Stephenson Amplification 30 Watt Head:

Features:

  • Single Channel Pre-Amp
  • Single Channel Power Amp
  • Power Scale Master Volume
  • F.A.T. Control (Feedback Attenuation Circuit)
  • Ultra Linear / Pentode Operation
  • Footswitchable Boost (Preamp Gain Boost)
  • Front Panel 3-Way Bright Switch
  • Power Amp Valve Select [P.A.V.S.]
    ***See Below for more on PAVS

Ffeatures common to all of our 30 watt amps:

  • Toroidal supply transformer with dual primary (120/240 vac operation)
    ***Specify at time of order so the power supply can be wired accordingly.
  • Custom output transformer
    ***Designed for dissimilar tube operation
  • Two 12AX7 tubes in preamp
  • One 6SN7 tube in power amp section
  • One 6SN7 tube in reverb section
  • Four tube dissimilar power amp: 2 x EL84’s blended with 2 x 6L6’s for peak power output of 85 watts
  • Any of the common octals can be used in the 6V6 tube location (6L6, EL34, etc.)
  • Heavy aluminum chassis with welded corners

Front Panel:

30Watt NR Front Panel

Gain - Controls amount of preamp distortion

Treble - High frequency control

Bass - Low frequency control

Mid - Midrange frequency control

Drive - Controls preamp signal output to power amp

Fat:
Feedback attenuation – Controls the amount of negative feedback employed in the power amp. Negative feedback is a common guitar amplifier method to control the tightness and gain of the power amp. Too much negative feedback can cause a thin, constricted sound, and too little can cause a bloated sound. With the Fat set to minimum, a great deal of negative feedback is employed, which keeps the power amp tight with less body and gain. With the Fat set to maximum, the power amp is running "open loop" (no negative feedback), for maximum gain, body and wattage from the power amp.

Power Scale:
Power Scaling (PS) - The world’s best and most transparent master volume. PS varies the amount of wattage the power amp produces by proportionally varying the voltages applied to the power tubes. With the PS set to minimum, the wattage output is only a fraction of a watt, and with the PS set to maximum, the power amp produces full wattage. Power tube life is greatly extended with the PS on settings less than maximum.

***More info on the Fat and Power Scale functions

Power-Amp Valve Select [P.A.V.S.]:

30Watt Power Valve Select Controls

V1 – V4 Switches

  • V1 controls the power tube socket labelled V1. This socket accepts an EL84 tube.
  • V2 controls the power tube socket labeled V2. This socket accepts any of the common octal tubes (6V6 etc.)
  • V3 controls the power tube socket labeled V2. This socket accepts any of the common octal tubes (6V6 etc.)
  • V4 controls the power tube socket labelled V1. This socket accepts an EL84 tube.
  • These switches are used to turn the power amp tubes on or off. Since each power tube (or Valve) has it’s own switch, any combination of settings can be used. There are many possible power tube combinations with these switches.

Dissimilar Tube Layout

Here are some examples:

  • Any tube can run all by itself producing a single ended low wattage amp
  • Any two tubes can be run together, V1 and V2 (or V3 and V4) can be run together for a 10 watt single ended dissimilar tube amp. V1 and V3 (or V2 and V4) can be run together as a push/pull 15 watt dissimilar tube power amp.
  • Any 3 tubes can be run together.
  • All 4 tubes can be run together for a 30 watt amp.
    *Note. If all switches are Off then the amp will not produce any sound.

 

 

Contact Info :

STEPHENSON AMPLIFICATION

Mark Stephenson
PO Box 176
Parksville, BC
CANADA
V9P 2G4

Tel: 250-954-2292
Monday to Friday 10:00 AM - 6:00 PM Pacific

stephenson@telus.net