Hiraga The Monster...

[fdegrove]

Hi,

maybe a blunt remark: I don't know if Hiraga still lives ? Maybe he can clarify some of the mystique around his designs himself ?!?!

He does and is now editor in chief of the French audio magazine "La Nouvelle" revue du son.

I very much doubt he will either have the time or inclination to explain the design choices.
All the techniques that were incorporated are very well documented in the isssues of the now defunct "L'Audiophile" magazine.

The development of the " Le Monstre" amp were a team effort not just Jean Hiraga on his own.

Cheers,

[rmgvs]

I built both the Hiraga class-A and the Monstre, several of each of them, and experimented a lot with using the offical parts from Paris and using common stuff. Besides that I heard some hand-built and factory built copies of them (not the Monstre, was not for sale in shops ever).

I wrote an article about them somewhere around 1998 in a dutch audio-journal.

My conclusions at that time:

- both are very fine and exceptional amplifers
- The Hiraga is less critical and sound slightly warmer than the Monstre
- The Hiraga class A can be built using quite normal parts and a cheaper power supply and still sounds very good (of course you can hear differences with the original parts though)
- The Monstre is a different story, I heart it very good sounding but also quite bad, the differences could be heart within one specific amplifier over time also
- Differences in sound did not alway correlate with price of the parts used, I also used car batteries and found the differences not that big. My advice is: just try different transistors and capacitiors (within reason of course, but you can try 3055 and 2955, it will work allright) and listen for yourself. We all know that Hiraga is a very special designer who knew what he did very well but who also had a great feeling for mystification, be your own judge, it is probable that you can better the original
- And no: both Hiraga's do not surpass or equal a very good tube amplifier on subjective grounds, sorry, they can come close to say a standard push-pull el84 amplifier (with the exception of the painstaking clarity and see-through of the Monstre, on some occasions).

rmgvs

[Fred Dieckmann]

Just out of curiosity I did a Spice model for the Monstre. The design is super critical of parts selection and even bias groups and Hfe selection for correct operation. THE DESIGN HAS VERY POOR PHASE MARGIN. Without the ability to make some very good high frequency measurements and without careful selection of parts (including measuring the Hfe), the chances of build an amplifier instead of a power oscillator are slim to none. The thing looks to be very sensitive to load impedance including speaker cable capacitance.

I would attribute getting the design to work more as evidence of dumb luck than skillful design. Turning the publishing the design for others to try to build could be described as irresponsible. Designs that twitchy on parts selection and excruciating demands on layout and speaker loads hardly strikes me as the work of "a very special designer" but more the work of a very special sadist.
When comparing this "design" to the forgiving and stable design projects by Nelson Pass, the title of very special designer goes to Mr. Pass. Nelson also does not practice mystification but provides theory, measurements, and practical advice. It makes me appreciate his efforts even more when contrasted with Mr. Hiraga's designs.

'The development of the " Le Monstre" amp were a team effort not just Jean Hiraga on his own'

Yes, and as Mark Twain said, "a camel is a horse designed by a commitee."

[grataku]

Originally posted by Fred Dieckmann
Just out of curiosity I did a Spice model for the Monstre. The design is super critical of parts selection and even bias groups and Hfe selection for correct operation. THE DESIGN HAS VERY POOR PHASE MARGIN. Without the ability to make some very good high frequency measurements and without careful selection of parts (including measuring the Hfe), the chances of build an amplifier instead of a power oscillator are slim to none. The thing looks to be very sensitive to load impedance including speaker cable capacitance.

I would attribute getting the design to work more as evidence of dumb luck than skillful design. Turning the publishing the design for others to try to build could be described as irresponsible. Designs that twitchy on parts selection and excruciating demands on layout and speaker loads hardly strikes me as the work of "a very special designer" but more the work of a very special sadist.
When comparing this "design" to the forgiving and stable design projects by Nelson Pass, the title of very special designer goes to Mr. Pass. Nelson also does not practice mystification but provides theory, measurements, and practical advice. It makes me appreciate his efforts even more when contrasted with Mr. Hiraga's designs.

Salut to that! The circuit was a real biatch to get to work, I always had the feeling that it was hacked through somohow, masking the complete lack of a clue in circuit design with a somehow super human hearing sense. It probably sounded best when it wasn't oscillating.
I am thankful you exist Fred!

[Fred Dieckmann]

Except on the occassions when I **** you off..... Hiraga may be a brillant designer, I just think releasing a design like that to the unsuspecting causes lots of heartache and bitterness.

[fdegrove]

Hi,

Hiraga may be a brillant designer, I just think releasing a design like that to the unsuspecting causes lots of heartache and bitterness.

Obviously you guys never read the articles.
This "Le Monstre" amp was meant as a study, a challenge if you like.
Nobody was encouraged to just build it, in fact by the time it was published, they already ran out of original components.

I certainly would not encourage anyone to build it before doing an in depth study of the design and delving deep into the articles as published in "L'Audiophile".

As for mystification, get real please.
The man is not seeking that at all, he just wants his privacy and wants to do his job.
If anything, he's a journalist with a background in electronics and he sure was ahead of his time realising the importance of passive and active components, be that in tubebased or semi-conductor based designs.

It surely deserves some credit when the work by him and his co-workers is still discussed more than twenty years after publication.

Sorry for the rant,

[jcarr]

Fred: I know one audio designer who deliberately designs his amplifiers to have some overshoot and ringing, because he prefers the sound this way. This person is a former Tektronix engineer, and he definitely knows how to stabilize an amplifier so that overshoot is well-damped and it settles quickly. Nonetheless, he adjusts his amplifiers so that on square waves there is clear overshoot and a couple of cycles of ringing. Claims that this adds more air and a greater sense of detail.

Makes life interesting when you try to work with someone like this...

regards, jonathan carr

[grataku]

I knew a reprisal from the franco-nipponic alliance was going to happen.
What do you expect to happen when one publishes an article on a premiere magazine with claim of outstanding sound, esoteric components and a sprikles the whole thing with a general aura of mysticism?


PS Fred you know that it's just one of those 'love to hate' kind of arrangements.

[Nelson Pass]

No designer or artist is perfect. We should admire the unique contribution that is made and take that away with us, leaving the rest.

[Tube_Dude]

I know one audio designer who deliberately designs his amplifiers to have some overshoot and ringing, because he prefers the sound this way

Me too!!!
This overshoot and ringing is because the square wave signal generator as a rise time must faster that any audio signal...so limiting the bandwith for good square wave reponse...can slow the amp only for the sake of good square waves photos...

One more case where measures and sound quality are not in step!!