Chorus Topologies?

[nego_veio]

I'm trying to learn a little bit more about Chorus types.

Can you guys tell me more about the topologies of Boss pedals like de CE-5, CH-1, CEB-3, CE-2, Chorus Ensemble, Dimension C, and other famous chorus like the EHX Small Clone, etc.

thank you.

[R.G.]

All choruses are short time delays. They are generally swept a bit by varying the time delay somewhat. They may vary in the details of how much and how regularly the sweep modifies the time delay. They all mix the delayed signal back to the dry signal. They may or may not have some amount of regeneration in the time delay, although this is rarer in choruses than in phasers and flangers.

[Pablo1234]

you need to break it down in blocks even with digital codex and software they all mostly work on the same principles.

Splitter - Dry/Chorus (I have seen true Stereo Versions where the Chorus is not mixed with the dry at all, its the one I like also)
Delay - Most of the ones you have listed are BBD if not all of them. The minimum and maximum delay times set the overall sound.
LFO to modulate the delay - this is one thing that greatly affects the sound of the chorus their are so many wave styles and or mixed waves its not funny, this is typically what separates them in sound.
Feedback/Regen - I do believe that Regen makes a chorus a Flanger but I may be wrong, All of the Flangers I have seen are nothing but Longer delay times with Regen.
Filtering - Rolling off the Treble and boosting the low mids is common in chorus but its anything you want it to be really.
Mixer - Mixes the Dry with the wet for setting how apparent the chorus is.

Go down load all the schematics you can find and break them down into categories like this and you will be surprised how similar they really are. It helps to draw them in a schematic editor and arranging them the way it works best for you too read them. A lot of schematics are mixed around to make it hard to identify stuff.

[anchovie]

Feedback/Regen - I do believe that Regen makes a chorus a Flanger but I may be wrong, All of the Flangers I have seen are nothing but Longer delay times with Regen.

It's shorter delay + regen in a flanger.

[Mark Hammer]

The majro difference in topologies between choruses is between single and multi-phase choruses.  The chief challenge with a chorus is that producing the detuning requires one to fall behind in time to get the slight drop in pitch.  Of course you can't continue to fall behind infinitely, so eventually you have to catch up.  That involves reducing the delay time so that the pitch rises.  The constant sharp/flat/sharp/flat wobble can be distracting.  What some choruses do is produce multiple delays, such that there is no singular sharp or flat version of the signal.

In the case of many string synthesizers from the 70's, there would be several non-synchronized chorus circuits run in parallel, each with their own BBD.  The Solina was perhaps the best known of these, but I think there was an Arp machine too.  I know the chorus on my busted Juno 106 has a pair of MN3009s run in parallel.

The Boss Dimension C and D units also provide a multi-phase chorus, except that the two BBDs are ganged to the same LFO instead of independent LFOs as in the examples above.  There is an inversion stage feeding the clock generator for each BBD, such that as one sweeps low (shorter delay time), the other sweeps towards a longer, higher delay time.  So, when one BBD goes sharp, the other goes flat.  The result is a more pleasing chorus sound with a less obvious pitch wobble, and the advantage of being essentially "three voices" instead of one or two.

Behringer makes a cheap Dim C clone, and Line 6, among what I imagine are many others, makes a digital emulation of it (included in the Space Chorus pedal and the modeller series).

All the other chorus pedals that the OP notes are essentially the same topology. as each other: a single-voice chorus.

[nego_veio]

thank you guys, that was so enlightening.

Just one more question:
I think i've read somewhere that the "ensemble" in the Boss chorus pedals names, mostly in the modern CE-5, means that it's something like a multi-voice and you can get a deeper chorus effect with it. So that's not correct? If they are all single voice, The Ce-5, Ch-1 Ceb-3 are basically "the same thing", probably with different filters or minor stuff?

Sorry, I really would like to know the practical difference between the Boss chorus pedals.

[Mark Hammer]

Yes, all the analog CE- and CH- series are single voice.  Only the "Dimension" units are dual-bbd.