Boss CE-300

[mlabbee]

Has anyone ever tried to clone one of these? I used to have one and loved it, but it's a rack unit and was a pain to try to integrate into my rig.  From the schematic (here: http://www.freeinfosociety.com/electronics/schemview.php?id=121)  it looks like two separate delay lines with a compander and expander. Anyone think this could fit onto a  pedal sized board? (I assuming you could get rid of the power section and replace it with a charge pump chip and get rid of all the muting and level metering circuits).

[Mark Hammer]

Something like a CE-300 is useful if one already has a stereo signal and wants to apply chorusing to it (e.g., the "stereo" output of a keyboard/synth).  This is, of course, different than those boxes that "stereo-fy" a mono input by deriving either wet/dry outputs, or sum/difference outputs.  This thing harnesses two entire chorus units to the same LFO, and applies common parameters (same tone setting, same wet/dry mix).

So I guess the question to be asked is "Apart from a) the inclusion of a compander to manage noise, b) the inclusion of a wet-level pot to manage intensity, and c) the inclusion of a tone pot to alter sonic character, what do you want that a dual-mono unit like this offers?".

That's not a criticism, but rather an attempt to find out what you need to salvage/extract from this overall circuit to meet your needs.  It may be the case that all you really want is a CE-2 with a couple of tweaks.

[mlabbee]

It is actually designed to work on a mono input (only)* and does "stereo-fy the signal - there's some info on it here: http://electro-music.com/forum/post-157704.html  The LFO's are actually the reverse of each other which gave it really nice sound.  If I'm reading the schematic correctly, the two op amps just above 'VCO Level" are both inverting the LFO signal, so that's how the LFO gets reversed between the delay lines - right?

Also, I seem to recall the tone knob having a pretty wide range - it was pretty useful (its been a few years since I had one, though).

*It is pretty much a guitar-centric unit, though I understand some keyboard players really like them.  In fact, my one criticism of the unit I had was that the input pre-amp was very easy to overdrive with a guitar - if I were to try to build a "revised" clone, that's one thing I would want to fix.

[Mark Hammer]

Gah! You're obviously right.       I have a humungous monitor at work, but the entire image does not show up on the screen all at once.  In an eager attempt to see the modulation arrangements (lower right), I nudged the input section (upper left) off-screen).  I also did not trace the paths from the LFO well enough to see there was an inverting stage.

So, essentially the CE-300 is a tricked out DC-2, if I understand it correctly?  I can see now why you find it so indispensible.  The DC-2 was one of the very nicest analog chorus units available for guitar.

If it's a DC-2 you want, Behringer makes a very inexpensive clone - http://www.behringer.com/EN/Products/CC300.aspx - although it lacks the wet-level and tone controls of the CE-300.  The gutshots I see posted online indicate it is a mix of through-hole and surface-mount components, so it is possible you could mod it to add those features.

[mlabbee]

That's interesting - I always assumed the DC-2 was something radically different circuit-wise because of the four push buttons rather than pots for controls. It does look very similar. It explains why I've heard the CE-300 referred to as the poor man's Dimension (though I think that's mostly in reference to the rack version of the Dimension).

So do the mode switches on the DC-2 just change the depth on the LFO?  I wonder if you could mod it (easily) to use a pot instead.

I'll have to check out the Behringer unit - has anyone had experience with them? I've had issues with Behringer reliability in the past . . .

[Fender3D]

In DC2 switches act as "different settings" of 2 otherwise pots (R36 and R38)..,

[Mark Hammer]

From what I can see on the schematic, the 4 buttons produce 4 depth settings of 3 different speeds.  It's not unlike the 4-position rotary switch on the Phase 100 that provides two feedback settings for each of two sweep widths.  Boss could have probably used a rotary switch as well - after all, they did with the Funny Cat and Double Beat - but 4 buttons just looks so much sexier than one solitary rotary switch.

Folks more accustomed to multiphase chorus units that use 2 or more BBDs will tend to view continuous controls as largely unnecessary, and a sign of weakness.  When you have more than one BBD, the wet signal is not as obviously flat or sharp as when there is a single wet signal going flat and sharp in cyclical fashion, so the need to have a width/depth control to tame the pitch wobble is much less urgent.