Thorens TD 204 Turntable Package Lab Report

Lab Report

Despite its built-in MM phono preamp being added to the 'bill of materials', Thorens' TD 204 turntable package still packs a very respectable punch. As shipped, the absolute speed is a little high at +0.43% [Graph 1, below] but this can be 'tweaked' via the deck's hidden controls. Otherwise the pitch shift will be inaudible to most and, besides, the DC motor and belt will likely slow slightly with age. Peak wow is very low for a basic DC design at just 0.03% and low-rate drift – a bugbear with many DC designs – is almost entirely eliminated. Also, while there is a cluster of flutter sidebands at ±12Hz, the peak-wtd 0.05% is well within Thorens' high ~0.2% W&F specification. The sealed main bearing is slightly noisier than average at –64.3dB (re. 0dB at 5cm/sec, DIN-B wtd) but the fairly lightweight (660g) alloy platter and heavy (225g) rubber mat improve the through-groove rumble to a respectable –67.3dB.

The design of the 9in 'J-shaped' TP 120 tonearm is based on the TP 150 [HFN Mar '22] with a similar, mid/high 14g effective mass – a good match with the pre-fitted AT-95E pick-up (£36 when available separately) which is light at 5.7g but has a low 10cu dynamic compliance. Meanwhile, the dynamically-balanced TP 120 arm's counterweight is calibrated to within ~5% over a 0-2g range (1g = 1.05g; 2g = 2.1g downforce) just as the encapsulated bearing enjoys low levels of friction (~10mg) with limited free play. Resonances within the arm are subtly different to those seen in the TP 150 with its primary break at a lower 90Hz followed by harmonics and other bending/twisting modes at 180Hz and 215Hz. These are joined by two higher Q modes at 475Hz and 625Hz [see CSD waterfall, Graph 2]. PM


Wow and flutter re. 3150Hz tone at 5cm/sec (plotted ±150Hz, 5Hz per minor division)


Cumulative tonearm resonant decay spectrum, illustrating various bearing, pillar and 'tube' vibration modes spanning 100Hz-10kHz over 40msec

Turntable speed error at 33.33rpm 33.45rpm (+0.34%)
Time to audible stabilisation 2-3sec
Peak Wow/Flutter (Peak wtd) 0.03% / 0.05%
Rumble (silent groove, DIN B wtd) –67.3dB
Rumble (through bearing, DIN B wtd) –64.3dB
Hum & Noise (unwtd, rel. to 5cm/sec) –60.3dB
Power Consumption 2-3W (1W standby)
Dimensions (WHD, with lid) / Weight 420x121x355mm / 4.8kg
Price £850 (inc. arm and cartridge)

Thorens GmbH
Bergisch Gladbach, Germany
Supplied by: Signature Audio Systems
07738 007776