Power Amplifier Kits
 World Designs 2016

For built versions of our preamplifiers and power supplies please visit our Build Service page.



Pre3 is an innovative valve preamplifier featuring low impedance drive to suit any power amplifier. This 5 input line level preamp is

essentially an SE triode power amplifier in concept. Pre3 uses an ECC82 double triode arranged as input voltage amplifier and power

output amplifier stages, the latter driving large output transformers.

The use of output transformers not only provides a low impedance drive but also avoids any possibility of slew rate limiting in the output

stage making the performance independent of the capacitance of interconnect cables. Thus the Pre3 will successfully drive long cables

connecting to power amplifiers near the speakers if you wish. Twin pairs of outputs allow easy connection to power amplifier and

headphone amplifier, or bi-amping. The output can be configured to provide a balanced line connection between the Pre3 and the power


Another advantage is due to the interwinding screens used in this advanced design. Effectively the primary and secondary windings are

isolated from each other allowing us to break the ground connection between preamp and power amp thus avoiding the possibility of

hum loops.

The Pre 3 is offered in standard and XL versions. The XL version has upgraded audio cabling, valves and Soniqs capacitors in the audio


Read the Hi-Fi World review of the Series 3 (Pre3/Phono3) on our Reviews & Gallery page.

The Pre3 requires a separate power supply, the PSU3. Please see below. External dimensions with valves: W135 x D314 x H82mm. Weight: 4.2kg

Standard version £495

XL version £570



PSU3 is a high performance choke power supply with separate HT and Heater feeds for both Pre3 and Phono3 preamplifiers and phono stages. The PSU3 supplies the correct, smoothed, HT voltage for each unit. It can be used with either unit individually or both together. Outputs are via low impedance, multi-way sockets &  plugs and umbilical cables supplied for use with our preamplifiers and phono stages. Offered in a single version only, the PSU3 features full Star Earthing and is supplied with Ultra Fast, Low Noise, Schottky Heater Diodes. External dimensions with valves: W135 x D314 x H82mm. Weight: 2.1kg

PSU3  £299


Pre Amplifier Kits