REV33 Headphone Accessories- Measurements Part 2

Moving on… I confess that I’m someone who doesn’t like headphones. Over the years, I’ve been exposed to all sorts of devices designed to remove the weird imaging inherent to headphones. The most successful ones (and I think particularly of the...

REV33 Headphone Accessories- Measurements Part 1

There was some recent buzz on diyaudio.com about a gadget called the REV33 (www.rev33.com) that goes between your headphones and the headphone amp, claimed by its sellers to reduce distortion, noise, and listener fatigue. Its promotion was accompanied by lots of...

RIAA Noise Calculator

Because of the inherent Johnson noise of any resistance, phono cartridges have a noise floor. It’s useful to know what that is so that design targets for phono preamps can be set. The cartridge resistance is surrounded by several reactances (e.g., the cartridge...

6SN7 5692 Tests

I’ve made no secret of my high regard for the qualities of the 6SN7 family of twin triodes when properly used as voltage amplifiers. My experience was affirmed by an interesting set of measurements presented by Morgan Jones in “Valve Amplifiers.”...