This preamp is based on the OD1 and OD2 channels of the original amplifier. Producing a very thick, saturated high gain tone, it was popular amongst metal bands in the mid-90's.
The original amp was a "hybrid" tube/solid-state design, but upon analysing the circuit, it quickly becomes clear that the tube functions as a simple hard-clipper stage, easily replaced with a set of clipping diodes, as lon as care it taken to match the clipping levels. As an added extra, we've added a second "Post" gain knob, which controls the signal strength going into this clipping stage, giving even broader range of sound possibilities.
Product Details - 8100 Gold
Controls
-
Bass, Mid, Treble - A classic 3-band tonestack.
-
Contour - Love it or hate it, this mid-tone control takes your sound from a fluffy mid-boost to ultra-scooped. There is a secret sweet spot around the 1.0-1.5 mark, be sure to look for it!
-
Gain - The main gain control for the preamp.
-
Post - Controls the gain in the hard clipping stage. When set low, gives a lower gain, fuzzier sound. At its maximum, the gain is significantly increased, and the high end increases considerably. Set to around 2'o'clock to match the gain and tone of the 8100.
-
Volume - Controls the output signal amplitude.
-
Channel Switch - Switches between the OD1 and OD2 channels.
-
Active Switch - Engages or bypasses the pedal with a relay (true bypass).
The original
The Valvestate series from Marshall was a big seller in the mid-to-late 1990s, popular among younger bands in the metal scene, both in America and Europe. It was affordable, high gain, and offered a "modern" sound, thanks to its (much debated, hated and misunderstood) Contour tone control.
The defining feature of the Valvestate 8100 was its "ValveState" technology, a hybrid design that combined a solid-state preamp section with a 12AX7 dual-triode tube in the signal path. This approach sought to capture some of the warmth and harmonics associated with tube amplifiers while maintaining the durability and cost efficiency of solid-state circuitry. In reality, the inclusion of a valve in the circuit is mostly a sales gimmick. Acting as a simple hard-clipping gain stage, the effect is easily replicated with a pair of diodes, without the need to add high-voltage circuitry into the mix. But it sure did help the sales numbers.
In recent years the amp has been re-discovered by tone-chasers, recognizing that the amp was a critical component of the mid 90's metal bands, such as Meshuggah, In Flames, Death, Dimmu Borgir and many, many others.
Features
- True Bypass with Relay switching.
- Soft-touch footswitches.
- Internal voltage-boost mechanism ensures circuit runs at same voltage as the original amp.
- Rugged 16 gauge (1.6mm) steel enclosure with textured powder coat finish.
- Solid aluminium knobs.
Technical Specs
-
Power Requirement: 9V DC, 190mA
-
Power connector: 2.1mm center-negative barrel jack
-
Dimensions: 145mm (W) 108mm (D) 61mm (H)
-
Dimensions (with packaging): 185mm (W) 130mm (D) 70mm (H)
About Preamplifiers
This is a preamplifier, and not a distortion pedal. We do not recommend connecting this device to the input of a normal guitar amplifier. Instead, it is best used in one of the following ways:
Connected to the Effects Return / Power Amp Input of a guitar amp
Connect your guitar to the pedal input, and connect the pedal output to the effects return. This bypasses your amplifier's built-in preamp, and the signal goes through the pedal instead.
Connected to a dedicated power amp
Some examples include the Seymour Duncan Powerstage, Harley Benton GPA-100, or the Mooer Baby Bomb.
Connect the pedal directly to an audio interface
For recording purposes, the pedal can be connected to either an instrument or line-level input on your audio interface. Using a speaker cabinet simulation plugin, such as an Impulse Response (IR) loader, to emulate the effect of a speaker cab is highly recommended.
