Power Amp OCL 100W by Transister MJ15003,MJ15004

This Circuit Power Amp OCL 100W by Transister.It old circuit,but nice circuit amplifier.
Use transister MJ15003 and MJ15004, power supply +38V,-38V 3A.
Output power 100W at Speaker 8OHM.

Read More and View Circuit
Power Amp OCL 100W by Transister MJ15003,MJ15004

Power Amp OCL by 741+2N3055+MJ2955

Circuit Power Amp OCL by 741+2N3055+MJ2955

This is old circuit Power amp OCL, But easy circuit and very nice. To use for play music in your home. It low cost too.
It use IC 741 or LF351(good) and Transistor x 4 (2N3055+MJ2955+BD139+BD140)
and little component.
Power supply volt +35V/-35V and 3A for Mono, 5A for Stereo.



PCB Power Amp OCL by 741+2N3055+MJ2955

Circuit Tone control adjustable bass-treble Stereo by IC LM348

Circuit Tone control adjustable bass-treble Stereo by IC LM348
PCB Tone control adjustable bass-treble Stereo by IC LM348

Loudspeaker Protection with Soft Start

This is a small protection circuit from loudspeakers, from DC voltage that likely to exist after some damage in the power amplifier. If a DC voltage is presented in the exit of amplifier, RL1 it interrupts immediately the line of loudspeakers preventing thus to reach in he. Parallel it provides a delay time of 3 seconds from the moment where the power supply will be applied. This delay protects the loudspeakers from undesirable bangs that are observed when open the supply switch. The Leds D 4-5 provide a optical indication for the circuit operation [D4 (green)=OK and D5(red)= delay or presence DC voltage]. The supply of circuit becomes from a symmetrical ±12Volts, which we can take from small independent power supply or from afterwards suitable demotion of main power supply. It will be supposed you make a circuit of protection for each final amplifier that you dispose. Proportional attention it should you show for the quality of RL1 that the contacts of will be supposed to bear the current that passes from he.

Source :: http://users.otenet.gr/~athsam/Lsp_protection.htm

TDA2030 amp OTL 15W

Circuit TDA2030 amp OTL 15W
PCB TDA2030 amp OTL 15W

Bridge adaptor by NE5534

Read More about Bridge adaptor by NE5534 circuit

HA1377 Bridge Amplifier BCL cap 17W (Car audio)

This is circuit Car audio Amplifier(Bridge Amplifier BCL) , It use IC HA1377, Supply Volt 12V-13V. Speaker 4 OHM. Nice Circuit and Easy to Build.

Circuit HA1377 Bridge Amplifier BCL cap 17W


PCB HA1377 Bridge Amplifier BCL cap 17W