USER MANUAL Hughes & Kettner VS 250 Stereo Tube Power Amplifier
Hughes & Kettner Stereo Tube Power Amplifier vs 250 Congratulations! You have just acquired a highquality sound tool which combines the sonic superiority of vacuum tubes with the optimum usefulenss of a guitar rack. The VS 250 incorporates the sum of our experience with vacuum tubes. May you enjoy the new measure of expressiveness and creative freedom it affords. The following operating instructions delve into the special features and capabilities of the VS 250 in detail.
FRONT Stand by There are two different levels of voltage controlling the tubes: 1) the basic voltage intended to warm the tube to minimum operational temperature. This voltage is always applied to the tube whenever the power switch is in the on position. 2) the operating voltage (plate voltage) which drives the tube. The operating voltage is turned off with the STANDBY switch. The green LED indicates the unit is in standby mode, the red LED above the STANDBY switch indicates normal playing mode.
With the SELECT switch you can alternate between PRESENCE 1 and PRESENCE 2. The triangular-shaped LEDs indicate which presence control is currently active. On the back of the VSZ50 there is one l/4” jack per channel for connecting a footswitch to select between PRESENCE 1 and PRESENCE 2. Please note: The PRESENCE controls do not affect the tone as strongly in TRIODE mode than in PENTODE mode! Mains Mains is the power switch of the VS 250.
Pentode/Triode The first guitar tube amps from the 30’s and 40’s utilized TREIODE power amp tubes. Since triodes tend to emphasize even-order harmonics, these amps had a very typical sound with a warm even tone, even when overdriven. Great for sweet, warm, full, fat blues. To obtain higher power levels, tubes were developed in the 50’s with 5 electrodes (PENTODES), and these have since become standard in all tube amplifiers. PENTODES likewise have their own typical effect on the sound.
Speaker Outputs Each channel of the Vs 250 has three speaker output jacks with different impedances: 4 ohms, 8 ohms, and 16 ohms. Use the jack which corresponds to the impedance of the guitar loudspeaker cabinet which you are using. All three jacks may be used simultaneously. If you wish to connect two &ohm cabinets to one channel, please connect one of the cabinets to the 4-ohm input, and connect the second cabinet to the first in parallel.
