Purity Audio Design Reference Balanced Linestage



Type : Class "A", Zero feedback, triode vacuum tube preamplifier
Circuit gain: adjustable from 5dB-17dB (with secondary autoformer option)
Input impedance: 100K Ω
Output impedance: <180  Ω
Recommended output load: >2000 ohms
Frequency response: 13Hz-35kHz -1dB
Total harmonic distortion: 0.05% @ 1V output
AC Power Requirements : 117/220/230/240 volts (factory wired)
Fuse: 1.2 amp fast blow (1/4" x 1-1/4")
Tube lineup : 6SN7 or 12AU7 ×2 (with adapters)
Dimensions : 16" Wide x 16" Deep x 6" High
Net Weight :
Shipping Weight:

US Retail Price: Contact Us - 

Power Supply - Solid State

- A large high current toroidal transformer
- Separate power transformer and DC power supply for remote control system

- Choke filtered power supply
- Polypropylene power supply filter capacitors
- StealthTM (Ultra Fast) diodes used throughout.


The multi award winning Reference linestage continues to get better. 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 with input impedances as low as 600 ohms. Extraordinary transparency of perceived sound which in turn assures the recreation of a three dimensional soundstage.

The Reference now incorporates Dynamicap capacitors in the output stage. Enhancements in the power supply include the use of high current toroidal transformers and 100% polypropylene filter capacitors. Tube filament power is now supplied by a high quality, highly regulated DC supply for the quietest possible presentation.

The Reference features a very short clean signal path and the same small 1db step size as the optional autoformer system  - giving a range from -60db up to unity gain.

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.  Single ended outputs also benefit from transformer coupling. 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.

Solid State Power Supply:

 Enhancements in the solid state power supply include the use of high current toroidal transformers and 100% polypropylene filter capacitors with choke filtering


- 0 dB negative feedback
- Pure tube design (no transistors)
- Autoformer attenuation/volume control (optional)
- DynamiCap capacitors
- 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 based source selector with no shared grounds
- No common ground between any inputs.
- 100% point to point wired - NO PCB
- ROHS silver solder used for the best electrical connection
- Selector switch engages relays located near RCA jacks to switch all inputs
- 2 6SN7 or 12AU7 tubes for stereo line-amplification
- Regulated DC filament supply for signal tubes
- Balanced output transformers 
- Balanced input transformers 
- Premium internal signal cable uses Silver Plated -Copper/Teflon

- Twin chamber design separated by aluminum plate effectively fights against RFI and EMI.
- 3 pair XLR balanced inputs
- 3 pair RCA single ended inputs (transformer coupled)
- 2 sets XLR balanced outputs
- 2 sets RCA single ended outputs (transformer coupled)
- All 4 sets of outputs active at all times allowing for multiple configurations for bi-amping or use of an active subwoofer(s)
- RCA high quality Teflon silver input jacks
- Neutrik/Swiss - XLR chassis connectors
- Remote Control for Volume, Balance, Mute, Phase Reverse & display off
- Chassis material: Aluminum
- Chassis finish: Black anodize
- Solid aluminum remote handset
- Made in USA
- Three years parts and labor warranty. 90 days on supplied tubes

Purity ​Audio Design
​Reference mk3

Award Winning Class A Balanced Tube Linestage