Recently, we have all witnessed the disappearance of many a good transistor, be it FET, MOSFET or BJT. Perhaps you know ofa good replacement?
Putting together a say cascode stage is know well enough in theory, but it's also known that while electrically compatible, some transistors make a particularly happy match, which simply sounds better than many others. If you know of such a pair, do tell.
You recently first used a transistor, or a complementary pair, and you feel it's a small discovery - let everybody know.
In short, let's all pool together our joint compound experience and help each other out.
Putting together a say cascode stage is know well enough in theory, but it's also known that while electrically compatible, some transistors make a particularly happy match, which simply sounds better than many others. If you know of such a pair, do tell.
You recently first used a transistor, or a complementary pair, and you feel it's a small discovery - let everybody know.
In short, let's all pool together our joint compound experience and help each other out.
Fine Oswaldo, but you should explain why is that so, so that someone who has never used them will know why he should.
I wanted to say as I did in another thread KSP94 as the only reasonably available TO 92 400 V PNP . If building an all NPN output stage at high voltage ( triples ) it is a useful device . RS worldwide have them still .
White cathode follower and not in valves ! Hiraga eat your heart out !
White cathode follower and not in valves ! Hiraga eat your heart out !
It works fine in a regenerative portable AM receiver, as I don't need extremely high audio gain nor quality.
I have a small FM transmitter bought from the petrol station for $8 . It took a few attempts to bypass the switch that never worked . It is connected to the TV sound section which is like MPS . I then listen via my Magneplanars and Quad FM3 tuner . Not because that was the plan . No , because it is so good ! It is for listening in bed and not disturbing others .
My father was in the Air Force . He bought a regenerative radio in Germany about 1952 . It cause problems for the RAF, he was told not to use it ( the PA system mostly ) ! He taught me electronics when 4 years old and mentioned regenerative radios then ! It started when I took the back off of the radio . All he said was " that point will kill you " . It was the output transformer and I still remember him saying how and why it works . He was right , he said the valve has high voltage and low current . The speaker needs low voltage and high current . The transformer has coils in a ratio to allow that to happen , the iron magnetically couples the coils and enhances the performance . Children are never too young to learn . The only time I got hurt was a DY87 diode , it was like Kung Fu and I jumped across the room .
Transistors of note
Exicon 10N/P 20 .
Valves of note , EL 84 , EL 34 and all ECC8.. . Why not ?
My father was in the Air Force . He bought a regenerative radio in Germany about 1952 . It cause problems for the RAF, he was told not to use it ( the PA system mostly ) ! He taught me electronics when 4 years old and mentioned regenerative radios then ! It started when I took the back off of the radio . All he said was " that point will kill you " . It was the output transformer and I still remember him saying how and why it works . He was right , he said the valve has high voltage and low current . The speaker needs low voltage and high current . The transformer has coils in a ratio to allow that to happen , the iron magnetically couples the coils and enhances the performance . Children are never too young to learn . The only time I got hurt was a DY87 diode , it was like Kung Fu and I jumped across the room .
Transistors of note
Exicon 10N/P 20 .
Valves of note , EL 84 , EL 34 and all ECC8.. . Why not ?
Forgive him , and me . Dvv surely we can talk cars ?
BU 208 . Can it be used in audio ? I was thinking a very high voltage amp . I am told SOA is poor .
Nige
BU 208 . Can it be used in audio ? I was thinking a very high voltage amp . I am told SOA is poor .
Nige
I am not going to be able to add any useful information to this thread but was wondering if I can make a suggestion for those of us following this thread. Would it be possible to do this like I have seen some of the group buy threads in that as each new transistor or transistor pair is listed that it is added to a common posting. In that I meas add your individual transistor to a list with the major properties listed in column form so it will be easy to see the list and compare properties. You can still have individual posts with comments about a particular transistor and where to use it but you would keep a running list that would continually be added to with new devices. Just a suggestion to keep it easy to find the complete information.
Thanks,,
Steven
Thanks,,
Steven
Thanks for starting this thread. It will help everyone, and I already had this topic on my roadmap for the second edition of my book. It pains me that some devices I mentioned in the first edition may no longer be available.
I might mention that I have some potentially conflicting information about whether the ThermalTraks have been discontinued, but I have not had time to dig more deeply and try to contact OnSemi directly. I'll look forward to hearing from any of you in regard to what you may have heard about the ThermalTraks.
It is also notable that just because a vendor decides to no longer carry a part, it does not necessarily mean that the part has been discontinued. In practice, of course, it may likely mean that it is more difficult to get or must be bought in larger quantities.
Cheers,
Bob
Semelab still makes a wide range of audio transistors with high speed and up to high voltages.
Products -TT electronics Semelab
Products -TT electronics Semelab
I have sometimes the opposite impression : there are a lot new semiconductors availlable.
Here he ROHM power portfolio :
http://rohmfs.rohm.com/en/products/...m_medium=email&utm_source=Rohm_etech_EMEA_SiC
SiC in on the way for example. I think that audio designer are a bit conservative and do not like change when the circuit they build with older semiconductors works so well.
Here he ROHM power portfolio :
http://rohmfs.rohm.com/en/products/...m_medium=email&utm_source=Rohm_etech_EMEA_SiC
SiC in on the way for example. I think that audio designer are a bit conservative and do not like change when the circuit they build with older semiconductors works so well.
This BISS transistors are potentially good for low voltage noise phono MC use :
Low VCEsat (BISS) transistors :: NXP Semiconductors
Zetex, now Diodes Inc. makes similar ones i tested. They habe Rbb´under 10 Ohm and low 1/F with good Hfe.
Low VCEsat (BISS) transistors :: NXP Semiconductors
Zetex, now Diodes Inc. makes similar ones i tested. They habe Rbb´under 10 Ohm and low 1/F with good Hfe.
The only real problem i have is the more or less unavaillability of super low noise P-channel J-Fets. I realy hope that Linear Systems gets their act together.
Hi Joachim . Dvv who started this thread loves J Fets . Super low noise P types would be great . Do you find them less fussy about input impedance ? I guess they must be ?
Do you use them in LTP ? Or do you go for the lower noise of a single input ? The better J FET's I saw were about 0.7 nV although I was warned not to compare with low Rbb transistors as the figures are not directly equivalent ( optimum impedance I guess when coils are about 5 R typically ? ) .
If in LTP how well do they balance as regards DC offset if in a circuit also tried with bipolar ?
2SA 1085 any good ?Think they are all gone now ?
Do you use them in LTP ? Or do you go for the lower noise of a single input ? The better J FET's I saw were about 0.7 nV although I was warned not to compare with low Rbb transistors as the figures are not directly equivalent ( optimum impedance I guess when coils are about 5 R typically ? ) .
If in LTP how well do they balance as regards DC offset if in a circuit also tried with bipolar ?
2SA 1085 any good ?Think they are all gone now ?
A BU208 has an hfe of less than 7. OK for switch mode power supplies and line output stages with a high current drive section. Audio in class A, B or AB; no good. Class C or D maybe.
Just in case anyone is as lazy as me a sample of Semelab . PNP high voltage seem a good choice . A screen grab so not the best .
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