#opamps — Public Fediverse posts

I can safely say that it's been a while since #DigiKey sold #resistors in pre-packed bags of 5 with included card labels. As their own brand. Made in Taiwan.

Or called themselves "Digi-Key Corporation".

More seriously, I found a bag of #components left over from my senior year of school, when we did our big final project. Mine was a computer-controlled slot machine. Components were seriously expensive then; I organized a group buy with 4 or 5 of my classmates through "Digi-Key", partly because they were cheaper than the local suppliers (see previous story about the "Two Weeks Ten Bucks" guys), but also because we could get quantity price breaks on stuff that was common between our #projects, like the 1 kΩ resistors. IIRC, the resistors cost about $0.30 each in the 5-packs, but the bag of 200 was *way* cheaper - about half that, I think.

These were ordered in 1997, so almost 30 years ago. In addition to #vintage resistors, I found ZTX549 PNP #transistors (still in stock at DigiKey today!), MJE2955T #PNP transistors (also still in stock!), 3 different brands of 741 #opamps, including made-in-Japan and made-in-Malaysia #NEC, TI ones from Taiwan and the Philippines, as well as #TI TL081CP and LM318P from Taiwan. Also a bunch of 74-series logic #chips and some weirder stuff, like a #Motorola MC14412, which is essentially a 0-600 bps (~baud) modem-in-a-chip.

So if you need some vintage components, hit me up 😉

#TexasInstruments #electronics #SupplyHouse #FoundAtHome

I can safely say that it's been a while since #DigiKey sold #resistors in pre-packed bags of 5 with included card labels. As their own brand. Made in Taiwan.

Or called themselves "Digi-Key Corporation".

More seriously, I found a bag of #components left over from my senior year of school, when we did our big final project. Mine was a computer-controlled slot machine. Components were seriously expensive then; I organized a group buy with 4 or 5 of my classmates through "Digi-Key", partly because they were cheaper than the local suppliers (see previous story about the "Two Weeks Ten Bucks" guys), but also because we could get quantity price breaks on stuff that was common between our #projects, like the 1 kΩ resistors. IIRC, the resistors cost about $0.30 each in the 5-packs, but the bag of 200 was *way* cheaper - about half that, I think.

These were ordered in 1997, so almost 30 years ago. In addition to #vintage resistors, I found ZTX549 PNP #transistors (still in stock at DigiKey today!), MJE2955T #PNP transistors (also still in stock!), 3 different brands of 741 #opamps, including made-in-Japan and made-in-Malaysia #NEC, TI ones from Taiwan and the Philippines, as well as #TI TL081CP and LM318P from Taiwan. Also a bunch of 74-series logic #chips and some weirder stuff, like a #Motorola MC14412, which is essentially a 0-600 bps (~baud) modem-in-a-chip.

So if you need some vintage components, hit me up 😉

#TexasInstruments #electronics #SupplyHouse #FoundAtHome

I can safely say that it's been a while since #DigiKey sold #resistors in pre-packed bags of 5 with included card labels. As their own brand. Made in Taiwan.

Or called themselves "Digi-Key Corporation".

More seriously, I found a bag of #components left over from my senior year of school, when we did our big final project. Mine was a computer-controlled slot machine. Components were seriously expensive then; I organized a group buy with 4 or 5 of my classmates through "Digi-Key", partly because they were cheaper than the local suppliers (see previous story about the "Two Weeks Ten Bucks" guys), but also because we could get quantity price breaks on stuff that was common between our #projects, like the 1 kΩ resistors. IIRC, the resistors cost about $0.30 each in the 5-packs, but the bag of 200 was *way* cheaper - about half that, I think.

These were ordered in 1997, so almost 30 years ago. In addition to #vintage resistors, I found ZTX549 PNP #transistors (still in stock at DigiKey today!), MJE2955T #PNP transistors (also still in stock!), 3 different brands of 741 #opamps, including made-in-Japan and made-in-Malaysia #NEC, TI ones from Taiwan and the Philippines, as well as #TI TL081CP and LM318P from Taiwan. Also a bunch of 74-series logic #chips and some weirder stuff, like a #Motorola MC14412, which is essentially a 0-600 bps (~baud) modem-in-a-chip.

So if you need some vintage components, hit me up 😉

#TexasInstruments #electronics #SupplyHouse #FoundAtHome

I can safely say that it's been a while since #DigiKey sold #resistors in pre-packed bags of 5 with included card labels. As their own brand. Made in Taiwan.

Or called themselves "Digi-Key Corporation".

More seriously, I found a bag of #components left over from my senior year of school, when we did our big final project. Mine was a computer-controlled slot machine. Components were seriously expensive then; I organized a group buy with 4 or 5 of my classmates through "Digi-Key", partly because they were cheaper than the local suppliers (see previous story about the "Two Weeks Ten Bucks" guys), but also because we could get quantity price breaks on stuff that was common between our #projects, like the 1 kΩ resistors. IIRC, the resistors cost about $0.30 each in the 5-packs, but the bag of 200 was *way* cheaper - about half that, I think.

These were ordered in 1997, so almost 30 years ago. In addition to #vintage resistors, I found ZTX549 PNP #transistors (still in stock at DigiKey today!), MJE2955T #PNP transistors (also still in stock!), 3 different brands of 741 #opamps, including made-in-Japan and made-in-Malaysia #NEC, TI ones from Taiwan and the Philippines, as well as #TI TL081CP and LM318P from Taiwan. Also a bunch of 74-series logic #chips and some weirder stuff, like a #Motorola MC14412, which is essentially a 0-600 bps (~baud) modem-in-a-chip.

So if you need some vintage components, hit me up 😉

#TexasInstruments #electronics #SupplyHouse #FoundAtHome

I can safely say that it's been a while since #DigiKey sold #resistors in pre-packed bags of 5 with included card labels. As their own brand. Made in Taiwan.

Or called themselves "Digi-Key Corporation".

More seriously, I found a bag of #components left over from my senior year of school, when we did our big final project. Mine was a computer-controlled slot machine. Components were seriously expensive then; I organized a group buy with 4 or 5 of my classmates through "Digi-Key", partly because they were cheaper than the local suppliers (see previous story about the "Two Weeks Ten Bucks" guys), but also because we could get quantity price breaks on stuff that was common between our #projects, like the 1 kΩ resistors. IIRC, the resistors cost about $0.30 each in the 5-packs, but the bag of 200 was *way* cheaper - about half that, I think.

These were ordered in 1997, so almost 30 years ago. In addition to #vintage resistors, I found ZTX549 PNP #transistors (still in stock at DigiKey today!), MJE2955T #PNP transistors (also still in stock!), 3 different brands of 741 #opamps, including made-in-Japan and made-in-Malaysia #NEC, TI ones from Taiwan and the Philippines, as well as #TI TL081CP and LM318P from Taiwan. Also a bunch of 74-series logic #chips and some weirder stuff, like a #Motorola MC14412, which is essentially a 0-600 bps (~baud) modem-in-a-chip.

So if you need some vintage components, hit me up 😉

#TexasInstruments #electronics #SupplyHouse #FoundAtHome

Subject: complaint about cargo-culting audiophools and the #marketers that exploit them

I saw a new #scam yesterday. Well, new to me. It's probably been around forever.

There are many, many #fraudulent products and ideas out there that target the self-described "audiophiles". And because such #audiophools never do double-blind tests, they always convince themselves of just how well the #scammy products work ("you are the easiest person for you to fool").

Examples of long standing:

Super-thick "oxygen-free copper" #cables for #speakers or #interconnects, being sold at 100x the price of regular cables.

Electrically shielded fiber-optic cables (!).

Paint pens to colour in the outer edge of CDs and DVDs.

Systems to run your equipment from #batteries so as not to contaminate them with that dirty mains #AC.

#Tubes / #valves instead of solid-state #amplification.

... and on and on.

Well, yesterday I was looking for some opamps (tiny little chips, used everywhere), and came across a place selling replacement #opamps for use inside stereo equipment. You can get perfectly good designed-for-audio opamps of good quality for a few bucks each. Upgrading your equipment to better opamps sometimes made sense in the 1970s, but not now. The ones used from the factory are fine.

But no, this one was selling fancy opamps, designed for *RF* use, not audio, which normally cost $10-20 each, in fancy little metal packages, for hundreds of dollars apiece.

"A fool and his money ..."

This will be slightly #geeky, and probably only of interest to #electronics hobbyists and #guitar players. I happen to sit in the intersection of that particular #Venn diagram.

When I was a teenager, having only been playing guitar for a few years, I owned a guitar #effects pedal that went on to become legendary - the Boss HM-2 "Heavy Metal" #pedal. Its sound is still ubiquitous in metal.

I don't have it any more. I think I traded it for an analog chorus, which was a seriously expensive pedal back then. Although I have other #distortion effects, I've missed it a lot over the years.

Well, lots of hobbyists build their own effects. And the circuit schematics for many effects, particularly the classics, are available online. So like many others, I decided to build my own HM-2.

This image is the schematic for the #HM2. It's not the most complicated pedal, but it's a league above something like an Ibanez Tube Screamer. As far as active devices go, it's got 6 #opamps and 10 #transistors of various types, along with a bunch of diodes for multiple types and stages of clipping, and the usual jumble of capacitors and resistors. Oh, and four potentiometers.

1/x

#EffectPedal #HeavyMetal #pedals #metal #DIY #schematic #circuit #hobby #OperationalAmplifier #TubeScreamer

This will be slightly #geeky, and probably only of interest to #electronics hobbyists and #guitar players. I happen to sit in the intersection of that particular #Venn diagram.

When I was a teenager, having only been playing guitar for a few years, I owned a guitar #effects pedal that went on to become legendary - the Boss HM-2 "Heavy Metal" #pedal. Its sound is still ubiquitous in metal.

I don't have it any more. I think I traded it for an analog chorus, which was a seriously expensive pedal back then. Although I have other #distortion effects, I've missed it a lot over the years.

Well, lots of hobbyists build their own effects. And the circuit schematics for many effects, particularly the classics, are available online. So like many others, I decided to build my own HM-2.

This image is the schematic for the #HM2. It's not the most complicated pedal, but it's a league above something like an Ibanez Tube Screamer. As far as active devices go, it's got 6 #opamps and 10 #transistors of various types, along with a bunch of diodes for multiple types and stages of clipping, and the usual jumble of capacitors and resistors. Oh, and four potentiometers.

1/x

#EffectPedal #HeavyMetal #pedals #metal #DIY #schematic #circuit #hobby #OperationalAmplifier #TubeScreamer

Can't believe the hiatus and suddenly an afrotechmods vid!
https://www.youtube.com/watch?v=e67WiJ6IPlQ

#OpAmps #LM741 #MCP600x #TLC081 #NE5532 #LM4562 #ElectricalEngineering #AfroTechMods

The Disappearing Capacitor https://hackaday.com/2024/12/12/the-disappearing-capacitor/ #bootstrapping #photodiode #MiscHacks #opamps

The Disappearing Capacitor - As part of a phosphorescence detector, [lcamtuf] has been working with photodiodes... - https://hackaday.com/2024/12/12/the-disappearing-capacitor/ #bootstrapping #photodiode #mischacks #opamps

I found the culprit... It's the #TL072 that goes into phase reversal because the gate and trigger signals are -12V when low.
After swapping it with a #LM358, the output signals for trigger and gate, including the LEDs work as intended.
This took a lot of time to find out, but I've gained some knowledge now.
#PhaseReversal #OpAmps #BugFixing

Finished #soldering the #perfboard yesterday. Sadly, it didn't work as intended. Now comes the fun part — analyzing and fault finding. Already fixed one of the issues by replacing a #capacitor with a bigger one. Now the trigger and gate are generated correctly, but the output buffer for them are constantly high. The sample and hold for the CV outputs worked from the beginning.
#diysynth #keyboard #OpAmps

I made a small voltage rail splitter using an #LM358 #OpAmp that I salvaged from an old motion detector.
I want to play around with #OpAmps and thought it would be nice to have a #circuit for creating a virtual ground reference with positive and negative voltages.
The boost converter is only for testing, I'll connect a 24V supply later.
Only thing I have to adjust is the inrush current.
I'll convert it to a soldered perfboard, too.
#electronics #diy #dualrail #powersupply #breadboard #KiCad

Op-Amp Contest: Virtual Ball-in-a-Box Responds to Your Motions - With the incredible variety of projects submitted to our Op-Amp Contest, you’d alm... - https://hackaday.com/2023/06/07/op-amp-contest-virtual-ball-in-a-box-responds-to-your-motions/ #analogcomputer #accelerometer #classichacks #miniaturecrt #ballinbox #contests #opamps #tl072

Op Amp Contest: Generate Spirograph Shapes Using Only Op Amps and Math - If you’re a child of the ’80s or ’90s, chances are you’ve spent hours tracing out ... - https://hackaday.com/2023/06/05/op-amp-contest-generate-spirograph-shapes-using-only-op-amps-and-math/ #hypotrochoid #epitrochoid #spirograph #toyhacks #mcp6004 #opamps #art

Using 7 dual #opamps (LM358) to generate PWM signals for driving a non-addressable RGB LED strip so that only one linear potentiometer is needed to sweep through the colours of the #rainbowFlag

Project inspired by
https://youtu.be/KMuTTQeQ4_c
in which @blitzcitydiy used a microcontroller to map a potentiometer to the range of hues

#PrideMonth #electronics #opampChallenge #LEDs

Three potentiometers control the duty cycle for pulse width modulation of the three colour channels of an RGB LED strip (non-addressable). The PWM signal is generated by #opamps (#LM358) configured as an oscillator and 3 comparators. An NPN transistor sinks the current for each of the LED colours.
#LEDs #electronics

Pulsating PWM using two #LM358 dual #opamps configured as a fast oscillator, a slow oscillator, and a comparator whose output is the source of one LED and the sink of another LED

No microcontroller required
#electronics #OperationalAmplifiers #LEDs

Hackaday Prize 2023: Explore the Basics of Neuroscience with this Electronic Neuron - Brains are the most complex systems in the universe, but their basic building bloc... - https://hackaday.com/2023/05/01/hackaday-prize-2023-explore-the-basics-of-neuroscience-with-this-electronic-neuron/ #artificialneuralnetwork #artificialintelligence #2023hackadayprize #thehackadayprize #neuroscience #science #neuron #opamps

Ask Hackaday: Split Rail Op Amp Power Supply - Water cooler talk at the office usually centers around movies, sports, or life eve... - https://hackaday.com/2023/04/20/ask-hackaday-split-rail-op-amp-power-supply/ #hackadaycolumns #superconbadge #askhackaday #opamps #parts

Circuit VR: Some Op Amps - Circuit simulations are great because you can experiment with circuits and make changes with almost ... - https://hackaday.com/2020/12/24/circuit-vr-some-op-amps/ #operationalamplifier #hackadaycolumns #simulation #simulator #falstad #skills #opamps #op-amp #opamp