It seems, I overlooked jaycee's question. Sorry!
One will find BF470/469 frequently in my designs and there are few (for me) good reasons for that: at one moment I've managed to obtain cheaply a significant quantity of them, I have BF470/469 simulation model in my SPICE program, they appear to exhibit more linear transfer characteristic than majority of similar units on the "current fashion" list,
and their internal capacitance's are significantly lower allowing less
problems and faster amps. Praxis proved me right for now. They use to be readily
available anywhere ( for previously mentioned reason I am not aware that they are discontinued?!), they are in a handy package-case and with very usable Uce and
dissipation.
Even thou I didn't test them as replacements, I strongly believe that something like MJE340/350 or newer version like BF869/870 (I think they are in different package?) should be adequate. Certainly, there must be at least a dozen of Japanese complementary pairs to fulfill requirements. Maybe Sanyo's 2SC3116/2SA1248 or alike...
Pozdrav od sveg srca za sve moje "zemljake", a ja bez razlike pod time podrazumevam sve one koji razumeju ove reci!
One will find BF470/469 frequently in my designs and there are few (for me) good reasons for that: at one moment I've managed to obtain cheaply a significant quantity of them, I have BF470/469 simulation model in my SPICE program, they appear to exhibit more linear transfer characteristic than majority of similar units on the "current fashion" list,
and their internal capacitance's are significantly lower allowing less
problems and faster amps. Praxis proved me right for now. They use to be readily
available anywhere ( for previously mentioned reason I am not aware that they are discontinued?!), they are in a handy package-case and with very usable Uce and
dissipation.
Even thou I didn't test them as replacements, I strongly believe that something like MJE340/350 or newer version like BF869/870 (I think they are in different package?) should be adequate. Certainly, there must be at least a dozen of Japanese complementary pairs to fulfill requirements. Maybe Sanyo's 2SC3116/2SA1248 or alike...
Pozdrav od sveg srca za sve moje "zemljake", a ja bez razlike pod time podrazumevam sve one koji razumeju ove reci!
Karlos, you must learn serbian or even better macedonian! 
Here on south of Europe we have some miracles in electronics too!
I'm glad for my neighbours from north, same for us macedonians!
Bora, radujem se sto tvoje znaje i iskustvo nalazi pravo priznanje, a diyAudio sajt je pravo mesto za svakog audio fanatika.
Najsrdacniji pozdrav! = (best regards)
Here on south of Europe we have some miracles in electronics too!
I'm glad for my neighbours from north, same for us macedonians!
Bora, radujem se sto tvoje znaje i iskustvo nalazi pravo priznanje, a diyAudio sajt je pravo mesto za svakog audio fanatika.
Najsrdacniji pozdrav! = (best regards)
By the way...i am sorry i wrote Bora's country name wrong.
Serbia is the correct name....i wrote Servia and this is wrong.
I am afraid that Servia can be something very bad.
Alike your wife's mother moving into your home!.... oh!...pain!!!.... oh!...do you like your mother in law?
hehe..i can send mine to you!...if you promiss not return.
regards,
Carlos
Serbia is the correct name....i wrote Servia and this is wrong.
I am afraid that Servia can be something very bad.
Alike your wife's mother moving into your home!.... oh!...pain!!!.... oh!...do you like your mother in law?
hehe..i can send mine to you!...if you promiss not return.
regards,
Carlos
Bora, your Goliath amplifier is a straight adaptation of Elektor's Crescendo amplifier. I wonder how it works at all, since you have used vertical mosfets and there is no Vgs, or Vbe multiplier or any other temperature sensing mechanism at work. If anyone has every tried this amp practically, thermal runaway should have occured some time or the other. Any explanations?
The other designs look great. Perhaps I'll try them out after I have finished with the GEM (testing prototype in two hours time!!)
The other designs look great. Perhaps I'll try them out after I have finished with the GEM (testing prototype in two hours time!!)
bf469 and bf470
I believe WES in Sydney still have BF469 and BF472 (higher voltage but otherwise same as BF470) I bought 30 BF469's a while back. http://www.wagner.net.au/
futurlec also has BF469's but they don't have bf470's or bf472's
Tony.
I believe WES in Sydney still have BF469 and BF472 (higher voltage but otherwise same as BF470) I bought 30 BF469's a while back. http://www.wagner.net.au/
futurlec also has BF469's but they don't have bf470's or bf472's
Tony.
Samuel Jayaraj said:
Thank you Samuel for noticing that mistake, and I apologize to all others too. Frankly, I never noticed that I typed IRFP models instead of 2SK1056/2SJ162 and that schematic (with a mistake) has been on my site for last few years. Disaster! Without Vbe multiplier, IRFP's would certainly have a sad destiny! Hopefully, anyone with experience will probably immediately notice another clue: bias trimmer is only 250 ohms and knowing the threshold voltages for opening IRFP's, will realize that current through drivers would have to be almost 300mA to produce necessary voltage drop for both sides.
The schematic is very similar to Crescendo (as well as at least a few dozen others one could find all over the WEB) which is one of more or less generic topologies well known and widely used.
!
JA NE DOZVOLJAVAM DA SE BILO KO NA TAKAV NACIN OBRACA BORI.BORA MI JE MNOGO POMOGAO U "SAZREVANJU" U OVOJ OBLASTI I MNOGO MU SE ZAHVALJUJEM JER SAM DOSTA NAUCIO OD NJEGA A ZELIM DA SE TAKO I NASTAVI.JA SAM DO SADA URADIO BORINO POJACALO STUDIO I UNIVERSAL I OBA SU PRORADILA.STUDIO JE PRORADIO IZ PRVE I BEZ GRESKE JE SVIRAO I DAVAO LEP ZVUK.KAZEM LEP JER NEMAM KVALITETNE ZVUCNE KUTIJE KAKO BI UTISAK BIO UPECATLJIV.
Sve u svemu,svako ko napravi neko Borino pojacalo se nece pokajati.
JA NE DOZVOLJAVAM DA SE BILO KO NA TAKAV NACIN OBRACA BORI.BORA MI JE MNOGO POMOGAO U "SAZREVANJU" U OVOJ OBLASTI I MNOGO MU SE ZAHVALJUJEM JER SAM DOSTA NAUCIO OD NJEGA A ZELIM DA SE TAKO I NASTAVI.JA SAM DO SADA URADIO BORINO POJACALO STUDIO I UNIVERSAL I OBA SU PRORADILA.STUDIO JE PRORADIO IZ PRVE I BEZ GRESKE JE SVIRAO I DAVAO LEP ZVUK.KAZEM LEP JER NEMAM KVALITETNE ZVUCNE KUTIJE KAKO BI UTISAK BIO UPECATLJIV.
Sve u svemu,svako ko napravi neko Borino pojacalo se nece pokajati.
!
I made boraomega Studio amplifier and I am very pleased with sound. I strongly recommend you too built this HI-END amplifier. My friend has also built Studio amplifier. Soon he will post those pictures’s here. I made also Universal amplifier but with IRFP240 and IRFP9240 instead 2SK1058 and 2SJ162.You can found something more if you click here http://www.hifi.co.yu/forum/viewtopic.php?t=551
I am currently working on Legend amplifier but with 8 IRFP250.
POZDRAV SVIMA.
I made boraomega Studio amplifier and I am very pleased with sound. I strongly recommend you too built this HI-END amplifier. My friend has also built Studio amplifier. Soon he will post those pictures’s here. I made also Universal amplifier but with IRFP240 and IRFP9240 instead 2SK1058 and 2SJ162.You can found something more if you click here http://www.hifi.co.yu/forum/viewtopic.php?t=551
I am currently working on Legend amplifier but with 8 IRFP250.
POZDRAV SVIMA.
