BiasPro Tube Biasing Tool

Bias/Plate Voltage Probes

biasPro, tube bias, bias probe, biasing tool

Shown from left to right:

  • BiasPro 8C: 8pin octal bias probe
  • BiasPro 9C: 9pin miniature bias probe
  • BiasPro VI-8C: 8pin octal bias/plate voltage combo probe
  • BiasPro VI-9C: 9pin miniature bias/plate voltage combo probe

Quadstage BiasPro Q10

biasPro, tube bias, bias probe, biasing tool

Four input bias switching unit (external multimeter required). 


Shown with a BiasPro VI-8C bias/plate voltage combo probe and a BiasPro 8C bias probe.  This is the starndard configuration which it allows testing most two tubed amps.  By addint two more BiasPro 8C bias probes, it allows testing four tubed amps.

Quadstage BiasPro MQ13

biasPro, tube bias, bias probe, biasing tool

Four input bias switching unit (with built-in readout meter). 


Shown with a BiasPro VI-8C bias/plate voltage combo probe and a BiasPro 8C bias probe. This is the starndard configuration which it allows testing most two tubed amps. By addint two more BiasPro 8C bias probes, it allows testing four tubed amps.

Product Names

  • BiasPro 8C: Bias probe in measuring cathode current on common 8pin octal tubes. 
  • BiasPro 9C: Bias probe in measuring cathode current on 9pin miniature tubes.
  • BiasPro VI-8C: Bias and plate voltage combo probe for common 8pin octal tubes. Allows measuring both the bias current and the plate voltage with a flip of the switch.
  • BiasPro VI-9C: Bias and plate voltage combo probe for common 9pin miniature tubes. Allows measuring both the bias current and the plate voltage with a flip of the switch.
  • Quadstage BiasPro Q10: Four input switching unit. Allows up to four tubes to be tested. An external multimeter is required.
  • Quadstage BiasPro MQ13: Four input switching unit with built-in meter. Allows up to four tubes to be tested. No external multimeter is required.

Supported Tube Types

  • 8-PIN OCTAL tubes:
    12E13, 1622, 5881, 5871, 5932, 6550, 6CA7, 6L6, 6V6, 7027, 7184, 7D11, 7408, 7581, EL34, EL37, KT66, KT77, KT88, KT120, KT150
     
  • 9-PIN MINIATURE tubes:
    10BQ5, 10P18, 15CW5, 16A5, 30P16, 30P18, 45B5, 6BQ5, 6CW5, 6P15, 7189, 7189A, 7320, CV10321, CV10709, CV2975, CV5094, CV8069, EL84, EL84M, EL84S, EL86, E84L, N119, N329, N709, PL82, PL84, UL84
      
  • 8-PIN OCTAL tubes for (Fisher and Scott hi-fi amps):
    7591, 7591A, 7355

Prices

Standard Configuration for the most two tube amps:

  • Quadstage BiasPro Q10 with (1 x BiasPro 8C and 1 x BiasPro VI-8C) or (1 x BiasPro 9C and 1 x BiasPro VI-9C): $120.00
  • Quadstage BiasPro MQ13 with (1 x BiasPro 8C and 1 x BiasPro VI-8C) or (1 x BiasPro 9C and 1 x BiasPro VI-9C): $160.00

Additional probes:

  • BiasPro 8C bias probe: $30.00
  • BiasPro 9C bias probe: $30.00
  • BiasPro 7591 bias probe (Fisher and Scott hi-fi): $30.00
  • BiasPro VI-8C bias/plate voltage combo probe: $50.00
  • BiasPro VI-9C bias/plate voltage combo probe: $50.00
  • BiasPro VI-7591 bias/plate voltage combo probe (Fisher and Scott hi-fi): $50.00

Ordering

Before ordering:

  • Know what tubes are in your amp. Make sure your tubes are listed under the "Supported Tube Types".
  • Determine if you'll need two additional bias probes (if your amp is equipped with four tubes.) No additional bias/plate voltage combo probe is required as the plate voltage is the same across all power tubes.
  • If your tubes are not listed under the "Supported Tube Types" then do not order. The BiasPro will not work for you.

Email to order:

Please email me via "Contact Me" with the following information:

  • Which standard configuration (Quadstage BiasPro Q10 or Quadstage BiasPro MQ13) with which probe type (8pin octal, 9pin miniature, or 7591), and number of additional probes you'll be needing.
  • The payment method (Paypal or check).  I'll send you an appropreate invoice.