Korg Nutube B1 Preamplifier PCB + Fairchild JFETs
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:
- 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:
- The Nutube. You will need to supply your own Nutube, and they are available from the diyAudio Store separately for $49.99.
- All other parts required to make the project
A complete parts kit and chassis are currently in the early planning stages, with no ETA.
I have built two nutube pre amps now...one 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 )
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.
All arrived and boxed nicely I order here all the time
I am very happy fast shipping well pack and vey good pcb quality very satisfy looking forward to built it
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++
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