A-class Preamp PSU

[44250]

A-class PSU,used in Clepsidra preamplifier:

 

[coolet]

hi apex,

any replacement for bc560c for "A Class PSU"

regards,
coolet

 

[apexaudio]

hi apex,

any replacement for bc560c for "A Class PSU"

regards,
coolet

You can use BC557, BC556...
Regards

 

[mihailo]

My Apex 2x15V 1A PSU for preamp. Change 1k resistor on PSU, with 4K7 trim. pot. and you can set voltage like in Apex PSU A class. I get +/-14.70V with ZD15V.

 

[mihailo]

Apex stereo preamp.

 

[apexaudio]

Shunt +/-18V

Simple Shunt PSU for Preamps

 

[apexaudio]

The shunt regulator has a practical advantage over the serial where the short circuit protection on the output needed to provide additional circuit here she gets gratis from the working principle of the regulator.

 

[csom]

PSU for preamps with Serial Regulator.

PCB for +/-15V PSU

Dear Apex,

1. As I see, the two 10R resistors after 4700uFd at post #22 has been labelled as 22R 1 Watt in the PCB Layout design at post #23.

Which one should I use?


2. Are all other resistors quarter watt in the circuit?

 

[AndrewT]

Csom the 22r or 10r have only 650mV across them.
Pd ~ 0.65^2 / 10r = 42mW, 22r is Pd=19mW

That's ~ 7% of the rating of a standard 600mW resistor.
You could 400mW or 500mW here.
If you have ¼W as your standard stock, then use them.

 

[csom]

Csom the 22r or 10r have only 650mV across them.
Pd ~ 0.65^2 / 10r = 42mW, 22r is Pd=19mW

That's ~ 7% of the rating of a standard 600mW resistor.
You could 400mW or 500mW here.
If you have ¼W as your standard stock, then use them.

Thank you sir for your kind reply. I will follow your words.

Pardon my ignorance but could you kindly tell me what are the advantages of this circuit over that using 7815 and 7915 in a preamp section made with opamp like TLO72 or TLO74?

 

[AndrewT]

..........I will follow your words. ..........

???
Would you be better to learn the tiny bit of arithmetic so that you too can select without the need to follow my words?

 

[csom]

???
Would you be better to learn the tiny bit of arithmetic so that you too can select without the need to follow my words?

Awwww Sire,
You are really ruthless!
Why torture a half-educated man leading him to the uncharted territory of mathamagic where the wizards reside?
And it's safer to "follow" the path of respected audio gurus like you and Mr. Mile and others.
hehe.


And my second question is still unanswered.

 

[AndrewT]

The answer to the second would be better from the designer of the amplifier and the designer of the regulator.

 

[csom]

Okay sir, thank you.

Awaiting the designer's answer now..........
Hope he notices this noob ( myself ) and bequeath his wisdom.

 

[csom]

PCB Ready!

Okay! PCB made, drilled.
I also applied a coating of resin dissolved in thinner to protect it from weather corrosion.

I bought TIP41C and TIP42c today.
But BF245A and BC560C are not available in my locality. Neither 2SK246.

 

[csom]

I ordered a local shop keeper to bring me the required parts. Today he reported that BF245A and BC560C are NOT available, neither 2SK246.

Could you kindly recommend any other alternatives?
Thank you.

 

[udailey]

I don't know the replacements but there are the same questions answered on this site. Search the site via Google.
Can you solder through the resin?

 

[mihailo]

I ordered a local shop keeper to bring me the required parts. Today he reported that BF245A and BC560C are NOT available, neither 2SK246.

Could you kindly recommend any other alternatives?
Thank you.

BC560 can be replaced with: BC557, BC556, BC 214, BC 416, 2SA1136..1137....
And BF245 with: BF244, 2N3819, 2N3823...

 

[AndrewT]

Why does any builder choose a project for which he/she cannot buy the correct components?

 

[csom]

BC560 can be replaced with: BC557, BC556, BC 214, BC 416, 2SA1136..1137....
And BF245 with: BF244, 2N3819, 2N3823...

Thank you so much sir.
I will try these alternatives.
Thank you for your patience with me. Much appreciated.