I combined the Nutube with a remote preamp kit and got to fit in the original cabinet. I was inspired by the photos of other builds and mounted the coupling caps on pins for future experiments. The Nutube replaced a Creek OBH 12 passive pre amp and sound is a clear improvement and i can play louder :-). Power amp F6, speakers Magnepan .7
Yet another outstanding, high-value piece of kit from the Store. Extremely rewarding, wonderful-sounding, and I simply can't fault it. Following the B1K thread, I swapped out the coupling caps for Jantzen Standard PP, and tried some potentiometer upgrades, settling on a Tocos Cosmos (what an amazing bargain itself). Good luck finding the log taper version - I got a 50k linear and added 5k log-faking resistors.
The end result is part of my best-sounding system ever.
it's just like that. When you find something and fall in love with it. DHT is not new to me, so this did not surprise me. But then after the first one, I built another. And another. Simple build, stunning sound. So this is the last one that I built, but not the last one to be built. This is a shot during the build. Used some very cool stuff like the stacked/mechanical volume control.
Building for the first time a pre amp and it was a great experience! The guide of Jim (very detialed step by step) and also some youtube videos where very helpfull. Thanks so much also Jim for the after sales! Did no upgrades so far, first going to try it on the F6 (still in build phase).
Tip: i used the pass guide for the last adjustments.
DIY noob. I built the stock kit over a weekend. As an old Navy Electronics Technician it was pretty easy, although I haven't soldered a PCB in 30 years. The build guide is very good.
I really wanted to like this preamp. Nelson Pass is a legend and the reviews are almost universally glowing. Unfortunately, the stock build was a bit of a disappointment for me. There was a significant loss of detail in the music compared to straight out of my DAC. The soundstage was flat as well. Multiple settings on the bias pots had some effect, but no real improvement in resolution. While it's certainly possible that I screwed something up, a thorough inspection revealed no errors.
I decided to give it one last chance by replacing all six of the 10 uf capacitors in the signal path with some mid-grade ClarityCap CSA polycaps. They can be had at Madisound for $18 each plus shipping. In addition to being relatively cheap, they are physically small enough to (barely) fit into the stock chassis.
I've read that polycaps make a big difference over electrolytics. The CSA's have a much tighter tolerance at 3% vs 20% for the stock electrolytics but I'm not sure that's relevant for coupling capacitors. So with no real experience in audio signal hardware, I decided to take the plunge and test the theory.
WOW! The CSA's made a HUGE difference. All the detail is back. I set the voltages at T7 & T8 to +10.5 VDC to suit my taste. The soundstage is deeper than the bare DAC but not quite as wide. That's fine. I can really "see" into the music again. Instrument placement is better than the bare DAC. The sonic presentation is just amazing now. Theory proven.
Another theory was also proven - component "burn in" is a real thing, at least for these CSA polycaps. As I giddily listened to all the little details resolving in my favorite tracks, I could hear the sonic presentation changing during the first few hours. It began to widen and "open up". With every few hours of play, the sonic performance just keeps getting better. Another theory proven.
I'm very happy with this preamp. It has a permanent spot in my system now. I HIGHLY recommend replacing the signal path caps with decent poly's. That $150 upgrade made a world of difference.
Cheers!
B1K is easy to build great sounding preamplifier.
Better power supply, better MKP caps and star grounding are bringing it to another level.
Thank you so much Mr Pass for making it possible !
:)
I did build the B1 preamp within 4 hours. The kit is of high quality, likewise the case, and the documentation.
I built an external power supply, which is an VRDN designed by Mark Johnson from the DIYAudio forum.
After the build, I checked the voltages as indicated in Nelson Pass' documentation for the NuTube preamp: T5 showed 0.59V, T6 showed 0.615V; I adjusted T7 to 9.505V and T8 to 9.51V.
Everything looked good.
I connected the preamp where my Quad 66 preamp was connected: between a hifiberry DAC and a QUAD 306 poweramp.
Result: the NuTube preamp has way too much gain (compared to the 66 preamp): totally saturated sound, and way too loud.
Ok, the Quads are known for being sensitive; however, when I restored my 306, I reduced its sensitivity from 500 mV to 1V (for full output power). I guess either the NuTube's input sensitivity id too high, or I must reduce the poweramp's input sensitivity to fit the NuTube's output.
However: it was a fun build.
Built with dact attenuator , non stock components and duelund wire. Few amtrans resistors as well. Musical ,smooth and lifelike with the bonus to adjust It at your taste. Again a breathtaking circuit!
Built two ACAs, (running them in bridge mode mono), then built the B1K as the pre-amp into the ACAs. Takes 30 to 45 minutes of play to warm up and then sounds super. B1K adds some warmth to the music. Both are great kits to build, it is surprising how good the combination sounds. Adjust voltages carefully on both for best sound - per designer recommendations.
This kit is a fun build. I suppose if you're in a hurry, you can complete it in one day, but I took my time and enjoyed the process. Built it just as provided with all the kit parts. Didn't feel any need to substitute designer parts in, as the standard parts all were of excellent quality. Opted to include an SMPS DC Filter P089ZB Kit and Pete Millett's NuTube anti-vibration mount as part of the build. Note only the blue foam on the anti-vibration mount fit. The B1 is paired with a set of ancient Welbourne Laurel tube mono amps with a Raspberry Pi running Moode Audio Player and a JDS Labs ODAC providing the inputs. I'm loving the sound. There's always a surprise in re-listening to music that I've heard many times before, as this combo is revealing details that I'd missed before. Great clarity and channel separation.
This is a high-quality kit throughout. It really amazes me that I was able to possess a Nelson Pass preamp design for such a great price. I enjoyed putting it together and appreciated the step-by-step directions. Thank goodness for BK1 thread, which identified my goof when I swapped a couple of resistors. It is a very revealing preamp and will make you reassess every other component in your system. I did notice that the Nutube got more microphonic over time. I ended up using the eraser trick in the instructions, which smoothed out the sound a lot. If I had to do it over again, I would build it with the Pete Millett vibration mount for the Nutube.
Fun and very easy kits to build i built 4 different revisions from basic to upgraded PSU with Clarity Caps. Definitely a difference in sound but all have sounded great. No issues with microphonics. I just use a type of sound deadening matt on the inside of the chassis and put some around the standoffs.
Super quality as always from the store. Great kit and very nice relaxed sounding with lot of laynack character. Highly recommended for those who want to try something different that traditional linestage amplification.
This was my second kit and from start to finish I had a great time building the preamp. The instructions were very easy to follow and the sound is superb in my system where I have paired it with an Amp Camp Amp. Thanks to Mr. Pass, DYI Audio store and the DYI audio community for helping novices getting started with their hifi audio journeys and dreams.
Thanks Mr pass for sharing this great kit with the world.
I build it in about a day and it was a lot of fun. The standard kit sounds great. Well balanced.
I startend replacing resistors with vishay dale, caps with nichicon fg and the coupling and output capacitors with elna silmic II. Each upgrade made the sound bigger and more clear. I did try out various caps prior to comming to this "endstate" basicly im in sonic heaven. Its that good. Well hete you have it, my Franken build, Well recommended
I have never build an amp before, it work out flawlessly from first attempt, sounds great with taste of tube with modern details and dynamic sound, even better after upgrade to a 25W linear PS.
Bought the Nutube and PCB/JFETs from the DIYA store, and sourced remaining components from Digikey (the Completion Kit was far and way backordered at the time) - Results were spot on at first power-up, even got lucky with zero Nutube noise - Sounds just wonderful as a front end for my DIY Pass A2.
All worked out well…definitely worth while.
Was very easy to build and sounds very good to me. I installed it inside a diy passive preamp which feeds my diy F6. So now it includes remote volume control and the ability to have it bypassed in case you want to eliminate it to avoid “too much of a good thing” for example, while playing my turntable with it’s tube based phono stage. As it looks, I rarely bypass the Korg because it provides nice sound improvement with all music sources.
This look is not the final, after proving the concept I’ll work on the look
