Zion Monos

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

Like many ampsandsound creations, the Zion, named for Zion National Park, began with a classic design known for its fidelity and absolute bandwidth from Stu Hegman of Harmon Kardon. Using the Citation V circuit as a touch point, we sought to find refinement through improved transformers and power supply optimizations.

The Citation V may appear as a simplified Citation II which serves as the bases of our Arch Push-Pull Flagship, but it still represents a high degree of sophistication and understanding of push pull amplification. It differs form the Arch with fewer gain-stages, shorter signal path and less feedback. This reduces output power, and linearity but adds a degree of humanity. Where the Arches are source accurate in reproduction without grain or sibilance, the Zions add a hint of warm while maintaining the all the detail and scale.

Zion’s genesis began with a blank slate knowing that the mechanical layout and power transformer were the weak links. In building the Zions, we chose a chassis large enough with room for layout and acquisition without compromise. There are no space constraints or thermal considerations and as such, wire layout is optimized for performance not compactness. When looking at the power transformer, we sought to exceed the requirements of stereo amplifier with the capacity of our mono power transformer. Our single power transformer can more than meet the demands of the original stereo amp, thus allowing a 200% overhead and the ability to roll tubes and minimize opportunity for the amplifier to encounter compression.The degree of over specification was intentional to ensure greater regulation under normal operating conditions or at full use, in short the Zions like to be pushed and sound best being challenged. Vacuum tube rectification was chosen to completely remove any silicone from the amplifier and reduce opportunities for grain to creep into the signal.

Careful attention was paid to the output transformers, as the original Freed transformers are simple in design, but phenomenally built. This circuit demands exceptional transformers. The Zion transformers are quite special, achieving a bandwidth of 4hz to 100khz without consequential frequency response deviations. This wide bandwidth matches well with the circuit, which utilizes a 12BY7A Video Pentode capable of exceptionally wide frequency response.

The Zion was also an early experiment in constructing a sophisticated amplifier on turret boards with point-to-point wiring, which most consider the standard-bearer for tube amplifier builds. There are absolutely no PCB boards used in this style of amplifier construction, and the internally-braced 12-gauge cold-rolled steel chassis, 25 lbs of metalwork per channel, is so massive it actually provides measurable damping which results in a quieter amplifier. The Zions will be noiseless even on horn loudspeakers exceeding 101dB/1W sensitivity.

Though customers have commissioned many Citation V clones over the years, the Zion exceeds any clone of a Citation V, while also being significantly easier to own and service. The Zion’s internal layout is much more cleanly arranged, and the internal AC and DC balance pots and bias adjustments have been moved to the outside of the amplifier for ease of service. Outside of swapping tubes, adjustments to bias and AC or DC balance will only be needed every few years, and the service can be provided by ampsandsound or a qualified technician. The upgrades in build quality and design improvements mean that a pair of Zions will maintain a stable balance and bias much more easily than an original Citation amplifier.

The Zions are fast, transparent and explosive in their dynamics. Bass is deep, authoritative and extremely textured, and treble extension is stunningly linear for a tube amplifier. Midrange clarity is simultaneously dense and arrestingly clear. The Zion still retains a hint of warmth and sweetness, and the presentation is not dry as the originals can sometimes be. This is an improvement over the original in every possible way, and achieves vanishingly low distortion numbers, less than 0.03% at 34W with 7581As. This is well in line with Stu Hegman’s original philosophy of low distortion. For most customers the Zion is all the amp they will ever need, and is representative of ampsandsound’s finest work.

Specifications:

Dimensions for each amplifier: 17x13x6

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

    4hz to 99khz @ 1 watt

    10hz to 50hz @ 10 watts 

Output Power with KT88: 60W RMS at 8 ohms

Output Power with 7581A: 42W RMS at 8 ohms

Output power with KT66s ~40watts Somewhat noiser than the 7581A but more holographic

• THD @ 1Watt 0.014%
• THD @ 5Watt 0.026%
• THD @ 20Watt 0.054%
• THD @ 39Watts 0.070% 

• Output Tube Compatibility: 6L6GC, 7581a (stock), 6550, KT88, KT120
• Included Tube Set: 2x12BY7A, 2x6CG7, 4x7581a, 2x5AR4
• Note: There is no replacement for the Input 12BY7A and we do not recommend rolling the 6CG7 driver tube.

*Power and Noise Specs are dependent on tube selection and will vary even with tubes from the same family. The provided power and noise specs were measured using new production 7581a output tubes.

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.