Yes, post 571 is correct for this input pair.
But just a tip that with higher power you also use a higher feedback divider (like Hiraga goes to 330 ohm/10 ohms in the 30 W version of Le Classe A).
The interesting part is that in this topology the output FET will have a different punch than in the F5 . . . and will definitely have a lower shoot-over. Good for e.g. electrostats or other complex drivers. (F5 exhibits overshoot at very high frequencies).
That explains my interest.
Thank you
Honestly I didn't heard big difference at the Class A with higher resistor on feedback or capacitor on feedback.
Actually I do not like capacitor on feedback on the feedback resistor very much. It get a bit muddy the sound..
If you exchange the 5 or 10W resistor for 0.33 that you can hear it right away. More dynamic, bass etc but the power transistors will get more load-- more heat.
To return to the LeMonstre I like these version. I want to test it.
I purchased the semis but one side they sent me not N type. Huge difference between the N type and with out.
I have to get the right mosfet. Also I prefer the red resistors from Parts Connexion.
I tried before Dale (not bad) Takman (not my cup of tea) but the PRP well balanced resistor (very little color or nothing).. I want to use that.
I never built the F5 but I built the Profet and not bad amp.
One think when we build a simple amp like these very sensitive to the parts what we use done to the wire to.
Thank you
Greetings Gabor
Honestly I didn't heard big difference at the Class A with higher resistor on feedback or capacitor on feedback.
Actually I do not like capacitor on feedback on the feedback resistor very much. It get a bit muddy the sound..
If you exchange the 5 or 10W resistor for 0.33 that you can hear it right away. More dynamic, bass etc but the power transistors will get more load-- more heat.
To return to the LeMonstre I like these version. I want to test it.
I purchased the semis but one side they sent me not N type. Huge difference between the N type and with out.
I have to get the right mosfet. Also I prefer the red resistors from Parts Connexion.
I tried before Dale (not bad) Takman (not my cup of tea) but the PRP well balanced resistor (very little color or nothing).. I want to use that.
I never built the F5 but I built the Profet and not bad amp.
One think when we build a simple amp like these very sensitive to the parts what we use done to the wire to.
Thank you
Greetings Gabor
Hi all
This is my amp here, Fake +/- 21v
Amp board, so my question those two variable resistors, what do you think one is dc-offset ? and the other Bias ? but i don't know which one is which.
This is my amp here, Fake +/- 21v
An externally hosted image should be here but it was not working when we last tested it.
Amp board, so my question those two variable resistors, what do you think one is dc-offset ? and the other Bias ? but i don't know which one is which.
An externally hosted image should be here but it was not working when we last tested it.
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Katip, this looks like the version I have which has more capacitors whose function I do not know.
A while back i accidentally shorted something and it blew one of those diodes but that was good it blew the Diode instead of the Outputs.
I have this amplifier already built running from 12vdc step up to -/+ 24vDC ~
Probably going to sell soon as I prefer the F5 amplifier however I could try upgrading the Carbon film resistors to Metal Film before making a decision!
The Hiraga 20w is a very good sounding amp, just think it could be better! atleast my amp..
A while back i accidentally shorted something and it blew one of those diodes but that was good it blew the Diode instead of the Outputs.
I have this amplifier already built running from 12vdc step up to -/+ 24vDC ~
Probably going to sell soon as I prefer the F5 amplifier however I could try upgrading the Carbon film resistors to Metal Film before making a decision!
The Hiraga 20w is a very good sounding amp, just think it could be better! atleast my amp..
Hiraga and F5
I have built both the Hiraga 20w and the F5 but I prefer the Hiraga without any hesitation (at least in my audio set-up). It is true that many versions of Hiraga super class A exist and the result could be different from one implementation to the other... Also I prefer the Hiraga with semi-lateral MOSFET output instead of BJT ( even with the very linear njw3201/njw1302)
Fab
I have built both the Hiraga 20w and the F5 but I prefer the Hiraga without any hesitation (at least in my audio set-up). It is true that many versions of Hiraga super class A exist and the result could be different from one implementation to the other... Also I prefer the Hiraga with semi-lateral MOSFET output instead of BJT ( even with the very linear njw3201/njw1302)
Fab
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2sk1530/2sj201
The schematic is the same but with different output trannies. It is a prototype and not ready for publication since this Hiraga design is sensible to used transistors and associated parameters. The parts values can change substantially and a study would be necessary to guaranty repeatable results for proper polarization of each stage....
Fab
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Class A is overrated, built only as an experiment one channel of the Hirage 20 w, sounded good, but my goodness such heat generated.Is it worth the time and expense, NO. I compared it tp the much more simpler ESP PS3A R.Elliott amp,upgraded output transistors,using a good regulated power supply running at 45 v and a bias of 150 ma, well well, it sounded on a par with the class A if not better.Simpler and cheaper to build.
Each one to his own opinion.
Each one to his own opinion.
"trolling" was not my intention i was only giving my opinion about a class of amplifier against another.
Trolling is that what you mean?
The art of deliberately, cleverly, and secretly p....g people off, usually via the internet, using dialogue. Trolling does not mean just making rude remarks: Shouting swear words at someone doesn't count as trolling; it's just flaming, and isn't funny. Spam isn't trolling either; it p....s people off, but it's lame.
But how can you evaluate the sound imaging of an amp with only one channel
.... Your comparison between these 2 amps is very questionable...except for the heat generation Fab
But how can you evaluate the sound imaging of an amp with only one channel
Fab
I did say that the class A sound was good, but at the expense of an expensive and bulky power supply and generated heat. My opinion was that, compared to a simpler and well designed amp, like the PS3, it was not worth the expense.Anyway that's my opinion.
Hi Rixsta,
I'm also interested in this amplifier because now i have some suitable radiators from a old telecom equipment and two trafos at wich i am winding as we speak..
I think that the only upgrade is from the post 587 from this thread. I have found the same schematic from diy audio bulgaria, where a guy tries to put a 4 ohm load on this amp.
http://bgaudioclub.org/gallery/albums/userpics/11837/HiragaShemat_~0.jpg
I think that in this schematic we have to use the BL termination for the 2sa970.
This is the forum were i found the guys that actually tested the schematic and posted some impresions and the results. Can anyone help us with some ideas (translation) from the impressions of the guys froms the link from below?
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