They have different pin out. I will have to test both by slight modification on perfboard if I will be curious enough. The 5459 has more Vp and good looking curves, is no slouch. It has potential.
I guess that the best will be to do 2SK170BL first so to keep near B1 and it remains interesting as a variation to DIYers, and after enough subjective evaluation, substitute 2N5459s and see what we have in hand for a much more accessible and cheap FET. I will use variable regulation with trimmers so I can get them B+,B- together or trim offset by introducing imbalance. That will let me listen for sweet spot PSU voltage as well. I will start with +/- 15V.
I guess that the best will be to do 2SK170BL first so to keep near B1 and it remains interesting as a variation to DIYers, and after enough subjective evaluation, substitute 2N5459s and see what we have in hand for a much more accessible and cheap FET. I will use variable regulation with trimmers so I can get them B+,B- together or trim offset by introducing imbalance. That will let me listen for sweet spot PSU voltage as well. I will start with +/- 15V.
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salas said:
Your vote please!
I managed to discover another 9 pieces 2SK170BL. I have a couple of good matches now. What do you prefer me to make and test? The 2N5459 symmetric supply B1 spin off, or a 2SK170BL one?
Hi Salas
I would prefer the 2SK170 (cause I'll get 3 matched pairs and one quad from a group buy). Further I would appreciate a circuit without the 10µF or the 1µF caps. But, the original Pass circuit would be a nice try, too. So, it's your decision (what to solder first
).Please feel free to share your measurements and listening impressions. Good luck and hot iron!
Skorpio said:
Hi,
I understand your arguments, but:
1. Why use +100$ for audiophike capacitors if they can be avoided with >1$ components? The other thing is part size....
2. Capacitors do not sound as good without voltage accross them
3. I was not thinking of a bad servo, but a good one
4. I have allready matched JFETs in circuit (9.53 and 9.55mA)
5. I have low offset, but would like the servo for longterm drift and safety. I do not have DC-protection...
I have now build the servo in and made it optional with a jumber. I have change the servo to only work in one single point, the output.
There is no sonic influence to me if the servo is in or not, but it my be because the correction it makes is so small?
Please read the datasheet.
IDSS-classes are perfectly normal and don't affect much a circuit unless you parallel them. Manufacturing low-noise jfets does require strict quality control.
Don't forget jfets are not "state of the art" devices (not from a manufacturer point of view at least), the same and even better parts existed already in the 80ies.
Today jfets just consume area in the manufacturing plant, are phased out of production to allow manufacturing of higher $ parts.
Have fun, Hannes
Basically what I have done by now
Found some spare time, and populated the perf-board. Done half the point to point also. I am putting together 1 positive & 1 negative regulated PSU, 1 output delay relay circuit and 2 channels of capacitor-less B1s. Hopefully in the next few days I will find time to finish it and test it little by little. Will report.
Next post includes the awfully sketched schematic.
Found some spare time, and populated the perf-board. Done half the point to point also. I am putting together 1 positive & 1 negative regulated PSU, 1 output delay relay circuit and 2 channels of capacitor-less B1s. Hopefully in the next few days I will find time to finish it and test it little by little. Will report.
Next post includes the awfully sketched schematic.
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