Sponsored by JLCPCB ($2 for 10 Boards): https://jlcpcb.com
First part of a 2-parter (probably). Decking timber and protoboard build of the vocoder analogue filters with KA2284 LED bargraphs. Includes tentative power-up 🙂
First part of a 2-parter (probably). Decking timber and protoboard build of the vocoder analogue filters with KA2284 LED bargraphs. Includes tentative power-up 🙂
diagram please ?
cok
Great series, Julian. For next vocoder version, save yourself some time by making the filters as pc boards, loaded with different component values for the different frequencies.
we missed seeing your face… do Q&A next time. 👍Like if agree 👍
Why don’t you design the pcb and get jlcpcb to make them for you for free, would be a lot easier than using perf board.
V-oak-coder?
personally i would remove all the LEDs and solder on some 5mm leds instead on a separate board to get a nicer light show. its a bit of a grind, but hey. the bundles of wire you get out of it are also nice and satisfying.
I was going to say "Take your time Julian, work at your own pace, finish your projects when you finish your projects" – Then I saw the "to be continued" message at the end and %&^%^*%$^ – I want to see it showing fancy flashing LEDs to some audio!!!!!!!!!!
I think Julian has 'Asbestos fingers' holding the wire. I'm a coward and use tweezers. I have a Soldapullt it's got lots of suction. Thanks for the interesting video.
wood-you got ripped off good style !
Yes, looking forward to seeing this running. BTW watching this from High Wycombe visiting family.
A crawl – more like glacial sometimes lol
Hi Julian unfortunately you're videos lately lack luster, please take this as positive criticism. Please continue your pic tutorials they were awesome. No offense intended bud, I'm greatfull you take the time out for these vids. From a loyal subscriber.
This is wonderful! I never thought about spectrum analyzer as being so approachable, the one next to me at my internship was $100K new (now it is "only" $30K) and terrifies me, so these look a lot more inviting!
I am looking forwards to episode 2!
hmm, i don´t know exactly where to start….ok:
The power supply may will cause the whole unit to operate quite odd, due to EM-interference. this is a non-shielded SMPS board, generating a lot of switching transients, also filtering looks al least inaprobiate when it comes to powering audio equipment.
I also don´t know what filter edge-steepness (Q-factor) you´ve designed. If you´re using 24dB/octave and going for 1/3rd octave mid frequency-spacing between two modules, you end up with not enough seperation. This will result in poor band-seperation, as the gain reduction bewteen two module band edges will only be -6dB, best case.(matched components estimated)
Usually the "light-show" is feeded from the envelope signal generated by each filter section, not the audio output. As you want to know when the envelope follower is saturated not the filter output…
When the envelope follower saturates the analzer circuit is then fed with a DC-offset generated by the envelope follover and usually causes "wild" behavior.
Also all these stuff is usually build-up "back-to-front"…it begins with the analyzer, if this works, you will then know from which level(s) the envelope generators need to swing for best case Signal/noise ratio and also minimal band-pass audio level distortion vs. output level. After building the ENVs you will see what audio input level you gonna need to provide maximum linear operation, as you gonna need this for minimum distortion of your anayzer modules.
And so on….until you are at the input jacks of your vocoder.
Anyway i really hope you initial build will at least work, and you will not end up smashing the whole thing onto your wall or floor, due to lousy performance.
My initial (OTA and J-fet based) phaser i built early 90s ended just like that, lousy overall performance, but high noisefloor and about 20% distortion due to limited headroom…
OMG if I would have known the severity of the project I wouldn't have mentioned it . }>
"[Spectrum analysers] are not very scientific"