Izzy Wizzy Audio

The aim was to build a MC sensitive preamp that was quiet, used only tubes and had a certain something that made you want to listen. This thing is quiet and if built properly, hum free. I have to put my head very near the speaker to hear a slight trace of hum or hiss at loud listening levels. The main design aim other than to make it sound good wa
Izzy Wizzy Audio - schematic

s to give the circuit a solid reference. Single ended circuits "pass on" virtually every bit of power supply noise. This noise may not be audible in its own right but it will modulate the signal passing through the gain stage. Part of providing a solid reference is getting and maintaining an unambiguous and relatively low impedance audio ground. The audio ground is a single foil conductor about 20mm long. All the audio components are connected to it using their leads only - no extra wiring is used. The circuit is shown almost exactly as it is wired. Another design aim was to trust the components to do their job. "A sound" was not the aim but it was designed to allow as much as possible to be heard detail wise but also to maximise the connection to the musician(s) and allow the musical message through. This is very hard to explain and I was surprised how delicate this balance was. The simpler it got, the better it became up to a point. The more iron/coils I threw at it, the better in these terms it became especially rhythmically. Any additions to "help" the circuit such as active/CCS loads and regulators etc got in the way. As the PSU got better, the less these things were needed. If the PSU is average, then these circuit "tricks" can be used to advantage as they isolate the audio circuit from bad power supply artifacts. After using dual mono supplies for years, it occured to me that it is impossible to provide a common...

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