Continuing our Mic Preamp Design Adventure… see past articles: Part 5: Designing the Printed Circuit Board Part 4: Amplifying mic level input signal Part 3: Distortion & Harmonics. Solid-State vs. Vacuum Tubes Part 2: Impedances & Loading – Adventures in building a Tube based Mic …
We’ve reached the point where our Hybrid Vacuum-tube mic preamp prototype works, and now we need to put everything together in an easy-to-assemble package, in other words a complete kit. So it’s time to design the Printed Circuit Board. Continuing our Mic Preamp Design Adventure… see past articles: Continue reading
Here’s an idea for a cheap solder fume extractor… helps keep away the smokey burning flux away from your face. You just need a small 12V computer fan (real cheap, or look in your junk computer parts pile), and a lab power supply, or 12V DC Adapter. Add a filter …
On our last blog, we talked about distortion and harmonics. http://www.fivefishaudio.com/blog/distortion-harmonics-solid-state-vs-vacuum-tubes/ and how this enriches 2nd harmonics in our signals. Here’s a nice animation showing how the 2nd harmonics get stronger the more we push our preamp harder, and note how we’re getting soft, assymetrical clipping…. thanks to our …
On my last blog post (http://www.fivefishaudio.com/blog/part-2-impedances-loading-adventures-in-building-a-tube-based-mic-preamp/), I added a buffer to the output of our vacuum tube stage. This additional buffer stage lowered the output impedance, while presenting a very high input impedance to our vacuum tube stage. This will allow us to couple to the next stage …
On a previous blog post, I’ve been experimenting trying to build a mic preamplifier incorporating vacuum tubes. If you missed it, check it out. http://www.fivefishaudio.com/blog/adventures-in-building-a-tube-based-mic-preamp/ 
I discovered a few issues with our prototype tube preamp circuit. First, it’s the low voltage …
Found some low voltage tubes on eBay, and that started a curiosity in researching and learning more about the history of these “space charge” tubes. https://en.wikipedia.org/wiki/Space_charge 
Basically, Space Charge tubes are designed to operate using low voltages, instead of using high voltages …
Yay! NK-72DI Mic Preamp kits are now shipping. I’m still slowly ramping up, but this is a milestone. I’m happy. Also, the assembly guide PDF is also finished and will be available on the website for download. 
I still need to update …
A customer’s build and comment regarding our SK-1DI Mic Preamp. http://fivefishaudio.com/500serieskits/sk1di/
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So let’s say you want to own some 500-series lunchbox modules, could be a mic preamp, compressor, or equalizer unit. The problem is you don’t own a lunchbox rack. Even a blank 6-space rack can cost a pretty penny, and you still end up with no modules after purchasing the …
