User manual HUGHES & KETTNER VS 250

[. . . ] The following operating instructions delve into the special features and capabilities of the VS 250 in detail. The Hughes & Kettner VS 250 is a twochannel tube power amplifier. As with all tube devices, there are a few things you should pay special attention to: ) Tubes require a specific operating temperature. For this reason a tube device needs a moment after power-up (depending on the operating environment about 20 seconds or SO) until it is completely ready for operation. [. . . ] The intensity of the PRESENCE control depends to a great degree on the guitar sound itself: a heavily overdriven sound with a great deal of overtone energy will respond to the PRESENCE control much more dramatically than will a clean sound with little overtone content. Over the last 30 years of tube amp tradition, two different types of PRESENCE control have established themselves as standard: ) the " British" type, which only affects higher frequencies, and only boosts, and ) the "American" type, which affects a broader range of frequencies from high mids to harmonic overtones, and can either boost or cut. Since both PRESENCE philosophies make sense, and both allow for very different characters, particularly with overdriven sounds, the VS 250 offers both types. The signal is unaffected when the control is in the in the fully counterclockwise position, the sound is 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. When the unit is powered up, the red LED above this switch will be on. It is good practice to switch each channel of the VS 250 to STANDBY both before powering up and before switching off. BACK Power Cord Jack This jack accepts the 110/120-volt power cord supplied with your unit. If you are on tour in Europe, this jack will accept a 220/240-volt power cord. (See "Main Fuse" and "Voltage Selector" below. ) Main Fuse For overseas use, change the fuse to match local voltage: 220/240 Volts -AT 2 1/2 Amp 110/120 Volts - Slo-Blo5amp Voltage Selector USA - 110/120 volts European continent and Great Britain - 220/240 volts Anode Fuse Operating voltage of the tubes, fused separately for each channel. . 1 Fuse rating: Slo-Blo 03 5 Amp or Slo-Blo 1/2 Amp 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. 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. This adds richness to the character of the sound, but also makes it rougher, with an "edge", lending itself spectacularly to rock-oriented music. Each of the two channels of the VS 250 can be switched separately from PENTODE to TRIODE mode. [. . . ] The LINE OUTS of a guitar preamp (or effect unit) are to be connected here, one to each channel. You could, for example, connect a cable from the second, parallel input jack of one channel to another power amp; or from Channel A of the VS 250 to its own Channel B, thereby using the VS 250 as a 2x50-watt mono power amp. 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. [. . . ]