1 x PT2399 Reverb

[M23Bomber]

Hello All, 

I saw the Cave Dweller  at Mad Bean Pedals, is it possible to make a very basic reverb based on this layout?

Did anyone try?

Regards

M.

[knutolai]

Reverb requires more delay lines. You can get the feeling of a "space" with simple delays, but if you are looking to build something to rival commercial reverb pedals you should look towards the various Belton Brick reverb projects

[M23Bomber]

Hello Knutolay, thank you for your reply. 

My purpose with a single IC reverb (and reverb circuits in general)  is to add it to some of my ongoing distortion pedals projects, to give them  "special space feeling" , that can be turned on immediatly when that particular pedal is activated. So that the audiance can have new level of depth.

By  "special space feeling" I imagine a kind of surround echo  as the one in concrete rooms or large basement filled with people.

Reverb requires more delay lines. You can get the feeling of a "space" with simple delays,

I quote you post and raise a question about it:

Would the original signal and the the one produced by Cave Dweller Reverb( assuming it is possible  ) be enough t create a "good" reverbsound?


Regards,
M.

[knutolai]

Would the original signal and the the one produced by Cave Dweller Reverb( assuming it is possible  icon_biggrin) be enough t create a "good" reverbsound?

You are describing what the circuit is already producing, so no. Getting really good reverb sounds either requires a DSP chip with a coded reverb algorithm or a network of delay modules with fine-tuned delay times. If you want to keep things simple I would advice you against going down that route.
If you are looking for a cheap way to add a "special space feeling" a delay circuit can do the job. Basically you could put together the cave dweller or a similarly simple pt2399 delay circuit, set the delay time low (around 4.7k resistance from pin 6 to ground) and change around the filtering for brighter repeats. Kinda gives a sound that you might associate with uncomfortable underground spaces.
Have a look at this thread: http://www.diystompboxes.com/smfforum/index.php?topic=88178.0
The "Sewer Pipes Ring-Verb" might just be what you are looking for.

[M23Bomber]

Hello again

Yes,the purpose is to keep the garage band and pub gig  in some of my distortiotion pedals, not making the best reverb pedal ever 


I appreciate the link it has another diagram to analyze and experiment till I get the sound I want.

Regards, M

[M23Bomber]

Hello knutolai 

FYI

I found an IC that will privide reverb, the ES56033E by ERSO, and the schematics have low part counts. I will experiment with this one untill the sound I want is obtained.

Regards,

M.

[Mark Hammer]

It won't be reverb, by any stretch, but more low pass filtering on the delay and added low pass filtering on the regen will yield something that moves more in the direction of reverb.  Whether that does what you need is up to you.

[merlinb]

I wonder if envelope control of the delay time could be made to simulate reverb? In other words, the delay is fairly long when the note is first plucked, simulating the early reflection, then the delay time is quickly reduced, creating a rapid collections of late arrivals...

[armdnrdy]

FYI
I found an IC that will privide reverb, the ES56033E by ERSO, and the schematics have low part counts. I will experiment with this one untill the sound I want is obtained.

I found a sound sample of a preamp/reverb/delay on youtube. (below) A guitar sample is featured toward the end of the video.

It is my opinion that this IC does not produce a very good reverb. It sounds like a fast slap back echo at best.
I agree with knutolai's comments about more than on delay to create a "good" reverb.
So far.....one of the best modules to come out that feature a more than acceptable reverb are the Belton bricks.
The brick's design incorporates three delay lines to achieve this.

[kingswayguitar]

sounds like a pt2399

[samhay]

I wonder if envelope control of the delay time could be made to simulate reverb? In other words, the delay is fairly long when the note is first plucked, simulating the early reflection, then the delay time is quickly reduced, creating a rapid collections of late arrivals...

Whether it sounds like reverb or not, this is an interesting idea for an effect. A FET as a variable delay resistor should be fairly easy to implement. 

[psychedelicfish]

I wonder if envelope control of the delay time could be made to simulate reverb? In other words, the delay is fairly long when the note is first plucked, simulating the early reflection, then the delay time is quickly reduced, creating a rapid collections of late arrivals...

You'd have to keep the pitch constant as you change the delay time, which could be difficult. Could you do it with PWM? If you had a nice sharp square wave changing the delay time you wouldn't have much audible pitch shift...

[Mark Hammer]

I wonder if envelope control of the delay time could be made to simulate reverb? In other words, the delay is fairly long when the note is first plucked, simulating the early reflection, then the delay time is quickly reduced, creating a rapid collections of late arrivals...

You'd have to keep the pitch constant as you change the delay time, which could be difficult. Could you do it with PWM? If you had a nice sharp square wave changing the delay time you wouldn't have much audible pitch shift...

The pitch would change.  Whether one is doing it in the anaog or digital domain, changing the sample rate quickly WILL produce audible pitch shift, similar to the Digitech Whammy pedal.  I'm not saying it would be uninteresting, but it wouldn't be reverb, that's for sure.

Again, I recommend at least trying my earlier suggestion of making the lowpass filtering a little heavier in both the main delay path and the feedback path.  So, instead of 100nf caps for filtering, use 120nf or maybe a pair of 150nf.

Keep in mind that part of what MAKES reverb reverb is that it sits way in the back of the dry/wet mix, and the fact that it lacks much top end is part of how it does that.  If one arranges to trim a little more top-end off the feedback signal with each iteration, that also lets you turn the feedback up more, without the sound getting too cluttered.

[Lurco]

I wonder if envelope control of the delay time could be made to simulate reverb? In other words, the delay is fairly long when the note is first plucked, simulating the early reflection, then the delay time is quickly reduced, creating a rapid collections of late arrivals...

Wouldn`t that pitch-up?

edit: ooops-seemed to have missed those posts above that already mentioned that.

[M23Bomber]

Hello All,

This circuit has the following schematic:


http://construyasuvideorockola.com/downloads/reverb.pdf

Here is a call to patience and breadboards to develop this preamp with reverb and delay  into a great pedal !!!!
But the PDF is in Spanish

Regards,
M.

[midwayfair]

I wonder if envelope control of the delay time could be made to simulate reverb? In other words, the delay is fairly long when the note is first plucked, simulating the early reflection, then the delay time is quickly reduced, creating a rapid collections of late arrivals...

Whether it sounds like reverb or not, this is an interesting idea for an effect. A FET as a variable delay resistor should be fairly easy to implement. 

Skreddy's delay does it with an LED and LDR.

I keep meaning to just build something like that, but I just don't need another PT2399 delay.

[pinkjimiphoton]

sounds like a pt2399

hmmmm..... wonder if it has the same lock up kinda issues as a 2399?

http://www.cbtricks.com/radios/galaxy/datasheets/ic/pdf/es56033.pdf

[pinkjimiphoton]

did anyone ever figure out what the delay time is with the ES56033E? if they'll combine shipping, i'm gonna pick up 2 of those and 2 ES56028E chips to experiment with... hoping they can maybe be adapted to the little angel chorus. be nice to not have to deal with latchups..