advertisement


Hiraga Le Monstre

Nice piece of test kit, but coming back to The Monster...

I am intrigued by Jim's Audio comment:
"Features : This is our updated and improved version. The low level section is constant current loaded, and fed by good-sounding Kubota regulator. In bench test and listening test, the amplifier has substantial improvement in speed and distortion performance in high frequency register. The noise and distortion is substantially lower. Sonically , comparing to the original design, it has a darker background, cleaner and more tranparency. "

So we have a very experienced listener (Jez) saying it's possibly the best amp he's heard and then we have Jim saying it can be improved substantially.
???

(Note that the Jim's kit is the 30W version which doesn't use the JFET input stage).
 
Nice piece of test kit, but coming back to The Monster...

I am intrigued by Jim's Audio comment:
"Features : This is our updated and improved version. The low level section is constant current loaded, and fed by good-sounding Kubota regulator. In bench test and listening test, the amplifier has substantial improvement in speed and distortion performance in high frequency register. The noise and distortion is substantially lower. Sonically , comparing to the original design, it has a darker background, cleaner and more tranparency. "

So we have a very experienced listener (Jez) saying it's possibly the best amp he's heard and then we have Jim saying it can be improved substantially.
???

(Note that the Jim's kit is the 30W version which doesn't use the JFET input stage).

It's a completely different amplifier as you say! Hiraga did "Le Monstre" and his "20W class A amplifier".

I should think that many examples of Le Monstre will perform very poorly as I don't consider it really viable to build one without a distortion analyser and get decent results. It's very difficult to build two that are exactly the same as well... even channel to channel.

As it has a fairly high output impedance it's likely to be more speaker dependent than most SS amps but into my Spendor BCII's and at volumes that are within its low power capabilities it was hard to imagine anything better to be honest... it had superb transparency, silent background, great imaging and soundstaging and, surprisingly maybe given it's poor damping factor etc, very tight and agile bass of excellent "texture".
 
Been reading this thread with some interest.
Jez,
That probably makes it a one-in-a-thousand, metaphorically as well as literally?
AP
 
The extra presets are a good sign but not much of the power supply is visible and unless it's just right you will get mains hum. My experience from the only example I've worked on leads me to believe you'll not get one working optimally without a distortion analyser.
 
As far as one can tell from the pics, it's not a disaster. It looks like the case is earthed (unlike the Ebay copy NCC200 amp he's also selling) and the mains wires look (mostly) insulated.
As Jez says, it's impossible to know if it is properly optimised.
It has a single supply for 2 channels which is not neccessarily bad but makes the grounding trickier - especially when the L&R inputs are physically separated.
Seems to have no CLC or CRC filtering, just C.

Same info as for tha Pass amp he has for sale.
Looks like he's some sort of dealer.

I wouldn't buy it. But then I like buiding amps myself!!

Oh, and it's not attractive IMO :)
 
I’ve asked him for details of the components he used, he replied that he’ll let me have them tomorrow. I’m not sure I have a speaker sensitive enough for them myself anyway.
 
As far as one can tell from the pics, it's not a disaster. It looks like the case is earthed (unlike the Ebay copy NCC200 amp he's also selling) and the mains wires look (mostly) insulated.
As Jez says, it's impossible to know if it is properly optimised.
It has a single supply for 2 channels which is not neccessarily bad but makes the grounding trickier - especially when the L&R inputs are physically separated.
Seems to have no CLC or CRC filtering, just C.

Same info as for tha Pass amp he has for sale.
Looks like he's some sort of dealer.

I wouldn't buy it. But then I like buiding amps myself!!

Oh, and it's not attractive IMO :)

Yep that's all I could see and there isn't enough PSRR in a Monstre for that to be enough to remove the hum...
 
I like the space age look!

FWIW, if you want to build your own, punkydawgs (on ebay) has genuine Toshiba JFETs.

FWIW #2, if @glenn jarrett still has the low-Idss LSK170s, paired with some higher Idss LSK170s they'd be perfect for the CCS on a J2. I sold two extra quads I had in 10 minutes flat.... (diyaudio link)
 
To those who can read French... The original article.

I believe it was never translated.

The PSU, the reason why he called it Le Monstre.

All else is poor copy.

Le%20MONSTRE.jpg
 
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?
 
You also have to factor in how much PSRR the topology has. This one has very little, and so needs a lot of filtering at the PSU end.

Also, if you want dual mono (separate L & R supplies) then you need at least 8 caps.
 
I have 10 x lsk170 Linear systems 2-3 ma range 2 matched quads and a pair from what i can remember
16 x 2sj74 original toshiba
6 x 2sk170bl original toshiba
 
You also have to factor in how much PSRR the topology has. This one has very little, and so needs a lot of filtering at the PSU end.

Also, if you want dual mono (separate L & R supplies) then you need at least 8 caps.

How little PSRR does it have? What's the 100Hz PSU ripple (mV) at 4 Ohms - for example?

Are 2off CRC better than 1off CRCRC?

Someone will have the numbers :)
 


advertisement


Back
Top