June 2010

It was just a year ago (TQR May 2009) that we first reviewed Austin amp builder John Grammatico's take on the narrow panel tweed Bassman – an exceptionally worthy perfor- mance amp richly endowed with a ton of tone. Since then Grammatico's obsession and obvious quality of listening compelled him to further tweak his original design with the assistance of Telecaster wizard Redd Volkaert, culminating in Grammatico having his own proprietary polyester/aluminum foil coupling capacitors made and sourcing bypass caps in Austria after evaluating virtually everything available in the USA. We asked John to describe the process and results he achieved in further tweaking his Bassman circuit...

I explored virtually every type of capacitor currently available or ever made for guitar amps, and I have examples of them all – new and old. In my discussions with engineers involved in current capacitor production and considering all the pos- sible variables, I had caps made to my specs by six different manufacturers and of those, two sounded really special. Once I heard what these caps could do, I was able to free up the negative feedback in the circuit, which gives the amp a little more shimmer and sparkle than a vintage Bassman. Just to make the amp more versatile and give it a range more into the blackface era, I also changed some values on the cathodes and the input of the phase inverter. The original Bassman amps can have this stark directness to them, but lacking bloom and shimmer... Players that don't care for that Fender sound often like the Vox sound because those amps have all that extra shimmer and sparkle, while the old Fender amps can sound too dry... They have warmth and roundness, but the notes decay quickly without enough bloom and depth.

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