The “it does everything” box.
The 517 provides a world-class transformer-coupled mic preamp, one-knob compression, DI circuitry with Vari-phase, Silk saturation and DI + mic blending capabilities – all in a single module.
GAIN
A 12-way precision rotary switch covering from Line (0) and Mic from 0 to 66 dB in 6 dB steps.
+48V
Engages phantom power on the microphone input, as supplied by the 500 series rack.
POLARITY
Push button inverts the polarity of the signal path. The symbol “Ø” is often used to denote opposite polarity.
COMPRESSOR
Based around a new LDR (light dependent resister) design, the 517’s opto-coupler compressor has been simplified to a single threshold control with auto make up gain. By default, the compressor is set to a fixed 2:1 ratio with fixed attack and release. To set the compressor, simply dial the threshold control down until the desired amount of compression is achieved. An LED light indicates when the compressor is active.
BLEND
The 517 can be used to combine and compress a direct signal and an amplified signal. To achieve this, use the DI for an instrument’s direct signal and the mic preamp for either the mic’d speaker cabinet signal or an entirely separate source (like a vocal microphone). The blend control allows you to achieve the desired tonal balance between the two sources.
SILK
Pushing the Silk button engages the Silk circuit, which enhances the source’s harmonic content in a manner very reminiscent of many of Rupert’s class-A vintage designs.
VARI-PHASE
The VARI-PHASE control rotates the phase incrementally, allowing two signals with the same source to be phase aligned. This control is most apparent when the signals being combined are at roughly equal levels, and is generally used when blending an instrument’s direct signal with its amplified signal, as captured by a microphone.
INSTRUMENT GAIN
Front panel TRS Input and passive through for hi-z sources. Continuous gain control from 0dB to 30dB.
THRU & INST 1/4” PHONE JACKS
These 2 jacks are used for instrument direct input and a THRU output to an amp, and are paralleled and wired together, as it is a passive design. Inserting a plug into either jack breaks the normal MIC input and the user has the full range of MIC GAIN and TRIM. These jacks have a 3 mega Ohm input impedance that will provide less loading (i.e. better highs) than most DI boxes, and the sheer amount of gain that is available makes this input extremely versatile.
