#Eventide harmonizer h910 history manual

In 1962, Manfred Schroeder (of digital reverb fame) published an article in the AES Journal about using frequency shifting as a method of increasing the gain of a PA system by up to 6 dB. The idea of using a time-varying system, such as pitch shifting, delay modulation, or frequency shifting, to increase the maximum gain of a system before oscillation occurs, dates back many decades. However, it is interesting to see how such a simple process can have a significant effect in a PA system вЂ“ by turning on the Anti-Feedback control, you can increase the gain of a microphone being fed into the H910. In modern terms, I would call this a chorus effect, with a triangle wave modulator. Increasing clockwise rotation of the ANTI-FEEDBACK control progressively adds a small up and down frequency shift to the output signal, which serves to decrease the effect of room resonance peaks on the signal which ultimately re-arrives at the microphone.

#Eventide harmonizer h910 history manual

When I was researching the Eventide H910 Harmonizer, I found it curious that the box had controls for both feedback and something called вЂњanti-feedback.вЂќ The service manual explains the anti-feedback control as follows: I put them in the same room and let them fight it out.вЂќ вЂ“ Stephen Wright вЂњFor my birthday I got a humidifier and a dehumidifier.