DIY Audio Projects Forum

Personally recomend to stayway from SE as you need output capacitor, this means the speaker takes the signal from transistor then through a capacitors. Thats allot of distortion, it maybe allright if your using hifi output caps though.

You should be able to build the higra with either 4x 10000uF and trasnfomers. Otherwise SMPS
Theres feedback so it shouldn't be too much of issue.

You need to be carefull with gournding to mains with SMPS or you'll humm. Also is recomnded to put directly at output of smps to ground a 2200-4700uF capacitor so the noise is very low.
No long wires to this cap as the noise is dependant on impedance of capacitor and wiering which causes ripple for buck converters.

Thanks for all inputs and thougs on this design.
I myself just started messing with amplifiers and PCBs and would like you input on my version of the Hiraga:

I'm making a SMD version of the circuit and changed some of the transistors. For the power stage I'll be using a MJL3281A / MJL1302A pair for example. The board itself is very small, only 100 X 50mm.

To power it all up I'll be using SMPS for now. Test it with 24v and 36v later.
Just waiting for the parts to arrive.

Design and project attached. Thanks in advance for the input.

Hi, I know it's a tall question, but would it be possible to push this design to 80watt per channel? Thank you

Yes but you will need to change/upgrade the output stage and their driver transistors, bias values, heatsink and power supply transformer and capacitors in the power supply.


-Dan

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My DIY Audio Projects:

• Jean Hiraga Le Monstre - DIY 8W Class A Amplifier
• Jean Hiraga's Super Class-A Amplifier

You will need full redesign of the output stage, also use multiple transitors in parallel.
The heatsinking required would be very high and virtually impossible to cool down.
Or very expensive to cool down.

Then you will need higher operating voltage, hint the output voltage can swing to approximatley the rails, you know the voltage and resistance. So you can estimate the peak power possible into a 4 or 8ohm speaker.
P = (V^2)/R

To give you an idea I have recently built 2 Krell monoblocks based on the ksa100 mk2 circuit. For 100W class A I have 2 x 5unit racks and they run quite warm/hot

_________________
My DIY Audio Projects:

• Jean Hiraga Le Monstre - DIY 8W Class A Amplifier
• Jean Hiraga's Super Class-A Amplifier

I also built a 30W Hiraga amplifier.
The bias is 1.5A, and the DC voltage is, after about 2 hours between 5mV and 15 mV.
The temperature of the radiators does not exceed 70 degrees C
I am satisfied with the sound of this amplifier

Hi Dan,
I used 2.2 microfarad capacitors at 250V at the input to the amplifier. Is this a problem?
Thank you ,
Raton