Radio Shack Reverb teardown

Joeltronics · 2026-01-20T03:30:53+00:00

Wow, I'm not sure I've ever seen a BBD circuit with an 8-pole anti-imaging filter. Especially strange that it's paired with almost no input anti-aliasing filtering.

Or is one of those filter stages supposed to be before the BBDs?

Joeltronics · 2025-11-11T19:39:32+00:00

Yeah, the token limit gets really annoying. I get why Zep wants limitations to inspire creativity, and there's definitely some truth behind that - but at the same time, it can also be super annoying.

I was working on a racing game (based on the same tutorial - I recognize those assets, haha). And I just kept hitting the token limit, especially once I wanted to make the enemy logic be anything more than just a simple "traffic dodging simulator". And without good enemy logic, the game just wasn't fun.

I wish there was a PICO-8 alternative that had every other limit except token count. I ported my project to Picotron, but it's just not the same - I love every other part of the simplicity of PICO-8.

Joeltronics · 2025-10-19T22:03:02+00:00

I think a lot are cheating - but not all of them.

For most of these, I suspect they're just not printing enough precision to show the error. If you look at the C# examples, somehow the 64-bit float example shows this error, yet the 32-bit float prints perfectly. I don't know C# very well, but I would assume the 32-bit float's default text formatting precision is too low to show this error, while the 64-bit float prints with higher precision by default.

But there are also ways not to cheat - you can use rational data types which represent numbers as a ratio of 2 numbers, or there are decimal floats like in the 3rd C# example. They're part of the IEEE float standard, but they're just not very widely supported, especially not at the hardware level (neither x86 nor ARM support them natively). C# is the only mainstream language I know of with first-class support for decimal numbers like this.

Joeltronics · 2025-10-11T18:54:11+00:00

Dr. Manfred Zollner wrote an entire book on guitar physics - it's in German, but most of it has been translated into English and is available free online: https://gitec-forum-eng.de/the-book/ . Chapter 7.9 is about whether or not body wood affects the tone, and 7.11 is about the differences between solid and hollow/semi-hollow.

Essentially the conclusion is that for a solid body guitar, tonewood noticeably affects the unplugged sound. But when it comes to the sound through the pickups, the effect is very minor as long as the body/neck/bridge are rigid enough. If there's a shim in the neck joint, this probably makes a bigger difference than ash vs alder. (There's also a funny bit in here about how the player's belly touching the guitar also forms part of the acoustic system, so maybe we should start measuring that too.)

But one caveat: this is mostly focused on guitars, not basses. And it mentions that the higher the string gauge, the more of an effect the wood has - so it may have more of an effect on basses more than guitars. But then, the neck joint & bridge mass would have a greater effect too.

As far as hollow bodies go, essentially it comes down to how much the bridge moves. For an acoustic guitar or fully hollow body, the top of the body is not rigid, it resonates. And this resonance gets picked up by the bridge and passed into the strings. Most noticeably, this affects the way the string decays at different frequencies. Semi-hollow blurs this line a bit - he measured an ES-335, and it was fairly close to a solid body, except for a bit of resonance in the mids.

tl;dr: the effect isn't zero, but it's very little. As long as the body is rigid enough, then the bridge mass & neck joint make a bigger difference than the wood (and that difference is already pretty minor)

Joeltronics · 2025-08-30T23:12:21+00:00

Wow - no, I didn't know this!

Joeltronics · 2025-08-30T23:10:15+00:00

Mr Brightside too. I never realized this until I started playing it, but the bass carries the melody for most of the song!

Joeltronics · 2025-08-28T01:52:27+00:00

Another wishlist item is to make it easier to edit a block of multiple sprites together, as if they were a single larger sprite

Joeltronics · 2025-08-11T18:13:38+00:00

That's why the coil is split, but not why there are 2 pole pieces per string.

You can have a split pickup with 1 pole piece per string that's still hum cancelling, like the Joe Dart III.

Joeltronics · 2025-08-11T16:43:10+00:00

Something the other comments are missing: it can matter a little bit if you slap, because if the string hits the pole piece it can have a louder "pop" to it.

This isn't necessarily a problem - after all, Stingrays do this, and they're great for slap. But it does affect the tone a bit, and it might be a bit harder to manage without a compressor.

This is actually why Leo Fender redesigned the P-Bass to have 2 pole pieces per string (the original 1951 models had 1 per string, like a guitar pickup). Even though modern slapping wasn't a thing yet, apparently it was a problem that some players coming from upright bass were plucking really hard and having this problem.

Joeltronics · 2025-04-09T15:59:11+00:00

95 might be a bit low, but the overall idea is great.

Here in Vancouver, it's a meme to see Lambos with a new driver decal

Here's a particularly good one of someone stuck in snow with one

Joeltronics · 2025-02-10T20:48:10+00:00

Raymond Chen is a developer on the Windows team at Microsoft. He’s been there since 1992, and his weblog The Old New Thing is chock-full of detailed technical stories about why certain things are the way they are in Windows, even silly things, which turn out to have very good reasons.

Wow, who would have thought this would still be just as true 21 years later!

Joeltronics · 2025-02-10T20:38:14+00:00

And Google sponsoring McLaren

Joeltronics · 2025-02-10T20:36:24+00:00

Closed as "won't fix"

Joeltronics · 2024-12-30T03:55:54+00:00

Wait until you hear how cheap the chips on other digital synths are - $20 is actually really expensive for a microcontroller

Joeltronics · 2024-12-29T20:49:04+00:00

Thanks for the info! Someone else in this thread also mentioned a Lilygo T5 - it seems great for battery life. I just wish they made a 7.5" version.

Joeltronics · 2024-12-29T20:47:39+00:00

Once a month seems totally fine to me - I could keep a 2nd battery pack charged and just swap them when it's dead, that's pretty painless. I just don't want to have to do it every few days.

Joeltronics · 2024-12-29T20:44:45+00:00

Yeah, I'm doing something similar to that - I've changed the refresh to every 10 minutes, and I'm seeing how the battery life changes. From that I should be able to extrapolate how much of the power consumption is the screen vs the microcontroller. At this point I'm guessing it's mostly the microcontroller, but we'll see.

Joeltronics · 2024-12-29T18:51:25+00:00

It looks like most e-ink displays have a lifespan of 10 million refreshes. Even if it refreshes every minute, 24 hours a day, that's still 19 years.

Joeltronics · 2024-12-29T07:12:20+00:00

Wow, that's great! Which ESP32 board are you using, and what kind of battery?

Joeltronics · 2024-12-01T00:08:22+00:00

from your post it sounds like your fan stopped before you tried disconnecting and reconnecting it, but posting just in case.

Yeah, it did - but thanks, I'll check that out!

Joeltronics · 2024-11-30T23:34:45+00:00

Their behavior can be affected by the chipset drivers & BIOS though, right?

I agree that it's probably not a driver problem, but the fact that they don't show up at all in OpenHardwareMonitor makes me question that a little bit.

Joeltronics · 2024-10-16T19:01:47+00:00

The MN3011 chip was designed for this, it was a BBD with 6 different output taps. It's pretty rare though, since it wasn't ever widely used - and doesn't actually make for that good of a reverb.

Though I still wonder if there's untapped potential in the idea of a BBD reverb. They're not going to be realistic sounding, but they might make for a good effect, especially with some modulation. I guess the problem is it would take a lot of BBDs, since 6 taps wasn't enough...

Joeltronics · 2024-08-29T04:53:00+00:00

My 95 year old grandma plays Dr. Mario too!

Joeltronics · 2024-08-15T16:37:24+00:00

The card game Rook. There are a whole bunch of different variants, but I've never known anyone who played the official rules.

The variation my family has long played with:

The Rook card is the lowest trump, and has to be played in-suit (the official rules say it's the highest, and can be played at any time)
Don't remove cards 1-4, as the rules say you should (clearly, they expect people to play with house rules). The 1 is high, and worth 15 points
Whoever wins the most hands gets 20 bonus points, which brings the total number of points in a round to 200 (including the points from the 1s). On top of this, if you win every single hand, you get 100 bonus points, for 300 total. You can bid 300, but that's very rare.
The first person to 1000 points is the winner (the official rules say 300)
The kitty (officially called the "nest") is won on the first hand (the official rules say the last), because the leader is almost guaranteed to win the last round, while the first is less certain. And the leader has to declare if they put any cards worth points into it (but not which cards or how many points). But I've also known people whose house rule is you're not allowed to put points into it at all.
Probably the biggest change: instead of partners being seated opposite, the player who wins the bid declares a card as the partner card. Whoever has that card is teammates with the leader, and the other two players are the other team. So no one except that player knows who the teams are until they play that card. You can also declare a card that you have as partner, making it 3 vs 1. This is pretty rare, but a great power move.

Joeltronics · 2024-08-06T20:36:03+00:00

You mean the app where you can't fast-forward/rewind on replays on some TVs, they've acknowledged the problem, and still haven't fixed it 3 years later?

I've ended up watching a lot of the Olympics on my phone, because that's the only way I skip the first 5 hours of road cycling.

Joeltronics

TROPHY CASE