What is PT2399?
The PT2399 is a single chip echo processor IC utilizing CMOS technology. The PT2399 performs low distortion (THD<0.5%@0.5Vrms) and low noise (No<-90dBV) characteristic for audio purpose, and pin arrangement and application circuit are optimized for easy PCB layout and cost saving advantage.
How PT2399 works?
In the PT2399, digitization is only used to delay the signal, nothing else ! The small DSP in the PT2399 stores only a sample of the sound in memory for a few milliseconds. Then it plays it back later without any sound processing added. Then, all the sound processing is done with 100% analog circuit.
How did a bucket brigade work?
What is a bucket brigade? It refers to an early method of firefighting before hand-pumped fire engines. The firefighters would pass buckets to each other to extinguish the blaze. Before firefighters arrived all able-bodied citizens would run to the scene with buckets.
Is memory man bucket brigade?
Dubbed the Memory Man, it was based on a low-noise analogue bucket-brigade chip from Panasonic. The Memory Man Deluxe hit the shelves in 1976, going through a number of iterations. Earlier units sounded darker and somewhat thicker due to the delay chip in play. Later units were cleaner with a bit more sizzle.
What is BBD chip?
A Bucket Brigade Device (or BBD) is an analog circuit contained within a small chip that delays an incoming audio signal. This “circuit-within-a-circuit” was the main reason why an analog delay could fit into stompbox form.
What is the pt2399?
The PT2399 is a CMOS echo/delay processor developed by Princeton Technology Corp. This digital chip includes an ADC (Analog to Digital converter), 44Kb of RAM to store the samples and a DAC (Digital to Analog converter).
What is the pt2399 Echo application circuit?
The PT2399 Echo Application Circuit is a quick way to see what the PT2399 is all about. If you do not have the exact component values for the capacitors, get as close as you can. 0.082uF capacitors can be very difficult to obtain. The ‘R’ value is best set at 1k, and the 20k potentiometer next to it keeps you in a safe range of delay lengths.
What is the output impedance of the pt2399 circuit?
The PT2399 circuit needs to be driven from a low impedance (<1Kohm). The output impedance of the chip is low but the R10 resistor (2K7 in Delay and 5K6 in Echo circuit) will raise the output impedance value (the load should have an input impedance >100K ideally).
How to determine the delay time of the pt2399?
The VCO (Voltage Controlled Oscillator) voltage will command the delay time of the PT2399, following the TABLE 1: VCO FREQUENCY VS DELAY TIME from the datasheet when the frequency of this oscillator is maximum (22MHz) the delay time is minimum (31.3ms) and vice-versa.