Hiraga Le Monstre

[Jeff Young]

How little PSRR does it have?

I don't know the exact figures for Le Monstre. I just know that one of the challenges of that topology (which is similar to the F5) is PSRR. (And to the Jim's Audio quote above, speed is not one of its challenges. You usually get off-the-charts slew rates with a CFA topology.)

 

[chartz]

Would quite like to build one of these. Wondering if we could get a group buy together...

Do they really need 2x Cap6 boards? Surely a single 350VA Traffo/ Rectifier and a 6x33000uF/ 2x0.5Ohm Cap6 would be more than up to the job?

TBH at 8W I would think that 4 decent caps with a pair of resistors would do it - Cap4?

The Hiraga amp was called 'monster' because it ran on car batteries and used 8X100,000 μF + 6X68,000 μF caps. He never used anything else back then (final version).


If you really want to get a nice Hiraga amp that works - and was intended to - work on mains, do the 20 W class A.
Le Monstre on mains is nonsense, sorry.

Hiraga 20 W (PCB lay-out):

https://revue-audiophile.pagesperso-orange.fr/FICHIERS/11/20W/20W.html

Final version here:

https://revue-audiophile.pagesperso-orange.fr/FICHIERS/15/CLASSEA/CLASSEA.html

 

[russel]

The Hiraga amp was called 'monster' because it ran on car batteries and used 8X100,000 μF + 6X68,000 μF caps. He never used anything else back then (final version).


If you really want to get a nice Hiraga amp that works - and was intended to - work on mains, do the 20 W class A.
Le Monstre on mains is nonsense, sorry.

Hiraga 20 W (PCB lay-out):

https://revue-audiophile.pagesperso-orange.fr/FICHIERS/11/20W/20W.html

Final version here:

https://revue-audiophile.pagesperso-orange.fr/FICHIERS/15/CLASSEA/CLASSEA.html

a capacitance multiplier psu like Linley hood did for his 10Watt class A design would probably suit Hiragas circuit.

 

[Dan K]

Russel, Do you have a link?

I was thinking of a single Cantabury Traffo, 300VA or so and a CRCRC filter with 6off Mundorf 33,000uF 40V snap in caps on a HackerCap board, 10W 0.5Ohm resistors. Problem is the Mundorfs are £26 each. They do however have an ESR of 6mOhms. Should do the job. Shouldn't it?

 

[martin clark]

The cap multiplier would be a much better return on investment - cheaper by a chunk; and deliver much better noise& ripple attenuation.

Example & description
https://sound-au.com/project15.htm

 

[Dan K]

Ahhhhh

I'm now wondering if I could use this on my Bedidi 25/25. Might be asking a bit much, it may draw too many amps

 

[Dan K]

Am I right in thinking that as this thing is only putting out 8w/ch then in reality it needs an 8x2x5 transformer - ie 80VA?

 

[sq225917]

Class a though innit, its burning 24 watts.

 

[Dan K]

Per Channel ?

That's 240VA then

 

[chiily]

The cap multiplier would be a much better return on investment - cheaper by a chunk; and deliver much better noise& ripple attenuation.

Example & description
https://sound-au.com/project15.htm

Martin,

I assume something like a Krell KSA50 could benefit from a cap multiplier cct? I've bought two pairs of big caps from my build but I have just about all the parts for a cap multiplier...

 

[russel]

Russel, Do you have a link?

I was thinking of a single Cantabury Traffo, 300VA or so and a CRCRC filter with 6off Mundorf 33,000uF 40V snap in caps on a HackerCap board, 10W 0.5Ohm resistors. Problem is the Mundorfs are £26 each. They do however have an ESR of 6mOhms. Should do the job. Shouldn't it?

Here is hoods original circuit https://sound-au.com/tcaas/jlh1969.pdf , Martin has linked to one that gives a negative supply as well which you will need for hiragas circuit. Make sure you get the semiconductors from a reputable supplier, high currents and fake transistors do not sit well together. Pay particular attention to the layout, which is covered in the link from Martin otherwise it will not be effective. The premium on Mundorfs seems excessive, I use surplus nippon chemicon 33,000uf 40V 105degree screw fit caps from a surplus supplier in my class A amplifiers, they were about six dollars each.

 

[russel]

Martin,

I assume something like a Krell KSA50 could benefit from a cap multiplier cct? I've bought two pairs of big caps from my build but I have just about all the parts for a cap multiplier...

Capacitance multipliers are best suited to circuits that draw a constant current, the krell circuit is a standard amplifier biased into class a, it has much better intrinsic ripple rejection anyway due to its design.

 

[Dan K]

the krell circuit is a standard amplifier biased into class a, it has much better intrinsic ripple rejection anyway due to its design.

Thanks russel, can you explain why?

 

[russel]

Thanks russel, can you explain why?

It uses a vbe multiplier to set the reference voltage for the bias current.

 

[Dan K]

I wonder if anyone could run up a batch of boards, similar size to Cap6, or mini Cap6. Perhaps a question for diyaudio.

 

[sq225917]

The most recent diyaudio stab at this

https://www.diyaudio.com/forums/gro...ve-rect-crc-cap-mx-class-power-supply-gb.html

 

[Dan K]

https://www.etsy.com/uk/listing/699...slb-class-a-psu?ref=shop_home_active_12&bes=1

£35+taxes just for the board! There's a lot of added complication/ BS too :-(

On my Bedini 25/25 I got 7.2mV with 2x68,000uF 40V Epcos for £42 from RS, getting that ripple down to what looks to be about 3mV could be expensive. Looks like I'll need some massive heatsinks too

...unless that's the price for the whole kit. If so then I'm in

 

[Dan K]

Active rectifier using 8 off twin diodes!

Just found out that the components are another $80 + postage

 

[sq225917]

The parts cost for my phonostage psu is nearly 400, the slb is cheap in comparison.

If you want to build a quiet hiagra this really is the way forward.

 

[Dan K]

Not exactly 'KISS', but does look awesome