peranders,
You probably already know it, but most japanese semiconductors
seem to be available in Sweden through Japan Electronic
Center AB www.jec.se They are not cheap, though. I suppose
their primary customers are repairshops.
Don't trust Elfa regarding discontinued devices. They give an
impression that devices are discontinued when they move them
to the special section of discontinued products or simply stop
selling them. This happened to four out of six transistors that
I was looking for, and that Elfa used to sell. After looking around
on the net it turned out they were all still in full production. Two
of them seem still available from Elfa, but they don't refill the
stock.
I don't mean to hijack the thread, but while we're at it, do you
know any good alternative suppliers to Elfa in Sweden? I know
about BHIAB, but are there any others I have missed that are
worth considering? By that I mean that they are either have
components that Elfa doesn't have or that they are considerably
cheaper. There used to be quite many a long time ago, but it
seems most of them are gone now.
You probably already know it, but most japanese semiconductors
seem to be available in Sweden through Japan Electronic
Center AB www.jec.se They are not cheap, though. I suppose
their primary customers are repairshops.
Don't trust Elfa regarding discontinued devices. They give an
impression that devices are discontinued when they move them
to the special section of discontinued products or simply stop
selling them. This happened to four out of six transistors that
I was looking for, and that Elfa used to sell. After looking around
on the net it turned out they were all still in full production. Two
of them seem still available from Elfa, but they don't refill the
stock.
I don't mean to hijack the thread, but while we're at it, do you
know any good alternative suppliers to Elfa in Sweden? I know
about BHIAB, but are there any others I have missed that are
worth considering? By that I mean that they are either have
components that Elfa doesn't have or that they are considerably
cheaper. There used to be quite many a long time ago, but it
seems most of them are gone now.
You can use them but beware of the large capacitancies
WHAT????
These are some of the lowest capacitance power mosfets out there and make great driver stages and output stages for line level circuits. They have been used in many great designs.
http://www.hitachisemiconductor.com/sic/resource/japan/eng/pdf/transist/e2081179_2sj76.pdf
http://www.hitachisemiconductor.com/sic/resource/japan/eng/pdf/transist/e2081241_2sk213.pdf
Design examples:
http://www.borbelyaudio.com/servo50.pdf
http://www.borbelyaudio.com/hybrid.pdf
I'm sorry that not everyone here will do even the minimal amount of research before posting advice. Maybe eventually they will get the message.
Art
WHAT????
These are some of the lowest capacitance power mosfets out there and make great driver stages and output stages for line level circuits. They have been used in many great designs.http://www.hitachisemiconductor.com/sic/resource/japan/eng/pdf/transist/e2081179_2sj76.pdf
http://www.hitachisemiconductor.com/sic/resource/japan/eng/pdf/transist/e2081241_2sk213.pdf
Design examples:
http://www.borbelyaudio.com/servo50.pdf
http://www.borbelyaudio.com/hybrid.pdf
I'm sorry that not everyone here will do even the minimal amount of research before posting advice. Maybe eventually they will get the message.
Art
Tuning the JC-2
Hi,
Peranders, my goal is to use this hotrod JC-2 in two versions one to drive any type of audio pro and consumer impedance that means that the output should be able to drive a 600 Ohm line.
The other is to drive headphones or a small bookshelf loudspeaker.
1. low impedance driving capability at least 600 Ohm
2. Driving headphone or and small loudspeakers with high efficiency.
3.I have ordered a shallco attenuator so my goal is the best electronics in my preamp box.
4. I also have ordered a faceplate from a machine shop made from 10 mm stainless steel.
Hi,
Peranders, my goal is to use this hotrod JC-2 in two versions one to drive any type of audio pro and consumer impedance that means that the output should be able to drive a 600 Ohm line.
The other is to drive headphones or a small bookshelf loudspeaker.
1. low impedance driving capability at least 600 Ohm
2. Driving headphone or and small loudspeakers with high efficiency.
3.I have ordered a shallco attenuator so my goal is the best electronics in my preamp box.
4. I also have ordered a faceplate from a machine shop made from 10 mm stainless steel.
Oh! Gosh
Maybe this is wrong forum for my questions and thoughts you must remember that I have a large amount of money that will leave my purse so a black hole will arise and maybe I can't buy food for a very long time.
I have tried to get some good schematics for my preamp project and I can't stick to the next best, I want the very best for the money.
Maybe this is wrong forum for my questions and thoughts you must remember that I have a large amount of money that will leave my purse so a black hole will arise and maybe I can't buy food for a very long time.
I have tried to get some good schematics for my preamp project and I can't stick to the next best, I want the very best for the money.
Re: You can use them but beware of the large capacitancies
The J79, K216 is very good as drivers but I was only pointing out to our fellow, depending of how he does, that connecting bigger fet's (larger capacitancies than before) can maybe give side effects. I suggest that you also try to help the thread starter instead of bashing your head into he wall.
artnyos said:WHAT????
I'm sorry that not everyone here will do even the minimal amount of research before posting advice. Maybe eventually they will get the message.
The J79, K216 is very good as drivers but I was only pointing out to our fellow, depending of how he does, that connecting bigger fet's (larger capacitancies than before) can maybe give side effects. I suggest that you also try to help the thread starter instead of bashing your head into he wall.
The JC design can drive 600 ohm load without problems (up to a certian level anyway) but small speakers....? Then you really have to have a more powerful output stage and also some feedback I gather. If you are in the fet business I suggest that you take a closer look att Borbelys stuff. All of his stuff is very well designed I think.
The JC design can drive 600 ohm load without problems (up to a certian level anyway)
Not at enough level to be useful for much.
"I suggest that you also try to help the thread starter instead of bashing your head into he wall." It is not the thread started who is causing me to hit my head against the wall. I am trying to help him but much of my time is taken up by correcting the frequent misinformation offered by other "helpful" posters.
Art
P.S
"Peranders,
They are available in Sweden and the price is about $10 for a pair of 2sk216 and 2sj79.
Can you attach them to the JC-2 output it would be very nice to get lower driving capability to this eminent design."
Can't you help out a fellow Swede who asked for you your advice?
Not at enough level to be useful for much.
"I suggest that you also try to help the thread starter instead of bashing your head into he wall." It is not the thread started who is causing me to hit my head against the wall. I am trying to help him but much of my time is taken up by correcting the frequent misinformation offered by other "helpful" posters.
Art
P.S
"Peranders,
They are available in Sweden and the price is about $10 for a pair of 2sk216 and 2sj79.
Can you attach them to the JC-2 output it would be very nice to get lower driving capability to this eminent design."
Can't you help out a fellow Swede who asked for you your advice?
Outbuffer suitable for 600 Ohm Load
Hi leiade,
If you download the following application note you will find in fig. 101 a Walt Jung like or double diamond buffer suitable to drive a 50 Ohm load gracefully. Fig 104 is even for 10 Ohm loads.
http://www.linear.com/pub/document.html?pub_type=app&document=50
Hope this helps.
Hi leiade,
If you download the following application note you will find in fig. 101 a Walt Jung like or double diamond buffer suitable to drive a 50 Ohm load gracefully. Fig 104 is even for 10 Ohm loads.
http://www.linear.com/pub/document.html?pub_type=app&document=50
Hope this helps.
Walt Jung Booster
Ok ! Elso
I will run this beast in my multisim maybe I can attach this to the output stage of the JC-2 but it would be more elegant to have FET's.
I have mailed the Positive Feedback regarding the mag where JC pooged the JC-2 but no answer ???.
I will also try to connect the ouput design from an early TAA where Erno show a bibolar design with fet output devices.
I had to get myself more time behind the Multisim so I can try som wierd models myself.
BTW I have found two German company's with great stuff cheap and esoteric
Ok ! Elso
I will run this beast in my multisim maybe I can attach this to the output stage of the JC-2 but it would be more elegant to have FET's.
I have mailed the Positive Feedback regarding the mag where JC pooged the JC-2 but no answer ???.
I will also try to connect the ouput design from an early TAA where Erno show a bibolar design with fet output devices.
I had to get myself more time behind the Multisim so I can try som wierd models myself.
BTW I have found two German company's with great stuff cheap and esoteric
JC-2
I will try one more time to help.......
http://db.audioasylum.com/cgi/search.pl
Enter JC-2 and John Curl in search field for two seperate searches. I do not believe that there was a "pooged" or updated version in the TAA or Positive Feedback. The origional schematic was posted in TAA, see below:
http://marklev.com/marklev/JC2/jc2schematics.jpg
I belive Mr. Curl has stated that the 2SK389 and 2SJ104 (Idss will have to be at least 10mA for 100 ohm drain resistors, for lower Idss the drain resistors will need to be larger)) were better choices for the jfets in this design. I would also suggest 2C2240 and 2SA970s for the bipolars. I believe that is sufficient information for this project. If not, you may be over your head on this and perhaps Peranders could design this for you.
Art
I will try one more time to help.......
http://db.audioasylum.com/cgi/search.pl
Enter JC-2 and John Curl in search field for two seperate searches. I do not believe that there was a "pooged" or updated version in the TAA or Positive Feedback. The origional schematic was posted in TAA, see below:
http://marklev.com/marklev/JC2/jc2schematics.jpg
I belive Mr. Curl has stated that the 2SK389 and 2SJ104 (Idss will have to be at least 10mA for 100 ohm drain resistors, for lower Idss the drain resistors will need to be larger)) were better choices for the jfets in this design. I would also suggest 2C2240 and 2SA970s for the bipolars. I believe that is sufficient information for this project. If not, you may be over your head on this and perhaps Peranders could design this for you.
Art
600Ohm
600 Ohm is that the pro have as a standard and I think it is the best, there are many things you can do if you have 600 Ohm impedance there are lots of transformers from any manufacturer in this area it's a common type so you can get one cheap if you have to run a transformer output.
You can also drive at least headphones my goal was to design a preamp that is a kind universal device for high end purposes and it also will do some job with my PC equipped with a Card deLuxe soundcard from DAL and so on.
I have seen lots of small mixers with PC possibilities but they are not good enough for an old hifi nut like me, I have to design my own hifi equipment as I can't trust the mainstream hifi ********.
600 Ohm is that the pro have as a standard and I think it is the best, there are many things you can do if you have 600 Ohm impedance there are lots of transformers from any manufacturer in this area it's a common type so you can get one cheap if you have to run a transformer output.
You can also drive at least headphones my goal was to design a preamp that is a kind universal device for high end purposes and it also will do some job with my PC equipped with a Card deLuxe soundcard from DAL and so on.
I have seen lots of small mixers with PC possibilities but they are not good enough for an old hifi nut like me, I have to design my own hifi equipment as I can't trust the mainstream hifi ********.
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