I do love a big giant knob on a module. Different sized knobs add to the visual interest of the panel.
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Thatās what she said.
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After a lot of printing, Iām done moving all my jacks to 3D printed nuts (and took the opportunity to change other widgets to make every module now have two colors)
Whites are outputs, anything else is an input.
See also:
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The Diode Ladder Filter is in the rack. I really like the sound. A slow CV from NLC Triple Sloths does a nice sweep.
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New on the table directly from the etching solution: my self made PCBs for @moritzklein VCO and VCA, and a small TDA2030 amplifier for single power supply based on the originial design from the data sheet.
Already finished in KiCad, but not etched yet: the @moritzklein Wavefolder.
Enough work for the free upcoming days
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I have the TDA2030 in my to do list in a module that will include a speaker. I assume that you went for the singly supply solution because you want to power it from a separate to the rest of the system supply? These amplifiers draw a lot of current, more than an entire system with 40 modules or soā¦
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Yes, thats the reason, and I will power it with more than 12V, e.g. the 19V from an old notebook power supply. I think I will design an extra enclosure, in the form of a bluetooth speaker.
I will power it with more than 12V, e.g. the 19V from an old notebook power supply
Exactly what I was thinking myself! A notebook switching supply will have plenty of juice and then some, which I was thinking of directing to a 9V regulator to power 9V modules as well as a couple of outputs on a front panel for use with guitar pedals.
I have a couple of concerns, however, about switching suppliesā noise and the DC coupling needed for the single supply. Hopefully the RC filter and the hefty 2200Ī¼F capacitor at the output will take care of these, but do let us know how it works out for you.
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Hey, I connected it all together with one of my quiet good Heco loudspeaker and a 19V / 3.5A notebook power supply, and Iām really happy with the result. Its really loud and there is only a slight noise. Before this I used my non- switching bench power supply with the same result, the amp took a maximum of 0.5A at 19V.
Hm, video upload is not allowed, so I cant deliver the audio quality. But I can say it really depends on the speaker quality.
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ok, this means the 7809 needs to burn 10V * the output current, then you need a really good heatsink. I would not load it with more than 200mA, and even thatās 2W of heat on the 7809.
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Building amplifiers is (almost) as good as building synth modules!
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Yes! And what would a synth do without an amplifier? 
And this small amp is perfect for a small case full of modules
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Yes, indeed. I do have proper heatsinks for every regulator (and on the TDA2030 as well) and the guitar pedals should not draw more than 50mA total at most. I will also most likely use a 12V or 15V brick. I have a full box of them so Iāll shop around!
Great to see that my intuition (that the TDA2030 should make a good synth amplifier) was correct! I have two donor speakers for the project both at 3ohm (which will be pushing the TDA2030 a little). One is from a Philips home theater rear speaker and the other from Logitech bluetooth speaker. I reckon either should be good enough for the project.
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From what Iāve seen you can get rid of the noise with a couple of LC low-pass filters, one where the power comes into the circuit, and one before the output. I saw this truck in s video about cleaning up noise in a PSU powered by a switching supply, and the two filter thing worked incredibly well. Iāll have to see if I can find the video. It was a few months backā¦
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This is interesting. The datasheet has a 200k/220Ī¼F filter on the supply which should cut everything in the audio range, but I was wondering whether a second filter could make a difference. It seems that it could, so Iād love to watch the video if you can find it!
The other solution is to regulate the 19V to 15V before itās fed to the amplifier. That should get rid of the switching supply noise I think, although Iād probably be an overkill for a TDA amplifier build as a little monitorā¦
I finally recorded something with my diy analog modular setup. I lack any sort of recording equipment other than my phone. I liked what I was jamming on so I just used the phone. It is simply laying on my mixer in front of my speaker.
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Great stuff! Really right up my alley.
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Iām glad you enjoyed it! I did an extend mix with some additional gear and better mix levelsā¦ hopefully. 
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Today Iāve finished the @moritzklein VCO. The PCB is 100% based on Moritz schematic, the design and the frontpanel is my own work. It needs to be calibrated, but its working as expected.
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