2N5457 and 2N5460 (MMBF5457 and 5460) -- I was surprised that the noise isn't as bad as in the old datasheets. They are, by no means, as quiet or "gm muscular" as the original Toshiba parts. The pins are arranged differently with the Fairchild devices.
If you can live with 7.5x10mm board size, then yes.
This is 5x5, true TO92 size :
http://www.diyaudio.com/forums/head...eadphone-amp-linear-audio-15.html#post3930254
http://www.diyaudio.com/forums/atta...h-headphone-amp-linear-audio-sot23_2_to92.jpg
Patrick
This is 5x5, true TO92 size :
http://www.diyaudio.com/forums/head...eadphone-amp-linear-audio-15.html#post3930254
http://www.diyaudio.com/forums/atta...h-headphone-amp-linear-audio-sot23_2_to92.jpg
Patrick
Could I use JFET, PMBF4393 Compre Transistores JFET Transistor JFET, PMBF4393,215, N-Canal, 30mA, 40V, TO-236AB, 3-Pines NXP PMBF4393,215 en RS Online y lo recibir en 24 horas. in place of PN4393?
Should work ok, as they're SOT-23 versions of the TO-92 part, which was the TO-92 version of the original TO-18 metal can part (2N4393). Some Ebay sellers in China offer a clamshell-type socket which could be used for testing/screening devices. One could also test them after mounting them down on an adapter board.
Let me know where you find a header with small enough pitch to accommodate SOT-23s as shown.
The only fets that could really use matching are the ones used for the bottom current source of the follower, and that's a matter of convenience so one can use all the same resistor for setting the bias current. You could roughly match the fets with IDSS sorting, experiment with the value of source resistor needed for a desired bias current (somewhere between 5-10 mA), and use that resistor for all the matched bottom fets.
Another alternative is to use the BSS159 depletion mode fet for the current source. The consistency of these devices right out of the bag make matching mostly unnecessary. If I recall correctly, ~200 ohms source resistor will get you about 10 mA bias current. Raising the resistor lowers the bias current. As usual, you should use a 1k stopper resistor from gate to ground to prevent oscillation.
The only fets that could really use matching are the ones used for the bottom current source of the follower, and that's a matter of convenience so one can use all the same resistor for setting the bias current. You could roughly match the fets with IDSS sorting, experiment with the value of source resistor needed for a desired bias current (somewhere between 5-10 mA), and use that resistor for all the matched bottom fets.
Another alternative is to use the BSS159 depletion mode fet for the current source. The consistency of these devices right out of the bag make matching mostly unnecessary. If I recall correctly, ~200 ohms source resistor will get you about 10 mA bias current. Raising the resistor lowers the bias current. As usual, you should use a 1k stopper resistor from gate to ground to prevent oscillation.
See the same at Mouser :
Infineon bss159 MOSFET | Mouser
BSS159N H6327 is random Vgs.
BSS159N L6906 is pre-selected in Vgs bands.
See datasheet P.1 & Figure 11.
Idss 130mA is IMHO way too overkilled as a JFET buffer for line level.
You may also wish to consider 2SK209BL, or 2SK2145BL (dual), both available from Mouser.
Patrick
Infineon bss159 MOSFET | Mouser
BSS159N H6327 is random Vgs.
BSS159N L6906 is pre-selected in Vgs bands.
See datasheet P.1 & Figure 11.
Idss 130mA is IMHO way too overkilled as a JFET buffer for line level.
You may also wish to consider 2SK209BL, or 2SK2145BL (dual), both available from Mouser.
Patrick
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I guess isn't correct, I guess the new attached one is the correct?
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