Which is a better sub for 2N5457: BF244 or BF245?

[gigimarga]

Here, in Romania, it's very hard to find 2N5457, but there are a lot of BF244/BF245.
Which of them is a better sub for 2N5457?
J201 can be used instead of 2N5457 (especially in ROG's Thor and Omega)?

Thx a lot!

[petemoore]

http://www.datasheetcatalog.com/datasheets_pdf/B/F/2/4/BF245.shtml
  Says it's an N channel, good for audio and radio frequencies, sounds pretty good for the intended purpose.
  Link to download on 245:
  http://www.datasheetarchive.com/preview/851030.html
  Looks like about the same thing, the second transistor in Omega is mosfet.
 

[gigimarga]

Thx a lot!

[George Giblet]

BF244 is pretty much the same as the BF245.  Both come in A, B and C suffixes.

The best sub for the 2N5457 is the BF244A/BF245A.   The philips cross reference seems to say the same thing:

http://www.nxp.com/acrobat_download/other/discretes/Philips_RF_Manual_2nd_edition.pdf

> J201 can be used instead of 2N5457

A lot of amplifier circuits will work with widely varying characteristics.  J201 vs 2N5457 shows just how loose a match you can get away with.

[gigimarga]

Thx a lot...only problem remains that i have a lot of BF245C ...but i will look after BF245A!!

[mac]

I'd say BF244/5 A.
I never had bias problems using BF245 A, I mean distortion, compressors, phasers, tremolos, etc.

I use BF245 C to replace MPF102, and 2SK117 instead of J201.

mac

[Plexi]

I'd say BF244/5 A.
I never had bias problems using BF245 A, I mean distortion, compressors, phasers, tremolos, etc.

I use BF245 C to replace MPF102, and 2SK117 instead of J201.

mac

I agree with that
No need to re-biasing the JFet


Which values are the most important to compare JFets?
I'm readint the datasheets

[mac]

Which values are the most important to compare JFets?
I'm readint the datasheets

Yfs, forward transfer admittance
Vgs(off)

mac

[Plexi]

Thanks mac!

[maiko]

MPF102   Tried this on projects
just research pinouts again

[distortionhead]

I'd say BF244/5 A.
I never had bias problems using BF245 A, I mean distortion, compressors, phasers, tremolos, etc.

I use BF245 C to replace MPF102, and 2SK117 instead of J201.

mac

voltage and bias settings? pinouts are the same? got some bf245c thinking of doing a distortion may be a bsiab ii thoughts on that?

[Plexi]

http://i218.photobucket.com/albums/cc93/ftrock/Transistorpinout.jpg

[mac]

voltage and bias settings? pinouts are the same? got some bf245c thinking of doing a distortion may be a bsiab ii thoughts on that?

I never breadboarded a BSIAB. But 245C can work fine.

mac

[Plexi]

I would use BF245 instead of the 2n5457, as Mac says.
You will not have problems with bias.

[distortionhead]

will try and get back.. first would like to try a simple fetzer valve circuit.

[Plexi]

Fetzer valve is great and simple to start.
It's good to learn and try some adds