Search found 125 matches

by forbin
Wed Sep 16, 2020 6:53 am
Forum: Music Tech DIY
Topic: CS-80 filter v2.3 for Euro & 5U
Replies: 168
Views: 14448

Re: CS-80 filter v2.3 for Euro & 5U

There was a version of this filter for the Shruthi on GitHub if people want a schematic to help out.
see: https://github.com/cs80/cs80_shruthi
I suspect that it is very similar?
by forbin
Mon Sep 14, 2020 7:13 am
Forum: Music Tech DIY
Topic: 4MS DLD diy
Replies: 6
Views: 389

Re: 4MS DLD diy

The second picture is to separate the noisy digital earth from the quiet analog earth. They are at the same potential but it allows the PCB tool to keep them apart.
by forbin
Sun Aug 23, 2020 11:27 pm
Forum: Music Tech DIY
Topic: AKM DAC problem
Replies: 2
Views: 89

Re: AKM DAC problem

I have used a different AKM DAC but they are all pretty much the same. Are you controlling the operating modes via logic or via SPI/I2C? If i remember correctly there is some interplay between using the logic control and the serial control modes. The signals are OR combined internally from my memory...
by forbin
Wed Aug 12, 2020 10:48 pm
Forum: Metasonix
Topic: More schematics
Replies: 8
Views: 552

Re: More schematics

Cool! but what we really need to build is the TM-7... as i'm getting older an Engorge button is becoming a necessity...
by forbin
Tue Aug 11, 2020 11:53 pm
Forum: Metasonix
Topic: More schematics
Replies: 8
Views: 552

Re: More schematics

The TX1 is a fascinating circuit but as Eric points out "Can't figure it out? Hire a Tech..."
Anway this MAY be of some assistance but on the otherhand it may be a complete red herring!
I found it an intersting exercise come what may... I might even build one!
TX1.png
by forbin
Mon Feb 10, 2020 6:38 pm
Forum: Music Tech DIY
Topic: In CV: an Arduino-powered virtual ensemble that plays Terry Riley's "In C" on CV/gate outputs
Replies: 11
Views: 941

Re: In CV: an Arduino-powered virtual ensemble that plays Terry Riley's "In C" on CV/gate outputs

Very neat with nice results. I may try butchering some of your code into my ornaments & crime for some experimentation, not really enough outputs but a starting point... Tanks for posting.
by forbin
Sat Nov 23, 2019 5:08 am
Forum: Music Tech DIY
Topic: Yamaha DK-40 synthesizer...
Replies: 0
Views: 375

Yamaha DK-40 synthesizer...

I scan the various online classified sites for old 1970's Organs with a third manual and scored a FREE Yamaha D80 recently. This organ has a sort of preset CS-15 embedded in it. I am going to use the IC's to make a clone since the rest of the organ is pretty sad where mice have chewed all the wires ...
by forbin
Mon Oct 14, 2019 6:59 am
Forum: Music Tech DIY
Topic: so has anyone built that fancy BERGFOTRON VCO?
Replies: 80
Views: 11605

I think I would have to advise against the bohemiath board as the trouble with it is that it needs a bohemiath squared front panel to do it justice! I have most of the board going but I have ended up just exposing the Haible divider and the wood wind shaper. I am seriously thinking of making separat...
by forbin
Sun Sep 29, 2019 8:20 pm
Forum: Music Tech DIY
Topic: TH x4046 VCO V/Oct tracking with different chips
Replies: 26
Views: 2320

I did a graph of tracking of ti, philips (nxp) and Fairchild 4046 devices on the em forum back when Thomas Henry posted the design. Found the Fairchild part was probably the best and the TI was pretty poor... didn’t have a Motorola part (think they are On semiconductor now).
by forbin
Tue Jun 25, 2019 7:16 am
Forum: Music Tech DIY
Topic: Weird, unique DIY modules
Replies: 22
Views: 1682

Yep all of nonlinear Andrew’s stuff is really left field and really “outside the box”. He has made some excellent twists on some really old school designs like his version of the Moog ladder filter. For some other options try the wogglebug and some of the Buchla older stuff on electro music.
by forbin
Sun Nov 04, 2018 9:55 pm
Forum: Music Tech DIY
Topic: Whst is a good design for a supersonic VCO?
Replies: 63
Views: 4457

The 4046 can be made into a reasonable VCO as per the Thomas Henry design over at EM. I built a PCB and did a fair bit of testing and it all worked pretty well. The tracking is pretty dependent upon the manufacturer! The TI one was far away the worst and the Philips and Fairchild ones a lot better. ...
by forbin
Tue Sep 11, 2018 8:41 pm
Forum: Music Tech DIY
Topic: Plaits DIY
Replies: 155
Views: 16706

Certainly looks very doable... My preference (as I am not manufacturing it) would be to move most of the components to the back and leave pots and sockets on the front -- easier to make them 0805. Pain for manufacturing but fine for hand soldering... I like the design and I can see why Oliver went t...
by forbin
Tue Mar 27, 2018 6:41 pm
Forum: Music Tech DIY
Topic: 4 operator FM percussion module
Replies: 8
Views: 1027

I built the Thomas Henry 8038 vco on fronik’s layout. I must admit to being fairly disappointed in its performance. Maybe it needs a revisit. I had a fair bit of grief getting 8038’s — do you have a source? Thomas’s book is very good though and worth buying the e-book version. Maxim made an improved...
by forbin
Wed Feb 28, 2018 9:13 am
Forum: Music Tech DIY
Topic: Divide by N COM @ +/-15?
Replies: 11
Views: 677

Sorry by mistake... Your absolutely right -- the NCOM is quite different from Jurgen's one and probably closer to CGS version...
by forbin
Wed Feb 28, 2018 8:39 am
Forum: Music Tech DIY
Topic: Divide by N COM @ +/-15?
Replies: 11
Views: 677

Pretty sure it will be Jürgen’s design as random sauce has bought the rights to all then as well as working with serge.
by forbin
Tue Feb 27, 2018 5:52 pm
Forum: Music Tech DIY
Topic: Divide by N COM @ +/-15?
Replies: 11
Views: 677

If it is random source then it will probably be based on Jürgen Haible’s design which is still in some archives. It was also in the bergfotron advanced vco. It is quite different in design from the cgs divider.
by forbin
Wed Jul 12, 2017 7:05 am
Forum: Music Tech DIY
Topic: Mutable Conversions to DIY Friendly PCBs
Replies: 177
Views: 23555

I have been slowly (and I do mean slowly) chipping away at this and have a sort of operational Braids that is ALL through hole and uses a STM32 eval board for the processor (this one http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-...
by forbin
Tue Jun 20, 2017 7:23 am
Forum: Music Tech DIY
Topic: Trevor Marshall VCA/Ring modulator - Eurorack
Replies: 55
Views: 3422

Trevor Marshall was one of my lecturers at WAIT years ago and I thought that the vcf was one of the more interesting elements of the 4600. He was heavily into switched capacitor filters at the time and made an ETI modem design using them. I have one of the envelope generators as well... he was a bit...
by forbin
Tue Nov 29, 2016 8:25 am
Forum: Music Tech DIY
Topic: Are there any analog phase modulation VCOs?
Replies: 141
Views: 11097

Did an all analog Phase modulated Sawtooth in Spice which looked like it might be OK. From memory you got +- 360 but you did get a few glitches... Never committed to a full circuit but if anyone is interested I will dig out the file... see: http://forbinthesynthesizer.blogspot.com.au/2013/06/stay-on...
by forbin
Fri Nov 04, 2016 2:03 am
Forum: Music Tech DIY
Topic: Digisound VCO PCB for CEM3340, low parts count
Replies: 6
Views: 743

Just be a little careful with that design as I fried a CEM chip with that as it has little protection on some of the pins that lead directly to sockets... the chip isn't that robust... (well this was the original one) The board has sat waiting for a replacement for over 25years! I am pointing the fi...
by forbin
Mon Sep 26, 2016 8:24 pm
Forum: Music Tech DIY
Topic: Electronotes Through-Zero VCO?
Replies: 26
Views: 2315

This is probably what spawned the whole thing about Jung and the LM13700 OTA saga: http://electro-music.com/forum/viewtopic.php?highlight=jung&t=50884 I think Ian was really just saying that you can do the -ve supply modulation on the LM13700. When you look at the internals of the 3080 Vs the 13700 ...
by forbin
Sat Sep 24, 2016 8:33 pm
Forum: Music Tech DIY
Topic: Electronotes Through-Zero VCO?
Replies: 26
Views: 2315

Did a layout for En129 over at em ages ago. It isnt the tightest but easy to press and peel. See http://electro-music.com/forum/viewtopic.php?highlight=electronotes+129+tzvco&t=40616 There was some useful follow up comments from sebo. You can avoid the interesting use of power line control of the 30...
by forbin
Sun Aug 28, 2016 3:50 am
Forum: Music Tech DIY
Topic: Announce Thread: Magpie Modular - uBraids - Braids in 8 HP.
Replies: 658
Views: 58463

Exactly the same as Braids - the OLED display is just emulating the 4 character LED display on Braids, at least as it stands. Firmware changes to make better use of the OLED would be possible if someone wants to take on the project. Having a bit of a look at schematic you could loose the AVR/2 x se...
by forbin
Fri Aug 26, 2016 10:24 pm
Forum: Music Tech DIY
Topic: Announce Thread: Magpie Modular - uBraids - Braids in 8 HP.
Replies: 658
Views: 58463

Like the display and panel.

I did have a look at your display INO... is your plan to use the Braids code without modification and get the AVR to pretend to be LED displays?
by forbin
Tue Jun 21, 2016 8:46 pm
Forum: Music Tech DIY
Topic: DIY-Project in SMT or TH? What do YOU want?
Replies: 30
Views: 1195

Interesting thread. I am happy with 0805 but much smaller than that is pushing it a bit for my old eyes. It's interesting that most people seem happy with the 0805 passives but struggle with the 0.5mm TQFP's. I went down the track of building a Braids clone with a 0.8mm pitch processors, which are M...

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