A90
Vacuum valve amplifier- Output RMS power: 2x 90 W / 180 W
- Speaker impedance: 4 - 8 Ohm
- Frequency response: 20 Hz to 20 kHz @+-1 dB
- THD+N: 0.8 % @ 80 W
- Input sensitivity: 2 V
- Type of inputs: XLR, RCA
- Galv. isolation of the input: Yes
- Galv. isolation of the output: Yes
- Feedback factor: ~10 dB
Introduction
A unique tube amplifier design and our current flagship.
With the help of tubes, the connection takes care of the simplest possible sound path, which is crucial for faithful reproduction.
A90 is separated from the signal source by an input transformer, which prevents the formation of ground loops and
affects the quality of the entire connection. The uniqueness of the amplifier is also the purely harmonic course of the supply current -
99% of amplifiers (tube or transistor) are not designed that way.
The symmetry of quiescent currents can be set by the user using the built-in ammeter.
Description
The A90 is equipped with 4x KT120 in the output stage and 4x EL84 in the driver stage. Bias points are chosen with "comfort" in mind
tube - nothing is pushed over the edge. Setting / checking the symmetry of quiescent currents is possible very easily
using the front panel ammeter. The ammeter can be switched to both final stage sections and the corresponding multi-turn potentiometers
set to zero deflection (using a screwdriver).
The input of the amplifier is fully (due to the input transformer) symmetrical. When using
RCA connectors (essentially unbalanced) must be switched to the RCA position. When using XLR connectors
it is possible to leave the grounding disconnected, or to connect it to the 1st pin of the XLR connector as needed. More information and examples
connections are listed in the user manual. The input sensitivity can be changed by the attenuation on the front panel. Attenuation is
changed with a switch, not a potentiometer.
The configuration of the amplifier can be as STEREO or as MONO (connection in the bridge).
The amplifier does not have global feedback, so there are no problems with stability due to phase issues. Feedback is used only locally and not "so much".
The amplifier is in the phase of being put on sale.
FAQ
It is possible to connect the A90 as a monoblock, i.e. bridged?
Yes, it is possible using the supplied interconnecting cable. For more information, please read the user manual.
Is it possible to use other tubes?
The A90 amplifier is currently user-invariant, intended for use with the KT 120.
Isn't the attenuation switch on the front panel interfering with the clarity of the audio path?
No. In the 0dB position, it is completely disabled. The usefulness of the input sensitivity is good for source devices with a large output level.
How can be the amplifier ordered and what is the delivery time?
You can order the product in our eBay e-shop or via e-mail. Since it is completed exclusively by hand, in case of insufficient stock, delivery is within 2 months from the day of the order.
