[FatActor]

When I starting learning circuit analysis in college in the 80's I would draw out the pedal schematics via hand-inspection of the board itself and try to figure out wtf they were doing. I didn't have access to part #s until I was in college (you couldn't just google a datasheet for whatever 8-pin DIP was on the board, you had to look through giant catalogs of them from each manufacturer).

Two things immediately jumped out at me ... first, that undergrad circuit analysis does not help understanding circuits designed by wizened experts ... and second, that even the simplest circuits require all kinds of considerations beyond the y=H(x) transfer functions (and that linear systems don't begin to describe what i was seeing). Humbling.

It would be interesting to see how the Chorus schematic from 1985 compares to the Chorus schematic of 2023.

[jimnotgym]

> It would be interesting to see how the Chorus schematic from 1985 compares to the Chorus schematic of 2023.

Is probably identical. The actual board is probably different in that they will have used surface mount to bring the cost down.

There is very little in the fx world that is not a tweak on a few classic designs... unless you are going dsp of course

[Tade0]

The 2023 Chorus would probably be fully digital instead of using a bucket-brigade device.

Even the humble DS-1 has now a digital version which, contrary to its analog counterpart "chugs".

I've always felt that the signal to noise ratio in digita circuits just wasn't there, but perhaps there were some significant advancements over the years in this field which I missed.

[jimnotgym]

True, delay effects are all probably cheaper to make in their digital form.

Overdrives are likely to be identical

[FatActor]

Would be great if we could get some actual screenshots of the boards rather than speculating. That's why I'm curious to see if 1985 is the same as 2023. Without data we're just guessing.

[atoav]

I am an electrical engineer that designs a lot of audio stuff including guitar pedals. Today manufacturers certainly would go digital for chorus/flanger/delays unless the appeal of analog BBDs is directly what they are going for.

Digital has one advantage: your one PCB design can become many different pedals. Just change the design of the case, maybe leave the RAM IC out in effects that don't need a lot of memory, put different code on it and congrats: 90% of your product range are the same PCB and the same parts which is nuch more economical than doing a new design for every product.

Exception: Fuzz, distortion, overdrive and everything where you rely on complex characteristics of affordable analog parts.

[jimnotgym]

The op asked about schematics, not boards.

It is not speculation at all, schematics for many many effects are available online. Manufacturers also freely admit to their pedals being clones of famous pedals. There is even a whole genre of pedals known as Klones because they are clones of a Klon. Have a look on Andertons YouTube and you will see them blindfold testing all the Klones, the Tubescreamer clones, the RAT clones etc. If you watch Josh Scott of JHS pedals he talks through how much they are 'exact same circuit' all of the time. Josh himself became famous due to a mod he made to the Bluesbreaker. Not as famous perhaps as Analogmans King of Tone (with a three year waiting list), which is a modification of a....Bluesbreaker. All the schematics are online. By the way you can buy dozens of King of Tone clones too, like the King of Blues, for 1/10th price.

When reviewing pedals it is common to say 'this is a modified x', or an 'x and y in the same box'

It is not even a secret that the analogue pedal market is selling the same pedals that were invented in the 60s-80's with minor tweaks for component availability. But of course they are, because what do most people want to sound like, of course it is their guitar hero from the 60s to 80s!!! I have a fuzz face for Hendrix, a big muff for Gilmour, and a Tubescreamer for SRV. All available today in exactly the schematic of the original, from multiple makers.

[FatActor]

OP here. Would be great to see some actual schematics of new ones. Can you point me to some? Here's the 80's pedal:

https://www.hobby-hour.com/electronics/s/boss-ce2-chorus-sch...

But can't find a modern Boss one. I guess they went to CE-5 after 1990:

http://thermionic-studios.com/wiki/images/2/26/Boss_CE-5Sche...

Guess I'll spend the next few days figuring out the diff.

My point is, you've provided just opinion. If you could have told me a thing or two about the actual circuits I might think you know what you're talking about. But rather than helping, you're just filling space with words in an attempt to sound knowledgeable.

[skinnyarms]

Just search for "overdrive pedal" on Sweetwater and you'll see a lot of pedals that have been around for decades. Read up on the newer ones and you'll see they generally just add novelty options and variations to classic designs. You can easily find comparisons of schematics by googling, though it's not as simple as "Tubescreamer 85 vs Tuberscreamer 2023" because of various small evolutions and models. Try "tubescreamer circuit comparison" to get a good start.

Delays are another story, search Sweetwater and you'll see it's dominated by digital options that bundle things modulation, stereo effects, and loopers. You won't see the same analog options as the 80's, or many analog options at all comparatively.

[klodolph]

A lot of the analog options are still around because bucket brigade devices are still manufactured. So you can get a Boss CH-1, a Memory Man, or something like that, new from the manufacturer.

[yummypaint]

To be fair, you might have had an easier time if you were pulling apart scientific equipment. Audio quality is so subjective that the circuits quickly become relatively counterintuitive as designers experiment with all manner of hacks to decrease part count and change the sound.

[FatActor]

This walkthrough is a amazing and covers a lot of what you just said:

https://www.electrosmash.com/boss-ce-2-analysis

This is why programmers tend to faceplant when confronted with analog circuits, it is absolutely black magic that can't be brute-forced. :)

[FatActor]

Found this awesome tear-down and walk-through of the CE-2 by a circuit expert:

https://www.electrosmash.com/boss-ce-2-analysis