PSU1 Upgrade Power Supply

Safety certified to IEC standard 60950.

The PSU1 linear audio power supply has a stabilized output voltage of +24VDC as well as a nominal 30V DC, at a down-rated 200mA. It is available with detachable DC cords fitted with plugs to fit 2.5mm (standard issue) or 2.1mm DC socket pins, and with detachable mains cord.

Two mains voltages are available: 115VAC and 230VAC. They have sufficient latitude to accommodate voltages from 90 - 130VAC and 180 - 260VAC respectively, when powering Graham Slee products.

The PSU1 is designed to be a remote power supply placed well away from sensitive equipment like turntables and cartridges which are susceptible to pick up of stray magnetic fields. For maximum isolation it is best sited off the hi-fi rack.

It uses a specially manufactured mains transformer made using top quality transformer steel thus consuming minimal excitation (core magnetisation) current whilst optimising transformer regulation. A benefit is that it keeps transformer buzz to an absolute minimum which is only audible at very close quarters.

Transformer secondary, rectifier and reservoir capacitor interconnections are kept to the absolute minimum length minimising charging current losses and interactions.

The output is regulated at a stable +24VDC suitable to power all existing Graham Slee audio products featured on this website (In April 2010 an unregulated 30VDC (nom.) output will also be provided for users wishing to use their own regulator).

The PSU1 can be used to upgrade the sound quality - sound-staging, more vivid tonal colour and bass detailing - of Graham Slee phono stage preamps and headphone amplifiers supplied with switch-mode or linear plug-top power supplies. Upgrading to the PSU1 has the effect of taking your Graham Slee phono stage preamp or headphone amplifier to a higher level of musical performance.