Power Amplifier Kits
For built versions of our pre-amplifiers and power supplies please visit our Build Service page. All of our pre-amplifiers require a PSU3 power supply and
are an excellent match for our phono stages and power amplifiers.
Pre3 CF
Pre3 CF is a valve pre-amplifier featuring low output impedance drive to suit any power amplifier.
This 5 input line level cathode follower (CF) pre-amplifier has a voltage gain slightly less than unity and provides an elegant method of
matching modern sources to power amplifiers. The Pre3 CF can be configured by the user to use a cathode load resistor or a Constant
Current Sink (CCS). The CCS provides an improvement in technical performance when driving long leads between the pre and power
amplifiers.
The Pre 3 CF is offered in standard and XL versions. The XL version has a gold plated valve base, upgraded audio cabling, valves and
Vishay / Soniqs capacitors in the audio path.
Read the Hi-Fi World review of the Pre3 CF on our Reviews & Gallery page.
The Pre3 CF requires a separate power supply, the PSU3. Please see below.
External dimensions with valves: W135 x D314 x H82mm. Weight: 1.3kg
Standard version £395
XL version £475
PSU3
PSU3 is a high performance choke power supply with separate HT and Heater feeds for the Pre3, Pre3 CF, Pre4, Pre4 CF and Phono3
& Phono3S pre-amplifiers 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 pre-amplifiers 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 £325
Pre-Amplifier Kits
Pre4
The Pre4 is derived from the highly acclaimed Pre3 pre-amplifier, now providing remote control of volume, input selection and a mute
function. In addition the Pre4 now has variable gain (up to +21dB) to match with a wider range of source components and an optional
balanced output for driving long interconnect cables.
Pre4 is an innovative valve pre-amplifier featuring low impedance drive to suit any power amplifier. This 5 input line level preamp is
essentially an SE triode power amplifier in concept. Pre4 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 Pre4 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 Pre4 and the power
amplifier.
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 Pre4 is offered in standard and XL versions. The XL version has upgraded audio cabling, valves and Soniqs capacitors in the audio
path.
Read the Hi-Fi World review of the Pre4 on our Reviews & Gallery page.
The Pre4 requires a separate power supply, the PSU3. Please see below.
External dimensions with valves: W220 x D314 x H82mm. Weight: 4.5kg
Standard version £815
XL version £895
Pre3
Pre3 is a valve pre-amplifier 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
amplifier.
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
path.
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 £585
XL version £665
Pre4 CF
The Pre4 is derived from the highly acclaimed Pre3 CF pre-amplifier, now providing remote control of volume, input selection and a mute
function, The Pre4 CF
features low output impedance drive to suit any power amplifier.
This 5 input line level cathode follower (CF) pre-amplifier has a voltage gain slightly less than unity and provides an elegant method of
matching modern sources to power amplifiers. The Pre4 CF can be configured by the user to use a cathode load resistor or a Constant
Current Sink (CCS). The CCS provides an improvement in technical performance when driving long leads between the pre and power
amplifiers.
The Pre4 CF is offered in standard and XL versions. The XL version has a gold plated valve base, upgraded audio cabling, valves and
Vishay / Soniqs capacitors in the audio path.
The Pre4 CF requires a separate power supply, the PSU3. Please see below.
External dimensions with valves: W220 x D314 x H82mm. Weight: 1.6kg
Standard version £625
XL version £705