{"id":6063,"date":"2023-08-30T18:43:16","date_gmt":"2023-08-30T23:43:16","guid":{"rendered":"https:\/\/pugix.com\/synth\/?p=6063"},"modified":"2023-08-30T18:43:20","modified_gmt":"2023-08-30T23:43:20","slug":"low-gain-dual-negative-slopes-hills-and-valleys","status":"publish","type":"post","link":"https:\/\/pugix.com\/synth\/low-gain-dual-negative-slopes-hills-and-valleys\/","title":{"rendered":"Low-Gain Dual Negative Slopes + Hills and Valleys"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

Filling out my 4U Serge rack project is a Serge design based Dual Negative Slopes plus Hills and Valleys from Low-Gain Electronics<\/a>. Of course the original Serge module names were Dual Negative Slew and Peak and Trough.<\/p>\n\n\n\n

The Negative Slew has always been one of my favorite Serge modules. I came across one around 1977 or 78 and took the trouble to draw out its schematic for my personal use. I built two Negative Slews for my 1980 DIY synthesizer. Somewhere around 1980 the Negative and Positive Slews were replaced by the Dual Universal Slope Generator. I’ve also built Ken Stone’s CGS82<\/a>. The Low-Gain 4U version was much easier to build.<\/p>\n\n\n\n

Negative Slew Functionality<\/h3>\n\n\n\n

From a 1970s Serge catalog: The DUAL NEGATIVE SLEW is one of the unique multi\u00ad-functional patch\u00ad-programmable modules in the Serge system. The module features two independent sections with wide range voltage controllable slew rates. The slew is active in the negative direction only and can be patched to perform a number of synthesizer functions. With the Pulse<\/strong> output patched to the Input<\/strong>, the module will oscillate for use as a voltage controlled sawtooth oscillator or pulse generator. An audio signal applied to the Input<\/strong> will be envelope detected<\/em>, and the complex envelope will be available at the output. If a pulse is applied to the Input<\/strong>, the unit will function as an envelope generator with a fast rise time and a voltage controlled fall time.<\/p>\n\n\n\n