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Korg Nutube B1 Full Kit

  • 2500


2019-12-27 update: Pioneer's batch 2 of completion kits is now available SOLD OUT. We have a limited number. You can read the overwhelmingly positive feedback here in the pioneer's batch feedback thread on diyAudio.

Once these sell out, the next step will be a pre-order available to everyone who is subscribed to the "Email Me When Available" full kit notification list. We expect to send an email in January about this.

At Burning Amp Festival 2017 Nelson presented a pre-amp using the Korg Nutube dual triode. The latest revision of the circuit available is now available complete with Fairchild JFETs and all directly supplied by Nelson Pass. 

Please check the following links for more information:

There are 4 elements to building a complete preamplifier. Purchase the elements separately, or all together as a "full kit" bundle for $299. To build a complete preamplifier you will need:

  1. Nutube ($49.99)
  2. PCB + JFETs ($25)
  3. Chassis ($129)
  4. Completion Kit ($99)

What's in the completion kit?

Everything else you need to complete the project other than 1, 2 and 3 above. It's an assortment of bits and pieces that joins the Nutube, PCB and Chassis together, turning the whole things into a "full kit", hence the name "completion kit". 

What are the chassis specifications?

  • Galaxy 230x170 full aluminum chassis, anodized black with white printing
  • Internal dimensions 40x210x170mm
  • LED hole ø2mm
  • Left switch
    • Hole ø6.5mm
    • 15mm x 15mm square rear recess, 7mm deep
  • Right switch
    • Hole ø6.5mm
    • 15mm x 24mm rectangular rear recess (allows for switch and LED), 7mm deep
  • Potentiometer hole ø10mm, with ø32mm round recess in the front ø8mm deep
  • Rear RCA holes ø10mm
  • Rear power switch hole ø11mm

Customer Reviews

Based on 9 reviews
Korg Nutube Pioneer Kit

Paired with a brace of ACA my system has never produced cleaner clearer music. My much loved 30 year push pull triode valve amp will be put away in it's original packing bested by a Korg Nutube and single ended transistor power. The Korg buffer has been favourably reviewed by professional audio reviewers against other pre-amps costing more than 10 times as much, without hearing such things it's hard to argue. I just need to build a phono stage to plug in to it now.

The Wall wart power supply that requires a travel adapter is a big disappointment - given a choice I'd opt for brick with a choice of international plugs (or a plug I can cut off and replace). Alps volume pot keeps the cost down but there are better sounding options when you are ready for not too much more- TKD, Tocos Cosmos etc. I built mine in Galaxy 2 U case so that I could mount the Korg vertically in full view and get more inputs into the back of the case with an elma switch and match the silver ACA cases I already have.

Korg Nutube B1

sourced chassis, Nutube, Board and FETS from DIYAudiostore
used Dale resistors, Nichicon KZ and Elna caps, Alp pot,, the sound, no cursing but its you know great. very great looking and pro with the chassis and can't believe the size. Does ring on input change but stops. Much Improved when hot glued Nutube to board. Value/price can't be beat. Using with DIYAudio F5 also built this year. Loving both. Much gratitude guys and thank God for NP

Love the B1 with Korg NuTube Pioneer Kit

I purchased the B1 with Korg NuTube PCB and triode last year and waited patiently for the chassis kit to be released. Surprisingly, Jason and Jim also released a Completion Kit, which eliminated my need to acquire the caps, resistors, and diode to complete the PCB. I’m glad I waited as this kit was easy to assemble with Jim’s (6L6) photos and advice. I still have to work to reduce/eliminate the NuTube microphony that flares up occasionally, but this is a special line stage preamp with incredible detail, separation, a large and deep soundstage with excellent imaging, and organic tonality. This is a bargain and will best many vacuum tube line stage amp kits currently on the market at a lower cost.

B1 Korg

Great and easy to build kit. At ~9.6V and inverted speaker phase a great match with my diy F6. Quite mellow, but wonderful, in front of my diy M2 running Altec VOTs. Great in front of hypex nc400 driving conventional 2 way speakers. Havent tested different 2./3. distortion profiles or different caps yet. A bargain as it sounds great as is, on top of that you can fine tune and tailor the sound to you system and to your liking.


Detailed, clear sound with some warmth. Hot glued the Nutube to the PCB. Microphonic whistle only when turned on, then goes away. A minor annoyance. Build was relatively straightforward for a beginner like me. Will be a real breeze once the build guide is released.

Wondrful sound from a great kit.

This pre amp is very impressive. Building the kit was easy to do because of the thoughtful layout of the board and the quality components included. The Nu tube is really neat when it lights up for the first time. This one is paired with an F5 amp and the sound is simply wonderful. I am very happy with the nuance that this pre amp brings to the sound field. It sounds so natural. The sound stage is expansive and pulls you in to the music in a different way than the WHAMMY and Starving student (both excellent) pre amps. Thank you's go to all behind the design and construction of this little gem. If you are on the fence about this one, just build it and listen. You will be happy you did.

Korg Nutube Pioneer Kit

As described, all good and easy to assemble. I set it to 9.5V. Would like to try to install better caps, silver wire and better volume pot.

I will be soon able to compare it to my Pass HPA-1 paired with FW SIT-3

Excellent sounding preamp

I thought this kit was easy to build, looks nice, and sounds great. It sounds as good as or better than some very expensive preamps, as long as I am not feeding amps with extremely low input impedance.

My only negative comment is that flipping the input toggle switch will initiate about 5 seconds of microphonics in the nutube. It would be nice if some manner of taming the microphonics were included in the kit.

My lasting impression is that this is the best bang for the buck I've ever encountered in an audio component.

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