Seems to be good. I may change slightly the layout to tight together the 2 input FETs. In this case they have to face each other. May have to bent the legs of one!
Thanks a lot.
are you sure?
I would expect any sensible fuse and any sensible MCB to open long before you have set fire to the transformer.
Yes you can use fuse but will burn.
It has huge charge when I turn it on, because I replaced the 4700-10 000uF (Rode advised) capacitors with 60 000uF
Andrew what ever work, I destroyed a 300VA transformer, after 3-4 month started to buzz very badly. It was a Plitron good (new) transformer but the heavy load did it that.
Now I use soft starter on the AC side.
Greetings
It has huge charge when I turn it on, because I replaced the 4700-10 000uF (Rode advised) capacitors with 60 000uF
Andrew what ever work, I destroyed a 300VA transformer, after 3-4 month started to buzz very badly. It was a Plitron good (new) transformer but the heavy load did it that.
Now I use soft starter on the AC side.
Greetings
.
My mistake. I was thinking about 'Le Monstre' at the same time. Also should wait tomorrow to start drinking! Actually tighting the input pair for thermal drift stability is not so important in these circuits.
Hello everybody. thanks for the replies. The toroidal transformer is very expensive here in my country. but I will buy another one soon. there was another pcb mentioned in this thread which has 2 layers. nobody has any comment on this. what do you think about that?(it is attached) I got to have it built for me but I'm not sure maybe the one that you suggest is better and I can make it myself. anyway thanks. If I make it I will post a nice picture here.
Thank you Gabor. Thanks everybody.
Ashkan
Thank you Gabor. Thanks everybody.
Ashkan
Hello
My advise to you keep it as simple is possible.
So many extra parts for DC protection?
I would use the schematic I posted last page , or the 24V. If you use good power supply you do not need electrolytic on the PC board.
I used 0.1uF Rifa AC capacitor there. That was the best to me.
I ordered some Solen thin foil caps to but good for nothing, I did try several other caps like Wima, Yellow Philips, Evox so on, these Rifa was the best.
If you can get capacitor like these I think that is good enough.
Greetings Gabor
My advise to you keep it as simple is possible.
So many extra parts for DC protection?
I would use the schematic I posted last page , or the 24V. If you use good power supply you do not need electrolytic on the PC board.
I used 0.1uF Rifa AC capacitor there. That was the best to me.
I ordered some Solen thin foil caps to but good for nothing, I did try several other caps like Wima, Yellow Philips, Evox so on, these Rifa was the best.
If you can get capacitor like these I think that is good enough.
Greetings Gabor
Attachments
Ash,
EI "standard" transformer often give "better sound" results, and if you can get one built locally ....
Can you post link to further info about the dc protection cct?
Gaborbela,
Are those Rifa caps the ones used as X2 for mains supply filters, etc from years ago? Still available or a current production equivalent?
EI "standard" transformer often give "better sound" results, and if you can get one built locally ....
Can you post link to further info about the dc protection cct?
Gaborbela,
Are those Rifa caps the ones used as X2 for mains supply filters, etc from years ago? Still available or a current production equivalent?
I do see a Y in the bottom right hand corner.
The Y is not in the familiar format Y1, nor Y2. I suspect this Rifa does not qualify as an X nor Y rated capacitor.
Ah, you have better eyes than me, Andrew -
I wonder if that part number is PME206, 260, 286, ? - a discontinued cap from awhile back?
Incidently, if anyone is looking for some 15003 or 15004 transistors, I have plenty of them from years ago - they're the big TO3 metal can ones - used them in the old Pass A40 amp with good results - possibly have some of the transistor sockets too.
I wonder if that part number is PME206, 260, 286, ? - a discontinued cap from awhile back?
Incidently, if anyone is looking for some 15003 or 15004 transistors, I have plenty of them from years ago - they're the big TO3 metal can ones - used them in the old Pass A40 amp with good results - possibly have some of the transistor sockets too.
Hello
Andrew those are old Rifa caps...
They are very old production but some places still available. I use those the last 20 years or so.
Usually I used them in the PS on the electrolytes (mounting caps) but these great on the PC board to, if you have place because they are large.
Some people advertise on Ebay as a paper capacitor. I don't know.
21 LOT RIFA PMR202MD6500K220 RC UNIT CAPACITOR 0.5uF 200OHMX2 10% 250V 42160 | eBay
NOS Evox Rifa PME271M X2 CAPACITORS CAPS .47mfd @ 250V | eBay
I never open up one to see what is inside.
Better than the Evox which also Rifa product. I also used in PP EL84 tube amp.
It has well balanced sound but with great dry deep bass.
Please chose which does not have built in resister! Many company use them in EMI filter.
Greetings Gabor
Andrew those are old Rifa caps...
They are very old production but some places still available. I use those the last 20 years or so.
Usually I used them in the PS on the electrolytes (mounting caps) but these great on the PC board to, if you have place because they are large.
Some people advertise on Ebay as a paper capacitor. I don't know.
21 LOT RIFA PMR202MD6500K220 RC UNIT CAPACITOR 0.5uF 200OHMX2 10% 250V 42160 | eBay
NOS Evox Rifa PME271M X2 CAPACITORS CAPS .47mfd @ 250V | eBay
I never open up one to see what is inside.
Better than the Evox which also Rifa product. I also used in PP EL84 tube amp.
It has well balanced sound but with great dry deep bass.
Please chose which does not have built in resister! Many company use them in EMI filter.
Greetings Gabor
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Hi, I just bought a nice PCB,
Stereo amplifer PCB Hiraga super 30W class A !!!
Looks very sturdy, military grade (thick, plated through holes).
I plan to make a variant i think like Hiraga mentioned in his article, with a FET-based Darlingnot.
albert
Stereo amplifer PCB Hiraga super 30W class A !!!
Looks very sturdy, military grade (thick, plated through holes).
I plan to make a variant i think like Hiraga mentioned in his article, with a FET-based Darlingnot.
albert
Hello,
I am a newbie interested in building Hiraga 20W amp for a long time. The one which I look at is from this site: JEAN HIRAGA - Le Monstre Amplifier PCB
I want to build it with MJ series output transistors. But, the common problem is with 2Sj74 jfet transistors. I know they can be found on e-bay.......and MCM site for $4 a pop. So, my question is; is it possible to use BJT transistors instead of jfets with preserving sound quality? I am not sure, but I think the orginal first version of Hiraga used BJT transistors in input stage.
I am a newbie interested in building Hiraga 20W amp for a long time. The one which I look at is from this site: JEAN HIRAGA - Le Monstre Amplifier PCB
I want to build it with MJ series output transistors. But, the common problem is with 2Sj74 jfet transistors. I know they can be found on e-bay.......and MCM site for $4 a pop. So, my question is; is it possible to use BJT transistors instead of jfets with preserving sound quality? I am not sure, but I think the orginal first version of Hiraga used BJT transistors in input stage.
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Hello
Honestly I don't think so!
I built a amplifier many years a go which sounded great. At the input was BC414C 416C BJT.
After 15 years I rebuilt the same amp, I did some mod and the biggest improvement was when I replaced the BJT to J Fet.
The improvement was so audible I was shocked.
You can try use BJT but after you will start looking different type to improve the sound. On the end will spend more than you buy a matched set JFet from the forum.
Even using 2SK170 & 2SJ74 GR type a bit step back I believe at the Monster. I do not want argue over these (my opinion, facts I tested), I built several Monster and Class A to.
One think the Le Monstre only 8W. The 20W Class A does not use JFet. Please look after these carefully.
Greetings Gabor
Honestly I don't think so!
I built a amplifier many years a go which sounded great. At the input was BC414C 416C BJT.
After 15 years I rebuilt the same amp, I did some mod and the biggest improvement was when I replaced the BJT to J Fet.
The improvement was so audible I was shocked.
You can try use BJT but after you will start looking different type to improve the sound. On the end will spend more than you buy a matched set JFet from the forum.
Even using 2SK170 & 2SJ74 GR type a bit step back I believe at the Monster. I do not want argue over these (my opinion, facts I tested), I built several Monster and Class A to.
One think the Le Monstre only 8W. The 20W Class A does not use JFet. Please look after these carefully.
Greetings Gabor
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I plan to make a variant i think like Hiraga mentioned in his article, with a FET-based Darlingnot.
Perhaps this one? (Fig. 2.)
What kind of output devices would you use?
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Hello
Yes that is what I wrote if you want the 20W Class A (Hiraga) you do not need JFet.
For the Le Monstre you need the JFet .
I built both and I would pick the Class A over the Le Monstre always!
I posted somewhere the circuit on the forum at the input with 20 or 22V Zener diodes. Use that not the 13V Zener type schematic.
I built them all, the orig 22V type sound much better. Look like you need that voltage on the input BJT.
Greetings Gabor
Yes that is what I wrote if you want the 20W Class A (Hiraga) you do not need JFet.
For the Le Monstre you need the JFet .
I built both and I would pick the Class A over the Le Monstre always!
I posted somewhere the circuit on the forum at the input with 20 or 22V Zener diodes. Use that not the 13V Zener type schematic.
I built them all, the orig 22V type sound much better. Look like you need that voltage on the input BJT.
Greetings Gabor
Thanks gaborbela. I will search for your schematic. I have seen schematic and pcb on this site: http://extra.newsguy.com/~stigerik/st-eng.html
This link was also posted at the beginning of this thread. Unfortunately the website is down and I did not save the information.
I will look for yours.
This link was also posted at the beginning of this thread. Unfortunately the website is down and I did not save the information.
I will look for yours.
Hello
Here i the schematic.
Please send me a PM with your address and I look up the lay out to you and I send it, probably I have somewhere.
Also you can buy on Ebay from Jim's audio good quality PC board.
I would do that all do I have many years experience manufacturing home brew PC board.
Those are good quality and cheap.
For the first 2 stage I advise use the orig BJT even do hard to find them.
For Power transistor ON Semi MJ11022/23 or MJ11024/25 TO3 metal case transistor.
Driver On semi MJE15030/31 MJE15032/33
I have the opportunity to test the original Hiraga transistors, these what I advise to you sound far better! Deeper bass, better sound stage, more control specially in mid-bass area. All over cleaner and better sound! The heart of these amp the PS! And use solid wire to hook up the TO3 transistors. Min 400mA but I would go 500VA transformer 2x18VAC.
Do not replace the small BJT transistors!
Greetings Gabor
Here i the schematic.
Please send me a PM with your address and I look up the lay out to you and I send it, probably I have somewhere.
Also you can buy on Ebay from Jim's audio good quality PC board.
I would do that all do I have many years experience manufacturing home brew PC board.
Those are good quality and cheap.
For the first 2 stage I advise use the orig BJT even do hard to find them.
For Power transistor ON Semi MJ11022/23 or MJ11024/25 TO3 metal case transistor.
Driver On semi MJE15030/31 MJE15032/33
I have the opportunity to test the original Hiraga transistors, these what I advise to you sound far better! Deeper bass, better sound stage, more control specially in mid-bass area. All over cleaner and better sound! The heart of these amp the PS! And use solid wire to hook up the TO3 transistors. Min 400mA but I would go 500VA transformer 2x18VAC.
Do not replace the small BJT transistors!
Greetings Gabor
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