Get extra SS jfet for backup, and having more Toshiba jfets in your drawer is a nice inventory. i just ordered another 8pairs of that tiny jfet 8mA from alweit. I'm pretty sure that Papa will keep going to use this little angel (devil).
isn't there a post saying that even a F7 clone will beat J2 original just kidding, maybe i read wrong number behind.
Oh I have bunch of them on hand, just want best ones for this particular application to be put away for that day.
Russellc
You need 2SK170G if you want them with 4-5mA Idss. (I think G goes from about 2 to 6mA Idss)
You can add a bit of resistance to lower the current passing through the jfet.
For example, see here:
A current source based on a JFET
You can add a bit of resistance to lower the current passing through the jfet.
For example, see here:
A current source based on a JFET
Pass DIY Addict
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Yep - just put a small resistor (5R or 10R) in series with the source pin to degenerate the current through the device and decrease the output level. I had to do this with my Pearl II phono stage because it was distorting with a 5mV output cartridge. Putting 20R resistors ahead of jFets with Idss of about 8.9mA reduced them to about 5.3mA each. Problem solved.
Anyone heard of source for SK170 with 4-5mA Idss ? Need two quads...I can find 6.5, but nothing below. Anyway to use 6.5 trimmed down to 4-5 Idss? I figure it doent work that way? I own only 1 pair of SK170 at 4.7 idss......
Russellc
Member NicMac is selling matched quads of 2SK170GR(een)
That is clever Eric!
Yep - just put a small resistor (5R or 10R) in series with the source pin to degenerate the current through the device and decrease the output level. I had to do this with my Pearl II phono stage because it was distorting with a 5mV output cartridge. Putting 20R resistors ahead of jFets with Idss of about 8.9mA reduced them to about 5.3mA each. Problem solved.
Got some J109BL for sale if anyone interested!
Is this the part originally specified for J2? (2SJ109BL)
Russellc
Last edited:
Russel, Toshiba 2SJ109-BL are the one used in J2.
I would be interested in a pair... What Idss?
I would be interested in a pair... What Idss?
They are BL devices with most Idss around 8 and can be anywhere between 6-12.
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