Arch Monos

***Please note that these come as a pair. 

The goal of the Arch is to showcase the fidelity and bandwidth that could be possible while still employing strictly analog circuits. Transcending the musicality of the 60s with the bandwidth and transparency possible in modern speakers the Arch seeks to offer true to source tonal character and significant power delivery to enable modern speaker fullest potentials.

Designing an amplifier that would outperform the Zions in bandwidth,  output and transparency was a tall order. This amp would need to express all of ampsandsound’s most closely held philosophies at an even higher level. More power or complex circuitry for the sake of increasing the cost was out of the question.  Where does one go, once they’ve scaled Everest?

After extensive listening and research, the Citation II was settled on as the basis for the design. This amplifier was designed to be an amplifier in the tradition of Harry Pearson’s Absolute Sound - something which had absolute fidelity resulting from the widest and flattest frequency response and as close to an absence of distortion as possible. This amplifier is the proverbial bigger gun for those customers who require even more power than a Zion.

The original Citation II, much like the Citation V, is underwhelming in the power supply. A significantly more robust version was in order, which can supply eight amps per channel, and allows for tubes capable of greater output than the original. This of course necessitated the design of the highest power input power transformer ampsandsound has ever designed. In the process of redesigning the power supply, careful attention was given to improving dynamics, RMS output, regulation and lower distortion.

Depending on the tube selection, the Arch will output between 60-100W in pure class A, and represents our absolute statement on power output. As with the Zion, everything on the Arch is capable of handling several times the rated output power of the circuit. The result is astonishingly low distortion, and a true-to-source amplifier with massive grip on loudspeakers. The output transformer on the Arch has a practically unheard of bandwidth of 2hz to 110khz at -3dB. Even the excellent original Freed iron does not achieve these kind of figures under real world test conditions. Total output power is 65 watts with KT88s and 85watts with KT150s. The total power is the measure of this amplifier’s magic - not because of the output, but because it achieves astounding frequency linearity and vanishingly low distortion while doing so. A tube amplifier that can reliably reproduce frequencies lower than 20hz is unheard of and one that can descend into the low single digits is mythical. Perhaps most important is distortion figures that would be considered remarkable for a well designed solid state amp, accomplished in a tube amplifier without a single regulator.

The chassis is 10-gauge cold-rolled steel, which imparts even greater damping than the Zions and makes for an imposing amplifier. The choice of 10-gauge steel was born of our founders ability to make singular decisions on the basis of performance without consideration to costs. Each choice in the Arch came about in the same manner, and reflects a pursuit of absolute performance not a proxy vote for profits. Each monoblock weighs in at around 100lbs, and represents the pinnacle of our philosophy: hand built on turret boards using ultra pure point-to-point wiring, with no expense spared in creation process or parts selection. Wiring assembly alone takes 18 hours per channel, and is done by hand, before inspection, break in, testing and validation.

This amplifier goes far beyond being a modification or clone of the Citation II. Instead, the Citation II serves as a touchpoint for an amplifier built to completely eliminate questions of output and distortion. The Arch is the pinnacle of the low distortion, high power spirit of the Citation amplifiers, and each unit is personally measured, tested and listened to by Justin Weber before shipping.

The sound of the Arch must be heard to be understood. Suffice to say, the Arch simply sounds like music, and demands partnering equipment of highest calibre.

Please contact us if you wish to arrange a demo.

Specifications:

Dimensions for each amplifier: 14x14x8

Ships in two Pelican Style hard cases 

Speaker Outputs of 4 ohms, 8 ohms, and 16 ohms

RCA and Transformer-coupled XLR Inputs 

Noise at idle ~ 2mv or less.

Frequency extension @ 1 watt 2hz to110khz -3db

Output power with KT-88s ~65watts

• THD @ 1Watt 0.012%
• THD @ 5Watt 0.022%
• THD @ 20Watt 0.039%
• THD @ 64.7Watts 0.051%

Output power with KT-150s ~85watts

• THD @ 1Watt 0.024%
• THD @ 5Watt 0.033%
• THD @ 20Watt 0.043%
• THD @ 83Watts 0.076% 

Output Tube Compatibility: 6550, KT88, KT120, KT150

Included Tube Set: 6x12BY7A

Note: There is no replacement for the Input 12BY7A

*Power and Noise Specs are dependent on tube selection and will vary even with tubes from the same family. 

Additional colors are possible as a special order... pleasecall or email for details.

All ampsandsound amps are handmade in Southern California buy a small team with quality being our first priority. Transformers are custom and hand-wound in-house for each amp, and parts are U.S. Sourced.