Signal Art U48 Premium Reference Tube Mic - Used  From Signal Arts

Representing simply the very best we can do, our premium edition U48 features a handcrafted, historically accurate K47 capsule made for us by OPR in Australia, a US-made BV8R transformer, a shielded custom-wound toroidal power supply transformer made by Avel Lindberg, NOS Western Electric 408a valves (including a spare set) meticulously cleaned (de-scaled), burned in, and selected by me and fitted with authentic Sandy Levy high-temp aerospace silicone tube dampers to eliminate microphonics, and a fully handmade and hand-wired signal path from end to end featuring a hospital-grade IEC power cable, premium Sommer tube micrphone cable, top of the line Gotham microphone cable, and all silver-plated teflon OFC hookup wire internally, lab grade custom PCBs, all soldered with Cardas tri-eutectic silver solder. 

Now, that's audiophile. :)

Our premium edition 48 is an elegant, open, detailed, clean, clear, rich, authentic sounding U48 microphone that we believe stands up perfectly well against microphones costing 2, 3, even 5x what we are asking.  Using nothing but the absolute best parts available and putting meticulous TLC into the build, the premium edition 48 is build to last a lifetime and create beautifully captured takes.  

The tube compliment is a matched pair of Western Electric 408a (6028) pentode valves that we have selected, cleaned (pin descaling), tested, and burned in.  We have tested every 408a variant out there over the years and to us, the Western Electric has the perfect balance of weight, presence, top end, and midrange.  It is neither muddy, nor bright and anemic, as some variants we have sampled.  To that end, we have invested in one of the largest reserves of this tube variant, to ensure a consistent product.  Each 408a is fitted with a custom tube damper ring made for us by hi-fi expert Sandy Levy using pure aerospace (high temp rated) silicon. 

We use mostly teflon coated silver hookup wire internally, and hand make both the 7 pin and 3 pin XLR cables using Gotham's finest cable stocks available from Gotham Audio LLC, the US division of the legendary high end cable manufacturer.  For the premium edition microphone, we even manufacture our own audiophile grade shielded Gotham IEC power cable.   

Our power supply enclosure is manufactured to our specs, made twice as dense as most other power supply enclosures.  This box is almost indestructible.  Inside is a beautifully hand-wired power supply starting with a shielded, over-spec'd hospital grade toroidal supply transformer, fed by an over-sized and shielded Corcom AC input EMI filter, and made with our own lab-grade '48 PSU PCB and premium Nichicon and other long-life components.

Our '48 body replica is sourced for us by a trusted US importer/assembly house and put together in California from both domestic and overseas sub-components.  

For this premium edition, we use a custom wound, American made BV8 transformer made just for Signal Art.  This transformer is a true BV8 in every sense of the word, utlizing the same original winding technique and turns ratio as well as the same size UI30 laminations as the original German part.  The results are simply open, rich, and musical.  The transformer is the result of several years of back and forth and prototyping, based upon our favorite specimen of the vintage German part, matching the sonic character, bandwidth, and THD profile of the original specimen, for the perfect vintage charm.

With the premium edition 48, we also include an extra selected (noise graded, cleaned, and tested) pair of 408a tubes.  We also include a custom made wood box for the 48.