# Echo - **Maker:** Synthrotek - **HP:** 4 - **Cases:** Eurorack 001 Installed · Synthrotek SeaHorse (same physical unit) - **What it does:** PT2399-based echo with voltage-controlled rate (formerly EKO); Rate, Feedback, Mix. ## Manual - [Product](https://www.synthrotek.com/products/modular-circuits/echo/) ## Jacks and controls Maker page names manual controls **Rate**, **Feedback**, **Mix**, plus CV of rate. Exact jack silk-screen (IN / OUT / CV): check panel / schematic linked from the product page. ## Good for Delayed or echoed copies of CV or audio; metallic / pitch-bent echoes when rate is modulated. ## Patches none yet