Search results

PSA for older folk (~60+): if you get a bunch of big, stringy floaters inside your eye, get thee to your eye doctor ASAP. I had that happen this spring, but eye dr said it was normal due to the gel inside the eyeball turning to fluid and pulling away from the retina, and no tearing or detachment...

Here is an attempt to show how a floating-point ADC system might benefit a field recorder (or other device) needing to cover a wide dynamic range with better performance than a single ADC. The floating-point ADC system comprises four different gain stages (amplifiers) with switches into the ADC...

This post attempts to explain where the SNR = 6N dB approximation comes from. ASR does not have the symbol font available, and after an hour or so of trying to fix things, I ended up just pasting the whole thing as an image. Sorry about that! I did attach a PDF of the original.

This post (originally from ~2014) introduces the basic operation of a linear power supply, showing voltage and currents at the input and output. There has been a lot of debate about power cords and their impact on the system. Aside from a defective or severely undersized cord I am a skeptic...

For phase p and frequency f group delay GD is the negative of the derivative of the change in phase with respect to the change in frequency: GD = -dp/df. In general phase is a function of frequency p(f); that is, phase changes with frequency. That's the math behind it. A change in phase is...

After skimming the passive volume control review, I was starting to run some numbers with the idea of a simple note and maybe sim circuit or spreadsheet showing how a passive volume control can affect frequency response (as well as volume, natch). But, I realized that I have a decent idea of the...

This article is to explore how line-level attenuators might affect the signal bandwidth. An attenuator is to reduce the signal amplitude from a source before it is applied to the next component. This could be between a DAC and preamp, or between preamp and power amp. Etc. The reason is usually...

This article is to explore how noise and distortion change through our system, and how different components can influence the final output. <Note 1: This article assumes some knowledge of performance terms, what frequency response and harmonics are, and so forth. There are other articles, many...

I missed that Merrill Skolnik passed away. Not audio-related, but a giant in the RADAR world. Back in the early 1990's I was presenting on a research contract I had with NRL and he sat in. I wasn't sure who he was until one of the program managers said "He wrote the book!" when we clarifying a...

<Yet another old, old thread reposted FYI.> I decided to play around with interconnects just a little. Mathematically, that is! First, I checked a number of preamp, amp, and AVR specs (tube and solid state, from Pioneer to Krell and Audio Research) and found a range of around 20 kohms to 100...

<Another old thread reposted, hope it is useful.> I have seen a few discussions about slew rate and thought it might be a worthwhile thread. Slew rate is defined as the amount a signal (voltage, current, power, whatever) changes in a given time period. For the math types, it is the first...

This post provides a quick comparison of how a distortion percentage relates to dynamic range in dB. That is, if an amplifier has 1% distortion, what does that mean? How soft (or loud) is 1%? Figure 1 shows a 1 kHz voltage signal with 1% second harmonic distortion (HD2) added. The spectral...

<Another repost of an old, old thread that may be interesting.> Room interactions are often discussed as one of the primary reasons similar (or even dissimilar) systems sound different. If you read the “Reflections and DACs” thread you saw how reflections and standing waves can interact along a...

<This is a repost of an old thread on a timeless subject.> Comb filter effects are a popular topic of discussion among audiophiles (and many others, of course). However, some audiophiles may not have a good concept of what they look like, why they may (or may not) be bad, and what they can do...

Not sure if this has been posted, but @jtwrace posted a new video blog with Ethan Winer on AV Nirvana: https://www.avnirvana.com/threads/the-intellectual-people-podcast-ethan-winer-realtraps.8903/ Long but interesting, vintage Ethan. :) - Don Edit -- Aarrgghhh, just saw it was posted...

This is a reprint of an article written ca. 2011-2012. I've been meaning to rewrite and update it, but Life and Work keeps getting in the way, so I am reposting the original as-is. Take it for what it's worth, an introductory take on one of the potential causes for differences in sound among...

This article provides a quick look at how bi-amplification works. The conventional scheme is to split the signal into two frequency bands before the power amplifiers that drive the speakers. The bass (LF) amp sees only LF signals and drives only the LF driver (woofer). The treble (HF) amp sees...

https://en.wikipedia.org/wiki/George_Segal Missed this. Actually know very little about him, but many years ago I was on the maintenance crew at a summer theater and dance camp in Steamboat Springs, CO for a local (to me then) college in Columbia, MO. I also helped with the horse crew, and...

May be interesting...

In the vein of my ancient "Pet Rock" objectivist vs. subjectivist post, I offer this new post about proving things (or not). O: The sun provides light and warmth. S: Light, yes, I can see that, but not warmth. O: What do you mean? You can feel the warmth, and we can measure it. S: The warmth...