2002 Orange AD30 head

History:

Orange is a British guitar amp company that was founded in 1968 by musician Cliff Cooper in London. The amps became popular among rock bands in the 1970s. After sales slowed down, the Orange shop closed in 1978 and Cooper built a small number of amps in the 1980s.

Gibson licensed the Orange name starting in 1993, but the Gibson era Orange amps were commercially unsuccessful, and in 1997 Gibson did not renew the license. Cliff Cooper regained control of the Orange brand.

Cooper hired Adrian Emsley as technical director, and Emsley designed the new AD series of amps released in 1998. Former Led Zeppelin guitarist Jimmy Page was an early adopter of the AD30 and started using it on tour, bringing recognition to the rebooted incarnation of Orange. In 2001 Orange opened a USA office in Atlanta, GA.

Also in 2001, Orange started making a Twin Channel version of the AD30. The Twin Channel version had Channel A and Channel B. Channel A was meant to be like the original AD30, and channel B was meant to have even more distortion available. By 2004, the original single channel version of the AD30 was discontinued and the AD30HTC twin channel head was the only AD30 head offered. Since then some guitarists have argued that the single channel version of the AD30 was tonally superior to the twin channel version.

Use:

JT’s Orange AD30 single channel is dated July 2002, and was likely bought new at one of Nashville’s music stores. It became a part of his session rig, initially as one of the a-la-carte amps he would have on the studio floor in front of him, and eventually earning a spot in the amp rack that would be set up to JT’s right, unseating the VHT Pittbull 45 which formerly lived in the higher slot of the rack.

The Orange head would remain in the amp rack for years. Around 2011 JT acquired a red Carr Artemus 2×12 combo, a design also based on the Vox AC30. The AD30 and the Artemus would coexist on sessions, with the AD30 in the amp rack and the Artemus on the floor. Eventually, around 2014, the Artemus would become the lone Vox-style amp in JT’s big cartage rig and a Marshall-style Reinhardt head took the Orange’s spot in the amp rack. The Orange was then set up on the amp shelf in JT’s personal overdub studio.

The AD30 single channel has 3 small knobs for bass, mid, and treble, and 2 big knobs for Gain and Volume. In its present condition, both big knobs are missing.

Specs:

The head measures 21.65″ x 10.63″ x 9.45″ and weighs around 35 lbs. When playing through this head, the guitar signal is first amplified by a 12AX7 preamp tube, then another 12AX7 drives the EQ stage. Signal then goes to a third 12AX7 used for the phase inverter. At this point the signal goes to the Class A power section comprised of four EL84 tubes. And finally, the signal exits through the 16 ohm and 8 ohm taps on the output transformer and from there goes through the cable to the speaker cab. This head has one 16 ohm output jack and two 8 ohm output jacks. It does not have a 4 ohm output jack and is not meant to be used with 4 ohm cabs.

Like a Vox AC30, the Orange AD30 is cathode biased, has no negative feedback, and is Class A with the power tubes working in push-pull pairs.

Cathode Biased:
Means the power tubes self-regulate the amount of current flowing through them. When the guitarist hits a note, the tube calls for more power and causes a spongier feel with more sustain. A convenient side effect of this is the power tubes can be changed without needing to manually re-bias the amp.

No Negative Feedback:
Negative feedback is when a small percentage of the fully amplified signal is taken from the output transformer and blended in with the (out of phase) signal at the phase inverter (before the power tubes). This reduces the gain and distortion of the amp. The Orange AD30 does not do this. No negative feedback means the amp has more power tube distortion and more present mids.

Class A Push-Pull:
In a push-pull amp, when the signal reaches the phase inverter it is split into two opposite positive and negative copies. Two power tubes amplify one copy (the positive), and the other two power tubes amplify the other copy (the negative). Splitting up the workload into positive and negative like this and recombining later is more efficient than having all of the tubes work on the entire signal. Two tubes focus on amplifying one half of the waveform while the other two tubes focus on amplifying the other half of the waveform. But since it’s “Class A”, it means the tubes never completely shut off, even when the half of the waveform they aren’t focused on is being amplified. A “Class A/B” amp would have the tubes focus 100% of their attention on half of the waveform, and shut off completely during the other half. Class A/B is more efficient than Class A, but Class A avoids the “crossover distortion” that happens in Class A/B amps when the waveform goes between positive and negative halves.