ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

previous: Jeff What is the switch on the front for... -- 2/11/2000 9:55 AM

Re: EH Zipper

2/14/2000 3:41 PM
Mark Hammer	Re: EH Zipper The schematic shows two switches. Not having a photo handy, I can't say which one is on "the front". However, one switch shown simultaneously alters the attack envelope of the unit so that it sweeps differently. The other switch appears to engage either one or two of two identical filter sections. The filter structure is unfamiliar to me, so this is far from a definitive answer, but if it DOES convert from a 1-pole to 2-pole (or 2 to 4) structure, you should detect a more pronounced resonance in one setting than the other...when you get it working again. The Zipper was probably the most controllable of the EH envelope-controlled units, so I'm curious to hear more about it from you, with respect to tone. I have an original Y-Triggered Filter and a homemade Dr.Q, and both are OK, but the Zipper seems to have more synth-like capabilities.

2/14/2000 3:41 PM

Mark Hammer

Re: EH Zipper

The schematic shows two switches. Not having a photo handy, I can't say which one is on "the front". However, one switch shown simultaneously alters the attack envelope of the unit so that it sweeps differently. The other switch appears to engage either one or two of two identical filter sections. The filter structure is unfamiliar to me, so this is far from a definitive answer, but if it DOES convert from a 1-pole to 2-pole (or 2 to 4) structure, you should detect a more pronounced resonance in one setting than the other...when you get it working again.

The Zipper was probably the most controllable of the EH envelope-controlled units, so I'm curious to hear more about it from you, with respect to tone. I have an original Y-Triggered Filter and a homemade Dr.Q, and both are OK, but the Zipper seems to have more synth-like capabilities.

Replies:

Jeff Thanks guys. I replaced the switch.... -- 2/15/2000 7:15 AM