WHAT can you expect of a phono preamplifier that retails in excess of US$50,000? Boulder Amps, of Louisville, Colorado, lists the features on the new 2108, its reference phono preamp and part of the 2100 range.
- All the audio electronics and control functions are house in a machined aluminium chassis, while the power supply and standby circuitry is in a separate casework. This is to prevent noise or hum from the power supply from interfering with sensitive high-gain audio circuitry.
- Multiple equalisation 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 curves enable correct and accurate playback of LPs made before 1954. It was an option on the older 2008 but standard on the 2108.
- An extra 10dB of gain for MC cartridges is provided. The noise floor reduction on the 2108 allows for an increase in gain for low-output moving coil cartridges, without an increase in the noise floor. Substantially improved low-level resolution and dynamic or transient response are the result.
- The 995 gain stage is used here; this is Boulder’s modular, discretely implemented, initial gain stage for to significantly reduce distortion and noise for better 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 aluminium housing.
- MC cartridge demagnetiser pass-through. A pair of RCA connections is included on the rear panel to allow the use of an external cartridge demagnetiser for certain MC cartridges.
- Fully balanced, dual mono construction. Inputs and outputs are high quality, full-balanced three-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 customisable “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. Cartridge loading is handled by a single high-precision resistor instead of any type of switched or remote controlled loading system. The tiny analogue phono signal is never run through any sort of switch or relay or multiple solder connections that would significantly increase loss and distortion.
- A selectable low cut filter with high-pass cut-off points of 10Hz, 20Hz, 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.
If all these features have convinced that the 2108 is worth an audition at least, well the model available and shipping now – the retail price is US$52,000.