Eduard, lots of interesting info there, thanks! The big krell's were just a stop gap whilst the 400kuf arrived that I had ordered, which I arranged into an CRC. I am still working out the best cable routing as this amp seems to be very very sensitive to that.
The Krell caps were actually 90v 40000uf as they came from a kma200
The Krell caps were actually 90v 40000uf as they came from a kma200
Hello,
Now there is even a translation available online.
The Class-A Amplifier Site - Hiraga 20W Class-A
My friend has been using his 20 watt Hiraga i build for him 30! years ago with the original capacitors as used in the '' official non diy model ''. 6 68.000uF caps but instead of a CRC supply i used a CLC with a 200mH 2,5A that was used by the French team in a single ended ONE transistor power amp and a 50 watt class A power amp. I asked the people in Paris if it could be used in these two circuit it would certainly be possible to use it in the Hiraga. Sure sure!
So i build a 30 watt with the 330.000uF and my friend got the 20 watt with the 68.000 uf caps but both with the same choke.
One of the original power supplies of '' le monstre '' used a 4 ohm resistor in its CRC supply. Hiraga wrote because of the low voltage the 8 watt even more sensitive regarding its power supply.
My friend was using a double C core transformer with enough VA but i had a nice 500VA r core that could be used to compensate for the extra voltage loss that we would get using a Lundahl LL2771 with its two coils in parallel to create a 700mH 2A and 2.8 ohm dcr choke.
Everybody would say 2,8 ohm IMPOSSIBLE but we did after all we were probably the first ones using the 200 mH in the Hiraga 20 and 30 watt amps.
If you dont wanna go this way and fear the 2,8 ohm you can go for the smaller ones which of course have less mH less DCR and influence.
My friend tells me it is has all the benefits he was hoping for. Much more effortless music, detail, spaciousness.
I truly believe that spending 250 dollars more in the caps will not give you the improvements the choke does.
Yes, there have been people using 10 mH chokes but i think one should go for the bigger ones.
Greetings, eduard
Now there is even a translation available online.
The Class-A Amplifier Site - Hiraga 20W Class-A
My friend has been using his 20 watt Hiraga i build for him 30! years ago with the original capacitors as used in the '' official non diy model ''. 6 68.000uF caps but instead of a CRC supply i used a CLC with a 200mH 2,5A that was used by the French team in a single ended ONE transistor power amp and a 50 watt class A power amp. I asked the people in Paris if it could be used in these two circuit it would certainly be possible to use it in the Hiraga. Sure sure!
So i build a 30 watt with the 330.000uF and my friend got the 20 watt with the 68.000 uf caps but both with the same choke.
One of the original power supplies of '' le monstre '' used a 4 ohm resistor in its CRC supply. Hiraga wrote because of the low voltage the 8 watt even more sensitive regarding its power supply.
My friend was using a double C core transformer with enough VA but i had a nice 500VA r core that could be used to compensate for the extra voltage loss that we would get using a Lundahl LL2771 with its two coils in parallel to create a 700mH 2A and 2.8 ohm dcr choke.
Everybody would say 2,8 ohm IMPOSSIBLE but we did after all we were probably the first ones using the 200 mH in the Hiraga 20 and 30 watt amps.
If you dont wanna go this way and fear the 2,8 ohm you can go for the smaller ones which of course have less mH less DCR and influence.
My friend tells me it is has all the benefits he was hoping for. Much more effortless music, detail, spaciousness.
I truly believe that spending 250 dollars more in the caps will not give you the improvements the choke does.
Yes, there have been people using 10 mH chokes but i think one should go for the bigger ones.
Greetings, eduard
Attachments
Hello,
There is a LOT of information written in the french l'audiophile magazines. Complete articles and sometimes updates when transistors ran out of stock or when better parts appeared on the market. Of course if you dont have these magazines and cannot read them. You will have to figure out who did manage to build a nice sounding Hiraga or a Le Monstre with totally different transistors.
greetings, eduard
There is a LOT of information written in the french l'audiophile magazines. Complete articles and sometimes updates when transistors ran out of stock or when better parts appeared on the market. Of course if you dont have these magazines and cannot read them. You will have to figure out who did manage to build a nice sounding Hiraga or a Le Monstre with totally different transistors.
greetings, eduard
Hello,
I think that the French crew probably new some ways to get a circuit more independent from the quality of the power supply. There were more [people involved than Jean Hiraga and they also did investigate regulated supplies. But the only amplifier where they actually used it was for the input stage of a 50 watt class A amp.
But they kept returning to big capacitors.
In the single ended Nemesis and in the 50 watt they explained why they switched from CRC to CLC power supply.
Back then, in the mid eighties there was just a 200mH 2,5A 1 ohm dcr available that both my friend and me used in 20 and 30 watt Hiraga after asking if it could be used in these Hiraga amps too. SURE they said.
Nowadays Lundahl does make some nice high current chokes that were mailny designed for heater supplies of direct heated triode power tubes. So now more mH and different current ratings to choose from.
The same friend for whom i build the 20 watt recently switched to 700mH 2A 2.8 dcr from Lundahl. Indeed 2,8 ohm but everything improved.
Now he is thinking about replacing the last 4 68000 uF by a new cap that is very similar technically to the 330.000 uF used in the 30 watt that i have build.
Probably just adding huge caps without the use of same kind of CRC or CLC filter will stress the transformer and rectifiers .
With the a 500 VA EI core my Hiraga would sometimes dim the light a little bit during switching on. But didnt need a soft start.
With le monstre there have been several upgrades to the power supplies. Starting with caps, adding batteries and there has been one that would work for 3 or 4 hours on a set pf batteries before recharging again. That was i think about en years after the first article in 1983. Now there are new types of batteries that '' contain '' more charge and can get more recharges. So that would be an easy way to go.
Greetings, eduard
I think that the French crew probably new some ways to get a circuit more independent from the quality of the power supply. There were more [people involved than Jean Hiraga and they also did investigate regulated supplies. But the only amplifier where they actually used it was for the input stage of a 50 watt class A amp.
But they kept returning to big capacitors.
In the single ended Nemesis and in the 50 watt they explained why they switched from CRC to CLC power supply.
Back then, in the mid eighties there was just a 200mH 2,5A 1 ohm dcr available that both my friend and me used in 20 and 30 watt Hiraga after asking if it could be used in these Hiraga amps too. SURE they said.
Nowadays Lundahl does make some nice high current chokes that were mailny designed for heater supplies of direct heated triode power tubes. So now more mH and different current ratings to choose from.
The same friend for whom i build the 20 watt recently switched to 700mH 2A 2.8 dcr from Lundahl. Indeed 2,8 ohm but everything improved.
Now he is thinking about replacing the last 4 68000 uF by a new cap that is very similar technically to the 330.000 uF used in the 30 watt that i have build.
Probably just adding huge caps without the use of same kind of CRC or CLC filter will stress the transformer and rectifiers .
With the a 500 VA EI core my Hiraga would sometimes dim the light a little bit during switching on. But didnt need a soft start.
With le monstre there have been several upgrades to the power supplies. Starting with caps, adding batteries and there has been one that would work for 3 or 4 hours on a set pf batteries before recharging again. That was i think about en years after the first article in 1983. Now there are new types of batteries that '' contain '' more charge and can get more recharges. So that would be an easy way to go.
Greetings, eduard
It is interesting, I have a 400va with 376kuf power supply at 16v (both channels), and that is a massive improvement from 12v and the big Krell caps. I am running it at 1050mA bias, and that seems to be the sweet spot in my system (6ohm Sonus Fabers).
My reference amp is ksa150 and the little Monstre gives it a good run for hte money with tighter bass, but ultimately loses compared to the sheer size of the sound coming out of the Krell.
I am spending about 50% or my time listening to the Monstre, which is saying something!
Going forward, I need to rewire it to tighten up all the lose ends and long cable runs and experiment with some induction in the PSU, but as a proof of concept, this thing is formidable.
My reference amp is ksa150 and the little Monstre gives it a good run for hte money with tighter bass, but ultimately loses compared to the sheer size of the sound coming out of the Krell.
I am spending about 50% or my time listening to the Monstre, which is saying something!
Going forward, I need to rewire it to tighten up all the lose ends and long cable runs and experiment with some induction in the PSU, but as a proof of concept, this thing is formidable.
Hello,
Yesterday i started with a chassis for a le monstre for a friend in Brazil.
This is a inside view
The 3 alu bars are there for rigidity and mounting 3 wooden panels high enough so the lundahl will be not touching the bottom plate.
The side with no bar will be bend 90 degrees upwards to close the frontside of the amp.The two heatsinks will be mounted on the bended side with some metal spacers to create a chimney effect and to stop heat transfer from the heatsinks into the chassis.
The ll2771 are not the actual ones that will be used because they are for another project. The ones used will be 700mH 2A in a choke input set up. There will be two 175 VA transformers so both halves of the supply will have its own rectifier and transformer. The transformers are so called split bobbin to reduce garbage coming from the wall.
The transformers will be mounted with a help of an extra piece of alu so all the connections will be inside the chassis.
Greetings, Eduard
Yesterday i started with a chassis for a le monstre for a friend in Brazil.
This is a inside view
The 3 alu bars are there for rigidity and mounting 3 wooden panels high enough so the lundahl will be not touching the bottom plate.
The side with no bar will be bend 90 degrees upwards to close the frontside of the amp.The two heatsinks will be mounted on the bended side with some metal spacers to create a chimney effect and to stop heat transfer from the heatsinks into the chassis.
The ll2771 are not the actual ones that will be used because they are for another project. The ones used will be 700mH 2A in a choke input set up. There will be two 175 VA transformers so both halves of the supply will have its own rectifier and transformer. The transformers are so called split bobbin to reduce garbage coming from the wall.
The transformers will be mounted with a help of an extra piece of alu so all the connections will be inside the chassis.
Greetings, Eduard
Attachments
Hello,
Next week i will ship it to Brazil. I just mounted some things to check if my '' engineering '' was correct. The making of the drawing, figuring out the position of the different parts and checking the dimensions of the dimensions of these parts online is time consuming. The cnc programming itself will take 30 minutes, the preparation off the tools can be 10 minutes but sometimes more and the machining itself will take 2.....4 minutes.
In the attachment you can see a pdf we are making for my new to build stand alone pom motor housing for my turntable. Le monstre can do with a few sheets of paper but this pom piece will be made on a 3 or 5 axis machining center that usually is told what to do by means of CAD/CAM software. Sometimes it is even possible to make your own diy program on such a machine yourself. It could well be that machining this POM will take 15. min max .
Yeah the power supply!!!
Total transformer weight 10lbs or 4,5 kilo Total 350 VA
Total choke weight 21,6 lbs 9,8 kilo
Most people here will say why not get a 1000 VA toriod which will need a soft start and will surely not be better than 350 VA and a pair of big chokes.
DCR of the choke 2,8 ohm. CANNOT WORK 95% will say but since a friend used choke input in a non symetrical power supply with a hefty current and 3,4 ohm dcr there are people who wanna try it as well.
He said difference between caps was much smaller with choke input because they are not beaten up like with a 1000VA toriod.
REMEMBER the original LE MONSTRE used a CRC supply with a 4 ohm resistor. So why would a choke with less dcr and a 12db filtering instead of 6 db will not be superior to a 4 ohm resistor. Later on the French published some designs using the 200 mH choke my friend and me later used in his 20 watt and my 30 watt Hiraga.
Greetings, eduard
Next week i will ship it to Brazil. I just mounted some things to check if my '' engineering '' was correct. The making of the drawing, figuring out the position of the different parts and checking the dimensions of the dimensions of these parts online is time consuming. The cnc programming itself will take 30 minutes, the preparation off the tools can be 10 minutes but sometimes more and the machining itself will take 2.....4 minutes.
In the attachment you can see a pdf we are making for my new to build stand alone pom motor housing for my turntable. Le monstre can do with a few sheets of paper but this pom piece will be made on a 3 or 5 axis machining center that usually is told what to do by means of CAD/CAM software. Sometimes it is even possible to make your own diy program on such a machine yourself. It could well be that machining this POM will take 15. min max .
Yeah the power supply!!!
Total transformer weight 10lbs or 4,5 kilo Total 350 VA
Total choke weight 21,6 lbs 9,8 kilo
Most people here will say why not get a 1000 VA toriod which will need a soft start and will surely not be better than 350 VA and a pair of big chokes.
DCR of the choke 2,8 ohm. CANNOT WORK 95% will say but since a friend used choke input in a non symetrical power supply with a hefty current and 3,4 ohm dcr there are people who wanna try it as well.
He said difference between caps was much smaller with choke input because they are not beaten up like with a 1000VA toriod.
REMEMBER the original LE MONSTRE used a CRC supply with a 4 ohm resistor. So why would a choke with less dcr and a 12db filtering instead of 6 db will not be superior to a 4 ohm resistor. Later on the French published some designs using the 200 mH choke my friend and me later used in his 20 watt and my 30 watt Hiraga.
Greetings, eduard
Hello,
Unfortunately the friend in Sao Paolo will build this Monstre as his first diy amplififier as a kind of initiation before building a single ended EL34 amp. My 30 watt Hiraga was my second solid state amp after a moderate class AB amp. The 20 watt Hiraga i build for my friend was his first serious amp and now he has been using it for about 30 years. Build with parts from Paris like all the transistors, cosmos bias pot, Shinkow resistors, Novea caps, double C core and the 200 mH chokes originally meant for two other Parisian audiophile projects.
About a year ago the zener for the input stage were replaced by Tent shunt supplies by a Dutch technician.
And recently my old 500 VA rcore replaced the original double C core because the LL2771 would give a larger voltage drop than the 200 mH
BIG IMPROVEMENT. Considering the fact that these chokes will survive its owner i think it is a pretty good return on investment.
Probably my friend will need serious investment both time and money to surpass his monster.
Greetings, eduard
Unfortunately the friend in Sao Paolo will build this Monstre as his first diy amplififier as a kind of initiation before building a single ended EL34 amp. My 30 watt Hiraga was my second solid state amp after a moderate class AB amp. The 20 watt Hiraga i build for my friend was his first serious amp and now he has been using it for about 30 years. Build with parts from Paris like all the transistors, cosmos bias pot, Shinkow resistors, Novea caps, double C core and the 200 mH chokes originally meant for two other Parisian audiophile projects.
About a year ago the zener for the input stage were replaced by Tent shunt supplies by a Dutch technician.
And recently my old 500 VA rcore replaced the original double C core because the LL2771 would give a larger voltage drop than the 200 mH
BIG IMPROVEMENT. Considering the fact that these chokes will survive its owner i think it is a pretty good return on investment.
Probably my friend will need serious investment both time and money to surpass his monster.
Greetings, eduard
Hello,
I could not resist quoting the only German Arthur i know.
Religion maybe be an excellent means of taming and training the perverse, obtuse and wicked biped race : but in the eyes of the friend of truth every fraud, however pious, is still a fraud.
Music does have immense power. The Japanese have published articles about the relation between the sign of Zodiac and the music you could play according to your sign. I didnt read it because astrology is as weird as a banana on a surfboard.
But anyway we will have to return to the subject.
The eleventh commandment could be whenever possible use a choke in your power supply. The way it works is so basic yet effective.
Greetings, Edduard
I could not resist quoting the only German Arthur i know.
Religion maybe be an excellent means of taming and training the perverse, obtuse and wicked biped race : but in the eyes of the friend of truth every fraud, however pious, is still a fraud.
Music does have immense power. The Japanese have published articles about the relation between the sign of Zodiac and the music you could play according to your sign. I didnt read it because astrology is as weird as a banana on a surfboard.
But anyway we will have to return to the subject.
The eleventh commandment could be whenever possible use a choke in your power supply. The way it works is so basic yet effective.
Greetings, Edduard
Hi Ed,
Your job on the chassi looks pretty good!
And I'm really looking forward to hearing my first hi end amplifier, especially to discover in practice what a choke input power supply can do for the audio system!
Regards, Nilton