Zeiler Audio PA-01 Power Amplifier.

Zeiler Audio’s high-end audio tube amplifiers are designed and manufactured entirely in Switzerland, where every step of the process embodies Ralf Zeiler’s commitment to quality, craftsmanship, and innovation. “In the world of audio equipment, design is often limited to the front. This is different with the high-end audio tube amplifiers from the Swiss manufacturer Zeiler Audio. Here, all elements from the controls to the smallest functional details have also been formally designed inside the enclosure. In addition to such typical Swiss design maxims such as objectivity and formal timelessness, the Zurich-based agency FOND Design also utilized the golden ratio to achieve an aesthetic and consistent design.”

The technical specifications of CNC milling technology were translated into a formal vocabulary. With optimal manufacturability, the milling geometries are also brought into focus here in terms of design, leading to a timelessly beautiful result. The CNC machining takes place at a specialized company in the canton of Lucerne. There, solid aluminum blocks are reduced to about 80% with a 5-axis CNC milling machine. What remains is a high-precision full-metal housing that has a number of unique features. It has a high-end feel with finely detailed forms that appear to be cast from a single mold. The lightweight metal enables cooling of the electronic components and tubes through efficient heat dissipation. The optimal positioning and mounting of all electronic components results in the shortest possible wiring paths. By avoiding and reducing disturbing resonances as well as providing perfect electromagnetic shielding, the enclosure contributes to the exceptional sound quality of Zeiler Audio equipment.
Milling is followed by surface treatment by a company specializing in electrolytic processes based in the Swiss Mittelland. The aluminum used is made of a special alloy to guarantee the best possible finish during the surface treatment. First, the enclosures are blasted by hand with glass beads to hide all milling marks and obtain a uniformly compacted surface. Then anodic oxidation gives the parts their typical matte black coloration and unique velvety feel. This complex procedure is also used for the coating of high-end camera housings and sports watches. All surfaces are coated with a hard anodized ceramic layer. It provides excellent wear and corrosion protection as well as very good electrical insulation and dielectric strength. A laser engraving exposes the aluminum for the filigree inscription on the back, which contrasts with the matte anodized background.
Ralf Zeiler’s goal is to achieve a perfect balance between sensual haptics, a timeless design and superior sound quality. The partners also play a decisive role in this. From design to CNC manufacturing to surface treatment, they embody classic Swiss values such as the pursuit of quality, craftsmanship and innovation in their daily work.

The assembly, wiring and soldering of all audio components up to the testing and measuring of every single device is done by hand in Kilchberg on the shores of Lake Zurich in Ralf Zeiler’s workshop. 
  • Extremely sturdy enclosure, CNC-milled from a solid block of aluminium
  • All surfaces are glass-bead-blasted and then anodized with a highly resistive ceramic coating
  • Power supplies mounted on suspended sub-chassis to mechanically isolate them from the audio circuits
  • Extremely reduced circuit design with parts chosen in extensive listening tests
  • Parts are manually channel-matched to close tolerances and hand-soldered point to point
  • Oversized choke-regulated power supplies and custom made power transformers
  • Internal wiring with cryogenically treated oxygen free copper
  • Customized Lundahl C-core output transformers
  • Intuitive handling, no adjustments required
  • The PA-01 can be switched ON/OFF automatically from the Pre-Amp → turn on/off the whole system with one switch
  • Gentle operating conditions ensure long tube life
  • Widely used, reliable tube types to ensure future availability without expert knowledge
  • Impedance matching for 4, 8 Ohm speakers, 16 Ohm option on request

Technical Specifications

Design: Single ended pure class A, 2 x 10 Watt
Mode: Triode connected, no feedback
Input Impedance: 470 KOhms 
Output Impedance: 4/8 Ohms or 8/16 Ohms option
Tubes: 2 x KT150 
2 x 12AX7 / ECC83
Power Consumption: 180W in operation, no stand-by
Dimensions: 480 (width) x 360 (depth) x 113 (height incl. feet) mm
Weight: 49 lbs (22.2 kg)