The Seven DAC can be upgraded to the Reference specification to further improve the musical performance from your valuable record collection. Graham painstakingly sources truly unique resistors that in such a simple circuit really bring out a richer and more intimate performance from the artist. We also upgraded the capacitors to a custom specification to work in harmony with the improved resistors; as in most development activities changing one thing in isolation hardly ever results in a balanced improvement. Graham says "it never ceases to amaze me how improving one component can impact the music in such a significant way, and also how long it takes to find the right combination to retain true harmony."
The Ultimate is the last but one step towards analogue perfection, and involves the use of solid silver wiring throughout the critical signal path, and silver interstage transformers. Silver as a conductor has the advantage of a more revealing and transparent reproduction of the music, however care needs to be taken to ensure that this is delivered in a complete and unified manner as sections of silver in a component in isolation rarely provide a benefit. Finding the right dielectric (insulation) for the cables is also critical to extract the best from this expensive material. Graham has also redesigned and built a more significant power supply that is unique to audio, which has the effect of making silences darker and dynamic shifts in the music more dramatic. The result is a little like cleaning your windows; you did not necessarily notice they were blocking any light, until afterwards.
The Seven GT DAC is the final step towards digital to analogue perfection, and involves the use of a completely new power supply circuit for all the critical stages. Graham says this power supply was 5 years in the making and makes a huge improvement in fidelity taking the Seven GT DAC to one of the finest performing DAC's ever made.