Dismal Manor Dispatches

MacOS Software Defined Radio with GQRX and RTL-SDR

Post author By davehamby
Post date March 30, 2019

Radio, like most else, has gone digital. In the early days of digital signal processing, pioneers realized that many modulation and demodulation techniques could be performed by digital computation.

As computers became cheaper and faster and integrated circuits became cheaper and faster, it was inevitable that the guts of radio receivers and transmitters would be mostly digital and that computers would do much of what went on inside new radios.

This post will describe the initial exploration of GQRX and RTL-SDR here at Dismal Manor. Most of what is already written on the Internet neglects to mention a couple of details the Moocher learned the hard way. Find out what these are after the break.

Audio

Personal Audio on the Cheap

Post author By davehamby
Post date March 19, 2019

Much written about personal audio is written to separate the established audiophile from a few dollars to buy a new gadget. This article is written for a student using Spotify or iTunes with headphones on an existing laptop.How can you begin a personal audio system and what are your migration paths going forward.

Audio

Why Digital Audio Systems Upsample

Post author By davehamby
Post date February 19, 2019

Digital audio systems since the beginning have used elevated sampling rates for processing while down-sampling the product to 44.1 or 48 KHz sampling rates for storage and transmission. These design decisions are attempts to satisfy the requirements of the sampling theorem using easily implemented anti-aliasing filters and reconstruction filters.

Audio Personal Computing

Roon in a BHYVE

Post author By davehamby
Post date February 13, 2019

FreeNAS 11.2 has been out for a few weeks. After some time running Roon on a Ubuntu equipped 2009 Mac Mini, I decided I’d give Roon a try in a BHYVE VM on the new FreeNAS build. This note recounts the experience so far. As usual, both FreeNAS and Roon have their secrets and they interact.

Audio

Gumby is a good gumby

Post author By davehamby
Post date December 29, 2018

I’ll try to avoid the schiit puns as Gungnir Multibit (Gumby) arrived and is settled in my audio rack. Gumby is a good Gumby! Jason Stoddard and Mike Moffat founded Schiit about a decade ago to scratch their audio design itch. Schiit has an unusual philosophy and take on high fidelity audio equipment, that it exists to serve the love of music and not to be techno-sculpture in the lounges of the rich. Rather than making a big statement piece for the wealthy, they began by making affordable $100 devices for those wishing for more than headphones plugged into an iBook. And they set out to show that you could build here of mostly US made stuff and be profitable.

Audio Music Personal Computing

Home Networks for Streaming Audio

Post author By davehamby
Post date December 27, 2018

I’ve not written on audio and networking in a while but over the holiday I read Jason Stoddard’s Schiit Happens about his return to the high fidelity equipment industry as co-founder of Schiit, a maker of personal audio and value oriented high end audio. I found the book after I had ordered my Schiit Gungnir Multi-bit DAC. Over the break I had also watched a video in which Mike and Jason (the founders) talked about how Schiit came to be and this, that, and the other thing. They are toying with the notion of offering a new product which Mike kept calling Schiit Pi. This got me thinking I should write about my streaming environment again as I had improved it significantly in 2018.

Audio Music

Roon and Tidal

Post author By davehamby
Post date December 18, 2018

About a year ago I installed Roon Audio and began using it without Tidal. In my original configuration, Roon Audio ran in a VM hosted by my FreeNAS storage server. It delivered audio to either an Apple TV or a Google Chromecast Audio. Both were connected to a Cambridge DACmagic converter by TOSlink. For the first year I passed on the Tidal subscription, assuming that it, like Apple and Amazon streaming, sounded horrid. Then I got curious.

Holiday Letter

2018 Holiday Letter

Post author By davehamby
Post date December 1, 2018

Best wishes for a wonderful 2019. Boy has it been a busy year. As 2018 closes, Dave, Nick, and Missy are well. Dave remains busy with club activities while the Greyhounds continue to keep our garden zombie free.

I’m now officially a Moocher

I turned 70 and started collecting Social Security. This should be a good bet as monthly benefits increase by about 30 percent. The design is neutral from an actuarial vantage point. Social Security will pay out the same total from commencement to median life expectancy. The bet you make is that you will live past median life expectancy, a good bet as most relatives who dodged early canecer have done so on both sides of the family. Most cancer cases involve risk factors like tobacco use, agent orange exposure, or alcohol abuse. I now actually have some income. Surprisingly, Social Security covers about 1/2 of my income needs.

Personal Computing Technology

UniFi Updates

Post author By davehamby
Post date November 2, 2018

A new switch, cloud key, and updated network video recorder joined the Dismal Manor UniFi stable this October. The Moocher checked firmware to discover that updating the core POE switch to the latest firmware required updating UniFi Controller. At that time, UniFi controller ran in a FreeNAS jail. So, the cheap intrepid Moocher tried to update UniFi controller in the jail. He quickly discovered he was in dependency hell. Find out how he got out after the jump.

Personal Computing

The Moocher’s New Printer

Post author By davehamby
Post date October 13, 2018

After many years of using a Canon Pixma printer, the Moocher decided that the time had come for its retirement. Like many things in computing, changing interface standards rather than aging led to its replacement.