savoy014

Original Post (September 2009) Here are some pictures of my DIY speaker filter inspired by several threads on Audioasylum. Very much like the Combak Enacom or the Walker High Definition Links, these are R-C networks or zobel networks that are applied in parallel across the speaker or the amplifer if you prefer (although they usually work better across speakers). They will filter out ultrasonic garbage that happens to be in your system and their efficacy across the band depends on the value of capacitor and resistor that you use. Why this project ? More out of necessity rather than vanity. The Alpha-Core Goertz speaker cables I use have much higher capacitance than average, enough to upset some amplifiers into oscillation. I thought I heard my AG1 speaker cables induce a hazy grain on the top end of my Hypex amplifier the other day. Maybe it was my imagination, but it was frightening enough to get this project up pronto. Zobel networks, besides their filtering effect also stabilises amp...

I have had the Kingrex T-20U for a few months now and so a post about this is long overdue. The Kingrex has been around for sometime and has garnered a reputation for being one of the best sounding of the many low powered Tripath chip powered amps out there. The designers of Kingrex must have paid careful attention to the many tricks that the DIY community were incorporating in Tripath amps as many of these tweaks and part changes can be found in the Kingrex such as :- 1. Film coupling caps 2. Premium air core inductors 3. Uprated low ESR local power supply caps 4. Heatsinked Tripath chip 5. Socketed op-amp for ease of opamp rolling (for the DAC only) The icing on top of the cake is the Burr Brown PCM-2702E DAC with USB interface. Looks like this amp is clearly targetted at the PC audio crowd and you can say is perfect for powering small speakers on a computer desktop. The T-20U is based on the Tripath TA-2020 chip which is capable of about 10-20 watts per channel into 4 Ohms (power va...

For all you Diva Audio M7 users out there, T.S. Lim has just revised his flagship M7 preamp. The latest revision combines two stages of modifications. The first stage involves new voltage supply filtering on both the B+ and the heater, combined with star ground wiring arrangement. The second stage is a rewiring of the tube arrangement to allow easier tube rolling, and the installation of a new internal bracket that allows higher quality smoothing capacitors to be installed. More on the tube rolling - previously the tube stages in the M7 are arranged as follows, the bottom tube uses one triode (the 12ax7 is a dual triode) as first stage, and the other triode as the second stage of the left channel. The top tube is identical and is used for the right channel. This then passes through the third stage in the middle tube (one triode for each channel). This means that you can only roll two different type of tubes at the most since the first and second stage use the same tube. The M7 is now w...