“Tower Power”

30 Aug “Tower Power”

In 1976, Ken Schaffer (an American inventor) partnered with Vega Corporation (California) to deliver the best wireless system ever made for guitars – soon spreading to other instruments (bass, acoustic stringed instruments, vocals, etc.).

Schaffer wanted to create the most transparent sounding device but luckily, he failed (according to his own memoirs). This wireless system had a sound of its own and musicians of the time quickly realized it, putting it to good use (Kiss, AC/DC, Van Halen, Pink Floyd’s David Gilmour, … ). Over 1000 Superbands and individual artists joined as Schaffer-Vega clients between 1976 and 1981, some of them using this particular system for over 10 years straight (live and in the studio) even after the introduction of newer and, theoretically, more efficient technology in the 1980s.

After years of research, once we at SoloDallas’ realized the breadth of the original SVDS use in those times, we have wanted the whole world to have that sound, and this time, in affordable packages. The Schaffer Replica line of products was born (2013).


After Ken Schaffer and Angus Young reconnected in 2014 thanks to AC/DC fanatic and SoloDallas LLC founder Fil Olivieri – after nearly 40 years of signal silence – with Angus Young using our Schaffer Replica to record AC/DC’s “Rock Or Bust” and touring for two years with a set of 4 Schaffer Towers, the world of professional musicians and amateurs progressively realized the technology’s potential for multiple uses. 

                    It’s all in the signal path!  


The audio technology incorporated in the original wireless system – and faithfully replicated by our engineers in our line of products – was never a no-nonsense chain of opamps, capacitors and other analog components. It had been designed, over a span of years, to allow for the original wireless system to work flawlessly – given the analog technology of the times – and with a great sound, too (“… it sounded great…” Malcolm & Angus Young, AC/DC, 2005 video interview for Family Jewels).

A metric ton of analog, vintage warmth 



All of our Schaffer Replica® line of products are an integration of the original Schaffer-Vega System’s X10 transmitter and EX63 receiver audio technology i.e., we have integrated together, on one board, the audio circuitry of both the original transmitter and receiver, minus all the wireless, outdated 1970s technology that didn’t take part in changing the sound of the instrument connected with the original system. 

Yesterday, Today And Tomorrow 

Our products today are, therefore, strictly non-wireless but can, just like any guitar pedal on the market today, easily be connected with any standard wireless system available commercially on the market.

Without having to go deeply into the complex technicals of this golden circuitry, we can understand the Tower’s various functions and its inner workings by looking at the front and rear panels of this 2016 model. 

Towers logo

Because the Tower is an integration of two (once) separated devices, we conceptually separated them via the Input and Output knobs on the front panel, the input knob corresponding to the X10 transmitter (with its own one black knob) and the Output knob corresponding to the Monitor Out of the original receiver. 

The Input knob will hence determine the input signal sensitivity of the entire audio path (resulting in a gain increase or decrease, but not only); the Output knob will regulate the amount of total boost via the very same and specific opamp responsible for the same exact function in the original system.

On the rear panel of the unit (please refer to the image above), we can see:


      • XLR output. With its own internal amplifier, it is a true XLR out. Works exactly as the other output BUT it’s balanced (originally requested by Angus Young and the producing team of AC/DC’s “Rock Or Bust”
      • Standard Audio Out: the standard audio output of our Tower and the most commonly used.
      • Foot-switch: because we intended the Tower to be operated just like a guitar pedal (on or true bypass) we provided it with an optional, remote foot-switch that can be plugged in
      • MODE Switch: given the extended use that our Towers have seen in the studio, we added a ‘hiss kill switch’ that essentially, will keep the sound of the Tower the same while still adding some boost, but by setting the switch to OFF flipping it downwards, the Tower will be functioning with one opamp cut off the circuit. This way of working also exists to emulate the original functioning of the SVDS wireless, where at least at first guitar players would come out of the system by the rear panel’s XLR output, where the boost wouldn’t occur. So essentially, this will be a cleaner, hiss-less operation
      • Optical Limiter: the Opto Isolator (technical name of the original limiter) was a relatively recent find in our subsequent reverse engineerings of such complex, vintage system.  It was placed in the original X10 transmitter and it would limit the incoming signal from the  instrument, before going into further mild compression though the first opamp of the compander for the compression-expansion phase (typical of wireless systems even today). You have the option of completely excluding the limiter from the circuit (by flipping the switch upwards) or leaving it enable and trimming its amount with the lower knob. Very useful for ‘note blooming’, added sustain and that snapping sound on cleaner and clean dirty sounds.


Fil "SoloDallas" Olivieri

We Are Rock 'N Roll People.

  • avatar
    Posted at 16:05h, 20 October

    Hello, and thank you in advance,

    If you choose to purchase a power source, other than batteries, what brand/model is recommended? Please provide options for both The Storm, and the TSR.


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