'Space and Time' reverb with pre-delay and tails

[samhay]

Time to reorder some 10k resistors.

It's been noted before that I have a bit of a penchant for 10k resistors. I buy them by the 100 from Bitsbox.

[bluebunny]

Save and shrink it I think. I always have problems uploading pics here.

Even if you can't resize the picture yourself, you can scale it when it hits the forum.  Just put height=nnn inside the [img] tag.  For example:

  <---   [img height=200]http://imageshack.com/blah...[/img]

Caveat: it doesn't make the picture download any quicker...

[Kipper4]

Thanks Mark.
I'll try to remember that for future reference.
Pic amended.

[onthetundra]

I have built it using the perfboard layout. I've found that it works mostly but the output is probably half of the clean signal. I'm not getting a ton of change when altering the regen pot too. Any thoughts?

[samhay]

In bypass, or with the mix pot fully ccw, it has a gain of 1, so something isn't right.
I guess, I suggest you start by double checking the wiring (there is a lot), followed by all your resistor values - they are mostly 10k, so shouldn't be too difficult.

Edit: Is it quiet in buffered bypass? If so, check the value of R13 (bottom left in the layout between the 1n and 1u caps) and for shorts/wrong traces around that op-amp.

[samhay]

An update:

While I still haven't boxed this up, I have promised myself that I will do it before I build anything else. I have made some progress though, and now have a version with soft switching (schem below), which works as intended except for a very slight switching noise that is most apparent with the delay and repeats turned up - think repeating taps of pink noise. I think this is probably contact bounce in the relay and am in the process of resigning myself to adding FET mute(s).

Before I go any further - Rich and anybody else who may have built this, do you get any switch pop / noise?

Edit - A quick word about the switching. This uses an old trick of mine to use foot taps and foot holds to do different things (like in some looper pedals). Tapping the footswitch - which is momentary - turns the effect on and then toggles between on and tails bypass via a relay. However, if you step and hold for long enough (200 ms at the moment), the effect toggles to true bypass via a second relay. In the case of this effect, being able to go to true bypass is pretty neat as you can set the feedback / repeats to very slowly reach self-oscillation, then turn this all off when it gets too much while still maintaing the option of tails bypass.

schem ('view' image for bigger version):


and this is what I am hoping to fit into a 1590B:

[Kipper4]

Looks like one Dead Astros breadboard monsters Sam.
As soon as I get some more bricks I will revisit it for you.
Ps that IC 6 pic thing looks complex. Might have to dig in a bit and find out about them. Maybe a feature I wish to add before boxing it too

[samhay]

Thanks Rich - I assume you don't have a programmer, so would be happy to pop a programmed PIC in the post if you want to have a play.

Also, if anybody is interested, I am happy to post the code - it is written in C for the XC8 compiler, is fairly brute force (simple debounce counter type approach with no interrupts), but works well enough and should be fairly easy to follow.

[samhay]

Well I bit the bullet and built the '2000' version on perf to see whether tidying up the ground would help with the switching noise. Thankfully it did - I keept the relay and PIC ground fairly separate from audio/PT2399/BTDR and the results are quite acceptable. If one wishes to build the smaller / sensible version with single relay to do the switching then I suspect that this will work with little attention paid to layout.

The build was a little bit tight and not as tidy as I would have liked - I have a few more things to add to my never again list. That said, you can fit 5 16mm pots, 2 dual op-amps, a PT2399, a BTDR-2, an 8-pin PIC and 2 DPDT relays in a 1590B if you really want too!


('view' image for a larger version)

[Cozybuilder]

This looks real good Sam- its now officially on the build list, moved up to number 3.

[samhay]

Not sure I should have called it a 'reverb' as it works nicely as a delay that you can mix a hint of reverb in. In any case, it is one of those circuits that you can start playing with and lose an hour or two.

[deadastronaut]

it is one of those circuits that you can start playing with and lose an hour or two.

they are the best ones imo...

that's a stunner man...nice build

edit: and you drilled pot tab holes too...

[electricco]

beautiful eatched box and the gold knob are awesome !! (....where to buy such knob? )

[samhay]

Thanks guys.

Rob - yes, you have to keep the pot tabs on. I guess if I was to do this in a more tidy fashion then I wouldn't drill all the way through the top.

electricco - not etched, it's just a toner transfer. Not sure where I got the knobs from, but probably somewhere in the UK. They have been in my drawer for quite while waiting for a build with 5 pots that all have knurled shafts.

[micromegas]

Also, if anybody is interested, I am happy to post the code - it is written in C for the XC8 compiler, is fairly brute force (simple debounce counter type approach with no interrupts), but works well enough and should be fairly easy to follow.

Hi Sam, just stumble across this thread.
I am highly interested in the code, just bought a icsp pic programmer and would be cool to give it some use. Playing with two relays is more challenging than playing with one .

Thanks for all your awesome projects.

Cheers,
Adán

[samhay]

No problem Adán, here you go:

Note that it is not very elegant and could do with tidying up a bit, but it does work as shown with the '2000' version schematic.

Code Select Expand


/*
* File:    pic12_relay_toggle.c
* Author:  samhay
* Date:    November 2014
*
* uses a pic12F675 and to be compiled with XC8
*
    * 3 states - true bypass, on, buffered bypass
    * state=1 = TB = both relays off
    * state=2 = on = TB relay on, BB relay off
    * state=3 = BB = both relays on
    *
    * pin 4 (GP3) is input-only, so this is our input; GP0,1,2,4,5 are outputs
    * pin 2 = GP5 = BB status
    * pin 3 = GP4 = on status
    * pin 5 = GP2 = TB relay - high = effect on
    * pin 6 = GP1 = BB relay - high = buffered bypass
    * pin 7 = GP0 = not used
    *
*
*/

#include <xc.h>
#include <stdint.h>

// Configuration
#pragma config MCLRE = 0FF              // ext reset
#pragma config CP = 0FF                 // no code protection
#pragma config WDTE = OFF               // no watchdog
#pragma config FOSC = INTRCIO           // int RC clock, all pins available for I/O

#define _XTAL_FREQ 4000000              // oscillator frequency for _delay()
#define __delay_ms(x) _delay((unsigned long)((x)*(_XTAL_FREQ/4000.0)))
                                       // define delay_ms to keep MPLAB X quiet

#define stomp GPIObits.GP3              // stomp switch

                                       // Global variables
uint8_t sGPIO;                          // shadow copy of GPIO
uint8_t state;                          // state counter

void startup()                          //turn all the LEDs/states on, one after another
{                                       // and intialise 'state'
   uint8_t c1;                         // Local variables

   sGPIO = 0;
   GPIO = sGPIO;
   for(c1 = 1; c1 <= 5; c1++) {        // toggle 2 status LEDs 5 x
        sGPIO = 0b010000;
        GPIO = sGPIO;
        __delay_ms(300);
        sGPIO = 0b100000;
        GPIO = sGPIO;
        __delay_ms(300);
   }
   sGPIO = 0b000000;
   GPIO = sGPIO;
   state = 1;
}

void whichstate()                       // define 3 states
{                                       // as sGPIO values
   /*
    * GPO  not used                    // this is not right, but
    * GP1  TB relay - TB off           // states 2,3 below
    * GP2  BB relay - BB on            // seem to work in the SaT
    * GP4  effect status (TB=1, BB=0)  // reverb
    * GP5  BB status
    */
       if(state == 1)                  // TB
           sGPIO = 0b000000;
       if(state == 2)                  // effect
           sGPIO = 0b010100;
       if(state == 3)                  // BB
           sGPIO = 0b100110;
}

void main()                            // main programme
{
                                       // Local variables
    uint8_t dbc;                       // debounce counter

    // Initialisation
    TRISIO = 0b001000;                 // configure GP3 (only) as an input
   
    startup();                         // power-up LED show and set initial GPIO = 0 and state = 1

   // Main loop
   for(;;)
   {
       for(dbc = 0; dbc <= 20; dbc++) { // button must be down for 20 ms before doing a loop
           __delay_ms(1);
           if(stomp == 1)
               dbc = 0;
       }      
       __delay_ms(1000);               // wait 1000 ms - not actually this long -- to fix
       if(stomp == 1) {                // stomp is depressed within delay - this is a tap
           if(state == 1)              // in TB
               state = 2;              // so go to effect
           else if(state == 2)         // effect on
                state = 3;             // so go to BB
           else                        // state must be 3 (BB)
               state = 2;              // so go to effect
           whichstate();               // read whichstate to determine new sGPIO
           GPIO = sGPIO;               // set new GPIO from sGPIO
       }
       else {                          // button held for >200 ms - this is a long press
            state = 1;                 //
            whichstate();              //
            GPIO = sGPIO;              // go to TB
       }

       for(dbc = 0; dbc <= 50; dbc++) { // wait for stable button up
           __delay_ms(1);
           if(stomp == 0)
               dbc = 0;
       }
   }                                   // end main for loop


}                                       // end main

// EOF


[micromegas]

Thank you Sam!

[samhay]

All my images were lost to the great dropbox public folder purge.
Here they are courtesy of imgur (click/view for larger versions):





The version I built (not sure where the layout went):

[Bisnoisy]

Thank you Sam

Is there any sound samples or demo ?

what's the max delay time ?

[stonerbox]

That design sets off fireworks in my heart. Minimalistic and delicious.