Now I have BC560C and BC550C of hfe value around 640 and within 1% tolerance, and I think I am ready to go.
Thanks Hikari1 for the guide.
Good luck, let us know what you think about the sound.
As always, I am in a problem. 
Just too much current at power up. I checked again the hfe of transistors and they show the same values as before.
I suspect these ;
My Jfet is 13mA grade. Is this fine?
The small red LEDs I use give 1.3V across them without light. What is the target voltage of LEDs?
I used 10 ohm pot between sources of K170 and J74, with wiper to the 220ohm R should I increase this value?
Two channels show similar voltage with mirrored values at voltage rails, so I think I did not miserably fail.
One thing funny I did was using the terminals for all parts..
Just too much current at power up. I checked again the hfe of transistors and they show the same values as before.
I suspect these ;
My Jfet is 13mA grade. Is this fine?
The small red LEDs I use give 1.3V across them without light. What is the target voltage of LEDs?
I used 10 ohm pot between sources of K170 and J74, with wiper to the 220ohm R should I increase this value?
Two channels show similar voltage with mirrored values at voltage rails, so I think I did not miserably fail.
One thing funny I did was using the terminals for all parts..
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I found that 47R for R2 R4 were 47K...... my aging eyes made mistakes again.
I checked the sign waves, voltages across the R2~R4 all fine at 0.4~0.6VDC, and LEDs are on.
Now I am putting this into my BA-3 pre chassis ...
I got the feeling that I may not need the cap at the output.
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Thank you all, now it is working.
I disconnected the signal board from my BA-3 pre and used batteries for now because the supply board cannot go to 12VDC. The output is via the 3.3uF Jupiter Bewax cap. LDR volume and DEFiSIT using 2SK182ES to Altec Valencia.
The feeling of 'SPACE' is different with this pre. Some well-recorded music makes you appreciate the stage width and depth.
I somehow feel the sound is more solid, maybe due to this soundstage?
I'd like to thank Nelson Pass, Juma, and Hikari1 for this build.
I think I have one good pre to compare the DHT pre that I am planning.
Now I have to work out how to house this pre...
I disconnected the signal board from my BA-3 pre and used batteries for now because the supply board cannot go to 12VDC. The output is via the 3.3uF Jupiter Bewax cap. LDR volume and DEFiSIT using 2SK182ES to Altec Valencia.
The feeling of 'SPACE' is different with this pre. Some well-recorded music makes you appreciate the stage width and depth.
I somehow feel the sound is more solid, maybe due to this soundstage?
I'd like to thank Nelson Pass, Juma, and Hikari1 for this build.
I think I have one good pre to compare the DHT pre that I am planning.
Now I have to work out how to house this pre...
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Hikari1, are you making any progress of attached circuit that you initiated?
I am intrigued..
No, I had actually built another of Juma's preamps amp and the follower stage to try it but I couldn't get the follower working...I am sure it can be done. But I got distracted and had to use the Jfets for another project. So I never completed the project. Plus, I have my doubts it would sound better unless you need the current drive, which I do not. But it would be nice to have for headphones. But I don't really like headphones that much...
If Juma gave us this current mirror preamp with laterals on the output I would build it.
This preamp is also the gain stage of his "cubie" amps which I am guessing sound very good as well. Maybe your next project?
I put 10uF Russian oil cap, replacing 3.3uF Beewax, and the balance feels in the middle.
Or does this oil cap(?) roll off some high or does this cap break in, I do not know.
Then I checked the DC offset at the output, a few millivolts, and removed the coupling cap. Now I have this solid feeling without the cap.
DC offset seems to drift within tens of millivolts. I need to watch this for more time or in the actual case.
Or does this oil cap(?) roll off some high or does this cap break in, I do not know.
Then I checked the DC offset at the output, a few millivolts, and removed the coupling cap. Now I have this solid feeling without the cap.
DC offset seems to drift within tens of millivolts. I need to watch this for more time or in the actual case.
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I am eager to use LSK BAF 2013 but my dac oouput impadance is few hundered ohms. So is there any way to increase LSK BAF 2013 input impedance?