I'm curious about the label printers you mention - been looking for one like that myself. Can you give a link or name?

Definitely you want your filter to be expo controlled; that's the bunching-up part of the problem if you don't do expo.

Also, you should put a simple lowpass filter inside your Arduino to smooth out the values before you output them.

One more detail: There are two main flavors of pot: Linear Taper, and "Audio" (or "Log") Taper. Usually, a linear taper pot, has a "B" in its description or part number, perhaps something like "B10K", and an audio taper pot's description or part number would have an "A" - something like "A10K". Doep...

Did you include compensation capacitors on the op amps? What op amps did you use?

supposedly the sine is very pure - apparently some FM enthusiasts don't use VCOs - just sine waves from filters. Even the tiny glitch on a typical VCO's sine wave is enough to cause real sonic "damage" in an FM setup. I've had much better luck with self-oscillating filters for FM (when I want sine ...

Schematic, please.

I had an old synth (Korg Poly-800 II) that went all nuts. I changed the battery, un-seated, cleaned, and re-seated all the connectors. That fixed it right up.

At my employer, it would be unacceptable to place a via on a pad. JLC is correct.

roglok wrote: ↑

Wed Jan 06, 2021 12:04 pm

jorg wrote: ↑

Tue Jan 05, 2021 10:25 am

...full-wave rectifier...

That looks very nice! I should measure the attack response as that's one of the key points of the Bissell design but would have to get the scope out of storage for that...

Looking forward to your observations!

One more thing. Can you share how long the cable between your PSU box and main unit is? And what gauge wire you used between them. Which connector-s? EDIT: Deja-Vu on this PCB layout and expo. I participated in another MW thread not too long ago where I remember suggesting building a thermal insula...

I don't see how this beats a carefully crafted full-wave rectifier with two-stage rectified ripple filter.

This includes a 2164 model in PSPICE and Tina TI formats. I've used it to develop various circuits.

If we assume the next circuit has an input impedance of at least 10K, you could insert a 16uF electrolytic in series. That would give a cutoff of 1Hz (or better, with most downstream modules). Because you know there is a positive offset, a polarized electrolytic would be fine (+side faces the VCO ou...

Think any of the euro spring reverb driver modules, but in a pedal. Maybe it doesn't actually exist other than that $300 French version ... I use an old speaker amp (just a few watts) with a series resistor to drive the spring. The series resistor is ~5x the DC resistance of the input coil; it flat...

Surprised no one mentioned the effect on modulations. Ideally, a VCO has both an expo input for pitch control, and a linear input (V/Hz, but scaled automatically to the expo value) for FM. Linear FM is very useful for a wide range of sounds. Skipping the expo input merely transfers cost to componen...

My studio is my bedroom, so I have a 9U Doepfer, iPads, drums, guitars, a 1980s Korg Poly 800 II, and miscellaneous pedals, FX, etc within a few feet of my bed. When I want to fall asleep doing synthesis stuff, I grab an iPad. Favorite apps: Audulus, Auria, Xynthesizer.

Delighted to see that TONTO has a happy home and a productive continuing life! Thanks for this update!

Any type of transducer can work. Typically, big springs require big movements. Older reverbs took advantage of the parts that were available; speaker drivers and guitar pickups. But as long as you can transfer the audio signal to movement, you can influence a spring.... Are you driving the spring i...

How do you drive/pickup a spring with piezos? Normally a rotary magnetic driver and pickup are used.

I have no idea what this is about.

KSS wrote: ↑

Sat Nov 14, 2020 6:32 pm

...some "dope" with a positive attitude comes along and convinces everyone to stretch a little farther, push a little harder so the water can be passed. Or maybe another "dope" is the negative type says just stop people, it's a lost cause...

Nerd joke alert!

I'll fess up to not fully understanding resistance, i.e. the resistance "inherent in a device" is something I hear a lot. Is that component based, like each piece of component is an adjustable nozzle? I'll just be as dumb as I am in this question. Metaphorically, is resistance a device's pushback o...

That's still not a schematic; it shows physical chip footprints, and you have said those aren't even the real chips.

Back in 1982, I implemented a wavetable 3-channel oscillator without aliasing. It was based on a hardware frequency divider and a DMA chip. There is a tradeoff of the master clock frequency vs frequency accuracy (ability to use large fine-grained divisors). But there's no aliasing. Just make sure to...

For a purely analogue approach, you could split the problem into two parts: an exponential converter, and a linear oscillator. There are plenty of examples of good expo converters around. For the linear VCO I would start here: http://cds.linear.com/docs/en/application-note/an14f.pdf You could look ...