Our perennial preamplifier, the HP 500, has been around for almost as long as OCTAVE and was in many ways responsible for defining our approach to building amplifiers. For over 20 years, this preamplifier has been the epitome for consistent excellence in sound quality and state-of-the-art tube technology.During this time, it has maintained its market-leading position thanks to regular design updates from OCTAVE.

OCTAVE recently developed the SE (Special Edition) version to mark the 25th anniversary of Stereoplay magazine, which first tested the original HP 500 in 1989. The SE brings the HP 500 preamp back to the current state-of-the-art once more. The use of two Siemens D3A (EF 184) pentodes provides the output stage of the HP 500 SE with a significantly greater bandwidth (0.2 Hz to 2.3 MHz, 6 dB).

The extremely low cut-off frequency is responsible for the clearer and more tightly defined bass, which provides the foundation for a clean low frequency register and a thrilling midrange performance. OCTAVE has also further refined the outboard power supply. MOSFET transistors regulate the high-voltage supply. Increased reservoir capacity, improved rectification with Schottky diodes, and end-to-end electronic stabilization all ensure a virtually noise-free supply voltage with a noise component of less than 300 µV. These measures contribute to the exceptionally high signal-to-noise ratio of 103dB.

In – and Outputs
The HP 500 SE features a total of six single-ended (RCA) inputs. Outputs included are one RCA Record output, two pair of RCA and one pair of balanced (XLR) outputs. The balanced (XLR) output is transformer coupled to provide ground isolation and perfectly phase-inverted signals with no group delay.

Tape Monitor
The Tape Play and Record input section is connected in the classic manner which allows monitoring of the signal, which is recorded at the same time. The Record output is buffered to minimize interaction with any type of recording equipment.

Power Management and Protection System
The preamplifier is equipped with a multistage Turn-On/Soft-Start electronic protection circuit to avoid stress caused by high inrush currents during the turn on phase. The unit powers up in a defined sequence, and during warm-up the output of the HP 500 SE is shorted to ground. The same occurs when the unit is switched off. This avoids unwanted signals being passed to the power amplifier. The lifetime of the tubes are extended considerably while their sound quality remains stable for many years due to this protective measure.

Optional Phono Stage
The optional internal Phono Stage always includes two independent inputs: one for MM (moving magnet) and one for MC (moving coil) cartridges. The selector for the inputs is in the rear front. A second selector activates the subsonic filter. Listening to older analogue records is recommended with a subsonic filter to avoid infrasonic signals.

The Input Impedance of the MM input is 47 k Ohm; the MC Input is adjustable between 37 to 500 Ohms. Gain of the MC Section is 80dB. 

Basic Model : HP 500 SE Line, optional with Phono MM/MC
Special Edition : Limited Edition to 100 pieces
Tube Complement : Input-Stage: 1 x ECC 82; Output-Stage: 2 x EF 184 (Siemens D 3A)
Design : Aluminium silver or Aluminium black

Formats
CD Formats : Red Book
Audio Formats : WAV, AIFF, FLAC, ALAC, OGG Vorbis, AAC, Windows Media-formatted content files, MP3
Internet Radio Provider : vTuner 
Disc Compatability : CD, CD-R, CD-RW

User Control
Front Panel : Touch-sensitive eject and shutdown mode function
TV Monitor : 4:3 and 16:9 customisable TV interface USB touch screen compatible
Web Interface : PC and Mac internet browser compatible Adobe Flash user interface
AMX Creston : Installer-customisable reference apps available
Handheld : User interface app for iPhone and iPod Touch devices

Streaming and Ripping
USB : Scan and play from FAT and NTFS formatted memory sticks
Network Shares : Scan and play from music stored on a network share
Network Storage : Rip to external network storage for expanded music storage
CD Metadata : AllMusic.com online, FreeDB online and local database
StreamNet : 6 user streams to NaimNet and NetStreams systems

Power
Supply Voltage : 100V-230V; 50 or 60Hz

Formats
CD Formats Red Book
Disc Compatability CD, CD-R

User Control
Front Panel Seven button matrix
Handheld R-Com

Power
Power Supply Options 555PS, 2 x 555PS

Upgrades
Power Supply 555 PS
Other NAC 252, 552 PS, NAP 500, 500 PS