Hiraga "Le Monstre"

Hi
I set up the printer to 29% when I print out. I still have the XP paint, I save it there and printer set up so on.
You can set up your printer other way to.
The size 68x72 mm from the corner L to other corner L.
The layout is flexible, you can adjust the legs all the components a bit.
Actually I do like to use most of my class A amp a bit oversized PC boards.
Greetings gabor
 
Hi
Terry it uses vertical mosfet.

I do have something similar with lateral mosfet, it was moded from the Hiraga. The guy who built it (actually he built several of them to his friend, himself etc.)
So I designed the layout and I built it but I was unable to get read of the offset. Probably I made some mistake with the layout:confused:
So I gave up the Hitachi latfet version. That one here you can find.
Megalith - Cooltune DIY Audio

The vertical is nice and to me better than the BJT at least less sensitive to the PS. Has more tubby sound.
Of course it need a good PS like every Class A amp :) It just not as picky like the BJT version.
Here is the schematic and the layout
Hi Gabor,

Do you have a component view? I'm having a tough time figuring out where everything attaches.

Thanks, Terry
 
Maybe someone would like to take a stab at it. I am attaching the schematic and foil pattern. This amp seems to be fraught with schematics matched up with schematics that won't work together. I haven't been able to figure this one out, but I can see that the 2SC2240/A970 have the wrong pinout for this layout.

Thanks, Terry
 

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Here are a few things I see right off the bat,
R9 and R10 are supposed both connect to the NFB but on your layout they go to ground.
R12 should connect to the collectors of Q1 and Q2. On your layout they connect to gates of M1 and M2.

Since you are already running resistors under the board I suppose I could fix these things by making the needed changes. I was just confused because I was under the impression the layout was designed to work with the schematic but it takes modifications to make it work. Now that I know that I can do it but first I need to know if the way you did it is the correct way or the is the schematic correct.

Thanks, Terry
 
Hi
Terry I do have several layout for these amplifier and to be honest I did lost couple of my layout for other amps to.
I used to store them in a old PC and when I got virus I lost most of my layout.
These and one more was saved on a memory stick, when you ask me for the silk I realised probably I gave the one with mistakes.
The amplifier was built but I no longer own it all do I plan it I will rebuild it. To me sounded better than the BJT version.
I will post another layout, I have to let you know different variation because I found in my box some 2SA872 - 2SC1775 transistors . I prefer those over the Toshiba.
At R9 and R10 I followed the original BJT version that is why those connected to the GR.
These difference occurred when Andrew T wrote way back that connection to the feedback is wrong. So I made that change on the layout and forget it.
The BJT version goes to the Ground, these goes to the ground by R11 which is 10 Ohms. I think both work .
R12 how I connected that was a mistake.
The way you had now it looks correct.
I will post the other layout to see I still have two of them accept those I lost.
Please forgive mi about that mistake.
I supposed to check before I gave it to you.
These lay out uses different Q3 & Q4 transistors. Also need to be checked because I'm not sure these was the good one.
Only I post these so you see, right now I don't have time to check it.
Greetings gabor
 

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Terry I didn't posted the second layout to motivate you to etch a new board.
Only I posted poste it because I mentioned I had several layout for these amp to prove it to you.
Also I lost few of them with several other amplifiers layout.
I used to store all my layout on my PC but after I lost it because I got virus now I started to use memory stick or burn them on a CD.
When I wrote about the original circuit that mean the BJT version, I do not have any other mosfet version.
These was built how the circuit it is and worked fine.
When you asked me for the layout that what I found at first and I posted thinking that is the good one.
After you asked for the silk, I was looking for it and I didn't found non so I made it to you and that time I realized I gave the wrong layout.
You know when you asked me I didn't wanted to say please wait a couple days.
Sorry about that! Please forgive me. After more research I found the second one which is correct only the small transistors was replaced with 2SA872 & 2SC1775.
The way you corrected that should work!
Greetings gabor
 
Maybe someone would like to take a stab at it. I am attaching the schematic and foil pattern. This amp seems to be fraught with schematics matched up with schematics that won't work together. I haven't been able to figure this one out, but I can see that the 2SC2240/A970 have the wrong pinout for this layout.

Thanks, Terry

I like very much the connection of R9 and R10 to the feedback/source connections. Now the VDS is constant.

Personally I would stick to the driver config of the output like in Hiraga's LeClasseA: not a 510 ohms between the two collectors/gates but both collectors go to the opposite rail with their own resistor. But I have no means to test it on paper.
 
Help with bias value please.

Hi,

Just built and tried 1 channel of Jim's Audio Hiraga, PCB : le Monstre.

I'm using a temporary power supply but will be using a cap multiplier for the final project.

I'm using +/- 14Vdc to aim for 10W/ch.

My question is : What should be my output bias in order to get about 8-10W into 8 and 4 ohm load ? I read in many places that the original bias was 0.5-0.6A. To lower THD I decided to increase the bias a bit.

My bias is now at 1.25A (1.25V across R11 :1ohm) and I can still go a little higher since my heatsink is a good size. (0.56C/W). Heatsink temp is at about 43C

Thanks for your help.
Eric
 

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No need to go higher, that is all the way biased into Class A. If you want to burn more power to pay more to Hydro you can do it, but not much gain sound wise.
After certain bias level you gain more on the sound quality if you play with your PS , component, capacitor quality , wires etc.
Just try out things you have in your box.

Funny not to many people test capacitors which made for cars. here is possible because the low voltage.
I do believe many people here drive and has car sound system
I do have a pair 1F Panasonic caps 30V but never tested yet.
Be aware with regulated or capacitor multiplier PS it tend to sound thin and sometimes kill the dynamic and the bass.
I used Elliot cap multiplier PS with 50 000uF Mepco each side, it was not bad but still I sold it on the end.
Very important in that PS the transistor quality. I know Elliot wrote use any cheap transistors, guess what a good Toshiba transistors made a huge sound:faint: improvement.
Greetings