Purity Reference
The original
Class A, Balanced, Transformer Coupled Linestage

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The Purity Reference is a Class A, transformer coupled balanced linestage and is the result of years of intensive research directed at attaining the most accurate reproduction of recorded music.  Unique topology and application of the most advanced technological resources and processes bring the Purity Reference to a threshold of excellence in sound reproduction.  To add to the  main features, the Purity Reference utilizes transformer coupling at both the input and output. Transformer coupling output results in a low output impedance making the Purity Reference a versatile unit that is capable of driving both solid state and vacuum tube amplifiers. Extraordinary transparency of perceived sound which in turn assures the recreation of a three dimensional soundstage.

The full function remote handles mute, balance, source selection and phase inversion. The volume is handled by a modified shunt type hybrid resistor design with precise 1dB attenuation steps.

The best sounding volume control next to autoformers is one that has the least resistance in the path and can maintain consistency throughout all frequencies, for this we chose to use relays.

With 3 sets of balanced inputs, 3 sets of unbalanced inputs and 2 sets each balanced and unbalanced outputs, connection possibilities are vast. When an unbalanced input is selected, the signal still passes through the input transformer maintaining a low output impedance as well as the resolution and transparency transformer coupling is known for.  Absolute phase and balance control are selected both through the supplied aluminum remote handset and the front panel controls.

As with all Purity Series products, the remote circuit has been granted a dedicated power supply including a separate, standalone power transformer as not to interfere at all with the analog circuit.

  • Type : Class "A", Zero feedback, vacuum tube preamplifier
  • Inputs : Unbalanced ×3,  Balanced ×3 (unbalanced inputs transformer coupled)
  • All inputs go through a balanced transformer (unbalanced outputs transformer coupled)
  • Outputs : Unbalanced x2/ Balanced x2
  • Function : Input selector, Remote Volume control, Phase Inversion, Balance, Mute, Display on/off
  • Circuit gain: 17dB
  • Input impedance: 50K Ω
  • Output impedance: <180  Ω
  • Recommended output load: >1000 ohms
  • Frequency response: 13Hz-35kHz -1dB
  • Total harmonic distortion: 0.05% @ 1V output
  • AC Power Requirements : 117/220/230/240 volts (factory wired)
  • Fuse: 1 amp fast blow
  • Tube lineup : 5814/ECC82(12AU7)×2
  • Dimensions : 17" Wide x 15" Deep x 7.5" High
Main Features
  • 0 dB negative feedback
  • Pure tube design (no transistors)
  • shortest possible signal paths
  • Very low output impedance to drive any tube or solid state power amp
  • Audiophile grade passive components used in all applications
  • Teflon tube sockets
  • Central one-point earth grounding
  • Fully hand assembled to insure the highest level of craftsmanship 
  • Relay driven, resistor based volume controls - 1 each per channel / 61 steps @ 1dB ea.
  • Relay based source selector
  • No common ground between any inputs.
  • 100% point to point wired - NO PCB
  • Special ROHS silver solder used for the best electrical connection
  • Selector switch engages relays located near RCA jacks to switch all inputs
  • 2 12AU7 tubes for stereo line-amplification ( tube life > 10000 hrs )
  • Supplied with 5814/12AU7 type tubes
  • DC filament supply for signal tubes
  • Balanced output transformers (Custom made by Electra Print for Purity Audio Design)
  • Balanced input transformers
  • Premium internal signal cable uses ultra pure copper/Teflon
  • Neutrik/Swiss - XLR chassis connectors
  • Remote Control for Volume, Balance, Mute, Phase Reverse & display off
  • All front & rear panel descriptions are laser engraved
  • Chassis finish: Black
  • Solid aluminum, laser engraved remote handset
  • Equipped with high quality IEC AC power cord
  • Made in USA
  • Two years parts and labor warranty. 90 days on supplied tubes

Power Supply

  • A large high current  transformer designed for Purity Audio Design,  RFI/EMI ultra-shielded for the main B+
  • Separate high current Toroidal transformer and DC power supply for remote control system
  • Choke filtered power supply
  • Polypropylene power supply filter capacitors
  • StealthTM (Ultra Fast) diodes used throughout.


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