Musings on thoughts audio and related subjects!

Musings on audio and stuff!

Well it has occurred to me recently to start a blog, mainly to elaborate on things that I talk about in my VE forum posts in relation to vinyl and related subjects and sometimes not so related subjects! I come from a technical background and that determines in large part the way I do things and my general hi fi and audio/ electronics 'attitude' but I am also a self confessed perfectionist! I have an abhorrence of some of the tricks of manufacturing and marketing especially when it results in massive overpricing. I love to DIY electronics and my belief is that well built DIY electronics can be easily as good as anything in the shops with an expensive price tag! For some years I've championed the circuit designs freely available through Elliott Sound Products in Australia and superb designs they are and they are mostly op amp based designs. His P06 phono stage for moving magnet phono cartridges absolutely blew me away when I first built a rough and ready prototype on a piece of surplus copper clad circuit board material. I was a little 'anti op amp' previously, but now I am a fan and appreciate their merits. Op amps can have some limitations, but in the majority of cases they make building top notch audio circuit designs easy and quite straightforward.

Component quality can make a difference, but don't go overboard! Resistors are a good example of where component quality can make an audible difference. I only use 'metal film' resistors in my audio projects and just the one's available through my local electronics hobbyist store. Their use, especially in audio preamps is very worthwhile, particularly for 'noise' reasons. Metal film resistors contribute very little thermal or electronic noise compared to the once exceedingly common carbon resistors used in older audio equipment. I have seen written that some people prefer carbon resistors for their 'warm' sound....well that's one way of describing the effect of component electrical noise! No thanks, only metal film resistors for me. Capacitors are an interesting story. I for one don't really think that capacitors 'sound' that different, but there are clearly some interesting differences in the electrical characteristics of different capacitor types. Wherever possible I use 'plastic film' capacitors of good quality (MKT's or standard polyester types). Ceramic types are theoretically inferior in signal coupling applications due to their 'non linearity' under some circuit conditions, but I have used them in signal coupling applications with no problems, however polyester or other 'plastic film' types are advisable. What about 'electrolytic capacitors'? Well, they have their uses but not for signal coupling applications in general and Rod Elliott has some interesting 'opinions' re tantalum electrolytic capacitors too! There are a number of interesting articles re component sound in the articles section of the Elliott Sound Products website that are well worth reading. www.sound.au.com

As an aside, general 'passive' component quality (resistors and capacitors) has radically improved in recent years, however this wasn't always the case. A while back I restored a beautiful little Dynaco ST-35 valve amplifier where most of the (carbon) resistors had drifted high (in value) and every one of the coupling capacitors was very electrically 'leaky'. The components dated from the very early 1970's. The carbon resistors were replaced with metal film resistors and the faulty capacitors replaced with high voltage (630 volt) polyester capacitors. That little amplifier now works beautifully and with probably better performance than when new. But I digress!

In the end, my feeling is that a good circuit design constructed with good quality components with good construction layout is a potent combination! My main audio electronics construction interest in vinyl is in the preamplifier area, as things like noise and general quality become more of a challenge given the small signal levels we are dealing with, however as parts of my long term (commercially) made system have failed I've replaced them with DIY designs, including the power amplifiers. As a result I've become quite a fan of the modern range of power op amp 'chip' power amplifier modules. Sonically they are excellent! They have their limitations, such as severe audio distortion when 'clipped' (overdriven). Apart from that, I have no complaints......and they are easy to build! I guess electronics DIY isn't for everyone, but I'm glad that my past life as a telecommunications technician and my long term general interest in hobby electronics and Amateur Radio have given me some skills that have allowed me to build some nice audio stuff. Having said that though, DIY construction is easier had one might think based on personal experience and observation. Personally I do wish that my mechanical and metal working skills were bettter, but even those have improved a little in recent years! If one is interested in improving their general 'soldering' skills this site is excellent. http://www.curiousinventor.com/guides/How_To_Solder More to come! Felix.