October, 2018 SFAS Event – David Gans Interviews John Curl


David Gans / John Curl 10/20/18 SFAS Event

Once again SFAS members were treated to the type of event that is only made available through the San Francisco Audiophile Society.  Two industry greats, David Gans(1) and John Curl(2) came together to share their experience and knowledge of the Grateful Dead and many things rock and roll and Hi Fi with Gans leading the way down memory lane.

David Gans began the discussion with talking about an immense treasure trove of recordings made by the Dead that were initially taped for the purpose of internal use of the band so they could listen to a concert and see how it sounded and what they might improve upon.  These recordings had mixed results as far as mixing and sound quality, but some of the recordings have since been re-mixed and released such as the 19 CD box set Pacific Northwest 73-’74 The Complete Recordings (https://store.dead.net/pacific-northwest-73-74-the-complete-recordings-19-cd-boxed-set-1.html0.

David played an example of one of these recordings which was a copy of “Trucking” from the May 19, 1974 Portland, Oregon show.  David felt this recording was a great example of the talent and innovation that the Dead could produce.  David then treated the attendees to a song from a recent studio album Drop the Bone! with David on vocals. While the music was great to listen to, there was a general agreement that for whatever reason the sound system was not up to par, so we moved to the interview/discussion between John and David.

David and John began the discussion by talking about the systems that led up to the design and building of the Wall of Sound.  During that time period John Curl and Bear (Owsley Stanley, also an audio engineer) worked together in the evolution of different ideas about how the sound should be developed and produced what ultimately lead to the creation of the Wall of Sound.

As described in Wikepedia the Wall of Sound “combined six independent sound systems using eleven separate channels, in an effort to deliver high-quality sound to audiences. Vocals, lead guitar, rhythm guitar, and piano each had their own channel and set of speakers. Phil Lesh‘s bass was piped through a quadraphonic encoder that sent signals from each of the four strings to a separate channel and set of speakers for each string. Another channel amplified the bass drum, and two more channels carried the snares, tom-toms, and cymbals. Because each speaker carried just one instrument or vocalist, the sound was exceptionally clear and free of intermodulation distortion.

Several setups have been reported for The Wall of Sound:

  1. 89 300-watt solid-stateand three 350-watt vacuum tube amplifiers generating a total of 26,400 watts of audio power. 604 speakers total.[3]
  2. 586 JBL speakers and 54 Electrovoice tweeters powered by 48 McIntoshMC-2300 Amps (48 × 600 = 28,800 watts of continuous (RMS) power).[4][5]

This system projected high-quality playback at six hundred feet with an acceptable sound projected for a quarter mile, at which point wind interference degraded it. The Wall of Sound was the first large-scale line array used in modern sound reinforcement systems,[6]although it was not called a line array at the time. The Wall of Sound was perhaps the second-largest non-permanent sound system ever built. The Wall of Sound can be seen in The Grateful Dead Movie, a documentation of the series of shows played October 16–20, 1974 at the Winterland Ballroom.”

One of the things that led to the demise of the Wall of Sound in late 1974 was the sheer impracticality of it.  There were 30,000 lbs. of speakers alone with a least two stages so one stage could be set up while another was being used during a concert.  After the brief break up of the Dead in October, 1974, the Wall of Sound was dismantled and when they began touring again in 1976 a more practical sound system was put in place.

Discussion the followed about horn speaker distortion and the replacement of the JBL horns with Electro Voice horns in the Wall of Sound.  John Meyer (of Meyer Sound) entered the picture and helped develop a more practical way to produce the sound.  After which John Curl and John Meyer left for job in Switzerland.

How did these electronic geeks wind up getting together?  They were all in the Bay Area during the ‘60’s and ‘70’s and worked for the same electronics shop at different times.  Around the same time frame Herb Green (photographer) took John Curl to Haight-Ashbury where he was introduced to Jerry Garcia in 1967.  At that time John was working for NASA where he met Ron Wickersham and they became friends and eventually left NASA to work for the Dead.  John also worked for Ampex tape machines.  Meyer came back from Switzerland a year before Curl and Meyer worked for Crystal Clear recording studio.  Meyer then hired Curl to help build direct to disk studio boards.

John then talked about his original solid state circuit design that was his first crowning achievement – this was the circuit that was in the Mark Levinson JC2 which, at the time, achieved great notoriety and accolades.  John talked about one of the moments that lead him to understand that the parts and design of a circuit can affect the sound quality irrespective of what the specifications indicate. This happened when Bear blew up one of the early circuits John had designed, so they re-installed a tube circuit that sounded better which drove John to make better sounding solid state circuits.

John then talked some about his CTC (Curl, Thompson, Crumb) Blowtorch preamp with no feedback and full symmetry circuit.  These were cost no object, built to order in 2000.  It was the best preamp John has ever built.

All-in-all another interesting and entertaining event for the lucky membership of SFAS.

(1) David Gans is the Nationally syndicated host of the weekly radio show, The Grateful Dead Hour; author of 8 books (and counting); musical recording artist with more than a dozen releases; touring musician with live performances weekly around the country; and highly sought-after lecturer on a multitude of Rock & Roll subjects.  There’s more, but you can go to his website (http://www.dgans.com/) to find the rest, or just ask David when he interviews John Curl on October 20th at The Shops at Hilltop conference room on the second floor.

(2) John Curl is one of the most highly praised audio circuit designers, with a history of creating timeless classics like the JC 2 preamplifier with Mark Levinson; the SOTA Industries Head Amplifier; and his own Vendetta Research Phono Stage.  But before he began designing consumer audio equipment he had worked building amplification for the Jefferson Airplane.  Later he would build the Wall of Sound for the Grateful Dead’s 1974 live performances.  Owsley “Bear” Stanley conceived the Wall of Sound as the largest concert system ever built.  The Wall could project high-fidelity music six-hundred feet from the stage, with acceptable audio quality for a full quarter mile before noticeable degradation of sound could be heard.  Stanley claimed quality sound was available for up to half a mile, but perhaps your personal mileage count varied depending upon whether you as the listener employed any of Owsley’s pharmaceutical enhancements?

San Francisco Audiophile Society

San Francisco Audiophile Society