Some of my experimental projects over the past years

Purpose of these projects

In order to advance in design of anything, testing and trying new things is the part of the process.  Sometime we succeed, sometime we fail.  Every failed project will pave the path to the next successful projects.  Below is a list of just a few of the successful projects which turn into multiple production models.

AG2022

An experimental project started in March 2022 and it started out as a test for a new heat sink.  As time passed, more circuits were added to this amplifier and ended up being used for new signal circuits and testing the upper limits of power supply design.

The power supply of this project currently stands at 37.75 million micro Farads.

A two parts video explaining the details of the AG2022, Part 1.

Part 2 of the AG2022 video.


NFS238

In 2015, I built a 28 watt per channel integrated amp featuring an adjustable tube simulator without using an actual tube, without realizing that tube supply would be in short supply a few years later. This tube simulator circuit has become very handy when designing new amplifiers.  Because of the adjustable natural of the circuit, it is like having several different tube types in the signal path without changing tube.  Our current model C312 preamp uses a very similar tube simulator as in the NFS238.


NSL prototype

A 28 watt per channel stereo power amp using 288 small signal dual op-amps.  Testing the limit of noise floor and the upper limit of how many small signal op-amp install in parallel to drive speakers. This led to the production model of NSL, 204NST and other headphone amps.


Brownie

Around 2009, I started a phonostage using mostly super capacitors.  It was a new and immature technology back then but I decided to have a look at them.  The Brownie phonostage consist of a total of 1,980 million micro Farads of super capacitor and is able to run for more than 26 hours without any ac power.  Later, I have added a feature in order for it to charge the super capacitors via solar panels.


Using Format