I can still remember the first time I heard AC/DC as a 10-year-old boy and how their music instantly filled my body with adrenaline. Little did I realize that moment would set me on a path in life that would become my destiny.
As a teenager, I spent countless hours with my guitar dissecting every detail of Angus and Malcolm’s guitar work and the equipment they used to achieve their signature sounds. I then began making YouTube videos to share the secrets I had learned. My YouTube channel grew into a massive community of 15k AC/DC and rock guitar enthusiasts worldwide. As we obsessed together over each discovery, I continued collecting vintage specimens of the guitars, amplifiers, and studio equipment in my attempt to perfectly reproduce the iconic sounds captured during AC/DC’s heyday. I had all of the right equipment and nearly mastered Angus Young’s technique, but still, something was missing. The searing guitar tone that caused such a strong visceral reaction in me as a boy still eluded me.
It wasn’t until 2011 that I made a discovery that would send me on a mission. One of the members of my SoloDallas.com community happened upon an interview with Angus Young in a Guitar Player magazine from 1984. In that interview Angus, who had always claimed he used no effects, revealed that he was, in fact, using the Schaffer-Vega Diversity System, or SVDS, wireless unit in the studio to reproduce his electrifying live guitar sound. I thought, “Could this be it, the missing link?”.
In my quest to find one of these original wireless units in working condition, I discovered that the man who invented it, Ken Schaffer, was very much alive and still inventing, in New York. Having moved on to pioneer other disruptive technology feats with Columbia University after his wireless invention lost use of its FCC-allocated frequencies to the then-emerging cellular telephone industry, Mr. Schaffer was intrigued that a persistent stranger from Italy would be asking about his long-forgotten invention so many years later. As it turned out, Ken still kept a couple of complete units as keepsakes. He obliged to send them to me.
The day the SVDS units finally arrived was one of heavily mixed emotions. I was extremely excited but prepared for complete disappointment if this promising relic turned out to be a total waste of time and money. But the moment I first plugged into the SVDS is another moment I will never forget. I can only describe it in two words, “Instant Angus”. The SVDS was more than just “the missing link,” it was “The Holy Grail” of vintage guitar tone. I later discovered that this was not only Angus’ secret weapon, but also EVH, Carlos Santana, Peter Frampton, Keith Richards, Jerry Garcia, and countless other guitar gods. David Gilmour even used the SVDS to produce his signature guitar tones on The Wall album and continued to use his Schaffer-Vega units for many years even after their precious frequencies were re-allocated to cellular telephones.
As soon as I began sharing my newfound discovery with my community everybody wanted one, but they were impossible to find. Since not many original units had survived the last three decades, I asked Ken Schaffer to help us extract the tone-enhancing portions of his invention from its original, now-illegal wireless section. We offered one hundred units on a first come-first serve basis to SoloDallas group members. We had no idea of the task that lay before us in the reverse-engineering process. Even to a team of expert engineers, it was a daunting task: when we opened up the SVDS transmitter and receiver we discovered a maze of interactive analog effects that each played a distinct role in the “Schaffer Sound”. There was an optical limiter, compressor, expander, EQ enhancement, line buffer, and an op-amp driven monitor output that Angus, EVH, and practically everyone else was abusing to push their amps into oblivion. After months of blood, sweat, and tears we succeeded in reproducing every tone-generating aspect of the original SVDS and aptly named it “The Schaffer Replica”.
What came next has to be the greatest moment in my life, next to my wedding day or the birth of my children. I received a request from Angus Young to personally bring our first Schaffer Replica Tower for him to try. His most iconic tone was instantly restored. I could’ve never imagined in my wildest dreams that I would one day be responsible for helping my musical hero reclaim the signature sound that started my journey. Once other musicians started receiving their “Towers.” as they became affectionately referred to as, and posting clips, I was hit with a barrage of requests from guitarists desperate for this tone. It was from this demand that the company SoloDallas was born and my purpose in life was realized. SoloDallas has now grown into a thriving enterprise with an assortment of products that have been embraced by many of the greatest musicians alive today. For this, I would like to say, “Thank you, Angus”.
“Here’s rockin’ at you, kid. I’m playing through a “Schaffer Replica” —a totally magical box invented by my long-time friend Ken Schaffer. It’s a big piece of Angus’ AC/DC “texture”. I wasn’t playing particularly loudly —it’s in the box. Earthquake time!
I just wanted to say "thank you" for this awesome pedal. This is one of the few products that I've bought has lived up to, and even surpassed any hype. What a GREAT pedal !!!
Last night i played a gig in Trondheim with my band Dirty Deeds! I didnt tell the sound Engineer about my new pedal and after the show he asked what kind of dynamite amp I played on! The sound was way back AC/DC 80 style and God im so pleased!!! Thank you.
Do you use any effects?
No. I just have a Schaffer-Vega wireless system. For me, it's probably the best.
– Guitar Player (February 1984)
The TSR is just the best invention in last 20 years hands down seasoned players will go just WOW with the tones you can get with it.... Awesome work all at SoloDallas unit #42 Gold is the S**T!!!