5 elements delay

[Gabi Smith]

Hello,

Iv' found in this book a schematic of a circuitry that can produce Something like a "rockabilly" slap-back. It's page 258 and 259 of the book. You can directly command the page 266.

http://lucmorton.com/lucstuf/pdf/Music%20Synthesizers%20-%20AMODAC%20-%20Delton%20T%20Horton.pdf

 I've tried the delay circuit on my breadboard with some pnp transistors I have at home but didn't had anything really exciting. It was like if the signal didn't go through the transistor.

So, what do you think about it? Which modern transistors can I try? And the mixer, is it a simple op  amp ?

Thank you guys.

[BuGG]

Where does it mention this circuit giving a slapback effect?      

Maybe I'm missing something, the "delay" you'll achieve from the circuit I'm seeing is fractions of a microsecond.   We're talking inaudible phase shifts here, miles away from any perceivable echo.

This looks like an interesting book, good find.  =)

[Gabi Smith]

Ok, as far i didn't know what a phase shift is (and i'm not sur that i know now), I was abbused by the word "delay".

Is it this effect that is build here ?

https://www.youtube.com/watch?v=AzPNEjauwyc

As far I'm a big user of delay and echo, it would be cool if I had a beginners analog circuit. Just a short slapback would be great. Do you know what would be the esayest way to delay the sound ?

[nocentelli]

Phase shift can be used to refer to audio signal that has some or all of the frequency content shifted out of phase by a small degree: Any RC network will shift certain frequencies by certain amounts, and although we can perceive differences/changes in phase shift quite easily, the actual delay is so slight it is not an echo-style effect. Phase-*shifter* circuits tend to additionally have an LFO that wobbles the degree of phase shift in a cycle, as in the video. The depth of the effect can be altered by either altering the blend of phase-shifted vs dry signal, and/or feeding some of the output back in for some resonance. The effect can vary from a typical chewy swoosh, to a watery vibrato or even a "harmonic tremelo" sound.

For actual delay/echo/slapstick/ADT effects you have no chance of doing it simply with analog, since analog BBD chips are fairly tricky to get reliably/cheaply/quickly, are relatively easy to destroy and usually require a few other chips to work alongside: However, it would be trivial to make a digital slapback delay with a PT2399, which are super cheap and available everywhere. There are several one chip delay schematics out there, and if you only wanted it for a single slapback you could lose the repeats pot and associated circuitry.

[Gabi Smith]

Ok, I've seen that the esayest delay is the crappy one of Alleesz. I'm waiting for some PT2399. It will be my first try.

Is the mixer of the phase shifting a simple op amp or is it a mini-blender effect?