Arche 1a

















Vacuum tube power amplifier - monoblock
To order, write to us by e-mail: info@jak-audio.com
Introductory price (one piece) with VAT: 8299€ 6299€
Description
Arche 1a is a tube power amplifier – monoblock. A fully balanced Push-pull architecture is used, from the input connector, through the driver, the power tubes to the output transformer.
The power tubes operate in class A. This means that their operating point is shifted to an area with higher anode current compared to class AB. This brings a significant reduction in “crossover” distortion and a more dynamic, detailed and pleasant sound performance.
Setting the operating point of the power tubes and their balance is ensured automatically. No adjustment is required when replacing them. Also, gradual aging of the tubes is not a problem, since the operating point is always automatically fine-tuned.
Arche 1a consists of only two active amplifier stages, which supports our philosophy: “less is more in many cases”. The fewer components through which the audio signal passes, the more transparency and purity in the resulting performance.
Between the driver and the power tubes, high-quality capacitors from Mundorf with the addition of gold and silver are used, and they are also impregnated with oil. The final sound performance is significantly influenced by the capacitors in this position, which is why we took great care in their selection.
In critical positions, we use Amtrans AMRG resistors and Vishay metal film.
The signal path uses conductors made of oxygen-free copper in combination with gold and silver. At the input and output of the amplifier, there are connectors made of pure gold-plated copper and bronze.
A great advantage of our power stage is the possibility of switching to three operating modes, which affect the interaction of the amplifier and speakers, thus changing the character of the music performance. Thanks to this, the Arche 1a becomes a universal amplifier that will probably get along with a wide range of speakers. The right mode will of course depend mainly on your taste. Specifically, there is an ultralinear mode, a triode mode without feedback, and a triode mode with feedback.
As for the feedback, it is active in the ultralinear and one of the triode modes. Specifically, it is a sonically popular local cathode feedback, which uses separate output transformer windings that feed the music signal back to the cathode circuits of the power tubes. Moreover, this feedback is minimal. No global feedback is used in the amplifier.
Behind the power tubes is an output toroidal transformer with the aforementioned cathode feedback. Its main benefits include a wide bandwidth and low harmonic and intermodulation distortion. As for the advantages in the acoustic area, we can include extremely fast and controlled bass, revealing even the smallest details, and emphasizing space.
The entire amplifier is powered by an audiograde toroidal transformer and exclusively linear power supplies. The anode voltage section uses high-quality filter capacitors in conjunction with an audiograde toroidal choke. At the same time, this voltage is activated only after the tubes have warmed up, which extends their lifespan.
High-purity, lead-free audiograde solder with a 5% silver content and 2% copper content is used to solder the components. This ensures perfect conductivity and durability of electrical connections and even greater transparency and details in the performance of music.
Our products are not mass-produced on a line. Each original piece is assembled component by component by our hands. Each electronic component is tested and measured before installation. After completion, a comprehensive functionality test and parameter measurement follow. Finally, each product is tested in our listening room to make sure that everything is as it should be.
Technical information
- Operating modes:
U/L: Ultralinear
T2: Triode with feedback
T1: Triode without feedback - Output power:
U/L: 30 W @ THD < 1 %
T2: 20 W @ THD < 1 %
T1: 20 W @ THD < 3 % / 10 W @ THD < 1 % - Output impedance: 4 and 8 Ohm
- Input sensitivity @ full power:
U/L: 1.8 V
T2: 2 V
T1: 1.3 V - Input impedance: 200 kOhm
- Input connector: 1 x XLR
- Number of channels: 1
- Architecture: fully balanced push-pull
- Class: A
- Frequency response @ 1 W:
U/L: 4 Hz to 120 kHz
T2: 4 Hz to 110 kHz
T1: 4 Hz to 110 kHz - Frequency response @ full power:
U/L: 15 Hz to 90 kHz
T2: 12 Hz to 90 kHz
T1: 12 Hz to 80 kHz - Harmonic distortion @ 1 W:
U/L: 0.012 %
T2: 0.04 %
T1: 0.08 % - Noise floor (ref. 1 W), excluding mains hum: -125 dB
- Mains hum components (ref. 1 W): -100 dB
- Damping factor:
U/L: 4
T2: 6
T1: 3.2 - Negative feedback rate:
U/L: 6.5 dB
T2: 4 dB
T1: 0 dB - Negative feedback type: local – cathode (no feedback is used in T1 mode)
- Heater: AC
- Tubes used: 1 x ECC81 (JJ), 2 x KT88 (JJ)
- Power consumption: 120 W
- Power supply: 230 V / 50 – 60 Hz / 148 VA
- Solder: audiograde (5% silver, 2% copper)
- Casing: black sandblasted anodized aluminum and highly polished stainless steel
- Weight: 12 kg
- Dimensions: 278 mm (width) x 258 mm (depth) x 175 mm (height without feet)
- Packaging: 1 x amplifier
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