"Bugle" Phono (discontinued)

The Bugle is a low cost solid-state phono preamplifier. It utilizes a split, passive RC-type equalization network that offers excellent flexibility for customization. The circuit is not the typical "feedback" type commonly used, but rather uses the opamps as pure frequency-independent gain stages. Two of these gain stages drive the equalization networks followed by a third gain/buffer stage to provide a low output impedance. The overall gain is thus optimally split between the three stages.

The Bugle is only available as a half-kit - a blank circuit board and plans, you'll need to buy the rest of the parts yourself from DigiKey. For a fully assembled phonostage, see the new Bugle2.

Read Michael Fremer's review in Stereophile. Or this Audio Asylum post. PowerSupply kit now available! Read some actual customer testimonials.

Bugle Phono



Input Impedance47k ohm plus 14pF
Output Impedance330 ohms
RIAA Response+/-0.5dB from 30Hz to 60kHz
Bandwidth (-3dB)15Hz to 150kHz
Distortion0.05% @1kHz
SNR74dB ref 5mV A-weighted
Overload55mV @1kHz
Battery Life16 hours

Reviewer Excerpts

"Over time we were so pleased with the Hagerman that it became the benchmark for the others ... The clear winner from this assortment was the Hagerman preamplifier ... Its performance was consistent across all recordings." - John & Sandra Schubel


Using stock parts, the RIAA equalization response was checked using a 1kHz square wave.

Square wave response (RIAA accuracy)

Here's a bode plot of frequency response (+40dB gain) using the OPA2134 opamps. The -3dB points were 13Hz and 450kHz.

Frequency response and equalization


Customer Testimonials