Hiraga "le monstre"

[ericfe1975]

the fact I designed fet devices to pick up radio frequencies at 15 years old could mean that basic knowledge is acquired, no to mention my industrial engineering degree (but that is another kind of relation to FET as we use it to control power devices .

[ericfe1975]

thanks a lot for the schematic! in fact i had in mind to replace the fets by a bc5xx in darlington.

[ericfe1975]

the bf245 is a FET the idea was a monstre with no FET at all ...

[juma]

Originally posted by ericfe1975
thanks a lot for the schematic! in fact i had in mind to replace the fets by a bc5xx in darlington.

Why would you need a darlington here?

Originally posted by ericfe1975
the bf245 is a FET the idea was a monstre with no FET at all ...

BF245C acts here as a constant current source (CCS) - you can use any 6mA CCS or just use 1K8-2K2 resistor instead of CCS

[Lumba Ogir]

ericfe1975,
what`s your problem with JFETs? You should stick to the original design, taking your confusing ideas into consideration, it`s most unlikely that you can improve it.

[darian]

Hello,

Actually, if you want to make a Le monstre without fets, it's basically becoming a Hiraga 20w, all bipolar :
http://www.tcaas.btinternet.co.uk/hiraga2.htm

and here on diyaudio:
Hiraga 20W class A

But the sound is believed to be different, more precise but less transparent from Hiraga himself opinion.

But once again, nothing wrong with fets and you get a nice quadratic curve from them, not a nasty exponential!

Regards

[ericfe1975]

lumba please explain which idea confuses you , i am sure we can help you.
Yes i have noticed that a monster without jfet is like a "la classe classe A hiraga " .

Well as Mr pass said, after all those years of progress for sure the monster can take some benefits.
the point is not "improving" the monster, here the point is trying a le monstre without jfet and hear it.

I do not belive that someone serious may have the arrogance to say " you know what? i am going to improve one of the best design in a class audio simply removing the fets"

and certainly this is not my case. I am not saying either that jfet sound bad. not at all!!! every jfeted amp i've heard sound very clear and warm.

thx for the schematic, i just got a good one in my own work, fully implemented thanks to the clarty of my ideas ( lumba )

see you later.

[danieljw]

Originally posted by darian
Hello,

Actually, if you want to make a Le monstre without fets, it's basically becoming a Hiraga 20w, all bipolar :
http://www.tcaas.btinternet.co.uk/hiraga2.htm

and here on diyaudio:
Hiraga 20W class A

But the sound is believed to be different, more precise but less transparent from Hiraga himself opinion.

But once again, nothing wrong with fets and you get a nice quadratic curve from them, not a nasty exponential!

Regards

Having built and listened to both amplifiers i would agree with this comment. both amplfiers are excellent.

-Dan

[neazoi]

Dear all,
I am thinking of powering this 8W amplifier using batteries only, and recharge them after use. I need to ask a few things in order to avoid spending extra money on this.

1. What is the current consumption of the amplifier? (each channel)

2. Can I connect two identical batteries in series in order to take +12V, GND, -12V ? (just to make sure)

3. I have two 80AH 12V deep cycle lead acid batteries. About how much the operation time will be?

4. Can I use just two batteries for both channels? (the same psu for both channels)

5. Finally, can I leave the batteries stand alone to power the amplifier or do I need to connect capacitors parallel to them? And what could be the effect in sound when using no capacitors at all? (not so fast responce, etc)


I yould appreciate a helpful answer in these five points which will save me extra cost.

Best regards

[JohanH]

some of your questions answered

http://forum.zelfbouwaudio.nl/download.php?id=16633

and ad 1) and 3) (if I'm not mistaken) 1A and therefore 80 hours.
I suspect the last hours won't be as good