audiophile preamplifier - 821 preamp
The 821 PREAMP
This entry-level audiophile preamp (entry level in cost terms, but not in performance) is available fitted with either 821 or 821A line stage modules.
The preamp will have a separate remote volume control option released later this year, which will also be a retrofittable upgrade.
It caters for 3 RCA stereo line level source inputs.
The preamplifier at various stages of construction and test
The 821 Preamp uses a zero overall feedback transconductance design first used in the G1 audiophile preamplifier now adapted in simpler form for use in the 821 and 821A modules.
The 821 Preamp uses a low inductance Litz PCB track layout for signal paths, a technique unique to Avondale Audio. The tracks on the amplifier board carrying signal are split into five parallel, thinner tracks thereby lowering the undesirable inductance found in thick PCB track. Such attention to detail extends even as far to ensure that the left and right tracks throughout the preamp are kept to the same length to within 1mm.
Housed in one of our small extruded cases, it matches the size of the MSX micro power supply.
Both versions of the 821 Preamp (the 821 and the 821A preamp) can be partnered with the MSX micro power supply, making a stunning combination on which to build a truly astounding system at an equally astounding low cost.
About the 821A Preamp
The audiophile version of the 821, the 821A, uses the same circuit as the 821. There are however many changes during the build accounting for the additional cost. These include large Polyester film rather than tantalum capacitors, precision Japanese Audio resistors and the time consuming process of transistor matching for every pair.