Schematic Rise

Saturday, November 8, 2014

Guitar Effect Pedal Power

A small box is fitted to the rear of the amplifier providing a 9V output for the effect pedal. The amplifier section gets 9V through a pedal switch. This power output and guitar signal input lines are combined into a single unit with multi-way cable connecting points as shown in the following figure.

Guitar Effect Pedal Power diagram :

Guitar Effect Pedal Power Circuit Diagram

The circuit can be divided into two sections: power supply and signal handling. The power supply section is built around transformer X1, regulators 7805 and 7905, bridge rectifier comprising diodes D1 through D4, and a few discrete components. The signal-handling circuit is built around two OP27 op-amps (IC3 and IC4). The power supply of about 9V for the effect pedals is derived from step-down transformer X1. MOV1 is a metal-oxide varistor that absorbs any large spike in mains power. IC 7905 (IC1) is a -5V low-power regulator. By using a 3.9V zener diode (ZD1) at its ground terminal, you get -8.9V output. The same technique is also applied to IC 7805 (IC2)-a +5V regulator to get 8.9V. Use good-quality components and heat-sinks for the regulators. This supply is more than enough for the five effect pedals.

The greater the voltage drop across the regulator, the lower the output current potential. Resistors R1 and R2 provide a constant load to ensure that the regulators keep regulating. Capacitors C3 through C8 ensure that the supplies are as clean as possible. It is very important to use proper heat-sinks for IC1 and IC2. Otherwise, these could heat up.

Working of the circuit is simple. The input signal stage uses a basic differentiation amplifier to accept the incoming signal and a voltage follower to buffer the output to the power amplifier. The differential amplifier is built around IC3. It works by effectively looking at the signals presented to its inputs. If the input signals are of different amplitudes, IC3 amplifies the difference by a factor determined by R4/R3 (where R4=R6 and R3=R5). If the input signals have same amplitudes, these are attenuated by the common-mode rejection ratio (CMRR) of the circuit. The value of CMRR is determined by the choice of the op-amp the auxiliary components used and circuit topology. You can use standard resistors.

With the values shown, you get an overall gain of unity.

The combination of resistor R7 and C13 serves as a passive low-pass filter, progressively attenuating unwanted high-frequency signals. The second op-amp (IC4) forms a simple voltage follower (its output follows its input), providing a low output impedance to drive into the standard power amplifier. Assemble the circuit on a general-purpose PCB and fit it to the rear of an amplifier. The unit must be compact, yet robust. So use a very sturdy aluminium extrusion for the cabinet in order to neatly house the assembled PCB.

To ensure simple operation, there are only three connections to the unit. First, mains power is tapped from the transformer. The second lead carries the 9V output to the amplifier. The third is the guitar signal input at the five-way socket for connection to the effect pedal.

Guitar Circuit with built in speaker

The idea to make a guitar with a built-in speaker came when I stumbled upon a fact that if I miss a pulse through the speaker, it will be heard far away.

Recall manual siren. Human hand, twisting it develops 0.1 horsepower, this is where it is 100 watts (RMS), and heard it on the entire city.Flashlight compared with 1500 Watt PMPO 1000W RMS projector brightness turned this flashlight shines brighter and more, even though there was a light bulb 5 watts RMS. Similarly, energy saving light bulbs, written on them two 100 watts and 8 watts. But this retreat. Also on imported musical instrument in writing all power PMPO.

So, if the distortion of the sound spectrum converted to a pulse with a large buildup of small capacitors and alleviate sinus large capacitors, then turn out so when mixed. Promoduliruyutsya under sinusoidal pulses, acquiring the height of its envelope. Pulses will hear anything away, because of their large growth. But due to the fact that they will have different heights under sinus, they will be perceived by the human ear differently, carrying information about the full spectrum of sound.

This transformation into pulses and sine and mixing occurs on a chip amplifier effective D2 (the chip I can not seem to pick up for this part, so did its own microassembly until painted, because it developed). Coefficient PMPO this chip gives the coefficient 300. That is, when consumption of battery power amplifier crown 0.8 watts (RMS) guitar gives out 240 Watts PMPO volume.

Scheme guitar with built-in speaker:

It is known that it is necessary for restaurants 100 watts to 300 watts shift halls (power amplifier goes 1 Watt RMS) for concert 1000 watt (power amplifier here goes 3.3 watts RMS). Coefficient PMPO 300 guitar can do it.

This part of the effective amplifier with limiting diodes D2 purely mine. The first part of the effective amplifier, tone and preamp made by conventional schemes. Power Amplifier taken from Marshall amp already built up a guitar at a frequency of 50 to 13,500 Hz. Did not want to reinvent the wheel.

The third chip preamplifier (preamp), stands for alignment voltage DC tone, if it comes to it a little, as well as for the formation of overdrive. If humps AFC voices raised high, they begin to be limited, there is an increase in their growth, rather than amplitude. Intermediate frequencies are soft, not isolated and then there is no loss spectrum and volume control on the ear remains.

D2 tuned to the frequency 1700 - 2200 Hz and generates downs 100 to 3500-4500 Hz. Input from 2 to 5 millivolts it does not distort.

Frequency obstructions on different chains, plus a capacitor input impedance or resistance, etc. I want to calculate, but a book with formulas passed back to the Institute, it is necessary to take it again. While doing the ear, with observations from other circuits and devices.Infringement at low frequencies not, because it is necessary for the effects of sound from 100 Hz, body volume allows guitars to make them.

The sound of this scheme, because such characteristics can be confused with the sound of bands such as Disi Asay, Metallica, Gaunz Roses, Kiss, Bon Jovi. It all depends on the setting of D2, and can be customized to fit our music. It adjusts for distoshn, drive, metal, electrical, acoustic, mixed. Channels are made entirely only without amplifier and the first part of the amplifier efficiently. In the diagram this channel is highlighted with a blue border.

That makes guitars with a slightly shorter scale length with pegs on the other side, that would have been smaller sizes. I think the small size would blend well with a large capacity.

Saturday, November 8, 2014

Guitar Effect Pedal Power

Guitar Effect Pedal Power Circuit Diagram

Tuesday, September 16, 2014

Guitar Circuit with built in speaker