I was thinking about creating a reverb/delay combo pedal with tails and effect order switching (delay->reverb and reverb->delay). I was thinking about fabbing my own version of the EQD Ghost Echo with the mods I want already built in so I don't have to cut traces or jam wires in occupied pads. As with most reverb pedals that I have seen, there is a dry signal and a path to get to the effect. I was thinking that I could use the dry signal of that pedal and throw a delay in the effect side. I figure that, by using the reverb's dry signal, I would save more space than if I had both effects AND a tails circuit board in a box.
I have read a previous thread (http://www.madbeanpedals.com/forum/index.php?topic=8058.msg70749#msg70749 (http://www.madbeanpedals.com/forum/index.php?topic=8058.msg70749#msg70749)) to figure out how to cut the path from the first op-amp section to the capacitor in the reverb effect and to connect Vb to both sides of the cut to prevent popping. The question is, do I have to also supply a Vb link to the delay as well? Would Vb (which I believe is 4.5V) interfere with how a simple delay (such as the Cave Dweller) works? Below is a little illustration of what I am thinking. The red box is the tails switch, and the blue circles are for the 3PDT. Would the simplest solution be to add Vb between the tails switch and A2 of the 3PDT?
(http://i.imgur.com/2qyShsR.jpg)
I found a couple tech help threads that list the voltage on pin 16 of the pt2399 as 2.5, but I also see a couple of schematics (Moodring and the EQD Ghost Echo) that appear to have close to 4.5V going into their respective PT2399s. Am I seeing things poorly, or would it be okay to apply 4.5V to the input of a Cave Dweller?
A few views, but no replies. I am going to talk this problem out loud, and if anyone wants to add/correct, I am all ears.
Do the first two resistors of the Cave Dweller act as a voltage divider? If so, wouldn't they drop down a 4.5v signal to 2.5ish? Just observing that there are similar setups in other pt2399 delays.
I'd take a look at bean's delays, compare the ones without tails to the ones with. Also I think one is switched. Yours is a little different but it should help. Also look up the data sheet. Wish I had more to offer but it sounds like a cool project!