2SK170 which to use gr bl or v? f?

[audio mind]

2SK170 which to use gr bl or v? The gr draws the least current the v the most although most designs I have seem to use the bl version any major sound differences between the three?

Does anyone know about a 2SK170BL ADDC: (F) version? No info on the data sheet from Toshiba for the "f'" version. Thanks to anyone with info on these......

 

[wintermute]

It might help if you specify what the application is depending on the circuit higher or lower current draw may be desirable.

Sure it might sound better if you use the right one, but it won't be because A BL universally sounds better than a gr, it will be because it is more suitable for that particular circuit, and for a different circuit the gr may be a better choice.

Tony.

 

[jackinnj]

Good place to start understanding is with Erno Borbely's articles which appeared in Audio Electronics 5/99. Erno seems to have taken his site down, but the articles appear in several places:

http://ken-gilbert.com/images/pdf/erno_borbely_on_jfets.pdf

There's not an easy answer -- it depends upon the impedance of the following stage and how the device is biased. There's a rule of thumb, however which states they sound best when biased to 70% of Idss.

 

[audio mind]

Thanks for the quick replies. I am using them to try out a few of the the moving magnet phono pres found on the web. I found out ADDC: (F) version apparently is the specific Toshiba batch code for the 2SK170BL. I am not sure if it is any better than non "F" versions.

I think most are using the "BL" version in the phono pre's but it is not usually specified. It is funny even the stop box people seem to like the BL over the GR stating it is smoother less harsh. Guess the high current "V" is harder to come by and maybe not used because of this?

Thanks for the Borbely article link. I scanned it but will read it more closely later on. Interesting.