fading effects in/out?

[Luhny]

Hi all, I've been lurking around here for awhile and have a question to ask. I'm a newb to the DIY stuff, but I have managed to complete my first pedal, the Rebote 2 delay from Tonepad. Excellent pedal, it sounds awesome.

My question is, is there any way to make the effect less pronounced when it's turned on and off? When I turn off the delay, it's too sudden. I'd like it to just do a nice fade so it's not so noticeable when I turn it off.

BTW, here's some pics if anyone's interested. This particular pedal is Pearl Jam themed, as Mike McCready is the main influence in my playing.

[R.G.]

Nice finishing work there.

The simplest way to do a fade in/out is to use JFET switching like the Ibanez line and put much bigger capacitors on the gate circuits of the JFETs. This does whtat you're looking for directly. It's possible to build this into an external box.

Another way is with a dual LED/LDR setup or with a dual OTA variable gain amplifier setup. The JFETs are much easier.

[smccusker]

are you sure you're a noob to diy?

[Dave_B]

are you sure you're a noob to diy?

No kidding.     Luhny, is that all inkjet decals?  Very nice look.

[niftydog]

for a delay, one good trick is to have the switch disconnect the input (ie; ground the input and re-route your guitars signal) of the circuit only. This way, when you hit the switch to "bypass" it, whatever delay repeats are still in the delay line will continue to sound, but no further signals are input to the delay.

[nelson]

That pedal certainly looks as if its a labour of love.

2 coats of different coloured paint. Some strategic sanding, and an inkjet decal.

Thats atleast my guess at the finish.

[Processaurus]

for a delay, one good trick is to have the switch disconnect the input (ie; ground the input and re-route your guitars signal) of the circuit only. This way, when you hit the switch to "bypass" it, whatever delay repeats are still in the delay line will continue to sound, but no further signals are input to the delay.

Thats how I'd do it, if you didn't mind your signal always going through the clean/delay mixer in the delay, and having whatever noise the delay chip makes getting mixed in.  That might not be a problem without anything but repeats getting fed to the delay's input.  If you want to try it, do this:

Find the 1uf cap that is in between pin 7 on the opamp, and the 15k resistor.  I'd cut the trace on the PCB (if you're using the PCB) between the + side of the 1uF and the junction right by it, so pin 7 is still connected to the 22K resistor.  OK, now what we want to do is switch the + of the 1uf between the junction mentioned before  (a wire hooked to the 22k resistor would work well) and a new 47K  (or whatever value is around) resistor to Vb.  The resistor to Vb is to hold the bias on the +end of the 1uF and prevent a big pop when switching the input back into the delay line.  To test it and see if you like it, just use a spdt toggle switch.  If it works well, disconnect everything except your LED wiring from your stompswitch, and hardwire the boxes input to the effect input, and the same for the output.  then change the test toggle switch for one of the poles on your newly liberated 3pdt stompswitch.  It will no longer be true bypass.   Whether that is an issue is up to you.  If thats a problem, I'm sure there is a way with a new toggle switch, or internal dip switches to re route stuff to make TB an option, and not have delay trails.  This is a simple way to get what you're after, though.

Nice work on the box by the way.

[Steben]

for a delay, one good trick is to have the switch disconnect the input (ie; ground the input and re-route your guitars signal) of the circuit only. This way, when you hit the switch to "bypass" it, whatever delay repeats are still in the delay line will continue to sound, but no further signals are input to the delay.

What about disconnecting the input to the delay chip. I would put a single switch around the 1uF and the 15k resistor at the input of the PT2399. The regeneration/repeats line remains untouched. The rest of the circuit acts as a unity gain.
Would it cause popping there?

Oh, yes: great great great finish!! 

[j.frad]

Great finish!

I like the idea of the fet switching RG proposed, I've tried to find layouts for fet bypassing in the past with no success because everyone always wants true bypass! So does anyone have information on fet bypass on Ibanez pedals?

[Luhny]

Hey guys, thanks for all of the compliments on the finish. Yes, it really is my first pedal. I did a lot of research before starting it, and to be honest I'm surprised it worked the first time. If it makes you feel any better, I've currently got a Guv'nor clone in the works that doesn't work at all    The enclosure started out black, but the decal wasn't visible enough due to me using clear. So I topcoated with yellow and sanded through to make it look distressed. The decal still didn't show too well, so I sanded down the areas where the decals went. I'm pretty happy with the results.

So let me make sure I understand this, because like I said, I'm a newb. I could throw a switch in by pin 7 as Processaurus says and that would affect whether the signal continues to get delayed? I wouldn't be opposed to throwing a second switch onto the pedal to serve that purpose, and having the other switch serve as the main bypass switch. Again, thanks for any help you can give me. Some of this is still a bit over my head.

[GFR]

for a delay, one good trick is to have the switch disconnect the input (ie; ground the input and re-route your guitars signal) of the circuit only. This way, when you hit the switch to "bypass" it, whatever delay repeats are still in the delay line will continue to sound, but no further signals are input to the delay.

For ultimate control you can do like Steve Morse. He has two volume pedals (or pan pedals?) one before the delay the other after the delay.

[Dave_B]

... I topcoated with yellow and sanded through to make it look distressed.

That makes me feel better.  I tried duplicating your distressed look in Photoshop and all I accomplished was losing an hour of sleep.   

[Xlrator]

That has got to be one of the most amazing finishes on a box. I will have to try that! 

[roknjohn]

For ultimate control you can do like Steve Morse. He has two volume pedals (or pan pedals?) one before the delay the other after the delay.

Not sure if this is what GFR meant, but if you used a dual pot for this, you could probably blend the amount of the delay with the clean or pre-delay signal, plus use as a foot controlled fade.

Another nod for your finish work. SWEEEEEET!

[Marcos - Munky]

Also, for fade in, you can build a Boss Slow Gear, or maybe a modded Ross/Dynacomp with attack and decay do the job for fade in and out.

PS: has anybody said you have a great looking box? 

[Mark Hammer]

In a great many pedals that involved combining two signals (delayed and nondelayed, phase-shifted and nonshifted, etc), many manufacturers "cancel" the effect by simply breaking the path between the wet signal and mixer stage, using a FET.  Both the input and output stages always remain in the signal path.  If they are well-designed and a delay pedal is fed a nicely buffered signal, then that always-on part should not matter much.

I'm a fan of "punch-in" effects that mimic the riff-wise application you find in post-production effects.  Naturally, I like the "trails" option found in the Line 6 delay pedals that permit whatever is in the digital buffer to keep going until they die out, even when the effect is bypassed.  So, I like RG's idea of upping the value of the smoothing cap on the switching FET.

Here is a slight extension of that idea to provide a kind of smooth changeover.

I said that normally ("normality" being defined by commercial delay pedals) a FET is used between the output of the wet path and the input of the mixing stage.  This comes after the point where the Regen tap is taken to feed back to the input mixing stage for creating repeats.  Imagine you have two FETs, one before the delay chip and one in the traditional location, with discrepant caps tio ground hence different switching lag.  The FET switch BEFORE the delay chip is fast, the one before the output MIXING stage is much slower.  Both FETs are governed by the same "side" of a flip-flop circuit. 

What happens here is that input to the delay is terminated, but whatever is in the delay path continues a little while longer.  HOW long would depend on the cap value chosen.  It would not be unreasonable to have a toggle to select lag/changeover time so that in one case you get an instant cancellation, and in another the delay signal hangs around for a split second or more.  It's as simple as picking a different cap value.

[petemoore]

  The enclosure started out black, but the decal wasn't visible enough due to me using clear. So I topcoated with yellow and sanded through to make it look distressed.
  ..Way to Work with it...turned out Great !!!