Boulder 500 Series
There are any number of expectations you may have when thinking of a Boulder. The 500 Series aims to exceed these expectations in every way possible: sight, sound, and feel.
The 508 phone preamplifier is pure efficiency. As the smallest Boulder in more than two decades, the 508 packs an enormous amount of performance in a single, small chassis. A chassis that is carved from a single block of metal, no less. All of the proper inputs, outputs, and adjustments are here. As is the one constant from every Boulder product since Day One: a stunning level of performance.

508 — Phono Preamplifier
• Simple selection of MC or MM modes via switch on the rear panel
• Elegant casework carved from a solid block of aluminum
• Balanced inputs mean the perfect interface with the balanced output of phono cartridges
• Integrated low-cut filter removes excessive low frequency information from warped or damaged records
• Balanced outputs to minimize distortion and drive long cable runs with no loss of fidelity
• Precision built and compact main PCB, produced on Boulder’s own surface-mount circuit board manufacturing machinery
Specifications: 508 Phono Preamplifier
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Inputs
1 pair balanced, converts to unbalanced
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Outputs
1 pair balanced
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Input Impedance, Maximum
MC: 100 ohms, MM: 47k ohms
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Output Impedance
100 ohms, balanced
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1 kHz Gain, RIAA
MC: 70 dB, MM: 44 dB
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Frequency Response, RIAA
±0.5 dB, 20 Hz to 20 kHz
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Distortion, THD
0.01%
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Noise (EIN), MC
116 nanovolts flat, 20 Hz to 20 kHz
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Maximum Output Level
16 Vrms
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Crosstalk, L to R or R to L
>100 dB or better 20 Hz to 20 kHz
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Weight
11.5 lbs. (5.2 kg)
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Power Requirements
100, 120, 200-240 VAC, 50-60 Hz
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Power Consumption
15W maximum
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