Hi Williams
Thanks for your post on setup of the amp my intended Transformer is 300VA 18-0-0-18v so may have to add a resistor to pull is down a couple of volts to get it close to volt after rectification as for heatsinks one of these should be fine MF35 or MF30-1F
Conrad Heatsinks - Products
Thanks for your post on setup of the amp my intended Transformer is 300VA 18-0-0-18v so may have to add a resistor to pull is down a couple of volts to get it close to volt after rectification as for heatsinks one of these should be fine MF35 or MF30-1F
Conrad Heatsinks - Products
hi colins,
the 300va, 18-0-18v trafo will supply +/-22vdc under the idle current.
i think you should be cool, no need of serial resistor.
must use a high current diode rectifier on heat sink, is getting hot.
my Le Monstre ( kit from HK ) is operating with +/- 30vdc in order to get
some more power.
NO FEAR, I use a very large heat sink.
If you have high efficiency spk will figure the great clean sound of it.
An amp like this, from a ready made company will cost twice comparable to DIY
with super high quality components, so don't worry is a good one.
Best regards,
Williams
the 300va, 18-0-18v trafo will supply +/-22vdc under the idle current.
i think you should be cool, no need of serial resistor.
must use a high current diode rectifier on heat sink, is getting hot.
my Le Monstre ( kit from HK ) is operating with +/- 30vdc in order to get
some more power.
NO FEAR, I use a very large heat sink.
If you have high efficiency spk will figure the great clean sound of it.
An amp like this, from a ready made company will cost twice comparable to DIY
with super high quality components, so don't worry is a good one.
Best regards,
Williams
Hi Colin,
Looks like I should have read your post more carefully - The schematic I posted is for Hiraga's "Le Classe A", whereas the last schematic you posted is obviously for a higher-power version of his "Le Monstre". I've also built Le Monstre, but only in the original 8W (or so) size. Nonetheless, I expect you'll need heatsinks about the size I described. The ones you posted from Conrad look pretty good, and I would guess that a pair of them (one for each channel) will be enough (YMMV, as always...). If I were you I would get the tallest ones they list (MF30-151.5 or MF35-151.5) because (a) if you use them as two sides of the chassis then they are higher, giving you more space to fit everything else in and (b) if you decide to try some other amp at a later date you'll be able to reuse them with more chance that they'll be big enough.
Cheers
Nigel
Looks like I should have read your post more carefully - The schematic I posted is for Hiraga's "Le Classe A", whereas the last schematic you posted is obviously for a higher-power version of his "Le Monstre". I've also built Le Monstre, but only in the original 8W (or so) size. Nonetheless, I expect you'll need heatsinks about the size I described. The ones you posted from Conrad look pretty good, and I would guess that a pair of them (one for each channel) will be enough (YMMV, as always...). If I were you I would get the tallest ones they list (MF30-151.5 or MF35-151.5) because (a) if you use them as two sides of the chassis then they are higher, giving you more space to fit everything else in and (b) if you decide to try some other amp at a later date you'll be able to reuse them with more chance that they'll be big enough.
Cheers
Nigel
Hi All
HK HIRAGA LE MONSTRE
It seems my Parts list is incomplete regarding the 5 Watt emitter resistors Values R11/12/13/14 Can anyone conform there Values for the HK PCBs I have contacted the seller but he doesn’t seem to understand what I am asking him so gave up
Ah right Seems the emitter Resistors R12/13 Are 1 ohm just a bit confusing for a beginner with so many variations of this Amp running at different voltages I guess adding a Speaker protection circuit would be a good idea as well any comments on this are welcome as I a bit quiet round there for some reason
Hi Wahab
Yep I am in a bit of confusion over the Transistor for this Amp there seems to be many variations of the build with different Transistors’ this is confusing me many of the 2S are difficult to get i have got
Following list
2SA872Ax2
2SB647x2
2SC2632x i think this is replacement for j75
2SJ170x2
2SJ103x2
Right so 2SA872/2SK170 could you pair up the correct transistors for the posted schematic of the HK Version with a replacement for 2SC1775 as I can’t seem to obtain this one see Schematic your help is appreciated as i am now total lost with 2S numbers
Yep I am in a bit of confusion over the Transistor for this Amp there seems to be many variations of the build with different Transistors’ this is confusing me many of the 2S are difficult to get i have got
Following list
2SA872Ax2
2SB647x2
2SC2632x i think this is replacement for j75
2SJ170x2
2SJ103x2
Right so 2SA872/2SK170 could you pair up the correct transistors for the posted schematic of the HK Version with a replacement for 2SC1775 as I can’t seem to obtain this one see Schematic your help is appreciated as i am now total lost with 2S numbers
Hi Colin,
the complimentarypairis2SC2240/2SA970.
They will work however the characteristics are different and some of the parameters such as Cob and Noise figure are higher. Having said that they are a common and well proven pair. They are just not quite as good as the originals.
-Dan
ithanks Dan but again all seem to have mist my point here i don't know how to ask this but what i would like to know are the transistors i listed OK as i was given then as alternative's to the originals so we can use the
2SC2240/2SA970 in place of 1775/170 what are the comp pairs for the others
and could you list alliterative pairs from my list
Think i will give up on this amp as i haven't got and cant seem to get 2SJ74/2SC1775 it seem anything other than the originals will change the impedance of the amp to much back to the tubes i think
Hello
I have access for the original power transistors and for the orig driver transistor .
Also very good replacement for the small BJT from Sanyo.
I can make a small group buy. If there is enough interest ,we can get as much so I can match them!
Price about $30US/a matched set for a stereo , depend how many guy interested! If there is enough interest we can keep the price low and can be matched!
No JFet .
Toshiba 2SD844 & 2SB754 Power trany
Hitachi 2SB716 & 2SD756 Driver
Sanyo 2SA1016 & 2SC2362 small signal (better than the orig BJT)
One week for these GB if amy people interested !!
Sincerely gaborbela
I have access for the original power transistors and for the orig driver transistor .
Also very good replacement for the small BJT from Sanyo.
I can make a small group buy. If there is enough interest ,we can get as much so I can match them!
Price about $30US/a matched set for a stereo , depend how many guy interested! If there is enough interest we can keep the price low and can be matched!
No JFet .
Toshiba 2SD844 & 2SB754 Power trany
Hitachi 2SB716 & 2SD756 Driver
Sanyo 2SA1016 & 2SC2362 small signal (better than the orig BJT)
One week for these GB if amy people interested !!
Sincerely gaborbela
Last edited:
No i only want one pair of each 2SJ74/2SC1775 i think everyone who wanted to build this amp have done so
Hi Colin,
Don't give up on the amp if you already have most of the parts. Let me ask a few questions, and make a couple of remarks.
1. There are many schematics floating around called "Hiraga Le Monstre", and at least two called "Hiraga Le Classe A". In post #530 you said you were undecided whether to make the +/-12 volt or the +/-22 volt version; is this decided now? Is the schematic you are planning on using the one in the link in post #526?
2. It may not matter much, but it is my understanding that the +/- 12v version is the "original" Hiraga version, with 8W output. The Class A Amplifier site has the original article, schematics and everything,
The Class-A Amplifier Site
and a version with modern equivalents can be found at
JEAN HIRAGA - Le Monstre Amplifier PCB
I have built the second one, but not the first, with original parts, but I believe danieljw (Hi Dan!) has built with everything original, and can tell you more. The one with modern equivalents is a fun project, and I enjoyed doing it and listening to it.
3. You aren't going to be able to do any of these circuits well without using a complementary pair of jfets. The originals are 2SK170/2SJ74, the "modern equivalents" circuit uses 2SK246/2SJ103, and I have also built that version with 2N5457/2N5460, although performance wasn't as good, maybe. If I understood correctly, your post #549 lists parts you already have. You are going to need to find either 2SJ74 to use with the 2SK170 you have, or 2SK246 to use with the 2SJ103 you have. You can get 2SJ103 from
Power Amp Kits by AmpsLab
If you are doing the +/- 22V version I would stick with 2SJ74, which you can probably also buy online if you look around. I'd also try to get the same grade as the 2SK170 you have (BL?).
Well, sorry I can't be more help, but don't give up on it.
Cheers
Nigel
Don't give up on the amp if you already have most of the parts. Let me ask a few questions, and make a couple of remarks.
1. There are many schematics floating around called "Hiraga Le Monstre", and at least two called "Hiraga Le Classe A". In post #530 you said you were undecided whether to make the +/-12 volt or the +/-22 volt version; is this decided now? Is the schematic you are planning on using the one in the link in post #526?
2. It may not matter much, but it is my understanding that the +/- 12v version is the "original" Hiraga version, with 8W output. The Class A Amplifier site has the original article, schematics and everything,
The Class-A Amplifier Site
and a version with modern equivalents can be found at
JEAN HIRAGA - Le Monstre Amplifier PCB
I have built the second one, but not the first, with original parts, but I believe danieljw (Hi Dan!) has built with everything original, and can tell you more. The one with modern equivalents is a fun project, and I enjoyed doing it and listening to it.
3. You aren't going to be able to do any of these circuits well without using a complementary pair of jfets. The originals are 2SK170/2SJ74, the "modern equivalents" circuit uses 2SK246/2SJ103, and I have also built that version with 2N5457/2N5460, although performance wasn't as good, maybe. If I understood correctly, your post #549 lists parts you already have. You are going to need to find either 2SJ74 to use with the 2SK170 you have, or 2SK246 to use with the 2SJ103 you have. You can get 2SJ103 from
Power Amp Kits by AmpsLab
If you are doing the +/- 22V version I would stick with 2SJ74, which you can probably also buy online if you look around. I'd also try to get the same grade as the 2SK170 you have (BL?).
Well, sorry I can't be more help, but don't give up on it.
Cheers
Nigel
You may want to send email to zhoufang - maybe he's got matched sets 2SK170/2SJ74, which would be very convenient!
http://www.diyaudio.com/forums/vend...ed-but-hard-get-they-here-12.html#post2275358
Cheers
Nigel
http://www.diyaudio.com/forums/vend...ed-but-hard-get-they-here-12.html#post2275358
Cheers
Nigel
Hi Nigel
Thanks for diving in to help
Yes I was thinking about doing the 8 Watter but went with the 20watt HK version I posted
I ordered parts from criclewood
Right I have got the following
2SA872Ax2
2SK170 BLx2
2SB647x2
2SC2632x2
I an told by cricklewood that I can use 2SB647 in place of 2SB716 and 2SC2632 in place of > 2SD756
2SB716x2 comp to 2SB647
> 2SD756x2 comp to 2SC2632
Right so Crackle wood are now suppose to be sending the 2SC1775 as I ordered but tried to send me the 2SC2240 in place of the 2sc1775 but some have said the amp impedance can change from 4 ohm to 20 ohms if non original parts are used
Hi Colin,
As a general rule I would stick to using complementary pairs in symmetrical positions. There are plenty of people here on the forum who can read a datasheet and see when a "non-complementary" part will work OK, or even better, but I'm not one of them.
The datasheets show 2SB647 is complementary to 2SD667, 2SC2632 is complementary to 2SA1124. I thought 2SC2240 was complementary to 2SA970, but the data sheet doesn't say so, so maybe my memory is faulty. (Anyone confirm/deny? Maybe they're just a commonly used pair?)
There are several places here on the forum where the question of parts for the Monstre is discussed. It's usually tricky, since some of the originals have been obsolete a long time.
Cheer
Nigel
As a general rule I would stick to using complementary pairs in symmetrical positions. There are plenty of people here on the forum who can read a datasheet and see when a "non-complementary" part will work OK, or even better, but I'm not one of them.
The datasheets show 2SB647 is complementary to 2SD667, 2SC2632 is complementary to 2SA1124. I thought 2SC2240 was complementary to 2SA970, but the data sheet doesn't say so, so maybe my memory is faulty. (Anyone confirm/deny? Maybe they're just a commonly used pair?)
There are several places here on the forum where the question of parts for the Monstre is discussed. It's usually tricky, since some of the originals have been obsolete a long time.
Cheer
Nigel