It’s not the whole truth though, as [Albert van Dalen] demonstrates with his tube preamplifier running ... takes the lower voltage. The circuit appears at first sight to be a conventional ...

[Justin Scott]’s tube preamplifier is a great example, with its novel use of a pair of Nixie tubes to indicate the volume to which it has been set. The audio side of the preamp comes courtesy of ...

Greek pedal maker Crazy Tube Circuits has unveiled the ... But, to go one step further, it also boasts a preamp and an additional dynamic enhancer circuit inspired by the Schaffer Vega Diversity ...