Yamaha DX7-IID : unstable feedback

video upload by Valmont

"It's the association between the DX7-IID and the Ibanez UE-405 echo that creates this flanged tube-chime effect, which sometimes kicks in depending on the notes I played. The DX7 plays a simple sawtooth-like bass, nothing weird. An unstable combination, hard to catch though!

The kick is driven by a modified Altai Analog Echo System (the weird thing sitting on the DX7-IID)
The snare goes into a 1979 Roland SIP-301 & then is sent to a 1985 Alesis XTC Reverb. The hi-hats go in the SIP too but not through the XTC loop.

More explanations :
The UE-405 is running its BBD echo at minimum rate, and feedback is just under the saturation threshold. Depending on the notes played by the DX7, the level sometimes goes above the threshold, creating that flanged highly saturated delay. Yet the BBD driver has a compressor/expander, so when I play longer-sustained notes the feedback loop calms down and the saturation decreases. Subtle sh!t very specific to analog delays :) The Altai is just a cheap echo box, the BBD isn't particularly interesting but the preamp section has a nice transistor stage that clips in an asymetrical way. Banger on kicks.

Oh and that white thing hanging on the racks is my Ibanez UE400/405 controller!"