EXSEQUOR REFERENCE  |  65W SET  |  MONOBLOCK POWER AMPLIFIER

The original Exsequor amplifier was one of our very first commercial design, and one of our proudest moments

“The original Exsequor amplifier was one of our first ever commercial design, and one of our proudest moments. Now with the MKII version, the Exsequor monoblock power amplifier has finally got it’s facelift.

Being our top SOTA offering for 9 years, it was unsurpassed by whatever new design we came up, and only outperformed by our statement Achilleas amplifier. The Exsequor is an amazing and timeless musical server.”

DESIGNER

Slide

The Exsequor Reference MKII

Working in Class A1, the Exsequor amplifier can deliver more than 65W in 8ohm or 4ohm loads. With it’s unsurpassed clarity, 3D imaging and breathtaking transients, with enough power to drive almost any floorstanding speaker, this SET amplifier is a class of it’s own.

We believe that SE non feedback amplification stages deliver the best overall sonic performance to the listener. Yet, almost all SET amplifiers do not have sufficient power to drive the majority of modern loudspeakers. One way of delivering enough power from a SET amplifier, is the use of many parallel mainstream tubes like KT-88, EL34 or big bottle tubes like 845 and the 805. Direct heated triodes with their super smooth sound are the way to go.

The 813 Tube

The tube of our choice is the 813, a 50W thoriated Tungsten filament tube with it’s 125W plate dissipation rating and probably the best big bottle tube sound we have ever tried in our labs, leaving far behind any version of 845 and 300B tubes. Almost all tube amplifier manufacturers with their light, slow and weak power supplies give a distinct flabby sound to the majority of these amps.

They get things worst by trying to drive the big output valve with small signal tube like 12AXXs e.t.c. As a result, the output tube, is under driven with the known results of limited frequency response and lack of acceptable transient response.. 


We chose to differ… the Exsequor monoblock tube amplifier is our opinion of how a SET amplifier without compromises should sound and how tube amplification should be implemented.

The Exsequor monoblock tube amplifier is our opinion of how a SET amplifier without compromises should sound and how tube amplification should be implemented

Driver Stage

Most SET amplifiers, use a small signal tube, usually RC coupled to the output stage. As a result, the final stage is well under-driven, compromising the sonic performance, giving the SET amplifiers their usual distinctive mellow sound. In order to drive a pair of big tubes with large grid capacitance the driver stage must be a small amp by itself.

We decided to build an amplifier inside an amplifier, so the output stage is driven without any compromise. Using the 814 tube, a Direct Heated Thoriated Tungsten tube, we are capable of delivering >14W in class A operation to the grid of the 813s, more power than many SET amplifiers deliver as their output.

We decided to build an amplifier inside an amplifier, so the output stage is driven without any compromise

Power from the driver tube is delivered to the 813 tubes by an amorphous double-c core, bifilar winded inter-stage transformer with exceptionally wide bandwidth and low distortion.

The driver stage and filament power supplies are located on the bottom chassis.The 814 driver stage PSU is dual tube rectified, triple choke filtered using low DRC chokes and using our SuperFilmCapacitors.
All three tube filament supplies are triple filtered using passive DC filters,and are inductively isolated from the signal path.

Output Stage

The output stage power supplies are located on the main chassis. It uses a tube bridge rectifier using the 6cj3 very high current , and extremely robust and quiet dumper diodes. We also use oil/film capacitors and our Super Film Capacitors.

Each of the monoblocks has an internal mains power filter, independent for each chassis /channel. Our dual filter for each channel makes the use of randon main power filters redundant.

Biasing

Both driver and output stage bias can be monitored and set/adjusted on the fly, with the use on the built in digital monitors, paired with biasing adjusting knobs. Users can adjust the bias on the fly even while music in playing! This is a highly flexible feature and the sonics can be tweaked based on the settings.

Aries Cerat system including: Kassandra Limited Edition DAC, Talos Limited Edition Phono Stage,
Impera Signature Preamplifier, Exsequor Monoblock Amplifiers & Symphonia Horn Speakers
Technical Specifications

SPECIFICATIONS

Output Power:

65W (A1)

Gain:

x3 (9.5db)

Noise floor:

<100db (Ref) unweighted

Tube list:

2 x 813, 1 x 814 (per channel)


Distortion:

-75db H2 @ 1W -55db H2 @10W

Signal bandwidth:

8Hz-110KHz @80% max power

Energy storage:

3000j

Power supply:

1,800VA power transformer

Inputs:

RCA, AC link proprietary input

Output impedance:

User selectable (impedance matching system)
1.6ohm (8ohm setting), 0.8ohm (4ohm), 0.4ohm (2ohm setting)

Tube Bias:

Adjustable bias on the fly

User readouts:

Output and driver online monitors

Capacitors:

No capacitors in the signal path.
SuperCapacitors used for output and driver power supply
(1mohm ESR capacitors)

Power Consumption (idle):

520W per channel

Dimensions:

610mm W x 590mm D x 525mm H (2 chassis stacked)

Weight:

170kg per channel