I will post here some of my tested cirsuits. Now I see, that it will be two more versions of BassMaster:
- BassMaster 74, TL074 based synth, +/- 12V;
- BassMaster 69, CD4069 UBE based synth, +/- 6V;
All of them will have the cheapest MT3608 DC-DC step up converter.
ATTiny 85 tested with exponential V/Oct table, and it's working fine. I only still can't make any good sounding LPF. It's possible to replicate Moog's transistor ladder LPF, but it's not my goal.
Here are some new circuits of BassMaster 69:
BassMaster69_PowerSupply.jpg
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Dual power supply
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BassMaster69_VCA.jpg
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VCA
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BassMaster69_SAWVCO.jpg
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Saw VCO
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I'm very interested in PCB, but I still not sure with circuit design.
I've already made new version of expo conerter, and some changes in power supply circuit. And I want to use iPhone as MIDI source. Now I've tested ESP8266 WiFi module as CV/G source for Korg Monotron, and it's working good with no audiable latency. Also BassMaster should have some another filter.
I'm wating for parts to solder and test new version of BassMaster, and then it will be great to help me with PCB.
Eurorack case still is too expensive for me. So, I decided to make 'tiny' rack for testing new circuits for BassMaster. Height of modules is 100mm, width 10X mm.
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I have tested several filters, even tried diode half ladder one. But I don't have enough knowledge to set them up well. Trials and errors...
Later I will return to the development of the diode filter (it sounds like boiling mercury, but I have still no success with resonance), and so far earned only Buchla-syle LPG.
But it works great!
First ATTiny85 is still used as signal source, and the second one is for vactrol LED controlling.
500Hz of Arduino PWM is not affect LDR. Now you do not need linear LDR because its possible to correct envelope by microprocessor. And I want to make sine modulation.
Joined: May 11, 2018 Posts: 5 Location: Netherlands
Posted: Tue Dec 11, 2018 2:25 pm Post subject:
Hammer wrote:
There is still a lot of work, but it is already possible to design a PCB I think.
Very nice sounds!
From the beginning of February I have time to design and order PCBs. You can refine your design in the mean time, and we can discuss some options (SMD/SMT, all in one PCB/pots etc mounted separately, etc).
Tell me please, can I use CA3080 with 5V single supply?
Barely so I think ... but depends ... output voltage swing seems limited to about 1.5V from the rails .. so that looses 3V .. leaving about 2V output swing at 5V. But voltage range minimum is specified as -2V/+2V .. so it should work at least.
Also it will need some biasing when operating on a single supply .. which may get a bit tricky with it's low-ish input impedance (like 10k worst case it seems) .. could use a regulator like construction to make the virtual ground at Vcc/2 to solve that.
But maybe you can get away with these limitations ... when you can deal with a 2Vpp output excursion around Vcc/2 .. by maybe adding an opamp after. _________________ Jan
also .. please don't march .. we are on a bridge right now.
are my design and I never tested them. Psyingo wanted to try them and found some weirdness for which he made modifications and said he made it work better. I don't know what he did and didn't get a copy of his schematic, so be warned, it may take some fooling around to get it to work. If I were to try it, I'd start with the upper and then the lower. _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat?corruptio optimi pessima
The last attempt will be to use digital potentiometers. And if the attempt turns out to be unsuccessful, then I will more accurately select the vactrols.
Joined: Nov 20, 2007 Posts: 1769 Location: West Red Spot, Jupiter
Audio files: 212
Posted: Sat Dec 15, 2018 5:44 pm Post subject:
I designed with 4007 and 4069 in non-digital mode just to see if it will work, did several things that didn't work perfectly but were useful anyway, like saw to triangle with BS sine output (for a Fatman). I view the 4007 as a CMOS transistor array with 3 of each P and N types, sorta connected usually conveniently. _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat?corruptio optimi pessima
I understand that, and it's great! And I always check such schematics. And I often sketch what I have checked. That's why I've been doing my synth for so long
I tried the second circuit with a stereo pot. instead of transistors, but I really did not like the sound of resonance. I have little experience, perhaps the input signal was high amplitude...
That's what I got:
4069_SK.jpg
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I can't hear any audiable clicks from fully breadboarded circuit. Maybe some hiss sound, but this is breadboard...
Using two analog oscillators it is possible to make an ADSR circuit without using a microprocessor. On the contrary, you can use a very small microprocessor, such as Attiny 10 for decay circuit.
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