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Stephenson Amplification

Standard Amplifier

Standard Amp

The Standard is designed for cleaner tones and relies on power tube saturation for its distortion tones, from very clean to vintage style British crunch.

It has a unique preamp design that uses 12AX7 tubes to emulate the fatter tone of a 50s-style all-octal-tube preamp.

Specs:

  • single-channel amplifier with hi and low gain settings
  • Power Scale™ wattage control
  • three-tube power amp that allows dissimilar tube combinations
  • custom-made Canadian toroidal transformers
  • foot-switchable gain boost
  • foot-switchable effects loop
  • 120/240 vac mains operation
  • Dimensions: 20 inches wide x 9.25 inches tall x 8.25 inches deep
  • Weight: 20lbs

Front Panel Features

Front Panel

Front-panel items:

INPUT SOCKET – VOLUME – TREBLE – BASS – MID – LOW-HIGH GAIN – POWER SCALE –ON/OFF – LIGHT


Gain Switch

Gain Switch:

The front-panel Gain selection switch is a two-position rotary switch that toggles between low and high gain settings.








Power Scale Control

Power Scale Control:

This is the amp’s wattage control. This technology was developed by Kevin O’Connor at London Power and is used under License Agreement.

Lower settings produce less wattage; higher settings produce more wattage.





Rear Panel Features

Rear Panel

Rear-Panel Items:

AC input – Ultra switch – Foot switch jack - Valve select – Speaker output – Effects loop

 

Ultralinear Switch

Ultralinear Switch & Foot Switch Socket:

Ultralinear operation has a smooth, warm sound. The Off position is the standard mode of power amp operation. Generally lower Power Scale settings sound fuller when the Ultralinear is enabled. The Foot Switch jack is a standard stereo ¼ inch connector for controlling effects loop and internal gain boost.





Valve Switch

Power Amp Valve Select:

These switches turn the 3 power tubes on or off. A variety of power tube combinations is possible with the 20-watt amplifier. Any of the tubes can be turned on or off; of course all turned to the off position produces no sound!





TubesThe tube on the left is an EL84 and is enabled with the EL84 switch.

The two octal tube sockets can accommodate several tube types and are enabled by switches V-2 and V-3. The tube types that can be used are: 6V6, 6L6, 5881, 6CA7, EL34, and KT77. Any combination of these tubes can be used with no re-biasing required, simply plug and play.

The EL84 and V-2 work together, producing one-half of the audio waveform, and V-3 works alone producing the other half of the waveform.

The example in the picture is an EL84 combined with a 6V6, and V-3 is using an EL34. This is one of my favourite tube combinations to use in this amplifier. The output signal is very balanced and it turns the 20-watt into a 30-watt!


Output

Output:

This is the speaker output section. The impedance selector is labelled 1- 2 -3 because any setting can be used with a 4ohm, 8ohm or 16ohm speaker cabinet. Use the setting that you like the best. When using different output tube combinations, listen to the different impedance settings to see what one you like best.




Effects Loop

Effects Loop:

This effects loop is a 6SN7 tube-driven parallel type with variable send and receive levels that will accommodate both pedals and rack gear. This loop is based on a design by Kevin O'Connor of London Power, I've been using it for many years now and it just works great.



Foot Switch

Foot Switch
Controls boost function
Controls effects loop









Chassis Features

Chassis

  • Custom made-in-Canada toroidal power transformer for low-noise operation
  • Custom made-in-Canada toroidal output transformer for full-bodied tone
  • Aluminum chassis
  • Two 12AX7 tubes in preamp
  • One 6SN7 tube in effects loop
  • One 6SN7 tube for phase inverter
  • Three-tube power amp. Single EL84 blended with two octal tubes (6V6 etc.).

Interested in a Standard Amplifier? See our Price Page for ordering information!