So I completed the "no frills" version of the B1K. All voltages came out within tolerances and I've set the bias at 10V per Mr. P's recommendations. I used a laptop with Roon, and an iFI Black DAC to feed it. I let it push my ACA to my Tekton Ulfberht speakers. I was shocked at how good it all sounded. The ACA had NO problem pushing my 100+ dB efficient Tektons using the gain from the Korg. Even the low end was present and accounted for with no sub connected. With 5 watts? Really? Thanks Mr. Pass. This is just awesome.
At this point I haven't even installed an off-on switch. But now I'm going to circle back with some additions and upgrades AFTER I finish the F5 build I have going because I'm very interested in how this will sound going from the ACA to the F5.
My wife loves my audio hobby and often listens. But she is also my most critical listener. She has bat hearing too. She was amazed with what she heard from the first song. That just never happens. Well anyway, below is my version of the B1K base version. Now on to the F5. Hope my beginners luck holds for a while.
At this point I haven't even installed an off-on switch. But now I'm going to circle back with some additions and upgrades AFTER I finish the F5 build I have going because I'm very interested in how this will sound going from the ACA to the F5.
My wife loves my audio hobby and often listens. But she is also my most critical listener. She has bat hearing too. She was amazed with what she heard from the first song. That just never happens. Well anyway, below is my version of the B1K base version. Now on to the F5. Hope my beginners luck holds for a while.
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Cheers
Mr. Kaneta San do always projects on the perfboards, small modules made one by one then wired together 🙂
Thanks for that information. The idea of using the Nutube in that application is very interesting. But at this point, I've built exactly two projects and I don't think I'm ready for one in Japanese yet.
Congratulations Your B1 Triode is sing nicely
This Akihiko Kaneta MC Phono is bit complex and with bunch of active components , cost are + twice ,
interesting design for filaments etc.
I have built two preamps so far using this case / "passive preamp", one an Aikido, the other Wayne's BA 2018 linestage.
Initially, in at least one of them I had hum issues as well. The fix I did was as follows: If you look at the relay board in the back of the unit, the left part of the board with the seven relays is the volume attenuator. At the front left of this board are two eyelets in the board, named "case" and "aground" respectively. (as you can see in the photos on the eBay auction).
I don't remember exactly if the relay board had been grounded to the case via the mounting screws, but with no audio cables connected, there should not be an electric connection between these two points and the case. You can check with an Ohm meter. If necessary, you might have to isolate some of the standoffs from the board.
Then, I connected the eyelet "aground" through a CL-60 to the case, but you can use a 10R - 100R resistor for this as well. The case itself is grounded / connected to PE / earth ground.
That gives a defined path between audio ground and earth ground / case without the risk of a ground loop.
This cured the hum completely for me.
Hope this helps, otherwise we will look into it in more detail. Since I have gotten two different units completely hum-free, the odds are good ... 🙂
Best regards, Claas
In the latest MJ (Japanese diy magazine) you will find the B1 Korg article
translated by Mr. Nakamura.
🙂
Off-topic:
I lived in Tokyo during the early 2000s for a few years. The Japanese are VERY serious about their hobbies and interests. So many of my friends would pick one thing to be passionate about (could be golf, photography or anything) and really dive in deep. It would become their life and their purpose outside of work or family. Which I think a lot of people here can relate to.
Also, it is pretty common for people to have a better understanding of electronics and to have used an oscilloscope while in school, etc. than here in the USA.
Since this is an English language site I think we are missing a lot of great content in other languages. It's a shame.
I am at home again and have attached two pictures of my Wayne's BA 2018 linestage build that uses this chassis. You can see the connection from "Aground" (or "A gnd", don't remember what it was named) to the case via a CL-60 (a 10R-100R resistor would work as well).
Don't remember if the board itself had a connection to the case via the standoffs, but in any case, I didn't change that.
Because I use an external PSU, I brought in PE / house earth on one of the wires in the umbilical to connect the case to PE. This in the end grounds the audio ground "Aground".
It also provides a proper safety ground to the case (which was more important with my Aikido build, because that's running 250-300V DC as B+ 😀)
Hope this helps, best regards,
Claas
Don't remember if the board itself had a connection to the case via the standoffs, but in any case, I didn't change that.
Because I use an external PSU, I brought in PE / house earth on one of the wires in the umbilical to connect the case to PE. This in the end grounds the audio ground "Aground".
It also provides a proper safety ground to the case (which was more important with my Aikido build, because that's running 250-300V DC as B+ 😀)
Hope this helps, best regards,
Claas
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I’m curious if both sides of the Velcro would work even better at vibration reduction... wouldn’t need a big piece, maybe 10x10mm at the biggest. Attach the glue sides to the NuTube and the PCB. Hmmmm... it’s intriguing, I should try it.
Does this qualify me as a "contributor" now? 
You folks are in big trouble now.
The other thing I did is to use spacers that are leftover from mounting computer motherboards over the years. I have a bag full of those. They are 6-32 so easy to drill/tap them into the bottom plate.
You folks are in big trouble now.The other thing I did is to use spacers that are leftover from mounting computer motherboards over the years. I have a bag full of those. They are 6-32 so easy to drill/tap them into the bottom plate.
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While trying to fix my volume pot, I think I accidentally shorted the pins of the NuTube and it doesnt light up anymore, how can I test to see if it's still good?
T7 and T8 are measuring ~21V whereas T5 and 6 are ~10V2.
T7 and T8 are measuring ~21V whereas T5 and 6 are ~10V2.
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Good afternoon gentlemen,
Sorry about that, I have a stupid question:
How much gain in Vrms is the B1 Nutube Triod preamp outputting ?
Thank you very much.
Regards
TYM
Sorry about that, I have a stupid question:
How much gain in Vrms is the B1 Nutube Triod preamp outputting ?
Thank you very much.
Regards
TYM
Good afternoon gentlemen,
Sorry about that, I have a stupid question:
How much gain in Vrms is the B1 Nutube Triod preamp outputting ?
Thank you very much.
Regards
TYM
Sorry about that, I have a stupid question:
How much gain in Vrms is the B1 Nutube Triod preamp outputting ?
Thank you very much.
Regards
TYM
Depends on your reference voltage.
Gain is about 16dB per Nelson's article.
There is a calculator here:
Decibels to Voltage Gain and Loss convert calculation conversion amplification amplifier electronics - sengpielaudio Sengpiel Berlin
Gain is about 16dB per Nelson's article.
There is a calculator here:
Decibels to Voltage Gain and Loss convert calculation conversion amplification amplifier electronics - sengpielaudio Sengpiel Berlin