Fender The Twin Owner Manual - Page 6

blAS atLINT OMPUT Ur OM OC STALE PO DPW WOW. TO Alf MISR .• KT BIM TO API VOLTS SUMO OCT SAL.00E TO • VOLTS ( 1,jeeilk, FOOT SWITCH CD ® 0 LALM= OUT II !Qv e Pelm. 0atm MOSTIPIO 0 0 0 EXT. OUTPUT MAIN EXT. SE9IES z, O SPEAKER PARA •" T2 ® 08 IMPEDANCE SELECTOR 8 16 OHMS J. BALANCED LINE OUT-This jack provides a transformer coupled, balanced, floating ground output, (on pins 2 & 3), which can be used to drive slave power amps, or with proper equalization as a send to a mixing console for recording or sound reinforcement. The optimum setup for driving slave amps from this output is to use speaker systems identical to those connected to the TWIN output and drive them with high power solid-state amplifiers (300 Watts Min.). Set the gain of the slave amps so that they do not clip at full output from the TWIN. The reason for this is as follows: One of the distinguishing characteristics between solid-state amps and tube amps is that most solid-state amps are effectively constant-voltage output for varying load impedance. Tube amps are a mixture of constant-voltage and constant-current and actually approximate constant-power output into a varying load impedance. This is important since speakers present a load impedance that varies with frequency. A tube amp actually puts more power into a speaker at low end resonance and more noticeably at high frequencies than a solid-state amp. This can be compensated for by equalizing the solid-state amp but in order to really duplicate the tube amp, the solid state amp must have much more headroom available: i.e. a 20 Watt tube amplifier driven into heavy clipping can actually put out signal levels equivalent to a 180 Watt solid-state amp. This nine to one ratio can get excessive when comparing to a 100 Watt tube amp and therefore compromises must be made in selecting a solid-state equivalent. The signal at the BALANCED LINE OUTPUT is a replica of the voltage present on the TWIN speakers. This signal can then be run through a solid-state (constant-voltage) amp connected to speakers identical to those on the TWIN and provided that the solid-state amp has enough headroom to never clip, the slave systems will produce an exact replica of the master sound. This can be a cost effective and reliable way to achieve large amounts of on stage power- while maintaining the "Tube Sound". We recommend using a Fender 2235 Power Amplifier with additional Fender "Wedge" speaker enclosures. If the BALANCED LINE OUT is used as a send to a mixing console it should normally be preequalized before going to the console input. What works well is to run it through a low-pass filter set at 5 to 6 kHz. The slope of this filter needs to be steep, i.e. third-order at 18dB per octave. A handy way to do this is to use- the lowpass output of an active crossover, or a parametric equalizer. By tweaking the equalization some very useful sounds can be obtained. K. EXT. SERIES JACK- Plug-in connection for extension speakers. This should be used in conjunction with the MAIN SPEAKER jack. It will connect in series with the main speaker therefore adding the (EXT. SERIES) speaker impedance to the (MAIN SPEAKER) speaker impedance: i.e. by connecting a 4 ohm speaker to each jack the total load is 4+4=8 ohms. The IMPEDANCE SELECTOR switch (N) would then be set to 8 ohms. (NOTE: An additional 8 ohm speaker can be connected to the EXT. PARALLEL jack for a total load of 4 ohms, set the IMP. SEL. switch accordingly.) L. MAIN SPEAKER JACK -Plug-in connection for speakers. For proper operation this jack should always be used first as connection to the primary speaker. (If this jack is used alone set the IMPEDANCE SELECTOR switch (N) to equal the total load impedance connected to it.) M. EXT. PARALLEL JACK -Plug-in connection for extension speakers. This jack should be used in conjunction with the MAIN SPEAKER jack. It will connect in parallel with the main speaker therefore reducing the total load impedance. i.e. by connecting a 16 ohm speaker to each jack the total load is (16x16)/(16+16) = 256/32 = 8 ohms. The IMPEDANCE SELECTOR switch (N) would then be set to 8 ohms. (NOTE: An additional 8 ohm speaker can be connected to the EXT. SERIES jack for a total load of 16 ohms, set the IMP. SEL. switch accordingly.) N. IMPEDANCE SELECTOR -Sets the output impedance of the amplifier. The setting should equal the total load impedance as determined above using the three output jacks. (The Fender Twin is supplied with two 8 ohm speakers connected in series therefore the total load impedance is 16 ohms, set the IMP. SEL. switch accordingly.) (Low Power Option: The Fender TWIN amplifier can be run with only two output tubes instead of four. This is done by removing the two inner 6L6-GC tubes. (the 2nd and 3rd large tubes, counting left to right), and setting the IMPEDANCE SELECTOR switch to one-half of the total speaker load impedance; i.e. with one 8 ohm speaker connected the IMP. SEL. switch should be set to 4 ohms. (Remember -half the tubes, half the impedance.) This will produce 60 Watts R.M.S. in the HI power setting and 15 Watts R.M.S. in the LO power setting.)