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quality sound, this preamp is a highly recommended upgrade with my F5 turbo amp and the wilson watt puppy

Excellent product. You can adapt these to any chassis you create.

Ran out of “free” time after the first one, and it sounded so amazing that I lost my sense of urgency for the second. But last night the wife went to bed too early. So I headed to my happy place and finished the second ACA. After setting the DC offset and running a couple of songs through it, I couldn’t resist sneaking quietly upstairs and removing the first one and bringing it downstairs. After hooking them up in monoblock configuration, I turned on some tunes to try them. They sounded amazing, and in my excitement managed to wake up the wife. It’s a good thing she has the patience of a saint. I can’t wait to try them together with my B1 nutube preamp. I’ll wait until she goes to work to put them through a proper workout. You guys are great, keep doing what you are doing, and I’ll keep enjoying my relatively new hobby.

This is an amazing value. To receive a pc board and the 4, matched semi conductors at this price is the deal of the century!

Using Nelson's 6-24 active crossover to biamp a system offers one of the biggest "bang for your buck" improvements available. While it took a fair amount of trial and error to adjust it to best suit my listening room, I now have a system that sounds like the best systems I've heard at audio shows, costing tens of thousands of dollars! If you were to buy a commercial active crossover of this quality, it alone would likely cost over a thousand dollars. Thanks Nelson and the DIYAUDIO team!!!

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.

I was very pleased with how this little amp sounds. It is fun to listen too and just has good energy. Sound wise it is between the Aleph J/Aleph 3 and F4. It drives my Klipsch Forte really easily and is a great match with a B1-K preamp. Build is easy, just be sure to watch the polarity on the caps and don’t mixup FET positions. I found he board nicely spaced, well labeled and easy to work with. About the only thing I wish was different is test points being at the board edge because the test points are a little hard to access. I highly recommend this project.

I have now used this for the Korg B1, and for other DIY preamps. It is just the right size and structure to make the projects sing

Just as described in the ad. Years of information in the space of a cigarette lighter!

Great parts and instructions. My 14yo boy and built and it sounds great. Really good.

Had this running for a year. One word: amazing.

Building process: straight forward but very tedious. It time means a lot to you, use professional build service. I would nit build myself again. Hundreds of small parts with 1000+ soldering points.

Sound: very musical - great for vacal.

Power: 9w seems very little. It does drive a pair of Kef LS50 (first version) quite well in my home office - small 12 x 10 ft. Consider these are less efficient speakers (85 db 1m 1w spl), and command 25w min to drive.

very good pcb with all parts you need. peparing and soldering easy going because of the gold surfaces.
then starting it with one power adapter per channel. ( +-18v / 140 mA , two pair of LM337/ BD140 ). the two led awaked.
Then making the right adjustments. connecting the preamp into the complete audio system. now the best moment for diyaudio
builders - the first music ! Thank you Mr. Wayne Colburn for this Burning Amp.......regards and have always a nice time for you and the team of diyaudio !

Like it very much. Easy to assemble and pre drilled/tapped holes make it so easy. Would love it cut right down the middle for mono configuration

I live in the UK, the boards JFETS and MOSFETS arrived within two weeks. The F5 Turbo is my most challenging yet surprisingly straight forward build to date. I used a 5U Galaxy enclosure and 2 X 625 VA Transformers 24-0-24v bolted vertically to the front panel it’s not pretty but functional. Thus the two large bolts in the front panel. Thanks to 6L6’s build guide the build was straightforward. I opted for the V3 build without the extra transistor. Care has to be taken with the components as the MOSFETS and diodes are identical. The biasing is a slow process but was eventually biased to 350 mV. The guide has excellent instructions. It sounds superb and slightly more dynamic than the normally aspirated F5 which also sounds superb. Thank you Nelson, 6L6 and all the team at DIY Audio.

HI, is very very perfect, sound is beatifull