Features
Now available in the UK only direct from Classic Audio Ltd. for £450, the SPARTAN 20 moving magnet and moving coil phonostage combines the MM section featured in the critically acclaimed SPARTAN 15 with a new selectable discrete MC head amplifier. The expanded design allows for a two-turntable setup, with separate inputs for each cartridge type, while retaining the same precise RIAA equalisation, low noise, and an extra LF X-Feed setting, to bring deeply transparent listening to a wide range of setups.
Front panel, showing controls
As a result of exhaustive optimisation in the moving coil head amplifier and its careful integration into the already very capable double-stage moving magnet circuitry, the SPARTAN 20 offers a comprehensive and practical feature set that promises a very accurate and engaging sound reproduction ...
- Fully discrete MC input amplifier running in low-distortion heavy class-A – only a decibel noisier than the MM input
- A dead quiet background from MM cartridges, with input amplifier noise specifically matched to their high impedance
- Tight RIAA equalisation and channel matching at ±0.1dB, far less colouration and imbalance than the typical ±0.5dB
- Dual turntable compatibility with relay-switched RCA inputs for MM and MC, via a selector switch on the front panel
- Two defeatable LF X-Feed settings help to cancel low-frequency surface noise on stereo discs while preserving bass
- Third order 23Hz subsonic decimates low frequency disturbances using hand-matched capacitors to flatten the response
- Mono switching to reduce noise and distortion on mono discs and make damaged discs more listenable
- Double parallel RCA line outputs allow connection to two line inputs, or a digital recorder for archiving while listening
- External, linear transformer based, ±17V power supply, eliminating switching hash and local magnetic field effects
![SPARTAN 20 phonostage rear connections](2000bs20rear1100.webp)
Rear panel, showing connections
These features, in tandem with the excellent technical performance soon to be described, make the SPARTAN 20 an ideal candidate for those considering a venture into the world of moving coil cartridges while retaining compatibility for moving magnet devices that they may already have. It also represents a solid choice for those looking to upgrade over integrated phono circuitry, or even bring a second turntable into their setup with a minimum of fuss. Although it doesn't feature any magical components or endless loading and gain of options questionable use, it realises far better objective performance than many 'high-end' offerings advertised at many times the price, all culminating towards a greater intimacy with the original sound.
![SPARTAN 20 phonostage silver version](1800ss20tilton1200.webp)
Silver face version, one of only four to be made
The first production batch of SPARTAN 20s are currently available in the UK only with black and silver laser-etched front faces, at an introductory price of £450. Units are expected to be available to worldwide in the latter half of 2024, with a slight 6% price increase to combat inflationary pressure on the business.
Build quality
The SPARTAN 20 takes its form in a compact enclosure that fits well into all manner of setups and permits it to be situated close to turntables to minimise cable length and potential interference. The thick sandblasted all-alumium metalwork brings the total weight to a solid 780 grams, while fully shielding all the sensitive circuitry contained inside, including, but not limited to these high-quality components:
- All through-hole technology, hand-soldered with 3% silver (SAC305) for lower heat stress than tin/copper formulations
- Double-sided PCB with ground planes on both sides for extra shielding and low crosstalk, on a fibreglass substrate
- Distortion-free hand-matched film capacitors in the equaliser, subsonic filtering, and critical coupling networks
- Panasonic FR series electrolytic capacitors throughout the design to hold onto performance and reliability for decades
- All resistors used are thin metal film types with a 1% tolerance, for high accuracy, consistency, and stability
- Both NJM2068 amplifier ICs are mounted in turned sockets, for easy replacement if damaged by external equipment
- Gold plated toggle switches in the audio path, rated for 50,000 cycles, rather than more common 10,000 cycle push switches
- Panasonic telecoms relays perform input selection and output muting, rated for millions of reliable switching cycles
- Corrosion resistant gold over nickel-plated RCA input and output connectors on the rear panel with inverted labels
- A substantial nickel-plated binding post for turntable grounding, accepting bare wires and banana plugs with ease
- Thick CNC milled front and rear panels with indelible laser-etched lettering and scratch resistant black anodising
- All stainless steel external screws - no future rust and a serious, timeless appearance to match the lifespan
![SPARTAN 20 PCB layout](1800bs20boardtilt1200.webp)
Hand-assembled PCB
All SPARTAN 20s are carefully hand-assembled from scratch in Kent, England, with parts chosen for their maximum contribution to the end result of the design. This puts it in contrast to many marketing-oriented products that select parts for their individually impressive characteristics, or simply great expense to justify a higher price, that don't translate to a better final performance when viewed holistically. Instead, the SPARTAN 20 contains a selection of parts that have a proven track record of stability, reliability, and consistency that when put together in the right way realise a level of performance that offers great value for money.
Specification
Parameter | Measurement | |
---|---|---|
Gain at 1kHz, 10kΩ line load | 40.8dB (110x) MM, 61.6dB (1210x) MC | |
RIAA accuracy | ±0.1dB, 40Hz to 22kHz | |
Channel balance | ±0.1dB, at 1kHz | |
Crosstalk, MM input | <72dB 20Hz to 22kHz | |
Signal-to-noise ratio, MM input | 78dB, 220Hz to 22kHz, 5mV cartridge load | |
Signal-to-noise ratio, MC input | 77dB, 220Hz to 22kHz, 500µV 10Ω/22µH | |
Overload margin, MM input | 25.5dB (19x), ref 5mV at 1kHz | |
Overload margin, MC input | 24.6dB (17x), ref 500µV at 1kHz | |
Maximum input at 1kHz | 94mV RMS MM, 8.5mV RMS MC | |
Maximum input at 10kHz | 450mV RMS MM, 41mV RMS MC | |
Maximum output, 3kΩ line load | 10V RMS, 20Hz to 60kHz | |
Maximum THD, MM input | <0.0006%, 40Hz to 22kHz, 10V RMS output | |
THD at max output, MC input | <0.001% at 1kHz, worst <0.004% at 10KHz | |
MM input loading | 50kΩ + 120pF | |
MC input loading | 120Ω + 800pF | |
Output impedance | 100Ω, or 200Ω dual mode | |
Minimum line load impedance | 3kΩ, or 5kΩ with 10kΩ | |
Subsonic filter | 22Hz, 3rd order, 20dB reduction at 10Hz | |
Low frequency crossfeed | 100Hz or 200Hz, 10 or 14.7dB at 40Hz | |
Power supply | Split linear ±17V | |
Power consumption | 5W at full output, 0.2W powered off | |
Dimensions (W*H*D) | 172*60*150mm |