Birdland Audio's Solid-Tube technology is a clever combination of bipolar and FET transistors working together to extract only the most desirable linear characteristics of each technologies. The Solid-Tube technolgy produces ultra-linear transfer function analog stages even in open loop, making it ideal for analog audio stages. The result is an exceptional audio rendition capable of delivering every detail with a fantastic level of neutrality.
The STLPF module transfer function is derived from the neutral second order low-pass 1/(1 + 2s + s2) function which has the advantage of producing a near-linear phase shift when approaching the corner frequency. Because linear phase shirt is equivalent to a constant time delay, it does not contribute to modifying the timbre or spaction position of instruments in the final spatial stage. Furthermore, the STLPF does not use capacitve AC coupling capacitors and so offers full bandwidth all the way down to DC resulting in excellent bass response.
The STLPF also hosts an internal power filtering and regulation to help reject possible noise in the power supplies, making it possible to achieve high SNR greater than 122dB, and greater channel separation between modules.
For more information, contact oem@birdland.comSTLPF overview
Solid-Tube LPF Solid-Tube output stage overview