Sunday, May 15, 2011

Vertex AQ Aletheia Dac-1


The Aletheia brand will be a range of electronics with a fundamentally different approach - the fusion of outstanding electronics design with all the Vertex principles of RFI and microphony control, right down to a component-by-component level (ie each chip, capacitor, resistor and so on.....).

So far our studies have been based around amplification, and DACs. We have looked at the various choices and options for these types of devices, working through all the major permutations. With amplifiers for instance, different classes of amplification, different power supplies, valve and solid state. With DACs we have again looked at power supplies, but also the options of different conversion formats, chip types and so on. Now of course, there is nothing at all unusual in this sort of work, its what you'd expect any design company to do. However, with our work its been a little different, because we include the problems and resulting behaviours of RFI and microphony interactions in every step of our analysis.
We are now at the end of the pre-production stage of the Aletheia dac-1 project. We showed the technology demonstrator DAC at Whittlebury Hall last year, and we were very pleased that everyone thought it sounded great. Since then we have carried out some refinements internally to the design - the main one being an upgrade of the output caps, to a pair of silver/gold Mundorf items. The other main piece of work (as ever) was finishing the casework.

The key features of this design are:
1.   A completely modularised design with very high levels of process separation, with extensive anti-vibration and anti-RFI/EMI techniques throughout.
2.   16-bit d to a conversion with no oversampling or filtering. DAC circuitry housed in EM absorptive box.
3.   Passive I to V output stage using Vishay resistors and Mundorf supreme silver/gold/oil caps.
4.   Ultra-high quality quad-stage power supply topology using mains pre-filtering, fully enclosed (EMI absorptive) 100 VA transformer on decoupling mounts, a discrete component pre-regulator and 4 second-stage discrete component regulators. The regulators are Pauly Hynes Design items, heavily modified with the application of anti-RFI/EMI and anti-microphony techniques.
5.   All wiring downstream of mains transformer is solid-core silver with EMI absorptive tubing.
6.   Digital input - s/pdif BNC, RCA and optical.
7.   Analogue outputs RCA and XLR.
8.   All signal sockets mounted on decoupled sub panels.
All this effort brings huge listening benefits, especially when playing more complex music. Most digital replay gets blurred, confused and harsh with such material, mixing and intermodulating the musical programme as the intensity rises. Conversely with the dac-1, complex threads and intertwining harmonic 'fibers' of dense passages remain rich, detailed, separated and accurate. Once heard, the Aletheia dac-1 is very difficult to ignore.
For a comprehensive description of the Aletheia dac1 please see the Handbook here. Aletheia dac-1 Handbook