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Re: BJFE-Baby Blue

PostPosted: 01 Feb 2018, 09:37
by Jone the Bone
Nick123 wrote:I think I have found an error in the last schematic.
Only the wiper of RV2 should be grounded.


There is no error. In this circuit it doesn't matter, it's only an another way to connect a potentiometer.

Re: BJFE-Baby Blue

PostPosted: 18 Feb 2018, 15:48
by momo lab
Hi everyone, I'm back!Sorry for not coming so long, but our country has a “Great Wall firewall”,So I have to resort to some network tools to normal visit。
BBOD I have completed the test, 1N4XXX diode for the circuit sound will be bright and thin, so I had to modify the EQ part.Parallel into a 102 capacitor will sound almost exactly the same。
I wish you have fun, thank you.

Re: BJFE-Baby Blue

PostPosted: 01 Mar 2018, 12:32
by Manfred
Hi momo lab,

I would very much appreciate it if could you measure the drain and source voltages an give the read values to us.

Re: BJFE-Baby Blue

PostPosted: 04 Mar 2018, 11:52
by momo lab
Manfred wrote:Hi momo lab,

I would very much appreciate it if could you measure the drain and source voltages an give the read values to us.
QQ截图20180304185035.jpg

Re: BJFE-Baby Blue

PostPosted: 04 Mar 2018, 16:01
by Manfred
momo lab wrote:
Manfred wrote:Hi momo lab,

I would very much appreciate it if could you measure the drain and source voltages an give the read values to us.
QQ截图20180304185035.jpg


Thanks for the hint, I checked the topic twice, but I have overlooked. :slap:

Re: BJFE-Baby Blue

PostPosted: 06 Mar 2018, 11:05
by Manfred
After the measurement, the first stage FET voltage is 4.62V and 1.72V, the second stage FET voltage is 4.72 / 1.68 and the third stage is 5.55 / 1.44.

I got a bunch of 2N3822 FETs, which are almost equal as the 2N5952 FET, except the maximum voltage and current values.
I ran a curve traces of it, to drawing in the resitor values in found characteristic curves graphic.
The graphical soultion gave values in the vicinity of the read values of momo lab's measurement,
therefore the 2N5252 seem to be the right choice.

Re: BJFE-Baby Blue

PostPosted: 08 Mar 2018, 14:11
by ray86
Fairly straight forward JFET circuit with hard clipping in the 2nd stage