UPKu LOWAYU JAYA: Bootstrap Buffer Based Preamp

Bootstrap Buffer Based Preamp

I have been playing with a number of variations of the circuit as a free standing preamp, headphone amp, 321/729 replacements and as a potential active crossover, any and all of which may happen if there is demand. There has been strong interest in all of the threads and my bootstrap buffer preamp is up and running nicely - and for the moment it's staying. The same board should also be very handy as a headphone amp - & I'll be trying that next week.

They are different animals in so many different ways and come from completely different design philosophies. . and these are only my own observations and conclusions - so Jiim & PD feel free to chip in...please!

The starfish is definitely and very firmly in the Naim mold...and I love it for many things...lots of bass, drive and pace it really rocks..., but I can't help feeling that it's adding it's own signature to the sound. It's obviously based on maximizing the potential of the classic Naim 321 and 729 circuits and that means sorting a complex grounding scheme and multiple local regulators for power supply sensitive circuits. Accordingly it has a large and somewhat expensive BOM and is a fairly complex build.

The Bootstrap on the other hand is so much simpler and follows a minimalist design approach with as few components as possible in the signal path - it also uses symmetrical power rails and minimizes ground points in the signal path. So the BOM is smaller, the build easier and much more economical - I'll post a BOM in the next day or so. The result in the early listening is a cleaner sound with incredibly low noise and distortion, and I believe a much more truthful and honest presentation of the source material with uncanny staging and detail retrieval.

It's my expectation that I'll end up using both, the Starfish in a larger system (active Briks..) and mainly for rock & large scale orchestral music, the Boostrap in a smaller system where I'm looking for more space and precision, blues, jazz and acoustic programme material.

I guess that one of my conclusions is that just as no one system will please everyone, no one system is best for reproducing all types of material - at least not for my ears.

Schematics