Need suggestions for a customized delay

[oliphaunt]

I would like to build a delay pedal with (at least) the following properties:

- Will have two modes, a "Normal" and a "Slapback" mode, footswitchable
- Mix, repeat, delay controls for the "Normal" mode
- In "Slapback" mode the repeats will be fixed at one repeat.  It would have separate mix and repeat controls for this mode.
- As much delay time as possible, at least 450ms
- Fit in a 1590 enclosure longways (approx 3.5" wide X 4.5" deep)
- Will be powered only by DC input, no battery, (I can provide 9,12 or 18V to the pedal)
- The delay will be used in "Slapback" mode almost constantly so the dry signal MUST be as clear and uneffected as possible
- Doesn't have to be analog but I prefer the warm "analog sound"
- I don't etch, so a PC board must be available or it must be a reasonable build on Vero or perf.

Other goodies are a plus, such as modulation, tails, and who knows what else.  I don't have an issue with buffers, this will come at the end of a long signal chain and an output buffer might be a plus.

Basically I am hoping to combine the properties of a slapback and a long delay into one circuit, in order to save space on a small pedal board I use for simpler gigs.  I use a Diamond Memory Lane 2 on my large board, and it does all of this and more except for one issue.  The mix is not adjustable between the two settings, so the long delay is usually not as loud as I would like.

I have been searching the forum and other sites for information about the various delay projects out there (AD3208, PT80, the various Rebotes and the Echo Base).  I know a project with these exact specs doesn't exist, but I am hoping that someone with experience with them can reccomend which one might be best suited to mod for my specs.

[jacobyjd]

Sounds like you want the sound of a Rebote 2.5 with some of the features of an Echo Base.

That being the case, I'd suggest swiping the filtering of the 2.5 (for the analog 'sound') and applying it to the Echo Base.

[slacker]

The tricky bit will be doing the switching between the 2 modes especially if you want it to be footswitchable. Apart from that it's just a case of picking a delay you like the sound of, the Rebote 2 or 2.5 or the Echo Base will do what you want, not sure if the AD3208 has enough delay time for you.
I'd pick the Echo Base because it's the only one with a vero layout. I think there's a perf layout for the Rebote 2.5 but there's no vero layouts as far as I know.

[jkokura]

I would think that you should build a pair of rebote 2.5's into your box, one with a resistor in place of the repeats pot selected for just one repeat. Wire it for a on/off and a A/B set of switches and you're good to go - two delays will be easier than trying to get one delay to give you both.

[cpm]

I would suggest a very simple slapback echo with one PT2399, as you say it will be its main use.
the circuit will be small, that fits in a small box, having only two pots: delay time and repeat volume

if you ever need longer delays, its a good idea to have another delay for that purpose, which would help the change from one sound and another while playing, because you dont have to move pots. Adjusting a long delay time can be tricky, and i dont like to mess with delay times once i settle on a nice spot, for as long as rehearsal or playing live.

[oliphaunt]

Thanks for the suggestions and thoughts.  I will start reading the large Echo Base thread from the start and learning more about delays but in the meantime I have a few questions:

Sounds like you want the sound of a Rebote 2.5 with some of the features of an Echo Base.

That being the case, I'd suggest swiping the filtering of the 2.5 (for the analog 'sound') and applying it to the Echo Base.

That sounds intriguing.  I only have experience with ODs and boosts and would love if someone would be willing to point me toward the filter sections of those two delays.

The tricky bit will be doing the switching between the 2 modes especially if you want it to be footswitchable. Apart from that it's just a case of picking a delay you like the sound of, the Rebote 2 or 2.5 or the Echo Base will do what you want, not sure if the AD3208 has enough delay time for you.
I'd pick the Echo Base because it's the only one with a vero layout. I think there's a perf layout for the Rebote 2.5 but there's no vero layouts as far as I know.

I thought you might suggest the Echo Base!    It's a wonderful sounding piece based on the clips I have heard with great features.  Nice work!

I have been looking at the switching in the Rebote 2.5 schematic and it seems like simply switching the control pots for different pots is easy enough as far as the wiring is concerned.  Having no experience with delay ICs though, I don't know how the chip will respond to a break in the controls.  It seems like this could cause some popping or other unwanted artifacts.  Has anyone tried this?

I would think that you should build a pair of rebote 2.5's into your box, one with a resistor in place of the repeats pot selected for just one repeat. Wire it for a on/off and a A/B set of switches and you're good to go - two delays will be easier than trying to get one delay to give you both.

I thought about this.  I also thought about using a mixer to blend the output of the two delays and the dry signal and have two independent delays that could both be independently switched on and off and allow trails!  However this project is about downsizing and simplifying when possible.  As my first delay build I don't want to get too complicated.

I would suggest a very simple slapback echo with one PT2399, as you say it will be its main use.
the circuit will be small, that fits in a small box, having only two pots: delay time and repeat volume

if you ever need longer delays, its a good idea to have another delay for that purpose, which would help the change from one sound and another while playing, because you dont have to move pots. Adjusting a long delay time can be tricky, and i dont like to mess with delay times once i settle on a nice spot, for as long as rehearsal or playing live.

I own a pile of cool delays and can do this anytime I want (and often do on my large pedal board), but the dual mode delay is a project I would like to attempt to challenge myself and to downsize from two delays for use on a miniature pedal board I use on some small gigs.

[svstee]

I built a Rebote 2.5 with footswitchable delay times with the idea of switching between delay and slapback/echo in mind. I think with any PT2339 based delay, you will run into nasty noise when switching delay times, like when you adjust the delay pot but much worse.