Studio Reference Amplifier

[apexaudio]

Regulated PSU is for single channel, two for stereo (dual mono). Stabil rail voltage is important for Reference Amplifier, it's simple PSU can be use for any DIY amplifier, and you can adjust different rail voltage for testing different amps.

 

[apexaudio]

Regulated PSU Pcb

Pcb size: 135x87mm

 

[apexaudio]

This is Speaker Terminal with Zobel Network and triac DC protect, I recomand only this protect for Studio and Labs Reference Amplifiers.

 

[macd]

RE PCB Please........

Hello Apex,

Any progress on the PCB? I want to build this amp. What about "switch on delay"? Is this not needed for this amp?

Regards
Macd😀😀😀

 

[apexaudio]

Hello Apex,

Any progress on the PCB? I want to build this amp. What about "switch on delay"? Is this not needed for this amp?

Regards
Macd😀😀😀

I will share final pcb design for SR50 and SR200 after test. What version you want to build SR50 or SR200? Amp have no any click from speaker whan power switch on, and I don't want any relay contacts on signal path for Reference Amplifier. DC protect with triac and 'switch on delay' with mute input is the best solution.
Regards

 

[macd]

RE PCB Please........

I will share final pcb design for SR50 and SR200 after test. What version you want to build SR50 or SR200? Amp have no any click from speaker whan power switch on, and I don't want any relay contacts on signal path for Reference Amplifier. DC protect with triac and 'switch on delay' with mute input is the best solution.
Regards

Hello Apex,

I am interested in the SR200 version. I will build your power supply PCB and speaker zobal network so long.

Regards,
Macd

 

[apexaudio]

Hello Apex,

I am interested in the SR200 version. I will build your power supply PCB and speaker zobal network so long.

Regards,
Macd

I suggest you to build switch on delay with mute input circuit from post #35 in thread: http://www.diyaudio.com/forums/solid-state/167363-mic-line-eq-preamps-4.html
Regards

 

[apexaudio]

Turn on/off mute with FET. Also can be add thermal protect with muting input over 90deg on heatsink.

 

[apexaudio]

FETs and 100k resistor is best to put on input terminal pcb or together with 'volume' pots, and 'mute' circuit on psu pcb.

 

[apexaudio]

My old amp have 'normal' and 'direct' inputs

 

[apexaudio]

@coolet

I use f100 pcb, and change it for testing prototype of SR50, and you can do that also, you can use your F100mkII pcb desingn as start point for SR50.
Regards

 

[apexaudio]

Regulated PSU with Dual TO220 diodes instead bridge rectifier.

 

[apexaudio]

BC560C instead 1N4148 in current miror for better simetry.

 

[apexaudio]

SR400

PCB in progres...

 

[apexaudio]

Schematic of Speaker Terminal.

 

[Mitchel]

Very nice. I'm reading everything, and I am very interested. I'll be building the regulated PSU for another amp of mine. Congratulations, and thank you!

 

[apexaudio]

Very nice. I'm reading everything, and I am very interested. I'll be building the regulated PSU for another amp of mine. Congratulations, and thank you!

If you get sound improvement with regulated PSU let us know, and post picture of your work.
Regards

 

[Mitchel]

If you get sound improvement with regulated PSU let us know, and post picture of your work.
Regards

I'll certainly post some pictures. What's the power rating for the zener diodes? Can it be 0,5W?

 

[apexaudio]

I'll certainly post some pictures. What's the power rating for the zener diodes? Can it be 0,5W?

ZF12 is 400mW zener diode.

 

[Mitchel]

Thank you. BD241/242 don't need heatsinking?