Originally designed by Bob Moog and released in 2000, the Classic MF-104 Analog Delay was manufactured as a limited edition release of 1000 units. A special "Bucket Brigade” delay chip was employed allowing the effect to remain completely analog. Unfortunately, the supply of these chips was limited and the final MF-104 sold in 2001. Since then there have been two reissues of the Classic MF-104, the MF-104Z and the MF-104SD. In that time, each has been added to a short list of the most sought after analog delays in history.