The Purity Master Reference is a Class A linestage fitted with a DHT front end based on our unique Harmonia DHT input circuit 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 Master Reference to a threshold of excellence in sound reproduction.  To add to the main features, the Master Reference now contains 4 completely isolated power supplies. We are using a dedicated power supply for each of the two tube stages as well as for the filaments and remote system. The output stage power supply utilizes tube power supply design based around the 5R4 rectifier.

The balanced version of the Master 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 Master Reference now incorporates the ultra clean Clarity Cap capacitors in both the DHT input stage as well as the 6SN7 output stage. Tube filament power is now supplied by a high quality, highly regulated DC supply for the quietest possible presentation.

The Master Reference features a very short clean signal path

Balanced Version

1 set of balanced inputs, 2 sets of unbalanced inputs. One set balanced outputs and 2 sets single ended output. 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. 


- 0 dB negative feedback
- Pure tube design (no transistors)
- High quality Clarity Cap 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
- Central one-point earth grounding
- Fully hand assembled to insure the highest level of craftsmanship 
- Relay based source selector
- No common ground between any inputs.
- 100% point to point wired - NO PCB
- Selector switch engages relays located near RCA jacks to switch all inputs

- 2 2A3 input tubes
- 2 6SN7 or 12AU7 tubes for stereo line-amplification
- Regulated DC filament supply for signal tubes
- Balanced output transformers (balance version)
- Balanced input transformers  (balance version)
- Premium internal signal cable 
- 2 pair XLR balanced inputs
- 2 pair RCA single ended inputs (transformer coupled)
-  1sets 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)
- Neutrik/Swiss - XLR chassis connectors
- Remote Control for Volume
- Chassis material: Aluminum
- Chassis finish: Silver or Black anodize
- Equipped with high quality IEC AC power cord
- Made in USA

Rendering at left will change as the Master Reference will now be produced by Raven Audio!

NOTE: The DHT input stage is NOT a cathode follower buffer stage. Our DHT input stage utilizes the full sonic potential of the DHT in use.

This page still under construction


DHT input stage

Class "A", Zero feedback, 6SN7 output stage
Circuit gain: 15dB 
Input impedance: 100K Ω
Output impedance: 600 single ended <180 Ω balanced
Recommended output load: >2000 ohms
Frequency response: 13Hz-35kHz -1dB
AC Power Requirements : 117/220/230/240 volts (factory wired)
Fuse: 2A amp fast blow (1/4" x 1-1/4")
Tube lineup : 2x 300B or 2A3 - 2x 6SN7 or 12AU7

                       1x 274B
Dimensions : 17" Wide x 16" Deep x 8" High
Net Weight :

Power Supplies

DHT Input Stage

- High current toroidal transformer

- Choke filtered power supply 

- Plate choke on each DHT

6SN7 Line Output Stage

- Choke input filtered power supply

- 5R4 rectifier

- DC Regulated filament supplies
  (one per tube)

Dedicated power supply for remote system

Purity Audio Design

Master Reference

2A3/6SN7 Preamplifier