it takes until Ll is reached from L4. The larger the Rl value, the sharper the attack.
Rates and levels determine the basic shape of the envelope, but the actual envelope shape is affected by output level and key scaling.
3.Output Level Buffer
Output level buffer receives data concerning key scaling, after touch, and output level from the CPU. Actual values used for Ll to L4 are determined by the data stored in this buffer. Key scaling changes the output level as shown below.