This project has been delayed due to COVID-19. Check this page for updates on availability.



The P15 tube preamp is now a regular item offered by Broughton Audio. These preamps will be made on a regular basis and put up for sale here. If it appears as “out of stock”, check back in a week for more inventory. Demand for the P15 is high, but we will work hard to keep up with production as much as we can.



Several updates have been made to make the preamp even more robust, and more accessible to users worldwide. Updates include:

  • Upgraded power transformer for even lower noise
  • Choice of mains voltage
  • Double copper plating on the PCB for improved reliability and heat dissipation
  • New production 6SL7 tube for improved reliability and consistency (more info below)
  • Upgraded audio jacks
  • Added ground lift



The P15 can only be purchased directly from this web page. If it is out of stock, you must wait until more inventory is made. Once back in production, they will be made on a weekly basis. There are no waitlists, preorders, or reservations. There will not be a specific day or time of release--the preamps will be put up for sale when they are ready to ship.


Please do not order more than one preamp, or combine your order with other pedals.




  • Overview
    The P15 is a tube preamp based on the classic B15 bass amplifier. It is an exact recreation of the preamp section, using one 6SL7 tube. The topology is based on the later models that place the Volume control after the first gain stage, followed by the second gain stage driving the Bass and Treble equalizer. A high voltage MOSFET cleanly drives both the line output and the transformer coupled balanced output.


  • Input
    The input is designed for mono instrument level signals via a 1/4" jack. 

    Additionally, the P15 has a "Thru" jack. You can use your input signal coming out of the Thru jack to feed another device, such as a tuner, or a bass amp. The P15 does not affect the signal of the Thru jack.

    The input is muted when neither jack is used.
  • Controls
    The Volume controls the amount of signal transferred from the first gain stage to the second gain stage. The Volume control can be set to reach a line level output when using instrument level signals. Tube overdrive can be introduced at higher volume levels.

    The Bass and Treble controls are standard shelving type equalization. With the knobs at noon, the frequency response is flat.
  • Output
    The balanced output is transformer coupled, and can drive long XLR cable lengths to feed a mixing console, or other equipment that accepts balanced signals. The ground lift button connects pin 1 of the XLR to the chassis of the P15. Releasing the button disconnects pin 1. Choose the option that provides the least amount of noise. Phantom power should not be used on the P15, but no damage will occur if connected.

    The line output is an unbalanced mono signal coming from the 1/4" jack. This is capable of driving power amps, or other equipment that accepts line level signals.

    Both outputs may be used simultaneously. 

    Due to the high level signal output, you may wish to use a pad (attenuator) on the receiving device. Set your volume and tone controls on the P15 as desired, and then add gain, if needed, at the receiving device.
  • Tube
    The P15 uses a new production JJ 6SL7 tube. Vintage tubes have become increasingly unreliable, so the new production JJ tube has been chosen for all future P15 production. We do not accept requests to use different tubes.
  • Mains Power
    When ordering, choose either the 115VAC model for North American voltage, or 230VAC model for European voltage.
  • Dimensions
    The P15 is 5.25" wide, 10.5" long, and 5.25" tall. It weighs 6 pounds.
  • Miscellaneous
    Shipping costs will update when you input your information upon checkout. International shipping is available. The P15 is shipped double boxed. The package dimensions are 14" x 8" x 8". All shipments are insured and come with tracking.

    The P15 does not come with a case. These cases will fit the P15:
    Gator GU-1309-06-WPDF
    Gator G-MIXERBAG-1306
    Apache 3800

    The P15 comes with a 10 foot power cable.

P15 Tube Preamp

  • We ship internationally. All orders will be shipped via Canada Post. Please limit your order to one P15 only. Do not combine with other pedals. Your shipping cost will appear at check-out.

©2020 Broughton Audio - Hand made effect pedals