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Post by funbun on Jan 23, 2021 20:18:48 GMT
Okay, I know that analog oscillators are difficult to track and keep stable thermally. I've read that some analog units have temperature compensation? Can someone elaborate? Will that "fix" the instability of an analog oscillator, or is it just a bandaid? Would a temperature compensated analog OSC ever be as stable or track as well as a digital OSC?
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Post by 101 on Jan 23, 2021 23:13:47 GMT
Hey funbun. Wouldn't that mean using a Thermistor and some sort of feedback loop? Do they actually incorporate that into some oscillator circuits?
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Post by funbun on Jan 23, 2021 23:30:39 GMT
Well, I don't know about the engineering side of it, but take Synthesis Techology's E300 Ultra VCO. It is totally analog, but rock solid in tracking with minimal thermal drift. Here's a demo. This guy is running Berlin school bass lines totally in tune and tracking like a missile. Totally old school Moog-like oscillator rock steady as a digital oscillator: He's got some kind of uranium/plutonium powered something or other in there to keep it that steady, lol! |
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Post by solipsistnation on Jan 24, 2021 0:08:51 GMT
The x0xb0x 303 clone uses thermistors. You can see them here: www.ladyada.net/images/x0xb0x/fab/vco/vco1.jpgThey're R100A and R100B. This is a fine way to compensate for temperature-based oscillator drift. Analog won't ever be as pristine and perfect as digital, but that's part of the appeal, I think. There's a lot of effort put into making digital oscillators emulating analog drift just a little so they don't sound TOO perfect, right? |
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Post by robertlanger on Jan 24, 2021 11:17:35 GMT
The current VCO already has a thermal compensation with thermistors, but, I admit, far from perfect. The special challenge with AE is, that everything has to happen in the smaller range of 0...5 volts, meaning that common circuits from the Eurorack world cannot be adapted.
But I'm evaluating the brand-new VCO chip from soundsemiconductor; this one looks promising and fits quite good in the supply range of AE. It only needs -5 volts additionally which can be derived via a DC converter.
So you can expect much better analog AE VCOs in the near future!
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Post by funbun on Jan 24, 2021 13:30:52 GMT
SWEET! Just checked out Sound Semiconductor's Web site: soundsemiconductor.com/ Wow! Looks like they have a tons of audio specific chips. Looking forward to the new VCO! What are we going to call it? VCO ULTIMATE? |
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