PAP-C1, Active Analog Two-Way Crossover

Designed and manufactured for PureAudioProject by PassLabs/FirstWatt, in CA, USA 

Optional: Distribution Boards for internal wiring (speakers input to drivers)

Shipped world wide with DHL or Fedex Express


Product Description

PAP-C1 is an Active Analog two0way Crossover, designed by Nelson Pass specifically for PureAudioProject open baffle speaker.

PAP-C1 is an updated design of the FirstWatt legendary B5 crossover. Based on the most recent JFet technology and due to it’s minimalistic design, the crossover circuits allow smooth and continuous -12db low and high pass filtering between 100hz to 550hz, and adjustable low-bass boost and upper-mid notch options.

Also, PAP-features a continuous ‘loudness’ on its front panel. This unique option allows optimal low/high balance at any volume, even at the lowest one…

General Specifications

  • Nominal Input Impedance: 15 Kohms
  • Output Impedance: 500 Ohms
  • Measurments made into 10 Kohm loads
  • High frequency bandwidth: -0.5db @ 100KHz
  • Power consumption: 4 watts, max power output 20W
  • Power Supply: Input 110-240v AC, Output 24v DC
  • Dimensions (W,H,D): 8.5″ X 3.12″ X 13″; 21.5cm x 8cm x 33cm
  • Designed and manufactured for PureAudioProject by FirstWatt, CA, USA



“Good afternoon Pure Audio Project, A couple of months ago I bought a PAP-C1 from you and in the meantime it has found its place in my audioset. That PAP-C1 does EXACTLY what is promised: dividing the signal between 120 Hz – 550 Hz (and have the options for a bass boost and mid/high equalisation).

The turntable is an air-stabilised air-bearing 400 kgs affair. It’s my main source. The preamp is a PT8/4019a tube affair with stepped attenuators from measuring gear. The poweramp for the woofer are 2 monoblocks based on the Eimac 35TG triode (ultra-parafeed; 8 watt). The poweramp for the midrange is a stereoblock based on a single pushpull pair of 6C45’s (2,6 Watt). The poweramp for the tweeter is a stereoblock based on the E2c (1,1 Watt).

The PAP-C1 sends the low (below 500 Hz) directly to the 35TG amplifier which feeds the woofer and the mid/highs to both 6C45 + E2c amplifiers.

I’m impressed with the PAP-C1 as it adds nothing to the sound. It “simply” divides the signal as promised…

Positively surprised by the amount of ripple/noise rejection of the internal capacitors…

This is indeed a seriously well executed audio gear!  Don’t know if it is the minimalistic and proper design, or component-choice, or the combination; it simply works perfect. Thank you for making this available.”


Optional: Bi-amping Distribution Boards

Bi-amping requires thorough cabling solution, connecting the output of your power amps with binding posts to drivers with various industrial terminals…

We solved this complexity by supplying a simple Bi-amping Distribution Board with binding posts that receive your favorite Speakers Cables (Banana or Spades) and Gold Plated Screw Terminals to which you connect the inner cables that run to the specific drivers

The Bi-amping Distribution Board is a single layer audiophile grade PCB, with outputs for main driver (full range, wide range, or tweeter) and two outputs for woofer. It features two output configurations for woofers, in series, when connecting to the center row of terminals, or in parallel, the upper row of terminals.


PAP-C1 (1pc), Distribution Boards (2pcs)

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