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Guide | Nutube – English
The kit you've pointed to looks like a realisation of the concept that Korg suggested previously. Nice to see them carry through with some hardware and bring it into reality.
I can't seem to find word out there of how this works out in reality. Who's going to be first with a review / install guide?
Hello !
The post I originally published here did not allow me to see the images I had integrated. I hope now they are finally visible ...
A new Korg B1 Nutube preamplifier is alive (and makes music ...) !
I received my package the day before yesterday only 7 days after the order. Almost faster than Amazon ! And I did not have any customs fees to pay ...
Two days later, I started assembling the kit and I must say that it is very simple when you already have some experience.
So, for beginners, I recommend using a soldering iron with the finest tip and a fine solder wire, with lead, because the lead-free solder does not give such nice welds and requires a temperature of the iron soldering of at least 400° C which is a lot for some components.
I also strongly advise to use an antistatic wrist strap when handling JFET transistors that are indeed very sensitive to static electricity !
The components are really very good, like the Dale resistors, the electrochemical capacitors and the Alps potentiometer.
By cons, I find that the connection pads on the printed circuit are too small, while it is not necessary for most, except for transistors and Nutube !
It is also a pity that there are no more convenient test points (with pins ?).
Another complaint : the wiring of the LED of the ON / OFF switch is not easy and the hole provided for the LED is too small, so the LED is almost invisible when turned on, it's a shame, so I replaced the original LED by a blue LED with a serial resistance of 2.2 kOhms and I inserted it in the hole provided for this purpose after having bored to 3mm. The connection of the LED is now with a plug-in connector. This is the only modification made to 6L6's work with the use of flexible wires and a larger gauge for 24 Volt wiring.
Otherwise, I must say that I am extremely satisfied with the result and especially the excellence of the sound ! (And I have absolutely no microphonic effect, but I do not listen to music at a high level ...)
Thank you once again to Mr. Nelson Pass for making public this achievement and 6L6 among others for his valuable advice throughout the many pages devoted to the realization of this project !
Here are some pictures of the different stages of construction and the final result.
Use of an antistatic wrist strap :
It must be connected to the earth, of course !
The printed circuit board is finished !
Mechanical assembly :
The Korg Nutube double triode :
Mounting of power resistors with little steatite posts :
Final wiring :
Wiring modified ON / OFF switch and LED :
In good company !
It's all for today !
The post I originally published here did not allow me to see the images I had integrated. I hope now they are finally visible ...
A new Korg B1 Nutube preamplifier is alive (and makes music ...) !
I received my package the day before yesterday only 7 days after the order. Almost faster than Amazon ! And I did not have any customs fees to pay ...
Two days later, I started assembling the kit and I must say that it is very simple when you already have some experience.
So, for beginners, I recommend using a soldering iron with the finest tip and a fine solder wire, with lead, because the lead-free solder does not give such nice welds and requires a temperature of the iron soldering of at least 400° C which is a lot for some components.
I also strongly advise to use an antistatic wrist strap when handling JFET transistors that are indeed very sensitive to static electricity !
The components are really very good, like the Dale resistors, the electrochemical capacitors and the Alps potentiometer.
By cons, I find that the connection pads on the printed circuit are too small, while it is not necessary for most, except for transistors and Nutube !
It is also a pity that there are no more convenient test points (with pins ?).
Another complaint : the wiring of the LED of the ON / OFF switch is not easy and the hole provided for the LED is too small, so the LED is almost invisible when turned on, it's a shame, so I replaced the original LED by a blue LED with a serial resistance of 2.2 kOhms and I inserted it in the hole provided for this purpose after having bored to 3mm. The connection of the LED is now with a plug-in connector. This is the only modification made to 6L6's work with the use of flexible wires and a larger gauge for 24 Volt wiring.
Otherwise, I must say that I am extremely satisfied with the result and especially the excellence of the sound ! (And I have absolutely no microphonic effect, but I do not listen to music at a high level ...)
Thank you once again to Mr. Nelson Pass for making public this achievement and 6L6 among others for his valuable advice throughout the many pages devoted to the realization of this project !
Here are some pictures of the different stages of construction and the final result.
Use of an antistatic wrist strap :
It must be connected to the earth, of course !
The printed circuit board is finished !
Mechanical assembly :
The Korg Nutube double triode :
Mounting of power resistors with little steatite posts :
Final wiring :
Wiring modified ON / OFF switch and LED :
In good company !
It's all for today !
Last edited:
No need for another J112, use what you have.
All the Jfets have been selected and sorted by Nelson himself (yes really) and the transistors in the package are all matched to each other. That some are J112 and some are J113 is inconsequential.
Jim, Jason,
is it possible to buy just a transistor kit + tube without the board?
I fancy trying this board. Already have Nutube from a P Millet buffer so can try to unstick it. The only problem is UK Royal Mail & Customs seem to be scamming us a lot. If something has £1 tax on it then RM take an £8 fee just to give £1 to Customs.
It is outrageous! All they do is put a sticker on.
Wondering if there is a way to ship by paying any Customs Tax up front or something?
It is outrageous! All they do is put a sticker on.
Wondering if there is a way to ship by paying any Customs Tax up front or something?
As usual, it took me forever to get around to installing these, but amazingly, I have time on my hands lately! They seem to make a big difference - I wasn't really noticing microphonics in normal listening, but when I changed the input switch or tapped the chassis I'd get some pretty longlasting ringing. I put the standoffs in and it's much better! Can't really hear any ringing from tapping, and only a little when switching the switch.
Thank you for the recommendation - highly recommended and much appreciated!
Stay well - wash your hands and don't touch your face!
Pete
There is a BOM in Nelson Pass' article:
http://www.firstwatt.com/pdf/art_diy_nutube_preamp.pdf
However there is an error - you need 4 pcs of 100 ohm resistors, not 2.
This BOM covers the parts going on the PCB apart from that you need Potmeter, wire etc.
Believe it or not, all the ducks are lined up to offer a pre-order in the next few days. We will be advertising it with the shipping to happen 90 days after the pre-order closes. I'd say we'll leave it open for a week.
What about just pcb+jfets+tube, still 90 day waiting time or can be shipped sooner?
Stay safe!
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