Vole - Enhancing Level Control

Vole is a new utility 1U module from Laine. It’s a dual volume control that adds some extra flavour.

Overview

There are two channels of attenuation and boost with soft-clipping. Between them lie Baxandall EQ shelf circuits, channel one with a gentle high shelf boost, channel two has a low shelf boost. The output of channel one is normalled to channel two. In practice this means you can plug a low level signal into channel one, boost it to obtain some saturating soft-clipping, and take the output from channel two. In addition to the clipping stages the original signal would have a low and high shelf boost, similar to a "Hi-Fi" EQ boost on consumer audio products. It can of course be thought of as a dual volume control and preamp, with a touch of low or high sweetening.

For sounds that could use a bit of sparkle run them through channel one, and maybe a drum track that would benefit from some punchiness through channel two. The EQ curves are subtle with low Q factors, providing 4dB of gain, on top of the full spectrum gain boost of the post-attenuator amplifier. Inputs are DC coupled and will pass DC signals with minimal waveshaping taking place. The Baxandall topologies are similar to those used in our "Stilts" EQ module, and the overall sound is open and reasonably transparent at medium gain levels. There are three LED level indicators per channel, with the third orange LED underneath the front plate indicating when soft clipping has engaged.

Specifications and downloads

• Intellijel 1U format
• Width 10HP
• Depth 31mm
• Power requirements ~25mA +12V/~25mA -12V (8mA at idle with no inputs)
• Impedance Input 100K / Output 1K
• CH 1: Wideband boost + 4dB High frequency shelf boost starting at 3.5KHz
• CH 2: Wideband boost + 4dB Low frequency shelf boost starting at 250Hz
• CH 1 output is normalled to CH 2 jack switch input
• Non-inverting outputs on both channels
• DC coupled inputs that can be used for CV control

• Modular Grid

User Interface

Typical Response Graphs

CH 1 at maximum gain settings

CH 2 at maximum gain settings

CH 1 to CH 2 in series at unity gain settings

Signal Flow Diagram

Audio Examples

Here is an example of the type of gain increase amounts that Vole will put out. First a kick drum is triggered with a constant clock measuring around 13.5V peak to peak. Next this is boosted with Vole CH 1 running into CH2 ,and trimmed to the point of clipping. This recording is taken from the output of CH 2. After this, another subtle boosting with different gain levels, slightly more clipping, with the outputs taken from both CH 1 & CH 2 then summed externally. The last example is the type of rail to rail hard clipping occuring when both channels are boosted to the maximum gain.

Here are three audio samples demonstrating Vole’s subtle tone colouring and clipping. First there is the input tone, a slightly asymetrical square wave signal at around 36 Hz. Next this is sent through volume fade in CH 1 of Vole (High shelf boost) from minimum to maximum settings, and back down. You can hear a slight boost on the high end, and some soft clipping. The third sound is the square wave fading through CH 2 (Low shelf boost.) As this is a low frequency source, the bass boost is more prominent, as is the clipping at maximum boost settings.

Here is an example of a full track run through Vole. The first sound is the original, a chuggy beat with some synth stabs. The next sound is this run though both channels of Vole in series, just at the point of soft clipping. The result is slightly chunkier with a bit of top end sparkle and fuller low end. It’s nothing radical but you should be able to hear the difference between this and the original. The next snippets is the mix run through CH 1 (Hi shelf boost) with a touch of clipping. The last is the mix running through CH 2 (Low shelf boost) where the bass and kick definitely have some more “oomph” present