Sjöström Audio

http://www.lebong.de
Lot's of nice looking stuff from Johannes LeBong, tube amps, phono amps, horn loudspeakers, etc. Text in german.
https://icepower.dk/products/amplifier-power-modules/icebricks/
Patrik Boström has designed ultra small and ultra high performing class D amplifiers delivering 400 watts! ICEPower has now bought the company and renamed his products to ICEbricks.
https://holtonprecisionaudio.com
Here are a bunch of interesting amplifier designs. Anthony Holton has been around for years and nowadays he has started to sell SMD designs which looks real good. Nice looking pcb's. He previous URL was aussieamplifiers.com
http://www.neurochrome.com
Neurochrome run by Tom Christiansen is based in Calgary, Canada. I founded Neurochrome in 2010 to provide well-designed high-end audio circuits to the DIY audio community and it quickly grew to a self-sustaining hobby. This early success provided me with...
http://sjostromaudio.net/shop/index.php
This is my own web shop where I sell my designs. Per-Anders Sjöström
http://waltjung.org/PDFs/Improved_PN_Regs.pdf
The latest article by Walt Jung about the well-known Jung Super Regulator. Must be read, very interesting.
http://www.ant-audio.co.uk
The famous Alex Nikitin, former chef designer of Creek Audio Limited, has put up a homepage with his interesting designs. The first one is a headphone amp which has no feedback and runs in class A.
https://www.atlhifi.com
Webshop located in Bulgaria which sells DC blockers, softstats and amplifiers for the DIY market.
http://www.hardwareanalysis.com/content/article/1842/extrema-reference-class-a-diy-amplifier/
This very extreme class A power amplifier designed by Bruno Putzeys (Sander Sassen's pcb design), has extreme performance. Check out the distortion measurements!
http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_1.pdf
This circiut is called diamond buffer or Jung super buffer (because of this article in the subject). The buffer can be used after an opamp with or without feedback, altough feedback is recommended. Part 1.
http://pmacura.cz/audiopage.html
Pavel Macura has made a couple of very nice amplifier designs. He sells also pcb's.
http://www.vinylzone.com/phonopre.asp
Interesting RIAA correction amp with an OPA637 as main part. The designer is Thorsten Lösch (or Loesch) alias Kuei Yang Wang.
http://www.ampslab.com
"Lot's of kits here, such as power amps and even the famous and patented Alexander amp.You can also download a better copy here http://www.sjostromaudio.com/hifi_files/misc/AN211_better_text.pdf"
https://alw-audio.co.uk
ALW has designed a very nice looking pcb for the famous Jung Super Regulator. He sells also pcb's and has also done a very good documention, very professional.
http://sound.whsites.net/project115.htm
Rodd Elliott's implementation of the so called Gainclone, long before the Gainclone concept was invented. It's LM3876 based but LM3886 will also fit. Boards are available.