GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Didital Things
In the Thread: Windows Based Transport: A quiet and capable Source?

Post Subject: Why 'transport'?Posted by item on: 11/2/2011

Part of the reason we call our computers 'transports' is to encourage people to think of the number-crunching part of an audio system in the same already familiar terms as a CD player - because all the same things matter: CD transports vary according to the quality of their clocking, board design, EM and RF rejection, (crucially) power supplies and distribution, and vibration control. Computer transports are no different: it's helpful to forget about where the music is stored, and consider very carefully the local playback environment.

Although digital storage and transmission is practically robust, a bitstream is highly susceptible to jitter and cable-borne rail noise (upstream and downstream) when streamed in real-time to voltage-amplifying devices like DACs and amplifiers.

There's some debate about whether a Sonos, Squeezebox, Olive, et al is a 'Server' . . . I would say not!

We make no bones about out the 'open source' nature of the DAT1, and actively encourage users to build something similar themselves by publishing instructions on how to do so, with or without our help. There's a lot of shared DNA with the CICS project.

It's a standard (but carefully selected) Atom motherboard. It runs Windows. So far so standard. But from thereon in, everything we do is with the aim of reducing interrupts, lowering rail noise and generally optimising for audio - which takes us into the fabrication of bespoke passive heatsinks, deep cryo-treatment, dedicated PCI cards for USB output (http://sotm-audio.com/sotm/products/tX-USB.htm), SATA filters, Stillpoints fabric, bespoke high-quality DC looms, external fully linear power supplies, etc. It's then possible to have a computer that sounds better than a high quality CD transport, even with Red Book material (see December 2011 HiFi World).

In an ideal world, the D-A stage would not share proximity or a power supply with the computer at all, so we make clear that the DAT1 is a transport only, designed for an off-board DAC optimised for USB, Firewire or some flavour of SPDIF.

The power supply and cases are the expensive part: the base machine (without PSU) is less than £1000, which isn't much more than the value of the parts.

Rerurn to Romy the Cat's Site