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Control B Evolution

Control B Evolution Control B Evolution

This new preamplifier perpetuates all the values which have established the reputation of the Control "B," adding some refinements in relation to the permanent search for more precise, more stable, more musical components.


All circuits are modular. Each printed circuit is dedicated to a unique function. This enables the user to change operating modes or to accommodate different components instantaneously and without adjustment.
The cabinet is specially designed with 25/10 mm iron sheet to insure maximum rigidity. This also protects against several types of electromagnetic radiation.


The front panel is designed in the tradition of high range hi-fidelity products. It is made with 10 m/m brushed and anodized, gold-hued aluminum plate.


Finally, and perhaps most important, the power supply is located in a cabinet separate from the preamplifier.
This separation of the power supply and the preamplifier results in a very low signal/noise ratio, and an appreciable, positive difference readily apparent to listeners.


Three models of the power supply are available:
The standard model, contained in an insulated housing, is excellent for all applications.
Refinement options start with the DRPS—the dual regulated power supply. This upgrade makes the preamplifier operate independent of main current variations and unaffected by them.

Three models of the power supply are available:
The standard model, contained in an insulated housing, is excellent for all applications.
Refinement options start with the DRPS—the dual regulated power supply. This upgrade makes the preamplifier operate independent of main current variations and unaffected by them.
The DRPS power supply uses 3 vacuum tubes:
Full wave rectifier ---------------------------------------------------- 5Y3
Error amplifier -------------------------------------------------------- EF184/6EJ7
Ballast tube ------------------------------------------------------------ 6Y6


Finally, the ODRPS—the oversized dual regulated power supply—is a state-of-the-art unit, and it is likely to remain so for many years to come. This component represents Verdier's contribution in the industry-wide quest for audio perfection, and we think we've not merely come close to that goal: We think we've reached it, and we think you'll agree.


This power supply uses 8 tubes
Main full wave rectifier ---------------------------------------------- GZ34
Reference full wave rectifier -------------------------------------- 5Y3
Error amplifier -------------------------------------------------------- EF184/6EJ7
Hum hunting circuit -------------------------------------------------- 2X EF184/6EJ7
Glow-discharge voltage regulator ------------------------------- 0B2
Ballast tube ------------------------------------------------------------ 2X 6080

We cannot overemphasize that the quality of the listening experience is directly dependant on the quality of the power supply. This is a universal postulate.


Function :
The CONTROL "B" EVOLUTION preamplifier includes 5 stereophonic inputs and a monitoring input/output. Maximum sensitivity and impedance are specified in the following:.
Volume is controlled by potentiometers separated on each channel.
Line Amplifier


The line amplifier provides the amplification and the impedance lowering required to connect the source to a power amplifier.


The 1st stage is a cathode follower which provides high input impedance and modulates the 2nd stage, working with constant current and providing the amplification and low output impedance.
Absolute phase is maintained.


A special arrangement of the circuit allows the line stage natural amplification programming, which is very convenient for adjusting the preamplifier to one or another amplifier/speaker combination with a naturally variable sensitivity.


The amplification is adjustable for the following values
The line amplifier includes 3 double triode tubes: 12AT7/ECC81/6201
Magnetic Cartridge Phono Amplifier
The phono amplifier is designed to provide the RIAA standard correction and the amplification which is required by moving magnet cartridges (MM).
Each channel includes 3 double triode tubes 12AX7/ECC83/7025 with very low noise and very low microphony thanks to their "frame grids".


The correction is of the passive type, which allows no feedback that could affect stability.
The input impedance is the standard 47K Ohms.
MM/MC Transformer
The amplification required for the use of a moving coil cartridge is achieved with 2 minuscule shielded transformers.


These transformers are wound on high permeability Mu metal (MU=10000) magnet circuits. The amplification is 10 (=20dB) and the input impedance, 4/40 Ohms.
With mobile jumpers, it is possible to switch the circuit instantaneously to use either a moving magnet or moving coil cartridge.

Test av Control B Evolution från tyska Image Hifi 3/2011 här

PDF för Control B Evolution och de 3 olika strömförsörjnings möjligheterna här