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Korg Nutube B1 Preamplifier PCB + Fairchild JFETs

Korg Nutube B1 Preamplifier PCB + Fairchild JFETs

  • 2500


Update 2 (Sep 18th): Clicking here will get you an email when pre-orders start. However we do now have a limited number of "pioneer" kits for brave souls to test, prior to starting pre-orders for the production run, if you are interested.

Update 1 (Aug 26th): A full kit (parts + chassis) to complement this PCB is currently at the prototype stage. We are making a first small pioneers batch available for purchase in September (here), the only place to find out when that becomes available is the B1 Korg thread itself. You will be able to buy it without the PCB+JFETs, if you already have them. We will open a pre-order in the middle of October for a full kit to the general public. To receive an email when the pre-order opens please visit this page.

At Burning Amp Festival 2017 Nelson presented a version of a pre-amp using the Korg Nutube dual triode. We now have the latest version of this circuit available in the store complete with Fairchild JFETs and all directly supplied by Nelson Pass.

Please check the following links for more information:

What's included:

  • PCB (5.5" x 3.25", mounting holes 5.0" x 2.75")
  • Fairchild JFETs and tweaking resistors (all direct from Nelson) for just $25

What's not included:

A complete parts kit and chassis are currently in the early planning stages, with no ETA.


Customer Reviews

Based on 16 reviews
Nutubes are versatile and sound great

I have built two nutube pre amps balanced one in a Galaxy 1U chassis, and one single-ended one built into an ACA chassis to make a Pass DIY integrated. Both of them sound really good and construction was straightforward with no problems except the third time I fitted a Nutube to its circuit board the little legs just didnt want to go into the little holes on the board. I used 3mm Sorbothane sheet to stick the nutube to the board and I have not noticed any microphonic effects. Good job, Nelson and DIYaudio ( thanks to 6L6 for the build guide also )

Beautiful sounding B1 KORG NUTUBE

The pcb is of very good quality. The diyAudioshop sent it very fast. Included JFETs are matched very well.
How does it sound? - Beautiful! Absolutely no hum or noise. Open wide soundstage. Interesting possibility
to adjust positive and negative 2nd harmonic. Together with my BA-3 poweramp great.
This little soundmachine is a giant!
Dirk / cubicincher


This preamp looks so tiny - but the sound is giant!
The pcb is of excellent quality, as well the matched JFETs. I would say it is not difficult to build.
Delivery time from diyAudiostore was very fast. Well packed.
How does it sound? - Fantastic! The possibilty to adjust the harmonic profile is a very cool gimmick.
Build it - Test it - Enjoy beautiful music with it!
Plays wonderful with my BA-3 poweramp and others.

Great little kit, builds into great system

Built one of these and shoe-horned it into the ACA enclosure to make a Pass Korg B1/ ACA integrated....the Amp Camp Amp sounded very good but a mite low powered until I found the Klipsch RP 600 M speakers ( approx $550 )...these are more efficient than most bookshelf speakers ( quoted as around 90dB/watt ). Prior to finding the Klipschs I built a pair of Super Swan horn enclosures for a Fostex 100mm single driver. That also sounds good and efficient enough but the construction of the cabinets is an interesting challenge not for the faint hearted. The Klipsch is a good choice.


High quality, fast shipping.


As ever, A++

B1 buffer with Korg

I haven't used it yet but the delivery time was great. I've ordered several things over the years and they are certainly high quality products at a fair price. The build guides that 6L6 does are great.
I would like to see the J-fet boards back in stock. Thanks

Pcb & matched jfets

Arrived on time, Korg Nutube.All were packaged well. Can’t wait to get this project built!

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