Madbean Ping (Reverb)

A great simple reverb from Madbean.
You can find his 1590G size boards and infos on his website.

The way the layout has been drawn you should be able to solder the brick directly to the board and lay it under it.

Death By Audio Reverberation Machine

Info about the original:
The Reverberation Machine is a synthetic atmosphere creator. Use the effect on any instrument to add depth and simulate different environments. Experiment and combine a variety of settings to obtain the perfect ambiance for your sound.
The controls on this pedal are straightforward. Volume, Altitude, Reverb Blend and two distinct reverb flavors: Bright Sunshine and Dark Star. Altitude adjusts the gain structure of the reverb and the clean simultaneously creating exciting new reverberation soundscapes that span from subtle to wild.
Although the controls are extremely easy to use and intuitive, there is a vast array of sounds. Everything from simulations of vintage amp verb, playing in a cave, large concert halls, and space ships being sucked into wormholes.

UPDATE! Test values between 0 & 10K for R1 to improve Bright Sunshine side.

Rub-a-Dub Reverb

And the standard version using the more widely available and cheaper BTDR2 bricks.  This is set to be around unity but if you want a boost then experiment with the 12K resistor.  18K will give you a slight boost.

Rub-a-Dub Reverb Deluxe

Request.  This is a 1776 Effects project with more info available here.  Check out their other projects and PCBs available at their store:

The Rub-a-Dub Deluxe utilizes the new Accutronics BTDR-3H. The
BTDR-3H allows the reverb decay to be adjustable. In addition, the
Rub-a-Dub Deluxe also adds a tone control (based on Culturejam’s
Box of Hall) and a trim pot to allow for a volume boost or cut.

ValveWizard Equinox II

Request, and also for those who want another PT2399 based reverb pedal.  Not one for the faint hearted with that many links and cuts! :o)

One thing you will notice straight away is that this doesn't have the usual 3PDT stomp switching to bypass the effect.  Because it has tails, the stomp will just turn the effect (and LED) off and not mechanically bypass the circuit, so in bypassed mode IC1 will just act as a buffer.  So the input and output wires go straight to the sockets, and only a SPDT stomp is required.

With this being a dual PT2399 build I don't think anyone will want to run it off a battery because if they do it really won't last very long, so this should fit fairly comfortably in a 1590B without making allowances for battery space, and especially with a single pot.

Info from Merlin about his project:

Equinox II: Reverb with Tails
This project came about because I wanted to roll my own reverb. A common way to do this is to use a tapped delay line, but no such chips exist any more. No matter; the result is the same as using multiple delay lines in series and/or parallel. Several DIY reverb effects use the excellent accutronics Belton Digi-Log reverb module, and the associated patent, US8204240, shows that it uses three PT2399 delay chips, one of which is modulated at a slow rate to give a more realistic spring reverb sound. The Accutronics module is not commonly avalable in Britain (also it's cheating to use a ready made effect module!), but I did have a tube full of PT2399s (I absolutely love these chips). I also wondered whether just two could do the job, and it turns out that for guitar use you can indeed get a primitive but usable effect this way. I think this makes the Equinox II the simplest DIY reverb project on the net at the moment!

In the Equinox II the reverb effect is acheived by passing the audio through two delay lines in parallel. One is arranged for a short delay (about 80ms), and the other a long delay (about 250ms). The outputs from each are summed and fed back to the input of the delay lines, and also mixed with the original audio via a mix pot- that's it. (I have an affection for one-knob effects.)

In detail, after passing through the input buffer the guitar signal is sent both to the output mixer and to the JFET analog switch. This switch allows the input to the delay line to be muted, creating bypass with tails (this is exactly the same as my Small Time delay).
Following the JFET the signal then passes through a 15nF capacitor which provides a little bass cut, to stop the reverb getting too muddy, and it then feeds into a second-order high-cut filter. This is also where the output of the delays lines is fed back in.
The output of this filter feeds the short delay line, and also the long delay line (via an unavoidable inverting buffer).
After the signals emerge from the two delay lines they are both summed and filtered again. All this filtering is necessary to reduce noise from the analog-digital-analog conversion inside the ICs.

I spent a long time tweaking the delay times, filtering, feedback, and mixing ratios, to get what I think is the most usable reverb sound using standard component values and the simplest architecture. My first Equinox prototype also had adjustable delay time on the long delay line, and a fat/bright switch. But I didn't find these to be very useful (at anything but the optimum delay time all you get are 'metallic bathroom' type sounds), so I trimmed the circuit down to the bare essentials, creating the Equinox II shown here.

To see more information including the schematic and a PCB for those who want an easier life, check out Merlin's page here, and a clip can be heard here which sounds pretty damn good to me!

And after discussions below, a version which omits the JFET and instead uses the second pole of the stomp to turn the reverb on and off.  This will also keep tails intact as per the original but because of the parts omitted has removed a link and a couple of cuts and is one column smaller.

Grind Customs FX Tenebrion Reverb

Another project from Rej in conjunction with another great DIY personality CultureJam, this time the Grind Customs FX Tenebrion Reverb which requires one of the smaller Belton BTDR2 bricks which are available with short, medium or long decay.

General Guitar Gadgets D-Verb

A nice simple reverb project that a few people have asked for, with this layout based around the BTDR-2H brick.  The short description from the GGG website:

This is a great sounding digital reverb project.  Based on the Belton Digital Reverb Brick.
This really is an excellent reverb and is also the base of some of the reverb units being built by Hermida Engineering, used by many big name guitarists.

I've left the original layout up, but this is one row smaller so thought it worth adding for anyone who wants to keep the size down:

Casper Electronics Echobender

Something weird to do with your extra PT2399s. From Casper Electronics :

The Echo Bender is a mix of multi FX pedal and noise maker.
It can process external signals like guitars, keyboards, mics and drum machines or it can create complex sounds on its own.

It can function in several different stand alone modes: 
-Warm analog sounding echo.
-Highly adjustable distortion.
-Ring mod style feedback.
-Complex noise generator.
-These modes can be used on their own or it can all be mixed together to achieve effects ranging from melodic and dreamy to chaotic and screamy.

The noise generating capabilities are especially interesting. The echo rate range has been set much lower than the standard echo pedal. When the rate is turned WAY down, the sound breaks up into blipping squeals and screeches. Combine this with distortion and feedback tones and a reverse decay setting and you’ve got a lot of variety and tonal complexity.

Video demos and additional information on the Casper Electronics site.

Cook Spring Reverb

This is the original Cook Spring Reverb design and not the "mark 2". Any spring reverb tank should do just fine...

So strike the above text. The tank type is crucial to get this design to work properly. I have no no idea what sort of tank it should be, so even though this is now verified, you should proceed with caution. The tank you have may or may not be suitable for the design. More accurate information about reverb tanks can be found here: http://sound.westhost.com/articles/reverb.htm

Box of Hall Reverb - culturejam

A nice little Belton Brick reverb build here.  As described by cj:

This one is pretty simple. It's the new smaller Belton/Accutronics brick and a quad op amp, a Reverb Mix control and a tone control I'm calling "Dampen". It's a dead-simple low-pass filter right off the brick's output (or rather, one of the outputs) in parallel with a fixed cap to ground. I got that little idea from earthones' suggestion of a tone control for the 2399 reverb I did. (credit where due!) I'd say this is about 75% similar to the application note, but with the added tone control, slightly different filtering, and buffered VREF.

I've tried this with the Medium and Long decay bricks. The Long can definitely get some cool ambient spacy sounds going on. And with the tone control at min, it's really bright (either brick type). The only difference I can hear is the decay time.

Circuit is verified and sounds pretty damn good.

Demo by Geiri:

You can get the Belton bricks from Musikding here.  I'd suggest going for the BTDR-2H because it's smaller, but have included a layout for the older BTDR-1H bricks as well, just in case someone has one they want to use.

Layout for BTDR-2H bricks:

and one for the older BTDR-1H bricks:

 

It seems to be very popular so here's the Box of Hall - Heavenwithin modded version.

Ersatz Verben psuedo reverb by culturejam

Designed by culturejam on FSB and CW, this is what he wrote:

Inspired by the Crap-Fi Delay by allesz, I decided to see if a similar simple circuit would work at lower delay times for reverb and slapback. It does.

Once the basic circuit was up and running, earthtones helped me refine it and make it much nicer. He's wicked smaht like that.

Delay time range is about 40ms up to about 140ms. As delay time is increased, more highs are rolled off by C4 (that was ETA's idea). So it's pretty much hiss/noise free no matter the delay time. 

He posted a demo here, and it sounds pretty good to me.  Something different to do with those PT2399s you've got.

Geiri's quick demo of his build:

And another clip with 100K as delay pot for longer delay times...: