On an earlier post, I mentioned I was working on a new preamp kit. (See here) On that post, I temporarily used a vintage St. Ives Input Transformer for my prototype since I ran out of my Carnhill Input transformers. Now, I’m going to replace that St. Ives …
Fresh PCBs from factory…. back in stock! OpAmp Test Jig PCB. http://fivefishaudio.com/diy/opamptestjig/ 
The board can be configured for either Unity Buffer or Amplifier configuration. For the Amplifier configuration, it can be selected for either Non-Inverting or Inverting configuration. Gain is adjustable via jumpers from …
A few months ago, I got an HP 8904A Multifunction Synthesizer, from DC to 600kHz (from eBay). Got it for a good price, fully loaded with options. The unit has (2) balanced/floating outputs, (4) internal channels, and can do “noise”, square, ramp, triangle up to 50kHz, and sine waves up …
It’s bound to happen when you have this much test probes, test leads and cables hanging around… 
So let’s say you have an RG-59 cable or something similar. It’s several hundred feet long but it developed a break somewhere along it’s length. The problem is it’s not obvious where the break is. Now what do you do? Option 1: Cut the cable in half, check each half …
Every sound/recording engineer is familiar with the terms unbalanced and balanced interfaces… more commonly referred to as “unbalanced or balanced lines.” Yes, everybody knows “unbalanced line” can be very susceptible to noise (for very long runs), and that “balanced lines” are more preferred because they’re quieter, i.e. not as susceptible …
CircuitLab.com is a cool web-based “workbench” where you can create circuits and simulate it. You can do DC analysis, Time Domain, Frequency Domain analysis. I think it’s a great learning tool to “experiment” with circuits and see what will happen. No special software need to be installed, you can run …
Our stock SK-1DI Mic Preamp uses a potentiometer for the gain control. It’s simple, it works, you turn the pot and you control the gain. But some users may prefer a stepped switch instead of a potentiometer, so they can precisely control the gain. It also makes “recall” easier as …
I’ve been trying to optimize performance of my new upcoming Mic Preamp Kit, the NK-72DI. It’s hooked up on my workbench to various probes and meters, and displays. I want to make sure that performance of this new Mic Preamp will be top-notch, and something my customers will be proud …
Just testing some PEQ-503 EQs before shipping out to customers. Each frequency band has two (2) selectable frequencies, and a bypass switch. It also has an overall EQ In/Bypass switch to let you easily make before & after sound comparisons. The equalizer’s smooth broad curves makes tonal adjustments easy and …
