Angstrom Research

Italiano

PREAMPLIFIERS

.:REFERENCE ONE

>>REFERENCE 2

.:REFERENCE SE

.:PHONO ONE

.:PHONO TWO

LINE PREAMPLIFIER
"REFERENCE 2"

The authoritative presence and results of the "Reference 2" preamp make it the brand's milestone and it really does deserve its expressive name, because it is the absolute reference for preamplification.
Capable of making any "decent" amp sound good and adding dignity to amps which have no idea of what the word decent means, Reference 2 is the nearest thing to natural you can possibly imagine.
Its absolutely easy and natural sound, and delicate, gentle but simultaneously strong sound, allow you to give in to the ecstasy of inebriating listening, creating the feeling of having eliminated everything unnatural between yourself and the music. At any volume, its reproductive capacity and endless spatiality are unaltered, without any sign of effort.
In the most difficult situations it flexes its muscles, supported by excellent power, but the dynamics issued are never overwhelming and arrogant, leaving room for naturalness and the sweetness of its soul.

"Reference 2" is a fully valvular preamp made and finished entirely by hand, operating in pure class A during the entire signal. Its architecture is designed on a structure which comprises two identical frames:
one for power, reproducing a sort of electricity pump capable of offering the advantages of battery power but without the consequent limits, and one for the signal, eliminating every possible disturbance or noise.
It uses a power supply totally regulated and stabilised with valves with four P-GRECO filters in the rectifier and no fewer than four independent regulators/stabilisers to power the signal output valves.
The power supply is independent for the filaments of power valves and audio signal valves, as well as being independent with regard to the anodic charge on the amplifying valves and the output buffer.
All the components used are subject to careful selection:
low ESR electrolytic condensers, carbon resistance with tolerance under 0.5% on the audio parts, individually tested and coupled valves. All the cabling is suspended with the use of the highest quality MIL standard 24 awg cables for high temperatures with combined Teflon/Arlon dielectrics, guaranteeing exceptionally high electric conduction (Coloumb).
Custom-made inducers and transformers.
Separate volume and gain selectors to enable adaptation to any type of final output.
Versatility sample, enabling the use of various types of valves on the output stage.

Available in the following version:

-base
-balanced, with totally symmetrical circuiting from start to finish, (without the use of transformers).
-with polypropylene condensers (fourth photo from top)
-with output transformers (SE series).

VALVES IN THE POWER SUPPLY

4 6AX4 / 6AW4 GT half wave diode
2 6FQ7 / 6CG7 double triode for errors corrector
4 6V6 GT regulator
4 6BM8 / ECL82 screen regulator and stabilizer 6V6 GT
4 OA2 WA vapor mercury gas diode screen control ECL82 pentode
4 85A2 neon gas diode

VALVES IN THE PREAMP STAGE

2 6FQ7 / 6CG7 double triode for errors corrector
2 6N7 input-output signal stage AUDIO GRADE TUBE (possibility for 6H30 valves to order)
2 6J5 buffer output stage AUDIO GRADE TUBE

TECHNICAL FEATURES

Gain = 24 db selected
Output impedance 300 Ohm
Distorsion = 0.5 %
Frequency response = 12 Hz to 35 Khz
Zero feedback
Noise = input 4 uV (100 db below 1-V input)
Dimensions in mm: 484L 404P 155H (every frame)
Weight: 48Kg

Download brochure [PDF]