That's funny, I thought you were saying the B1 Korg wouldn't work for I/V or something.
Actually, yes. Clarity pretty-much across the frequency range. Especially on the high end. The low end seems tighter too. The noise level was extremely low to start with, so no change sensed there. If you have PS noise, I'm sure this would help.
But I generally shy away from such listening analysis associated with things like Power Supplies, Cables and such since so many think they don't actually make any difference. And that use to be me, so I just keep my head down.
But I generally shy away from such listening analysis associated with things like Power Supplies, Cables and such since so many think they don't actually make any difference. And that use to be me, so I just keep my head down.
It's not that you couldn't conceptually, but I don't think it would be easy and
possibly not worth the effort.
possibly not worth the effort.
The Korg B1 PCBs are back in stock, and everything is available from the still-presently-secret "pioneers" page Korg Nutube B1 – diyAudio Store
Now that the PCBs are back in stock, after a day or so I'll make an announcement to the main kit waiting list about the pioneer batch, of which we still have some left.
Now that the PCBs are back in stock, after a day or so I'll make an announcement to the main kit waiting list about the pioneer batch, of which we still have some left.
finished b1 korg
I recently completed my B1 Korg. Basic build.
-T7 and T8 set at about 9.5V
-using Triad power switching supply advised by Nelson Pass
-I only connected one input for the moment (I tried 2 inputs, but it was a pain soldering the toggle selector, and I got hum, probably my fault, will give it another try when I have time)
I did try using the B1 korg as a buffer, bypassing the Alps RK27 100k pot (using my dac volume control), it sound much clearer that way, the Alps volume control takes away some detail.
I did not inverse polarity because I have a small room with bass problems, inverse polarity cancels out some bass making the sound bass lean.
Sounds pretty good on my ACA and M2X.
I think the big volume knob is cool, my girlfriend says it looks like a shower faucet...
I will be building the BA3 preamplifier too, always nice to have 2 flavours to switch around.
Thanks Nelson Pass for the design.
I recently completed my B1 Korg. Basic build.
-T7 and T8 set at about 9.5V
-using Triad power switching supply advised by Nelson Pass
-I only connected one input for the moment (I tried 2 inputs, but it was a pain soldering the toggle selector, and I got hum, probably my fault, will give it another try when I have time)
I did try using the B1 korg as a buffer, bypassing the Alps RK27 100k pot (using my dac volume control), it sound much clearer that way, the Alps volume control takes away some detail.
I did not inverse polarity because I have a small room with bass problems, inverse polarity cancels out some bass making the sound bass lean.
Sounds pretty good on my ACA and M2X.
I think the big volume knob is cool, my girlfriend says it looks like a shower faucet...
I will be building the BA3 preamplifier too, always nice to have 2 flavours to switch around.
Thanks Nelson Pass for the design.
Attachments
I just bought on of the pioneers kit. Thank you Jason / Nelson. If I read 6 moons it says "the output impedance of the Nutube is something like 100K off the plate if I recall correctly. This does depend a bit on the load line for the part. I have been loading it with 330K on the plate. That seems pretty optimal and gives me 16 dB or so gain. Lower values would give the lower gain I prefer but don't seem as optimal sonically so there it is. The Jfet buffer has an output impedance of a couple of hundred ohms." my goal is to pair the B1 Korg Nutube with a Firstwatt SIT-3 so I would ideally need 16db or so gain. How can I obtain it? Finally I Hope output impedance of the Korg Nutube matches well with SIT-3. Any suggestion? Thank you!
per quote - you have 16db of gain with Korg B1
last stage being JFet buffer with Rout of ...... low enough - perfect for driving SIT-3
remember that SIT-3 is also having buffer as first input stage , so Rin is high ........ exact value in User Manual
lcky bstrd , having SIT-3 .......
last stage being JFet buffer with Rout of ...... low enough - perfect for driving SIT-3
remember that SIT-3 is also having buffer as first input stage , so Rin is high ........ exact value in User Manual
lcky bstrd , having SIT-3 .......
Here is my "Mini Pass Labs" B1 Korg. Note this is a modified build, so you will notice some differences. Voltages were right in line on power up. After warm up, dialed it in and numbers are solid. Now to try it with some Anaview (Abeltec) mono blocks I built earlier this summer.
Guess you don’t like electrolytics in the signal path.
Do I see a lack of input caps? No caps before the first stage? Is this safe if your source has no DC?
Do I see a lack of input caps? No caps before the first stage? Is this safe if your source has no DC?
Here is my "Mini Pass Labs" B1 Korg. Note this is a modified build, so you will notice some differences. Voltages were right in line on power up. After warm up, dialed it in and numbers are solid. Now to try it with some Anaview (Abeltec) mono blocks I built earlier this summer.
Yes very nice and compact build!
Could you share what value coupling caps you used.
Thanks. nash
Not secret, just don't want to confuse anyone, but because you asked, here are the caps.
NOTE: This is NOT how Nelson's design is spec'd.
Blue caps - Panansonic FC 4700uF
Brown caps - Elna Silmic 1000uF (audio grade)
Yellow caps - Audiocap Theta 2uF
White caps - Gen 1 Sonic Cap 6uF
All Elna by passed with RTE REL-CAP 0.01uf under the board.