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Step 3: Shaping the Orange Sound
Cliff Cooper on the University Sound Lab Tests
“During 1969, we sampled the sounds used by a number of top guitarists—among them, Peter Green, Marc Bolan, and Paul Kossoff, all of whom liked to spend time in the Orange Shop just chatting and playing guitars. We asked these and other professional guitarists to plug into our mixing desk, play around, and find the sound that they liked best. We were then able to measure the sound characteristics and decide what changes were needed to the Orange amp circuitry. We would then send these circuitry changes to Mat up in Huddersfield so that he could incorporate any modifications into our amplifiers. Basically, it was a question of what our customers wanted.
“As Orange became more established, we found that a lot of people liked our amps, but it wasn’t across the board. Many guitarists told us that our amps just didn’t sound as loud as some other makes, watt for watt. Using signal generators, oscilloscopes, and other measuring equipment, we measured an Orange OR120 amplifier in our workshop. It gave out a true 120 watts RMS (root-mean-square). We then measured another famous make of 100-watt amplifier, which gave 96 watts output—but it still sounded much louder than the Orange amplifier. We just couldn’t figure out why this was. At the same time, we tested the distortion levels. The other amplifier had a far more distorted sound than the Orange amp.
“I arranged a meeting with a leading ear specialist with a practice in London’s Harley Street. He explained to me how the brain can register distortion as pain in order to protect the mechanism of the ears. The jagged harmonics produced by the distortion work the ear’s conducting bones harder, and this is perceived by the audio nerves as an increase in sound level. The original Orange amps were especially clean sounding, with very little distortion. And so it was, in fact, the clean sound that was the root of our problem. So, thanks to the ear specialist, we had solved the mystery. In order to correct the situation, we gave the amp a lot more gain and modified our circuitry in a different way [than] the amplifiers we had tested. The main changes were to the tone stack at the front end and the phase inverter. These changes gave birth to the ‘Orange sound’ and were incorporated in the first ‘Pics Only’ amps—our amps with hieroglyphs. The sound perhaps is best described as ‘fat’ and ‘warm’—more musical and richer in harmonics, with a unique saturation in the mids band. It also improved the sustain. That said, choice of sound, naturally, is a personal thing.”
The Pics Only Graphic: Root of the Orange Sound
Mick Dines elaborates on the Pics Only amp. “The ‘Graphic Valve Amplifier’ was designed inhouse by John James in 1971, and manufactured during the period 1972–75. It was soon nicknamed the ‘Pics Only,’ a reference to the front-panel graphics which were unique at that time. Earlier versions had Woden or Drake drop-through transformers, later ones had Parmeko. A four-channel PA version was introduced (pictured at top right). Some Pics Onlys were made and sold right up until 1975, especially Slave 120 Graphics (pictured at bottom right), in order to use up stock and components. There was often this kind of overlap when a new Orange series was introduced.
“Early Graphic Pics Onlys soon became known as ‘Plexis,’ because they had a plastic reverse-printed Perspex panel secured on an orange steel backplate fixed to the chassis. The amplifier was secured into the cabinet with four front-panel fixing bolts with plastic seating washers. The panels on later Pics Only amps were not plastic, but silkscreen printed metal plates with no visible plates.
“In hindsight, the graphic icons were perhaps a bit too big and prominent on the Plexi. So in 1973, we went back to the drawing board and redesigned the front panel, as well as making other electronic modifications. The result was the Graphic 120 ‘Pics & Text’ amplifier. The Pics Only was the start of the new sound that everybody associates with Orange, and it has influenced the design and sound of Orange amps ever since.”