Anniversary Custom
dual core, ultimate step-up transformer for moving coil cartridges


“the Rothwell is a keenly priced and beautifully executed step-up transformer”
Hi-Fi Choice April 2019
full review

The Anniversary Custom is revolutionary in the world of audiophile mc step-up transformers being the only transformer in the world to feature dual cores (per channel) for hum-cancelling, giving at least a 20dB reduction in the pickup of external magnetic fields. It also features a very low-loss core material, multi-layer winding and adjustable loading for both the primary side of the transformer and the secondary side. The bandwidth is wide and flat with excellent transient performance. These features make this the ultimate step-up transformer for today’s state-of-the-art low output moving coil cartridges.
Hum-cancelling design
The Anniversary Custom employs two transformer cores per channel rather than the usual one, enabling the cancellation of any hum picked up from stray external magnetic fields. This unique feature, found on no other step-up transformer in the world today, allows the user to enjoy music with an exception signal-to-noise ratio.
Hand-wound coils
We carefully hand wind each transformer in-house using multi-layer winding techniques to minimise inter-winding capacitance and maximise the high frequency extension for beautifully clean transients.
Primary load adjustment
This facility lets the user select different loading resistors on the primary side of the transformer which act on the cartridge directly to alter the load impedance it sees. Six settings are available to fine tune the performance.
Secondary load adjustment
This facility lets the user select different loading resistors on the secondary side of the transformer which not only alter the load impedance set by the cartridge but also have a subtle effect on the performance of the transformer itself and can extend the low frequency response of the cartridge/transformer combination and damp the high frequency response. Six settings are available and used in conjunction with the primary load adjustment there are 36 possible combinations available to fine tune the performance of the cartridge.
Cartridge compatibility
The Anniversary Custom is optimised for cartridges with output voltages in the range 0.3mV to 0.5mV and with coil impedances in the range 4 ohms to 6 ohms. This makes it ideal for use with many cartridges from Ortofon, Lyra, Koetsu etc. It is also compatible with cartridges with any coil impedance of 12 ohms or below.



turns ratio
voltage gain
core material
input impedance (aka cartridge load impedance)*
optimum transformer load impedance**
cartridge compatibility (o/p)
cartridge compatibility (imp.)

20dB (x10)
dual ferrite
user adjustable
47k + 150pF
18Hz - 65kHz (+0/-3dB, 6 ohm source)
0.25mV - 0.9mV
internal impedance <12 ohms
135 x 200 x 50 mm

*This is the load presented to the cartridge.
**This is the optimum load for the transformer, ie the input impedance of the phonostage that the transformer feeds into.


How to buy
The cost is 795 (uk retail) and units can be obtained from our hi-fi dealers (full list) or by contacting Rothwell Audio Products directly by email or telephone (+44 (0)1204 366133) or from the online shop.

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