The highest end Boulder Audio co. phono preamp model 2108
Features and improvements in the 2108 include:
- Multiple Equalization Curves. In addition to the standard RIAA EQ curve, the 2108 features
three additional curves selectable via a front panel button: FFRR, Columbia, and EMI. These
equalization curves enable correct and accurate playback of LP records made prior to 1954. An
option on the 2008, these EQ curves are now included as standard on the 2108.
- Dual Chassis Design. All audio electronics and control functions are contained within a machined
aluminum chassis and all power supply and standby circuitry is housed in separate casework to
isolate noise and prevent noise or hum from the power supply from interfering with sensitive
high-gain audio circuitry.
- +10 dB Greater Gain for MC Cartridges. The reduction of the noise floor of the 2108 has allowed
for an increase in gain for low output moving coil cartridges without an increase in the noise
floor. The net result is substantially improved low-level resolution and dynamic or transient
- 995 Gain Stage. The 2108 uses Boulder’s own 995 gain stage, a modular, discretely
implemented, initial gain stage for significantly reduced distortion and noise. This reduction
results in substantial improvements in clarity and low-level information recovery. All 995 circuitry
is potted in a proprietary epoxy resin for consistent thermal stability and increased reliability and
then mounted in a precision-machined aluminum housing.
- MC Cartridge Demagnetizer Pass-through. A pair of RCA connections is included on the rear
panel to allow the use of an external cartridge demagnetizer for certain MC cartridges.
- Fully Balanced, Dual Mono Construction. Inputs and outputs are high quality, full-balanced 3-
pin XLR connections and all audio circuitry is executed in a dual-mono configuration for increased
isolation of the left and right channels.
- Three Inputs and Two Outputs. Three inputs per channel are available for connecting multiple
turntables or tonearms, each with customizable “Personality Cards” which can be tailored to
meet the resistive and capacitive loading needs of specific phono cartridges. Dual outputs are
included to feed both a main listening system and/or a recording system.
- Quiet Logic System for Switching and Controls. All functions and controls are actuated with a
logic system to eliminate any internally radiated noise, such as that from a microprocessor.
- All Cartridge Loading and Gain Settings are Performed on Boulder’s Input Personality Cards.
All cartridge loading is handled by a single high-precision resistor instead of any type of switched
or remote controlled loading system. The tiny analog phono signal is never run through any sort
of switch or relay or multiple solder connections that would significantly increase loss and
- Additional Features: Other features include a selectable low cut filter with high-pass cut off
points of 10 Hz, 20 Hz, or Out, selectable true mono mode for monaural recordings played on a
stereo cartridge, and extensive damping and shielding for each of the main power transformers
to eliminate hum pickup in the audio stages or audible chassis buzz.
Full specifications for the 2108 are as follows:
Balanced Inputs 3 x 3-pin XLR
Balanced Outputs 2 x 3-pin XLR
Input Impedance MC: maximum 1000Ω, MM: 47kΩ.
Resistive and capacitive loading adjustable
on individual Personality Cards.
Output Impedance 100Ω Balanced
Phono Equalization RIAA, Columbia, EMI, FFRR (London/Decca)
Maximum Output Level 28 Vrms
Distortion, THD 0.005%
1 kHz Gain, RIAA MC: 70 or 60 dB, MM: 50 or 40 dB
Noise (EIN), MC 160 μV A-wtd, 275 μV flat, 20 Hz to 20 kHz
Frequency Response, 20 Hz to 20 kHz RIAA: ±0.10 dB
Crosstalk, L to R or R to L -100 dB or better, 20 Hz to 20 kHz
Power Requirements 90-120V / 200-240V, 50-60 Hz
Power Consumption 75W Max