly and graciously by Synth DIY guru Jim Patchell. He designed a 4-Pole 24dB/Octave state-variable multi-mode filter for this. That’s synth-speak for WOW. It sounds great. Thanks Jim. Way to kick a--!

Keyboard control: OK, I had to make some concessions here. Rather than designing an analog keyboard input module and trying to find and stock keyboards (they’re hard to find anymore in small quantities), I went digital and provided a MIDI-CV input module. It’s actually integrated into the power supply module, which makes this a double-wide module and isn’t available as a stand-alone module. I originally designed the system using a commercially-available MIDI-CV controller but, it had limited function, the manufacturer was hard to communicate with and they didn’t want to give me any reasonable OEM pricing. Sooooooo, I had a MIDI-CV controller designed to my specifications by Scott Rise of Division 6. This turned into one of the coolest modules. (even if it is d*g*tal) Read the module descriptions for a full description. This allows the owner to use any MIDI generating keyboard they desire, or any MIDI generating sequencer control. Mmmm- 16 systems, each utilizing a different MIDI channel. Yes, it blows the “Basic and inexpensive” philosophy out the door. But, it was actually less expensive to design and manufacture than pay the “not-so-OEM” pricing offer’s I was quoted for something less versatile. We all win. I’m negotiating with Scott (a nicer way of saying “convincing”) to produce versions of this in other formats or stand-alone units and allow me to offer them for sale on the web site." [Read this thread for more]. via Scott in that thread: "The rumors are true; I will be coming out with a standalone version of the MIDI-CV converter. As far as an exact time frame, I'm not entirely sure yet. I need to get through the MMM launch stuff first.

I also want to get some input from people like you who might possibly have a need for such a converter or are already using one. What would you like to see it do? Now is your chance to help shape it and make it useful. The initial version is going to be based on the one I designed for the MMM but some things will need to be different. For example, should the mod wheel continue to drive a separate 0-5v output or should it modulate the main CV? Does it need an S-Trig output?

Later down the road I will be making a multi-out version that has even more features, so even if your suggestions don't make it in this version they would probably make it into the next one."

click here for the full letter. click here for the modules. click here for the main site.
And don't miss the forums.

Friday, September 21, 2007

5th annual Pacific Northwest Synthesizer Meeting

"The 5th annual Pacific Northwest Synthesizer Meeting will be:

September 29th
10:00 AM to 3:00 PM

Renton Technical College
Building C, The Technology Resource Center Room 111 3000 NE 4th St Renton, WA 98056

Late breaking news: The Mattson Mini Modular will be unveiled at this meeting. Yes, the happily married Jim Patchell will be present.

More information about the meeting is available at www.sound-photo.com. Unfortunately I have not updated the site from last year. Lazy or busy. The room has changed 111 which is the larger room next door.

I know that someone wants to carpool from Vancouver Island. It is probably okay to make one solicitation on these lists. In the past people have carpooled from Portland.

Take care,
John
www.sound-photo.com
www.antenna-farm.com"

Note: This will be the first public appearance of the Mattson Mini Modular, so if you want to see it and you are in the area, please come. If you have a synth to bring, feel free to bring it as well.

Thursday, September 20, 2007

MMM JP VCF

Mattson Mini Modular JP VCF
Jim Patchell Signature
Multi-mode Filter

Jim Patchell's DIY Synthesis

Many of you might recognize the name Jim Patchell. For those of you that do not, Jim is about as respected as it gets in the Synth DIY community. He started his first synth project back in 1973:

"Well, this project was started in 1973, or there abouts. I was at Santa Barbara City College at the time. The library there had Radio Electronics magazine, and I would go there to read and do home work. When I saw the article on building your own synthesizer, I was hooked immediately. This was, of course, the legendary Paia 2700. Some of the circuits were build as is, others I didn't like. The VCO was one of those. I used the national semiconductor application notes for the LM324 to build the voltage controlled triangle oscillator. Back then, I had no money to speak of, so everything was pretty much built from salvage parts. The LM324 was a free sample. They were not cheap back then. I did buy some LM741/747/748 type opamps to make some of the modules. All of the transistors were salvaged. Pots were a very strange collection of pots salvaged from old radios (I could kick myself for that misdeed)."


Low Pass Filter pictured. He's contributed quite a bit to the synth community. You can see a bit of his work in the following three sites.

The Jim Patchell Synthesizer D.I.Y. Web Page
Jim Patchell's First Synthesizer Project
A New DIY Synthesizer Project

He is also responsible for the electronic design and PC Board layout for the MIKADO Analog Sequencing System posted here.

Wednesday, July 25, 2007

PNW 2007

"The next Pacific Northwest Synthesizer Meeting:
(Is this the fourth year or the fifth year?)

September 29, 2007
10:00 AM to 3:00 PM

Renton Technical College
Building C, Room 111
3000 NE 4th St
Renton, WA 98056

A new economical modular synthesizer may be announced and demonstrated.

The now happily married Jim Patchell may come up again from SB. (We gotta do some serious string pulling.)

Too bad we can't talk Cynthia into visiting the Pacific Northwet with modules.

Bulgarian Pizza will be served at Noon as usual. (Please contribute $$)

James hair will be the color of Carbon111 this year.

I will post additional information on my website soon. The old information gets you on the right track.

Please RSVP with requirements.

Take care,
John
www.sound-photo.com
www.antenna-farm.com"

You can see images and videos of previous PNW Events here.

Wednesday, January 24, 2007

MIKADO Analog Sequencing System

Prototype analog sequencer project on the Techno Toys site. Title link takes you to more info including a sample, details for each module and an image of the hardware in the flesh.

"Mikado is a configurable analog sequencing system, optimized for controlling a small (2-4 voice) analog modular synthesizer.

Mikado was designed to meet the need for a flexible, non-traditional hardware sequencer. A primary design goal was to include several modules for creating and manipulating rhythms using dividers, logic, and manual input. Flexible voltage sequencing, quantizing, signal routing, and manual inputs were other necessities.

Mikado is a "semi-modular" sequencer ala the Fenix or Serge systems, rather than discrete modules as other systems are. This is in keeping with the goal of controlling a small system, and reflects the designer's needs. Mikado could also serve as the heart of a larger sequencer system by adding modules from other manufacturers. In the present design, banana jacks are used for patching, though other types of jacks could be used by changing the front panel drilling accordingly.

Mikado's module complement and front panel were designed and specified by Jim Johnson. Electronic design and PC board layout are by Jim Patchell. PC boards for this project will be made available, and a customizable front panel is also available. It should be noted that, while the remaining material on this page describes the sequencer's specified configuration, the circuit and PC boards will have some additional capabilities, such as extra LED drivers, some additional sequencer modes, etc.

Modules
Mikado's module complement is as follows:

* 1 Master Clock
* 2 8x2 Sequencers
* 2 Quantizers
* 1 Pattern Generator
* 1 Transposer
* 2 Analog Switches
* 1 Sequential Switch
* 2 2-input Logic Gates
* 1 4-input Logic Gate
* 3 Logic Inverters
* 1 Type D flip-flip
* 1 One-shot
* 1 Binary Divider
* 1 Prime Divider
* 1 Divide-by-N
* 2 Gate Switches
* 2 Gate/Trigger Buttons
* 3 Toggle Switches"


Via Exsurdo in the comments of this post.

Friday, October 20, 2006

PNW Synth Meeting This Saturday

Just a reminder that the PNW Synth Meeting is this Saturday. Title link takes you the previous post with some pics.

Pacific Northwest Synthesizer Meeting

Saturday, October 21, 2006
10:00 AM to 3:00 PM

Renton Technical College
Building C, Room 110
3000 NE 4th St
Renton, WA 98056

No charge. (Contribute for the Pizza) Free.

There will be several more first time visitors this year. Please bring
synths that you have brought in the past. Don't forget power cords, patch
cords, adapters. I am planning on having a small Mackie mixer and powered
speaker for your use.

Performances are welcome.

Talks are welcome.

Lookers are welcome.

Good Lookers are welcome.

Jim Patchell will not be coming this year. A pending marriage takes
priority.

More information at www.sound-photo.com

Take care,
John
www.sound-photo.com
www.antenna-farm.com
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