American high-end manufacturer Boulder has expanded its acclaimed 800 Series with two new components aimed at serious audiophiles seeking reference-level performance in a more compact form factor. The new Boulder 851 monoblock power amplifier and Boulder 808 MM/MC phono preamplifier bring technology derived from the company's flagship designs into enclosures that are easier to integrate into modern high-end audio systems.
Designed to match the dimensions and styling of the existing 800 Series—including the Boulder 812 DAC Preamplifier—the new additions continue the company's philosophy of delivering uncompromising performance without requiring oversized equipment racks.
Boulder 851: Compact monoblock with flagship technology
The new Boulder 851 monoblock amplifier is based on engineering principles developed for the Boulder 861 stereo power amplifier, translating much of its technology into a dedicated single-channel design.
Each amplifier delivers 100 watts into 8 ohms, doubling to 200 watts into 4 ohms, while remaining stable enough to produce peak power of up to 350 watts into demanding 2-ohm speaker loads. Boulder says the amplifier retains the brand's trademark combination of exceptional control, transparency, and effortless authority despite its compact footprint.
A major highlight is the introduction of Boulder's Smart Current output stage, making the 851 the first amplifier in the 800 Series to feature this advanced output architecture. The design is intended to provide wider bandwidth, lower distortion, and greater efficiency while maintaining the company's renowned sonic accuracy.
The amplifier features fully balanced XLR connectivity, heavy-duty 6 mm speaker terminals, and an extensive protection system designed to safeguard both the amplifier and connected loudspeakers. Boulder specifies total harmonic distortion at just 0.002%, while frequency response extends from an exceptionally low 0.015 Hz all the way to 150 kHz (-3 dB), highlighting the amplifier's wide-bandwidth design.
Despite its performance, the chassis remains surprisingly compact, measuring just 30.5 × 30.5 × 8.9 cm and weighing approximately 10 kg.
Boulder 808 brings reference analog performance to the 800 Series
Joining the amplifier is the new Boulder 808 MM/MC phono preamplifier, positioned between the company's 508 and 1108 models. The new unit is designed for vinyl enthusiasts looking for a substantial step up in analog performance without moving into Boulder's largest and most expensive phono stages.
Like the other 800 Series components, the 808 shares a beautifully machined aluminum chassis with the 812 DAC/Preamp and 861 Stereo Power Amplifier. Boulder has paid particular attention to internal shielding, mechanical rigidity, circuit layout, and noise suppression to maximize low-level detail retrieval from vinyl playback.
Designed for both MM and MC cartridges
The Boulder 808 supports both moving magnet (MM) and moving coil (MC) cartridges and offers balanced XLR inputs and outputs throughout the signal path. Additional features include mono playback mode and a selectable low-pass filter for greater flexibility when optimizing vinyl playback.
One of the more distinctive features is Boulder's Personality Card system, allowing MC cartridge loading to be configured using replaceable cards mounted on the rear panel. Loading values can be adjusted up to 1,000 ohms, while MM cartridges operate with the standard fixed 47 kOhm input impedance.
Gain is specified at 70 dB for moving coil cartridges and 44 dB for moving magnet cartridges. Frequency response is rated at 20 Hz to 20 kHz within ±0.25 dB, while total harmonic distortion is an impressively low 0.01%.
Availability
Boulder has not yet announced pricing or availability for either the new 851 monoblock power amplifier or the 808 MM/MC phono preamplifier. Both models are expected to further strengthen the company's 800 Series as a more compact alternative to its flagship electronics while maintaining the performance standards for which Boulder is known.
Join the discussion
Share your thoughts, listening impressions or product experience.