The Stoel Music Systems Spring Reverb is a flexible spring reverb module with extended features. In addition to standard level, wet/dry mix, and tone emphasis controls, the feedback control re-introduces the reverb signal back at the input. At low settings, this increases the density of the reverb. At high settings, it will cause oscillation. The level at which oscillation occurs will depend on the reverb tank used. In addition, a 100% wet output and a feedback input jack allow for external feedback signal processing. For example, by sending the feedback signal through a filter, unique reverb textures can be created, and the feedback control can be further exploited for sound design.

Reverb tanks use electromechanical technology dating back to the 1940s, so some noise is expected, even under ideal conditions. If the case is moved while the reverb is turned up, the user may hear a loud “crash” sound. This is caused by the springs hitting the sides of its metal enclosure. This behavior is normal. When locating the reverb tank in the case, place it as far away from the power supply as possible to avoid picking up hum and noise. A switching power supply is generally quieter than one that uses large transformers. Some level of hum and noise is expected in any installation due to the nature of the electromechanical reverb spring and magnetic pickups. Experimenting with the placement and orientation of the reverb tank may be necessary to achieve the best results. Mechanical noise can be minimized by using the included mounting grommets and mounting the reverb tank away from vibration sources such as speakers or drum pads. High signal levels will also reduce the signal-to-noise ratio, resulting in better sound quality.

We recommend the following reverb tanks (not included):

9.25” long reverb tanks
8EB1C1B: Horizontal/open side down, 3 Spring, Short Decay
8EB2C1B: Horizontal/open side down, 3 Spring, Medium Decay
8EB3C1B: Horizontal/open side down, 3 Spring, Long Decay
8EB2C1A: Horizontal/open side up, 3 Spring, Medium Decay

17” long reverb tanks
4EB3C1B: Horizontal/open side down, 2 Spring, Long Decay
4EB2C1B: Horizontal/open side down, 2 Spring, Medium Decay
9EB2C1B: Horizontal/open side down, 3 Spring, Medium Decay
9EB3C1B: Horizontal/open side down, 3 Spring, Long Decay

All Stoel Music Systems modules feature aluminum front panels with a durable high-gloss white finish. For a crisp appearance and exceptional durability, the front panel markings are digitally printed at high-resolution with UV-cured ink. Mounting holes are plated to significantly reduce screw rash. The power connection features polarity protection to prevent accidental damage to the module if it is connected backward.

Each module includes a 12” long 10-pin to 16-pin ribbon cable compatible with the Eurorack standard, M3 mounting screws, and a complimentary sticker.

Includes standard level, wet/dry mix, and tone emphasis controls, the feedback control re-introduces the reverb signal back at the input
Reverb tank and cable not included
By sending the feedback signal through a filter, unique reverb textures can be created

Technical Specifications

Width	6 HP
Depth	33 mm
Current Draw	+12V: 35mA, -12V: 7mA, +5V: 0mA