jcjr CosmoDepot
Copyright (C) 2019 and later James Chandler Jr
Version: 1.0

Web: http://www.errnum.co
Contact: errnum@gmail.com
License: GPL - http://www.gnu.org/licenses/gpl.html

Contents

Download and Installation
Description
Controls
Runaway Feedback Protection

Description
CosmoDepot is a Reaper jsfx Multi-Tap Chorus/Delay/Reverb plugin. Possible uses include: Simple or Multi-Tap Stereo Chorus, Simple or Multi-Tap Stereo EchoChorus, Simple or Multi-Tap Stereo EchoChorus with Reverb.

CosmoDepot is a 24 Tap delay line with two different feedback paths and 32 independent random-rate modulation LFOs. Delay Loop time is adjustable between 125 and 1000 ms with additional Pre-Delay time adjustable up to 200 ms.

Eight delay line output taps are configured as four stereo output pairs. Any combination of one, two, three or four stereo output pairs can be selected for the wet output. The Output Tap mix can optionally feedback to the delay line input for repeat-echo effects. Each of the 8 delay line Output Taps has its own independent sine wave random-rate frequency modulation LFO. Output Tap frequency modulation amount adjusts from zero up to +/-20 Cents. When Output Taps are modulated, you get up to 8 different delay times, each independently pitch-modulated at different, constantly-changing random LFO rates.

An additional 16 delay line Reverb Taps are not directly heard on plugin output. However with non-zero Reverb Tap feedback, the 8 Output Taps get smoothed out with reverb added to the delay line by numerous recirculating feedback images from the 16 Reverb Taps. Each of the 16 Reverb Taps has its own independent sine wave random-rate frequency modulation LFO. Reverb Tap frequency modulation amount is adjustable from +/-5 up to +/-20 Cents. So the reverb recirculating "mini-echo" images are multiplied on every loop by 16 different delay times, each independently pitch-modulated at a different, constantly-changing random LFO rate.

A final eight random-rate LFOs can independently randomly AutoPan each of the eight Output Taps, should such depth of depravity ever become desirable.

Salute the Space Station
Lately waxed nostalgic about old Ursa Major Space Station. Been decades since I used one. About 1980 I worked a studio whose "highest quality reverb" was an Ursa Major Space Station. Loved it on vocals, horns and guitars. Did not like Space Station for drums or percussive instruments such as grand piano. Space Station sounded too clattery to me on drums and some other percussive sources. Even with the smoothest densest setting I could find, Space Station on drums didn't sound like reverb-- Rather, those sparse clattery reverb tails sounded like a drumkit getting kicked down the stairs.

However, that low-density multi-tap delay overlaid with low-density reverb sounded great on vocals, horns, guitars, etc. Could make a track sound saturated in verb though the actual Space Station decay time remained quite short. This allowed lively reverb enhancement without muddying the mix with unnecessarily long reverb tails.

My memory was somewhat rosy. Viewing Youtube Space Station videos, was reminded that Space Station had more "terrible" settings than great settings, at least to my taste. Had forgotten about all those crappy-sounding control combinations because I did not use the "bad" settings. Always used the Space Station adjusted as fat/lush as this early primitive box could deliver.

This elderly opinion ain't guaranteed gospel. Youtube vids generally describe Space Station as a great glitch machine. Many Youtube demos proudly process crappy drum loops with the Space Station to make em sound even crappier! News Flash: Geezer Seen Yelling At Sky!

So anyway CosmoDepot is not intended to be a Space Station clone. CosmoDepot has vague similarity to Space Station's signal flow block diagram. CosmoDepot time constants and features differ from Space Station but I wanted similar fat low-density short-decay multi-tap verb for vocal, horns and guitar.

Maybe CosmoDepot could be a glitch machine but I did not intentionally coddle glitch machine features. Glitch fans might test and let me know.

To my ear, among other things CosmoDepot can be good for the targeted purpose of fat short multi-tap echo-reverb on vocal, horn and guitar. To my ear CosmoDepot drums sound like kicking the drumkit down the stairs, which is similar to Space Station drum results. So MAYBE CosmoDepot is a candidate glitch machine or maybe not.

Controls

Pre-Delay [ms]
Range: 1 to 200 ms
The Pre-Delay before audio enters the main Delay Loop. For example a 100 ms Pre-Delay prevents any wet output for at least 100 ms after audio enters the plugin.

Reverb crowded close behind the source audio can make an instrument or vocalist sound too distant even when using short reverb decay. Pre-Delay creates time separation between source audio and reverb, helping an instrument or vocalist sound "near the listener but in a reverberant space."

However when CosmoDepot is used as a multi-tap chorus it may sound better with minimal Pre-Delay, mixing the delay taps along with the source audio "as soon as possible". Chorus FX often have only tens of ms total delay. Even at its 125 ms minimum Delay Loop Length and no Pre-Delay, CosmoDepot has wider delay footprint than many simple chorus effects. On the other hand you might like using CosmoDepot as a multi-tap chorus with significant Pre-Delay, which would be like connecting a Chorus stompbox to the output of a simple Delay stompbox.

Delay Loop Len [ms]
Range: 125 to 1000 ms
The default Delay Loop Length, similar to the old Space Station, is 250 ms. The ability to change the loop length over a wider range differs from the old Space Station. The Output Taps and Reverb Feedback Taps retain fixed time ratios regardless of Delay Loop Length. For example if a certain tap might use 60 ms delay at 250 ms Delay Loop Length, then that same tap would have 30 ms delay at 125 ms Delay Loop Length and 120 ms delay at 500 ms Delay Loop Length.

In other words, all the taps have a fixed "spacing ratio" how they are spread out to fill up the Delay Loop. As Delay Loop is adjusted shorter, the taps keep the same ratio but are crowded closer together in time. As Delay Loop is adjusted longer, the taps keep the same ratio but are spread farther apart in time.

CosmoDepot uses different tap delay ratios than the Space Station but even with that and other differences, CosmoDepot may sound more reminiscent of the Space Station near the default 250 ms Delay Loop Length. Longer or shorter Delay Lengths may sound good in proper context but Delay Lengths in the ballpark of the 250 ms default may be most promising for Space-Station-Like tasks.

Rvb Taps Feedback [Percent]
Range: 0 to 100 Percent
The 16 Reverb Taps are never directly-wired to the plugin output. Only the Output Taps are wired to the plugin output.

You never hear the Reverb Taps when Reverb Tap Feedback is set to zero. When you turn-up Reverb Taps Feedback, a mix of the 16 Reverb Taps feeds-back to the delay line input. The multiple tap feedback makes "reverb-like" build-up of numerous close-spaced copies of the delayed audio. Then you finally get to hear all those little mini-echoes mixed together on the Output taps.

With Reverb Tap Feedback set to zero, CosmoDepot acts as a no-reverb multi-tap echo/chorus FX. The number of output taps, tap modulation and spacing is set by other controls. So you might first find a no-reverb multi-tap echo/chorus sound that you like. Then if it sounds "too dry" you could gradually turn up Rvb Taps Feedback to "add a little reverb to the multi-tap delay". As Rvb Taps Feedback is increased, the reverb gets denser and the reverb decay time gets longer. Rvb Taps Feedback should not be set any higher than it needs to be. If Rvb Feedback is set so high that it rings too long or blurs the desired multi-tap delay effect, then back it off to taste.

Rvb Taps Mod [Cents]
Range: +/-5 Cents Pitch Modulation up to to +/-20 Cents Pitch Modulation. (A Cent is 1/100th of a Semitone)
Pitch modulate the Reverb Taps. Each Reverb Tap has its own LFO for a total of 16 Rvb Tap LFOs. Each LFO runs at its own rate randomly-chosen between 0.5 and 2.0 Hz. Every time an LFO finishes a wave cycle and begins a new wave cycle, that LFO picks a new and different random rate between 0.5 and 2.0 Hz. So all the LFOs are running at different rates and all the LFO rates are constantly changing.

Extensive randomization is intended to give a fat non-repeating chorus feel. Rvb Taps Mod can make chorus ear candy but also serves a mission-critical purpose-- Old-fashioned multi-tap delay line feedback is not stable under all conditions. Without at least a little feedback modulation we can't achieve useful reverb density. Modulation allows more feedback before obnoxious runaway oscillations.

When using big Rvb Taps Feedback, the higher you can set the Rvb Taps Mod, the less-ringy and more stable the reverb. Though you don't always need "real dense" reverb and therefore your Rvb Taps Feedback might not always be near max. Ringing is rarely noticeable at smaller levels of feedback. Modulation higher than +/-7.5 or +/-10 cents might begin to sound out-of-tune, depending on your ears and the nature of the source audio.

If you find yourself setting more Pitch Mod than you really wanted just for longer reverb tails then possibly try a different plugin with more stable architecture.

Output Taps Feedback [Percent]
Range: 0 to 100 Percent
There are 8 mono output taps arranged as 4 stereo pairs. You can select any combination of the 4 stereo taps. Whatever combination of taps is currently in use, whatever you hear, gets global feedback to the beginning of the Delay Loop.

This works like the feedback control on about any common echo device, stompbox, echoplex, space echo, whatever. If 8 taps are selected then all 8 taps are summed and fed back to the Delay Loop Input. If only 2 taps are selected then only those 2 taps are fed back to the Delay Loop Input. Whatever taps you hear get fed back. This differs from Space Station echo mode.

Especially with the Reverb Taps Feedback turned down and only a few Output Taps selected, this gives the typical decaying repeating echo. Small number of feedback taps has more predictable long-repeat big feedback behavior. Depending on instrument and musical context, long-repeat echoes may runaway easier when using a large number of output taps.

Of course repeat echo will work with all Output Taps selected and big Reverb Taps Feedback but the result might sound too dense.

Output Taps Mod [Cents]
Range: 0 up to +/-20 Cents Pitch Modulation. (A Cent is 1/100th of a Semitone)
There are 8 Output Tap LFOs. Each Output Tap has its own pitch modulation LFO. They work just like the Rvb Tap LFOs described above.

Any non-zero Output Pitch Mod is obviously directly audible in the Wet Output mix. If you only select a single Output stereo pair then you would hear one delayed, random pitch modulated output on the Left Output Channel and a different delay, different random pitch modulated output on the Right Output Channel.

Similarly with any combination of two Output stereo pairs, you would get two different-delayed, different pitch modulated echoes mixed on the Left Channel and two different-delayed, different pitch modulated echoes mixed on the Right Channel Output.

Same deal for other combinations including the max "all four stereo pairs" combination where you get four different-delayed different pitch modulated echoes on Left Channel Output and another four different-delayed different pitch modulated echoes on Right Channel Output.

CosmoDepot behaves closest to a typical simple chorus with minimum Pre-Delay and a short Delay Loop Length near 125 ms. Set Reverb Tap Feedback to zero and a big Wet Mix Percent. Select only 1 or 2 Output stereo pairs and then adjust Output Taps Mod to taste.

If you keep these "chorus box" settings and select 3 or 4 Output stereo pairs then it becomes a fatter multi-tap chorus. Because many different vibratos are mixed together, it becomes a "group chorus" effect rather than the common simple "vibrato doubling" chorus effect. No law forbids cranking the Rvb Taps Modulation and Feedback to further detune and fattify the stew though at some point a little more may become too much.

With longer Delay Loop times, CosmoDepot behaves like modulated echo or modulated multi-tap delay (depending on how many Output Taps are selected). Old tape Echoplex had semi-random pitch and tape dropout "gargle"-- A never-repeating weird vibrato that made fat chorusy echo. Feedback long-repeating echo trails may be most predictable using only 1 or 2 tap pairs but your mileage may vary.

Low Freq Damp [Hz]
Range: Range: 40 to 400 Hz
Low Freq Damp sets -3 dB cutoff frequency of a first-order (6 dB per octave) high pass filter which is applied to the [Input+DelayFeedback] mix. Therefore fresh input gets filtered before its first pass thru the delay but CosmoDepot Dry output is never filtered.

If delayed audio feeds back to the Delay Loop input then recycled audio gets additional filtering. If multiple repeat echoes are audible then the repeated echoes are more heavily filtered every time they recycle thru the delay loop. If Low Freq Damp is set fairly high for a non-muddy intelligible echo then repeated echoes continue to lose bass as they decay.

The default Low Freq Damp is set to 100 Hz because bass reverb seems senseless. It is hard to mix non-muddy punchy kick and bass even if we don't add gratuitous low frequency reverb rumble. But please set it however you like.

Hi Freq Damp [Hz]
Range: 1000 to 10000 Hz
Hi Freq Damp sets -3 dB cutoff frequency of a first-order (6 dB per octave) low pass filter which is applied to the [Input+DelayFeedback] mix. Therefore fresh input gets filtered before its first pass thru the delay but CosmoDepot Dry output is never filtered.

If delayed audio feeds back to the Delay Loop input then recycled audio gets additional filtering. If multiple repeat echoes are audible then the repeated echoes are more heavily filtered every time they recycle thru the delay loop. Typical natural reverb has fairly fast decay of very high frequencies. If your reverb or echo sounds too "pingy" then try turning down the Hi Freq Damp to taste.

AutoPan Mod [Percent]
Range: 0 to 100 Percent
Autopan uses another 8 LFOs. Each Output Tap owns its own LFO. As with the Reverb Feedback Mod and Output Tap Mod LFOs, AutoPan LFOs run at constantly changing random rates varying between 0.5 and 2.0 Hz.

Zero AutoPan Mod does nothing to the output. With zero AutoPan Mod there are from 1 to 4 (depending on Output Tap Selection) Delay Tap Outputs hard-panned Left, and a complementary different-delay set of from 1 to 4 (depending on Output Tap Selection) Delay Tap Outputs hard-panned Right.

100 Percent AutoPan independently random-rate AutoPans each of the Selected Tap Outputs between Hard-Left and Hard-Right, which sounds most "dramatic" with only 1 or 2 stereo pairs selected. With all four stereo pairs selected and eight different-delay, possibly different-modulated taps, with each tap independently hard-panning at its own random LFO rates-- The effect may sound unfocused. It works as advertised but I expected a hipper sound.

100 Percent AutoPan with all 4 stereo pairs selected can be reminiscent of degraded tape dropout. Maybe 100 Percent AutoPan is worth a try for degraded tape effects?

AutoPan is possibly more useful dialed back to 25 or 50 percent.
At 50 percent: Rather than the Left taps hard-panning all the way between Left and Right, the Left taps only AutoPan between Hard-Left and Center. Similarly rather than the Right taps hard-panning all the way between Right and Left, the Right taps only AutoPan between Hard-Right and Center.
At 25 Percent: The Left taps only AutoPan between Hard-Left and Mid-Left and the Right taps only AutoPan between Hard-Right and Mid-Right.

Output Taps Selection Menu
Range: All 15 possible combinations of the four Output Tap stereo pairs
Simple text graphics indicate the active stereo pairs. [X] denotes an audible stereo pair and [_] indicates a muted stereo pair. For example the menu item [X][X][X][X] explains that all four stereo pairs are audible-- 8 taps total with four Taps hard-panned Left and the other four Taps hard-panned Right.

Similarly, the menu item [X][_][_][X] indicates that both the earliest and latest stereo pairs are audible but the middle two stereo pairs are silent.

Left-most Taps in the text list have early arrival and right-most Taps have later arrival. However left-most early taps are separated by bigger time intervals and right-most late taps are separated by smaller time intervals. Acoustic room echo typically has a few wide-spaced early echoes followed by more closely-spaced late echoes.

Stereo pair 1: Arrives earliest with the Left Tap earlier than the Right Tap.
Stereo pair 2: Arrives next with the Right Tap earlier than the Left Tap.
Stereo pair 3: Arrives next with the Left Tap earlier than the Right Tap.
Stereo pair 4: Arrives last with the Right Tap earlier than the Left Tap.

Wet Mix Level [Percent]
Range: 0 to 100 Percent
With a zero Wet Mix Level no delay or reverb is audible.

Inserted on an individual track: Typical useful echo/reverb values might be 100 Percent Dry with Wet in the ballpark of 20 to 50 Percent according to taste.
Inserted on an individual track: Typical useful chorus values might be 100 Percent Dry and about 75 Percent Wet. Adjust Wet to taste for best-sounding chorus.
Inserted on a Send: As with any delay or reverb, typical useful values might be zero Percent Dry and 100 Percent Wet.

Dry Mix Level [Percent]
Range: 0 to 100 Percent
With a zero Dry Mix Level no Dry plugin input is audible from the plugin output. With 100 Percent Dry Mix Level the plugin dry output level is identical to the plugin input level (assuming that the Output Gain control is set to 0 dB, unity gain).

Inserted on an individual track: Typical useful value might be 100 Percent Dry.
Inserted on a Send: Typical useful value might be zero Percent Dry.

Output Gain [dB]
Range: -24 to +6 dB
The plugin's Master Output Level Control. If the plugin gets too loud or too quiet then you can compensate here.

Runaway Feedback Protection
CosmoDepot intentionally uses a rather old-fashioned not-always-stable delay topology. In order to get "near-infinite repeating echoes", some settings have enough excess gain to enter unbounded feedback oscillation. In order to get "close to the edge" you need sufficient gain to sometimes go all the way over the edge.

Most CosmoDepot settings are stable but you can find a few unstable combinations. Try minimum Reverb Mod and also minimum Output Mod, with max Reverb Feedback and also max Output Feedback. That should do it! Then you could damp the resultant runaway oscillation by boosting Tap Modulations or by backing off one of the two Feedback controls.

Runaway Oscillation Protection is a limiter on the Delay Loop Mixed Feedback input. The feedback limiter is designed to never engage except when runaway feedback causes sustained stupid-loud audio oscillations. The Feedback Limiter uses relatively slow 20 ms Attack with a long 1 second Release. The relatively slow Attack should prevent the Feedback Limiter from un-intended gain reduction caused by occasional brief normal music peaks louder than 0 dB. Long Release can suppress self-oscillation for an appreciable time, giving you opportunity to adjust whatever control is set wrong.

Slow Attack and long Release gives the Runaway Limiter a "hunting" behavior. If Delay Loop level rapidly rises because of runaway oscillation, the 20 ms Attack responds "pretty quick" but takes long enough that the envelope can rise pretty high above threshold. And then the long Release keeps the feedback gain low for a few seconds. Over-threshold audio doesn't just limit level to the threshold. The Runaway Protection limiter turns down the gain MORE than necessary to merely limit to the threshold.

If you decide to intentionally put CosmoDepot into self-oscillation then the limiter exhibits this hunting behavior:
_1 Oscillation grows until the limiter grabs.
_2 Oscillation level drops, sometimes -18 db or more.
_3 Self-oscillation might grumble to itself at this lower level for awhile, possibly evolving in tone.
_4 If you keep the settings "over the top" long enough the limiter eventually relaxes.
_5 The oscillation recovers until it finally gets loud enough that the limiter "beats it down" again.
_6 Yadda Yadda Ad Infinitum

If you intentionally put CosmoDepot into self-oscillation and leave it thataway then this getting-louder-then-softer hunting behavior repeats indefinitely.

Depending on various settings, you can get a few "not completely shabby" spooky air raid sounds or flying saucer self-oscillations. CosmoDepot does not offer a real wide palette of self-oscillation sounds because self-oscillation is an accidental topology side-effect and not a core feature. CosmoDepot was not written to be a flying saucer feedback machine. Someday it might be fun to write an interactive flying saucer feedback machine, which would want a different control set for best flexibility.

Download and Installation
Download CosmoDepot Here--> jcjrCosmoDepot.zip

If you do not know how to install jsfx plugins into Reaper then here is an excellent instructional video-- How To Install JS Plugins Video

  1. First unzip jcjrCosmoDepot.zip yielding the un-compressed folder jcjrCosmoDepot.

  2. Open the jcjrCosmoDepot folder to find a jcjr folder inside.

  3. Contents of the jcjrCosmoDepot/jcjr folder--

    a) jcjr_CosmoDepot : The jsfx effects code.

    f) jcjrCosmoDepotManual.html

  4. If you do not already have a folder titled jcjr in your Reaper effects folder, then copy the jcjrCosmoDepot/jcjr folder into your Reaper effects folder.

  5. Otherwise, if your Reaper effects folder already contains a jcjr folder, then copy the ENTIRE CONTENTS of your new-downloaded jcjrCosmoDepot/jcjr folder into your already-present REAPER/Effects/jcjr folder. This will add the new CosmoDepot files to any plugins already installed in the REAPER/Effects/jcjr folder. For example if you have installed both jcjr RMSComp and jcjr PeakLimit 2 plus jcjr CosmoDepot, then the Reaper effects folder would contain one jcjr folder. That single jcjr folder would contain all three plugins' code, all three plugins' required files, and the three manuals, one folder for the RMSComp manual, a second folder for the PeakLimit 2 manual, and the "naked" CosmoDepot html manual. CosmoDeopt manual does not link images or audio files and therefore does not require a folder to keep it tidy.


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