ex1C02_1. RMS Feedback System (delayr, deltapi, delayw)

The order output (delayr) and then input (delayw) is important. Also we may have any number of taps (along the delay line) using deltapi.

# ex1C02_1.py
# RMS Feedback System (delayr, deltapi, delayw)

from moduleCsound import *

tags(1)

header(ksmps=32)

# global sine table with 1024 points
add("giSine    ftgen     0, 0, 2^10, 10, 1 ;table with a sine wave")

# envelope restricts asnd (input) to 0.4 second
# thus each delay is also 0.4 second duration
# we show input to delay system at end (with delayw) 

add("""
instr 1
; envelope - rise to 0.2 (0.1 sec), hold at 0.2 (0.2 sec), fall to 0 (0.1 sec)
kamp        linseg 0, .1, 0.2, .2, 0.2, .1, 0
asnd        poscil    kamp, 440, giSine         ;initial input
a0          delayr    1                         ;delay line of 1 second
a1          deltapi   0.5
            delayw    asnd
; sum of delayed signal at 0.5 sec as well as 1 sec
a2          = a0 + a1
            outs      asnd, a2
endin
""")

tags(2)

# instrument 1 played for 2 s
# input (0 - 0.4 s)
# delay at 0.5 sec (0.5 s-0.9 s)
# delay at 1 sec (1 s - 1.4 s)

add("""
i 1 0 2
""")

tags(3)

writeRun(__file__)

Output: