4 ms·

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

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 4y ago
> 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 4y ago
  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 4y ago
    True, delay effects are all probably cheaper to make in their digital form. Overdrives are likely to be identical
    - FatActor 4y ago
      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.
      - skinnyarms 4y ago
        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 4y ago
        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.
      - atoav 4y ago
        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.
      - 4y ago
yummypaint 4y ago
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 4y ago
  This walkthrough is a amazing and covers a lot of what you just said: https://www.electrosmash.com/boss-ce-2-analysis 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 4y ago
Found this awesome tear-down and walk-through of the CE-2 by a circuit expert: https://www.electrosmash.com/boss-ce-2-analysis https://www.electrosmash.com/boss-ce-2-analysis

jimnotgym 4y ago

> 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 4y ago
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 4y ago
  True, delay effects are all probably cheaper to make in their digital form. Overdrives are likely to be identical
  - FatActor 4y ago
    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.
    - skinnyarms 4y ago
      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 4y ago
        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.
    - atoav 4y ago
      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.
    - 4y ago

yummypaint 4y ago

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 4y ago
This walkthrough is a amazing and covers a lot of what you just said: https://www.electrosmash.com/boss-ce-2-analysis 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 4y ago

Found this awesome tear-down and walk-through of the CE-2 by a circuit expert: https://www.electrosmash.com/boss-ce-2-analysis https://www.electrosmash.com/boss-ce-2-analysis