Preamp PCB with TL072

Welcome back to Free Circuit dot com ,Today,We take the preamplifier circuit with TL072,You can connect with Guitar,DVD player or Iphone.

The preamplifier circuit is shown in the figure has some interesting characteristics that separate “normal” on the assumption that there is such a thing. The circuit was built by an amplifier TL072. This design is simple and offers an excellent range of tones. The structure is designed to obtain a large amount of profit, which is ideal for guitarists who want to fully distorted “fat” to get his job. It is the figure of the circuit.

The preamp uses a dual op amp that any amplification. The single transistor is an emitter follower, and maintains low output impedance after the master volume control. As shown in the figure, with a classical guitar input, it is possible to obtain very large overdrive sound by winding up the volume, then the captain of an appropriate level.

Preamp Assembly layout

The frequency response is deliberately limited to the lower end plate to avoid extreme highs and cut to help reduce noise and the response to the normal requirements for the guitar to a minimum. If you TL072 OP AMP, as shown, you will find that the noise is a problem, especially at high gain with lots of treble boost. I recommend that you use an OPA2134 audio file at a premium, you will find what is perhaps the quietest guitar amp you’ve ever heard. In any gain setting, there is more noise guitar pickup is the prototype circuit noise and carbon resistors preamplifier.

The amplifier is very easy to get on the board, and an innovative tone defeat. Rather than disabling the sound system completely, they are massively de-sensitized, and defeated the  have a maximum range, . This can be increased if desired, so that you can have two settings of tone, a rising standard of 10 dB and a cut and the other with a very subtle 3dB boost and cut – that’s enough (surprisingly) a very minor adjustments to the way you need for day-to-day hearing.

Otherwise, the design is fairly conventional, with a great advantage over other models that require almost no cable. Transfer of the source is as you want – I suggest you bring a rotary switch on the rear of the enclosure, and a shaft extension with the tree in front. This leads to a minimum of wiring and reduces crosstalk from other active inputs.

Picture 1 - A and tone controls

Circuit Description

The input stage is shown with a gain of 2 times (6dB), configure and also acts as a buffer circuit for tone control. The tone control is a fundamental type Baxandall, but the addition of R117, 118 and 119 provide the flexibility and ease of reconfiguration, which is not the traditional arrangement.

Picture 2 - Balance, volume and output stages

R119 is the hard part of this circuit (which is unique, too

- I have not seen before, this technique is used). As it is 100k, which limits the range of tone control to a reasonable + /-10dB. To increase more and cutting, R119 (R219 and receive) can be omitted altogether. Conversely, reducing the value of a small area, will also, with about 6 dB at 20 Hz and 20 kHz to 7.5dB with 22K.

The sound system (and overall) performance is shown in Picture 2 (in increments of 10% of pot), and it appears that the midrange is hardly affected. This is in contrast with the majority of drawings in which the controls are aligned to 1 kHz, and it is a very audible in the media. For those who want absolutely no use of tone controls, I suggest that the  both without tone controls are designed and in line with true minimalist design.