The "Old" switch can radically alter the tone of the Dark Storm.  For starters, it sounds more like a vintage piece of gear.  It does this by switching to a different impedance tap on the custom-wound LBA-MCX4 mic input transformer.  This tap is one that aligns closely with that of mic input transformers from the late 1950's-early 1960's.  When this is engaged, a 12dB boost in volume is also achieved.  The frequency response is reduced a little and the harmonic content is increased a little by this switch.  Normally, the frequency response is exceptionally flat throughout the bandwidth of 13Hz-25.5kHz.  The Old switch brings it back to old-school territory with a flat zone of 34Hz-23.3kHz.  The sound of this function can be described as one that is more focused and round with a tone that is not overbearing.  A lot of clarity can be maintained, but certainly some will be sacrificed when using the Old feature.

The Gain knob is an active control for the mic preamp stage.  It can add thickness and when pushed beyond half way, distortion.  With the gain all the way down audio will pass with about 25dB of gain and audibly more headroom than any other configuration.  Up all the way an you can get a fuzz-like distortion.  At >95% of the knob's rotation is where you dig into the distortion.  During the prototyping stage I removed the ability to get audible distortion from the gain knob and very shortly after decided it was best to put it back in.  It's a cool sound that's proven to be useful in my studio work. 

The DI input features a discrete, class A, JFET preamplifier stage of its own, plus it uses 2 transformers back-to-back!  The front panel 1/4" input feeds into the very high input impedance of a JFET transistor, which is how an impressive amount of high frequency detail is captured.  This is then buffered by a BJT transistor to drive an LBA-MC15 transformer (wired as a step-down transformer) which pairs to the MCX4 mic input transformer.  The MCX4 is the same transformer with the Old switch attached, which means you can apply the Old color to the DI signal.  With Old engaged, the tone becomes more focused and pronounced in the mids and sounds more tube-like in it's sonic presentation of headroom.   

The Trim knob is a passive volume attenuator which comes post input section, but before the output amplification stage and output transformer(s).  It can allow the user to dial in loads of gain (or distortion) and then attenuate the output volume to a suitable level.  There are dual outputs which can be used at the same time.  There is a transformer balanced +4dBu XLR line output, which uses a massive "LBA-Fat Sally 0.2" output transformer.  In parallel with the output of this transformer is an LBA-20SX steel-core transformer, which converts the 600 Ohm output to 145k Ohms for the Hi-Z 1/4" output.  This 1/4" output can be fed to FX pedals, an instrument amplifier, or to a power amp.  When using the DI input and the 1/4" output, your signal will be going through all 4 transformers.  A microphone source to the XLR out will run through 2 of the transformers, but the 1/4" transformer coupled output can also be utilized simultaneously.  That might be useful for tracking in a DAW with high latency, as you could run the XLR into the DAW and the 1/4" to an external mixer/headphone amp for latency-free monitoring.

There is a passive Low-Cut filter switch at 58Hz with a 10dB per octave slope.   There's also phantom power and a polarity reversal switch.  On the back side are ground lift switches for both the 1/4" and XLR outputs separately.  The Dark Storm is powered by a 48VDC international power adapter, which is included in this listing.  An IEC cable will be included for North American buyers.  The Dark Storm is housed in a 1U half-rack enclosure and will come with adhesive gel feet attached.  A stereo pair factory racked into a 19" enclosure with rack ears is an option.