Hiraga MC Phono Preamplifier

Finding I liked Moving Coil cartridges I tried my hand at yet another MC preamp. This one is a Jean Hiraga design and uses matched low noise bipolar transistors pairs and a +/- 6V source. The transistors Hiraga specifies are no longer available. But better replacements are the Analog Devices SSM2220 chips at $11 each (you need two). Hiraga specifies very large storage caps so I juiced this compact build with 1F (1,000,000uF). Plus I added 220uF low ESR caps and 0.22uF snubbers for better mid-range performance. Since this image I mounted an external switch to select between 220, 100 and 45 ohms of loading. A 25 turn trim pot allows adjustment of "0" volts on the input and Russian PIO caps decouple the output.

Mark – Mongrel Dog Audio