May Meeting: Jeff Haagenstad, Exogal
The Twin Cities are a hot bed of hi-fi product development, and few folks have seen as much consumer electronics development as the guys involved in local startup Exogal. Unlike many of our local audio heroes, Exogal is a digital audio company, and last year their Comet DAC took the audiophile community by storm.
April Meeting: Hi-Fi Hodge-Podge
A member freshly returned from the Audio Expo North America will give a show recap, covering the quality contenders and exciting new trends developing in the audio world.
Additionally, a member will be demonstrating his newly built Pass-designed V-FET amps, with a description of the building process. We'll also be hosting a discussion on DIY audio renderers.
And lastly, we'll host a gear swap meet. Bring some goodies to trade.
February: Roger Sanders of Sanders Sound Systems
As expected, Roger Sanders did not disappoint. Our guest speaker for the February 2016 meeting of the Audio Society, Sanders is founder and chief engineer at Sanders Sound Systems in Conifer, Colorado.
During the evening teleconference, he regaled the standing room–only crowd with stories, theories, science and opinion on a variety of topics, including the roots of power amplifier “sound” or character, the challenges of designing a loudspeaker that meets his stringent requirements, and the best way to test gear for repeatable, statistically significant results.
Occasionally interrupted by a feline family member, Sanders gave in–depth advice on overcoming common audiophile misconceptions, while clearly interpreting both highly technical details of transducer physics and power amplifier design criteria, and explaining basic for the less geeky members in the audience…
All in all, a well received get–together, with several attendees mentioning that it “…was the best meeting ever.”
Roger sent us an email follow-up to the meet:
I am pleased that your members enjoyed my presentation. I certainly hope that they will start doing some valid testing as it is a waste of time to do anything else.
Note that the testing parameters will vary depending on the devices being tested. For example, preamplifiers don't clip. Therefore you don't need an oscilloscope to test them. You need only match levels, use a switch box, and do the test blind.
For components that do not have gain, you do not need to match levels. So for testing things like interconnects, power cords, power conditioners, power regenerators, and the multitude of "tweaks" out there, you only need to use a switch box and do the test blind. If you need any help, feel free to ask.
January: Bring and Brag Listening Session
We had an intensive listening session on the ASM system using tracks brought by members.
A nearly complete listing is as follows:
Artist; Album; "Track"; Label; Format
Leo Kottke; 12 String Blues; 2 tracks, second was "If Mama Knew"; Oblivion Records; CD Rip of LP
Toshiko Akiyoshi/Lew Tabackan Big Band; Roadtime Shuffle; “Tuning Up”; ; LP
Buddy Guy and Junior Wells; Alone & Acoustic; "Catfish Blues; ; CD
A swing band (West Wind?) entire album recorded in Jim Reynolds' small studio in 2 hours.
Dire Straits; Brothers in Arms; "Ride across the River"; Mobile Fidelity; (DSD)
Amsterdam Concertgebouw/Chailly; Mahler 3rd; Excerpt; Decca; CD
Willy Dixon blues track on LP, possibly from Blues All Stars
Miles Davis; A Kind of Blue; "All Blue" ?Label; 45RPM EP
Bob Dylan; Blood on the Tracks; "Tangled Up In Blue"; Mobile Fidelity Remaster; LP
The Trashmen; Surfin' Bird; "Surfin' Bird"; Garrett; CD
Don M.also brought by a new below resonance subwoofer (designed by himself and Bill R?) to try in our system for the night.
November: Digitizing Vinyl
Our very own president, Oliver Masciarotte gave a presentation on digitizing vinyl from his experience as an audio engineer. He also included an impressive demonstration using pro or semi-pro sound cleanup tools on poor recordings.
Board member Chuck Bottemiller also gave a presentation on a simpler cheaper way to do it using a Pro Audio interface (Focisrite Scarlett 2i2) and the freeware recording tool Audacity.
Both presentations had in common:
Realize that ripping vinyl or tape is done real time so it takes a loooong while.
Get the disc as clean as possible
Use the best gear/turntable/recording devices available within your budget.
Plan on spending almost as much time separating tracks and adding metadata as you did making the recording.
A lively Q&A followed, including feedback from several working mastering engineers from the audience.
Special guest Jim Hillegass from JRiver, the popular enthusiast media player, joined us to demo and discuss their popular software. Questions varied in depth, and we covered everything from media tagging to equalization to audio drivers.
We appreciate JRiver's presence, and the group discussion that followed became a point of departure for all topics computer audio.
September: Audio by Van Alstine
Frank Van Alstine will be presenting his ABX Comparator as well as a few other products by his brand Audio by Van Alstine. Comparisons are fun, and it should be a breeze with this nifty tool. And it's always a treat to have a presentation from one of our own.
Don M. provides a brief synopsis of the events:
Frank showcased some new products including a combination DAC/Preamplifier, the ABX Switchbox Comparator, and a prototype pair of 1 kilowatt monoblock amplifiers.
Frank first described his new VisionDAC/Preamplifier that has a built in DAC using a pure Class A analog output section and single coax input for digital. It also features an optional phono preamplifier with adjustable gain for both moving magnet and moving coil cartridges as well as having an array of cartridge load settings. Other options available include buffered tape outputs, remote control, and stereo phase inverted balanced outputs. Digital inputs can also be customized. The retail price as shown (DAC/Preamp plus phono in silver case) was $1999.
The ABX Switchbox comparator was also described in great detail. The unit has inputs and outputs that enable comparison of pairs of preamplifiers, stereo power amplifiers, and up to three sets of speakers simultaneously. A/B switching is done via a remote control. Single and Double blind testing can also be performed. Great care has been applied to assure an invisible sonic imprint as well as masking any ability for the listener to detect which device(s) are in play based on switchings. The retail of the ABX Switchbox Comparator is $999.
Frank started the Switchbox demonstration with a comparison of his prototype monoblocks to an older AVA stereo power amplifier. The differences in sonics were quite obvious and favorable to the new monoblocks.
The club also supplied some preamplifiers and amplifiers to be compared. We listened to an all tubes based linestage preamplifier, a hybrid preamplifier, a sample of our in house DIY BA-3 project preamplifier, and a DIY version of an Icepower stereo class D amp with linear power supply. Differences in sonics between compared units ranged from barely perceptible to fairly perceptible.
For double blind testing, LED's are off and when the user performs a switch, the comparator randomly chooses to switch devices or not. Once eight listening sessions are over, the user can then use the remote to reveal the order of the devices played. For example, ABAABBBA would be a possible order. The idea here is for the listener to take notes durring the session and then compare those notes to the order revealed.
The value of such a versatile and high quality switching device became quite obvious to many in the audience.