The development of the DSHA-1 is what brought about ecp audio in the first place. We had always been tube aficionados, and we had frankly never heard a solid state amp we really liked. The DSHA-1 changed all that. Indeed, it is the amplifier we use for day-to-day listening. As we developed the circuit, it became clear that the DSHA-1 was special in its presence, clarity, and sheer musicality. And in its exceptional bass. Yet it is tube-like in its warmth. Quite a trick for a few transistors.
The DSHA-1 is quite unlike any other amplifier on the market. The fully differential topology uses Lundahl amorphous core input transformers to provide passive noise-free voltage gain (selectable to 6dB or 12dB). The novel MOSFET based output buffer couples to the headphones through nickel core output transformers, and it can drive both balanced and unbalanced headphones equally well.
The differential topology provides distortion cancellation, and it has the advantage that there is no coupling of the signal to ground, and thus there is near total isolation of the audio circuit from the power supply. What this means is that power is not derived from power supply capacitors, and delicate mids and highs do not need to pass through noisy capacitor banks. Thus, unlike other amplifier topologies that cram 10's of thousands of microfarads of capacitance into the power supply to provide bass power, the DSHA-1 requires less than 1uF. The result is a purity of sound and bass power seldom heard from a headphone amplifier.
Additionally, the DSHA-1's input transformers serve several functions beyond gain. First, they act as phase splitters for those with single ended sources to provide a differential signal for the output stage. That means that the DSHA-1 works just as well with a single ended source as with a balanced one. All you need to use a single ended source are interconnects terminated with an XLR connector. Second, good quality input transformers (and the Lundahls are the best in the world) reject upwards or 120dBs of common mode noise at 60Hz. This not only results in an extremely quiet amplifier, but it also renders the interconnect used nearly immaterial.
Like the L-2, the DSHA-1 is so quiet that, even with low impedance headphones, you cannot tell it is on. There is no noise, no hum, no buzz, no hiss -- nothing, just silence. Additionally, the DSHA-1 conveys such depth into the music with such a black background, that all of the subtleties come through even at low volumes. The first milliwatt, where the micro-detail resides, comes through cleanly and clearly.
Designed for exceptional synergy with Grado headphones, the DSHA-1 is also an excellent choice with other dynamic headphones, including those from Sennheiser, Beyer Dynamic, Audeze, AKG, and many others.
The DSHA-1 is available from $1995.00 shipped within the USA. Each amplifier is assembled in the customer's choice of wood, and comes with a dedicated power supply and an adapter for using regularly wired headphones (as opposed to balanced). We invite you to audition the DSHA-1 in person in Chicago, or to try out our demo program. Please contact us to order, or for more information.