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WAMP - 1 W guitar amplifier

A simple two stage mosfet class a guitar amplifier

2015/07/02-11:51:46

Sounds much better than any chip amp, overdrives nicely with a booster in front of it. Sounds clean with good compression, high output impedance, can drive 8/16Ohms cabs (even 4Ohm).

Some oscilloscope pics:

Have fun!

Etiquetas/Tags: class a, mosfet, guitar, amplifier, diy

2015/06/30-22:59:04

Etiquetas/Tags:

Simple guitar 5 band EQ using the BA3812L chip

Simple-EQ

2015/06/25-22:28:31

I'm planning on building a simple 5 band EQ using the BA3812L chip but changing the frequencies to more suitable values. The frequencies that I'll be using are the ones from Mesa Boogie DC-5 amp. Here is the schematic:

And here is a copy of the Mesa Boogie DC-5 owner's manual about a similar EQ.

The capacitor values were obtained using a simple GNU/Octave script:

#1;
# Calculations for a simple EQ: BA3812L 
# All resistors in Ohm and capacitors in F

R0=1.2e3;
R1=68e3;
Q=.7;

f=[80 240 750 2200 6600];

C0=1./(2*pi*R0*Q*f);
C=Q./(2*pi*R1*f);

Q=1;
C0=1./(2*pi*R0*Q*f);
C=Q./(2*pi*R1*f);

disp("Q=1")
disp("        Freq      C0 (uF)    C (uF)")
disp([f' floor(C0'*10^12)/10^6 floor(C'*10^12)/10^6])

One can relate the octave bandwidth N to quality factor Q by the expression latex2png equation or inversely latex2png equation This is important because one would like to be able to control the complete frequency range of the guitar signal.

For the EQ frequencies 80, 240, 750, 2200 and 6600, roughly a factor of 3 for consecutive frequencies, and a Q factor of order 1 one gets a 1.5 band width in octaves, so because of the ratio of the EQ frequencies one can, with this Q=1, control the full interval of frequencies between 40Hz to 10kHz.

I think I'm getting it right?!

Here are the capacitors values fitted to the standard values freq real_freq real_Q C*1 C*2

f    f    Q   C*2    C*1
80   83   1.1 1.5u   .030u 
240  257  1.1 .47u   .01u
750  830  1.1 .15u   3n
2200 2137 .9  .068u  1n
6600 6260 1   .022u  .36n

Etiquetas/Tags: EQ, guitar, BA3812L

1W class A mosfet power amp

... for guitar

2015/06/17-22:02:29

Etiquetas/Tags: guitar, mosfet, power amplifier, amp, class A, 1w

Voltímetro para electricistas amadores

do Tratado de iniciação à T.S.F.

2015/06/02-16:02:53

Etiquetas/Tags: electricidade, DIY

Teaser for my new guitar amplifier

1/4W to 3W class a mosfet amplifier

2015/05/13-21:51:24

Here is my new class A mosfet amplifier 1/4W to 3W guitar amp.

More pics and sound samples later.

Etiquetas/Tags: DIY, guitar, amplifier

Awesome! This page is mobile-friendly.

How Googlebot sees this page.

2015/04/21-08:41:45

How Googlebot sees this page.

Etiquetas/Tags: Google, mobile, diale.org

1x8

Guitar speaker cab

2015/04/04-10:02:21

Etiquetas/Tags: guitar, cab, DIY

Poia

Porções de dicionário, ou outras?

2015/03/05-17:17:31

O dicionário que uso no Emacs não conhecia a palavra poia. Estranho.

Era esta a intenção que procurava: porção de dejectos.

Etiquetas/Tags: poia, dicionário

Recordar é ...

viver

2015/03/05-17:10:10

Escreve hoje e por um dia um novo director do jornal Público. É tempo de recordar o desabafo pífio de MEC sobre o interessantíssimo livro de J. Magueijo. Passado este tempo continua exacta a frase:

"É porque o gajo não lê. Só pode ser isso." — MEC

Certamente que há

"...tanta gente muito mais habilitada do que eu para cagar postas de pescada." — JM

Sim há mas só para arrotar, para cagar estás cá tu e olha que é uma bela poia.

Etiquetas/Tags: público, 25 anos, magueijo

Palavras chave/keywords: página pessoal, blog

Criado/Created: NaN

Última actualização/Last updated: 02-07-2015 [11:51]


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