Bass Bosster For Electric Guitar

Electric guitar has been a very popular instrument with modern teenagers. Its usefulness and variety of sound is greatly enhanced with use of electronic effect units. The simplest and most economical in the list of such devices are the various units that alter the tonal quality of sound emanated from the guitar. The bass booster described here, when used in conjunction with a good quality medium impedance pick up and medium priced guitar would produce the bassy sound often found on huge bass guitars. The circuit diagram given in Figure 6 shows that it is a straight forward direct coupled amplifier with feedback applied from collector to 

Bass Bosster For Electric Guitar

circuit diagram

base of each transistor.This feedback  applied through capacitors C4 and C5 is frequency selective by nature. The impedance of the capacitors decreases with increasing frequency which means less amplifier gain. As a result higher frequencies are attenuated more in this amplifier as. Compared to low frequencies. The value of capacitors C4 and C5 can be any thing between. 001 Mfd to .05 Mfd but both of these should be of the same value . using a larger capacitor for these would give more of bass boost. If desired, different capacitors may be switched in for varying degrees of bass boost. Resistor R1 is a simple level control.

Guitar Practice Accompaniment Drummer

A close look at this circuit would show its apparent similarity with the last project. In fact it is a mixture of the project number four and three. It should be a welcome relief to all those amateur guitarists who have so far been at the mercy of their  drummer for their practice. This low cost device does many tricks that its expensive big brother automatic drummer does. It produces a bass drum sound on any every beat and can provide a woodblock sound on any of the two different beats in a bar. These beats may be adjusted to be simultaneous or separated depending upon the positions of potentio-meters R1,R5 and R8. the circuit diagram is given in figure 5. Here transistor Q1 provides the basic timing pulses which are coupled through R20 and C7 to the base of a two transistor Twin-T oscillator whose feedback components are so chosen as to give the sound of a bass drum, when shocked into oscillations. The pulse on R1 is also utilized as in last project to deposit charges on capacitors C2 and C3 through isolating diodes D1 and D3. When available, capacitors C2 and C3 should be of the low leakage tantalum type. The amplitudes of charges across C2 and C3 increase with every successive pulse from the clock generator. At some point during the voltage build up Q2 and Q3 fire, either simultaneously or independently and rapidly discharges C2 and C3 respectively.the 

Guitar Practice Accompaniment Drummer

circuit diagram

resulting pulses that appear across R7 and R10 are then coupled to the base  of the woodblock oscillator through isolating diodes D2 and D4. potentiometers R5 and R8 can be varied independently so that frequency dividers Q2 and Q3 fire at different rates to produce a wide variety of syncopated rhythms. The two Twin-T oscillators are almost identical in operation consisting of one common emitter and one emitter follower circuits. Presets R19 and R29 are so adjusted that with no pulse applied to these transistors there is no continuous oscillation. A slight shock like that given from a pulse should be sufficient to cause its oscillation which should then decay naturally. By varying the value of components in Twin-T oscillators shown below each transistor pair other instruments may be imitated. The balance potentiometer adjusts the balance between the sounds of the bass drum and the woodblock. The output should be fed into the auxiliary amplifier.

Accented Beat Metronome

The simple metronomes described so far only provide a variable rate beat and as such are useful for only simple musical lessons. Most of the music is composed on so many beats per bar scale. Audibly one out of a number of beats, selected by the operator sounds louder than the others to put emphasis on that particular beat. The complete diagram that uses five transistors and two diodes is given in Figure 4. Unijunction  transistor UJT Q1 is wired as a conventional RC Relaxation Oscillator whose basic repetition rate is determined by the components R1,R2 and C1. every time C1 discharges through the base emitter junction of Q1, a positive going pulse is produced by R4 in the base B1 of Q1.these basic beats are coupled through C4 to the direct coupled amplifier consisting of Q3,Q4 and Q5. In addition to providing basic pulses the 

Accented Beat Metronome

circuit diagram

positive going section of the pulse available at the base B1 of Q1, also charges capacitor C3 through diode D1. diode D2 shorts any negative going portion of the pulse. Capacitor C3 therefore accumulates a charge over a number of cycles and eventually reaches the firing voltage of Q2, whereupon a reinforcing pulse is produced, the charge required to fire Q2 depends on the voltage at which the bias across the junction goes forward which is controlled by reducing the potential on B2, so that the junvtion potential must also drop. R5 was chosen so that in the prototype at maximum resistance it lowered the junction potential so far that the unit triggered on every input pulse while at minimum. The preset R6 limited accentuation to no higher then one in six. This range would encompass any musical scale in use today. These accentuation pulses are fed to the base of first audio amplifier transistor Q3 where it is mixed with the main pulses coming through C4.