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

Active Filter vs Passive Filter

👉 Download Now from Google Play
🔗 https://play.google.com/store/apps/details?id=com.piembsystech&pcampaignid=web_share
🌎 https://piembsystech.com/difference-between-active-filter-and-passive-filter/

#ActiveFilter #PassiveFilter #AutomotiveEmbedded #EmbeddedSystems #SignalConditioning #AnalogDesign #PowerIntegrity #EMIFiltering #ElectronicsDesign #ECUDevelopment #ADASDesign #AutomotiveElectronics #SensorFiltering #AnalogCircuits #OpAmps #AutomotiveInfotainment #EmbeddedLearning #PiEmbSysTech #OpenSourceLearning #TechEducation #SelfLearning #ElectronicsEngineering

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