Features
Available in the UK only direct from Classic Audio Ltd. for £500, 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
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.
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
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 |
