Signature Technologies.
This Milwaukee company produced tubed preamps, amps and dynamic speakers under the names Nobis and Signature. Brian Bienfang and his wife Michelle operated the company during the heyday of local entrepreneurial electronics repair and product manufacture. In my early audio adventures, Brian became a source for both equipment and Sound Investments a friendly place to hang out and converse about audio and life. Products of note that I still own today are the SRp-7 tubed preamp, SRd-20 tube buffered CD player, SRa-8 70 watt EL34 mono, SRa-9 200 watt 6550 mono, SRM2.1 2 way speaker and the flagship monolithic SRM.7. Some are still in use in a secondary system, others are idle.
All the electronic components could be characterized by their tube prevailing influence, and the speakers by an honest, full bodied sound.
Alas, as time moves on, Signature also has become part of the "cottage" industry lore. How many manufacturers will address a blown tube circuit while you wait and /or watch the owner at the repare bench? Fortunately, we have a very competent repair shop, Audio Ventures who is familiar with Brian' s designs and has rescued me when needed.
Signature Technologies - another "out of business" but not totally forgotten.