J'avais demandé des précisions à Mark Hammer sur son "jet plane sound":
What people often refer to as more of a "jet plane" sound tends to have two principle aspects to it. One is that it is harmonically rich (usually provided by some form of distortion), and the second is that the sweep goes very high. When the minimum attainable delay time is very very brief, the lowest notches in the spectrum tend to be at the very top of the hearing range and generally outside the range of the speakers. As a result, with a very short minimum delay, as the delay time is increased, the notches produced start to move into the audible range, becoming more and more numerous. It is the "infection" of the audio signal with notches that people tend to report as being a more dramatic sounding flange effect.
As an example, with a delay time of 1msec, there will be notches produced at 500hz, 1000hz, 2khz, 4khz, etc. All of those are audible. If one were to shorten that minimum delay time to 250us by reducing the number of delay stages from 1024 to 256, the lowest notch produced is now at 2khz, with another at 4khz, and another at 8khz. Sweep that delay from 250us to 5msec and you got from only a couple of audible notches to lots and lots.
The MN3207 chip can be clocked much much faster than it is in the BF2, so as to produce shorter delay times than it normally does. The problem is that the circuit would have to be radically overhauled to do that. The BF2 normally has a shortest possible delay time of 1msec. The MN3209 chip is absolutely pin-for-pin compatible with the 3207, such that without having to change anything about the clocking circuit, the minimum time can be reduced to 1/4 of a msec (250us "microseconds"), merely by popping one chip out and the other in. What one forfeits, however, is tha ability to produce the longer delays, since the entire delay range would shift from 1-13msec down to 250us to 3.25msec.
VENTE A PERTE PEDALES ET BAFFLE HAUT DE GAMME
"J'ai l'impression que certains ici ne prennent pas la guitare assez au sérieux... J'en ai surpris en train de s'amuser... Dommage..." - Zepot
FAUVE ? "imiter Thierry Roland qui imite Grand corps malade, c'est pas donné a tout le monde" - Mia Wallace
