Aries Cerat

High Performance Audio

Nil Satis Nisi Optimum

Your Perception About HiEnd is About to Change!

  • 1
  • 1
  • 1
  • 1

Concero 25 Monoblock Tube Amplifiers


rsz 1011737

The new redesigned Concero 25 is our flagship of our smaller Prestige Series, a Direct Heated Tube Single Ended Monoblock amplifier.

The new design is designed using a blend of technologies used in our previous Concero 25 and Concero 65 amplifiers, modified to use the 845 tube.

As always we again endeavoured to produce a design that has all the sonic virtues of only the best of the best Single Ended amplifiers, but with absolutely none of their shortcomings.

Output stage

The output stage is based and designed around the 845 tube. The power supply,biasing circuit and output transformer is based on the tried and successful designs of the previous Concero 25 design.

 Output is rated @ 20W, via a massive output transformer, with selectable 2, 4 and 8 ohm secondary winding selector.

The output transformer weighs more than many SET amplifier's total weight. The highest quality massive core of the output transformer used in the design, is mandatory for delivering true undistorted higher and lower bass, and driving any speaker through complex musical content. Many SET amplifiers get distortion when driving speakers with complex music,because of core saturation.Our output transformer can easily take 60W at 20Hz ,so at 25W intermodulation aftifacts are next to zero.

rsz 1011723

Driver stage

Driving the output tube, is a major task, which almost all SET amplifiers fell short, using tubes not adequate to the task. Tubes with high Rp and small current swing capabilities. For the redesigned Concero 25,we went ahead and used the driver stage used in our bigger models like the Concero 65.The driver stage is designed as a small SE amplifier by itself,with it's own power supplies,transformers,bias stage and filament supplies.The driver stage can deliver more power if asked than most SE power amplifiers.

The driver tube is the 814 DHP and is transformer coupled to the grid of the output tube using a very wide-bandwidth inter-stage transformer. No RC coupling is used in any of our amplifiers.


Separate power supplies are used throughout our design, using 2 toroidal transformers rated at over 900VA total.Separate toroidals are used for driver stage,output stage,filaments and bias circuits.


Driver and output power supplies are ground-choke filtered and energy banks are over 4000 joule per channel.

rsz 1011724

Filament supplies

Both the driver and output tubes are Direct Heated tubes,that is their filament psu is part of the signal current loop. Any noise/hum present in the filament supplies will be amplified by the gain of each stage. Filment suppies is a major source of noise and sound degeneration in DHT SE designes.

As in all of our DHT SE amplifiers, the filaments are fed with tripled filtered DC current. Filters are triple PI CRC filters bringing noise and hum at almost unmeasurable levels. This is one of the factors that the Concero 25 is one of the quietest amplifiers on the market,regardless of technology.



Both driver and output stage bias can be monitored and set/adjusted on the fly,with the use on on-line digital current monitors,paired with biasing adjusting knobs.User can adjust the bias on the fly even while music in on!

rsz 1011698

Low/medium gain version

The amplifier comes standard in the low gain version (x1 gain) as well as the medium gain version (x7).

To get the maximum performance out of the amplifier,a high gain ,high output preamplifier is preferred.


Concero 25 elevations blk


•Power : 20W ~ 25W depending on bias setting

• Gain:  X1 (x7 medium gain)
• Noise floor: <-100db A-weighted
• Power Bandwidth: 15Hz ~ 80Khz -3db @ 20W
• Tube list: 1x Elrog 845, 1x RCA 814 (per channel)
• Power Consumption @ idle: 200W

Dimensions: 550 mm W x 430 mm D x 280 mm H
Weight : 65Kg each, unpacked.


90146552 3089907604373632 7533292347065368576 n


rsz 89951214 1131508993877202 8692487055134949376 n


rsz 90293439 210249703399309 8749895284525367296 n


rsz 90412952 249281699427377 166698229197438976 n


rsz 1011734 1


rsz 1011707


Tube Reference Amplifier

 Our first ever commercial design ,and one of our proudest moments, the Exsequor amplifier,finally got it's facelift. Being our top SOTA offering for 9 years, it was unsurpassed by whatever new design came up. Only outperformed by our recent statement Achilleas amplifier,the Exsequor is a timeless musical server.


rsz exsemain


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 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 we ever tried. 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 underdriven with the known results of limited frequency response and lack of acceptable transient response..
We chose to differ…

rsz exse3

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

rsz exse2




- Max Power Output : 65W (A1)
- Power Consumption (idle) : 520W
- Power Bandwidth (@ 60W) : 15Hz-60Khz(-3db)
- Weight (each, unpacked) :170KG

-Noise floor: -100db unweighted

-Impedance matcher system: 1-2-4-8-16 ohm user selectable

Exsequor elevations black


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. 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.


rsz exse4


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.

The output stage power supplies are located on the main chassis.It uses a tube bridge rectifier using the 6cj3 very high current ,extrmely robust and quiet dumper diodes.

It uses oil/film capacitors and our SuperFilmCapacitors.

Each of the monoblock has internal power mains filter ,independent  for each chassis /channel.The dual filter per channel makes the use of random power main filters redundant.





rsz exseball


Login Form