Tuesday, March 18, 2014

Pistonhead to Audiophile

I can't believe it's been one whole year since i last posted on this blog. Perhaps it's time to greet the loyal visitors, if any, and update them with how stuff is going on my side. First, a somewhat interesting chart.

I'm surprised this blog is still getting pageviews, averaging 200-300 of them daily. Thanks to you!

So where am i these days? The Dog is still here with me albeit a lesser priority, mildly speaking. I'm having less and less time to work on her with me preparing to start a family of my own. The urge to build something is always there, however. I can't stand doing nothing with my free time, no matter how little it may be. There's always that need to balance the stress from work and building something works for me.

As you may have guessed from the headline, DIY Audio is what i do lately. I personally believe DIY Audio is what got most of us solder-slinger, tin-fume-breathers started on electronics, me including. It's definitely not something new for me. I still remember the first time my AM radio and my tiny speaker made that sweet old tunes when i was still in junior high.

Isn't DIY audio as time consuming as working on cars? Well, yes and no. Yes it can be time consuming but not if you have more time-window to do it. You see, working on engines, bikes and cars for me means being in the garage and doing it at daytime while DIY audio means this..
That's my bedroom floor and the photo is taken nighttime. You can now see that shifting my hobby closer to my bed allows me to work on it more! The nagging from mom to clean up the room is more intense though..

Anyway, here's what i have finished so far..
Quite lovely isn't it?

Here's what i finished first when i started (or re-started) this DIY audio thing: a CD player from an old PC DVD ROM.

It plays CD only, so no MP3 nor DVD, but it's been working flawlessly so far. I only use it for transport purpose, feeding the digital output to the TDA1541 Digital-to-Analog Converter below.

I got the DAC pre-built from Ebay and coupled it to my DIY Aikido tube preamplifier. Here's the internal shot.

From then it's goes to the Hybrid Power Amplifier below. It's basically a common cathode tube stage followed by a MOSFET source follower, having a BJT buffer in between to cope with the MOSFET input capacitance..

Those bulbs above are part of the circuit, providing bias for the MOSFET stage. Cool, eh? It glows dimly, just beautiful for late night listening session. The power-amp then finishes its job with a pair of customized "bookshelf" speakers. It's a Thonet & Vander KURBIS speakers, customized by bypassing the internal chip-amp and feeding the drivers directly to the hybrid.

Currently i'm still finishing an OTL headphone amplifier. It uses TV-sweep tubes and back-to-back power transformer to provide the isolation from mains.

I doubt this blog attracts any fellow DIY-audio hobbyist but if it does and there is request for me to detail the build, i might start another blog focusing on DIY audio. That's a big maybe.. but hey anything can happen.