Skip to content

Rocktron ValveSonic Black Plate + Rackmount Guitar Amp Preamp, 4x 12AX7 Tubes


Manufacturer's Description

ValveSonic Black Plate +

Rocktron introduces another four-tube monster preamp! Producing tones only possible with tubes, Rocktron and LA Custom deliver the goods with the new ValveSonic Black Plate + all tube guitar preamp!

Providing unprecedented sonic versatility with another four-tube monster in the ValveSonic series, the Rocktron ValveSonic Black Plate + model captures the tone of the iconic American combo known for its pristine clean sound and smooth overdrive when cranked up. We’re talking 50’s “Hybrid Tweed” to 60’s classic “Black Plate” Panel. But this ValveSonic takes it even further providing the hot-rodded tones of the classic California amps. All this with a single preamp!


  • The Valvesonic Black Plate + features a front panel input jack.
  • The 1-2 switch affects the input of the tube stage in the preamp.
  • When switched to “1”, the unit provides the more modern “hot-rodded” type of input used on the classic “California” style amps.
  • When switched to “2”, the unit provides the classic type “Tweed” and “Black Face Panel” type “American” amps.
  • The Tight switch is used in conjunction with the 1-2 switch; in the up position the input is “tightened up”.

Bright Control:

The ValveSonic BRIGHT control is a five position switch that provides four different bright variations to the overall tone found in classic American and “hot-rodded” California amplifiers, with 0 being off and 5 being the brightest.

Gain Control:

The GAIN control is used to determine the amount of GAIN Input level driving the ValveSonic tubes. Boost can be obtained by flipping the Boost switch to the On position. The Boost works in conjunction with the “+” switch. When the Boost switch is On and the “+” switch is in the down position you will obtain an extra gain stage. When the “+” switch is Up, you obtain an additional gain stage and essentially add an entire tube to the front end, replicating the “hot-rodded” California style amps.

Bass, Middle and Treble controls determine the amount of these various frequencies present in the signal.


The EQ 1 & 2 switch replicates the two different style EQs that were used in American amplifiers over the years. In the Up position, (position 1), the 50’s “Tweed” EQ is replicated, providing a more modern midrange emphasis. In the Down position, (position 2), 60’s “Black Plate” Panel EQ is replicated.


The ValveSonic series features a unique AFTERBURNER switch. This switch works in conjunction with the DRIVE control, providing yet another gain stage after the EQ section of the preamp. When the AFTERBURNER is turned On, this switch emulates a post phase inverter master. When On, you can utilize the Drive control to adjust the amount of Drive present in the AFTERBURNER stage.

High Cut Control:

The ValveSonic also features HIGH CUT control to adjust the High Frequency cut in order to roll off some of the high end “sizzle” when the high gain is used. The Master control determines the output level of the preamp.


  • Input Impedance: 1M Ohms
  • Output Impedance: <100 Ohms
  • Input: 1/4" mono unbalanced (front & back)
  • Output: 1/4" mono unbalanced (line out & instrument out)
  • Tube Type: 12AX7EH
  • Power Consumption: 20w
  • Power Requirements: 100 ~ 120VAC/1.0A, 220 ~ 240VAC/.05A
  • Dimensions: 19" x 6.5" x 1.75" / 482.6mm x 165.1mm x 44.5mm
  • Weight: 5.5lbs / 2.5kg