The following is a brief explanation and some tips on the controls of the Ozone Series to help you get the most out of your Oxygen.
18W Ozone Series
1. Power Scaling:
The amp uses the London Power, power scaling technology. When the scale control is on full, the power scale is essentially out of the circuit in a figurative sense, as the voltage to the output transformer is wide open. This of course affords max volume, which is sufficiently loud for most situations despite the nominal 18W rating.
With the volume at around 3 o’clock, the amp should be quite loud and clean with a hint of underlying breakup. As you scale back, the volume will begin to range back as well, but more importantly the output stage will begin to break up and start adding those wonderfully even order harmonic elements that really make the tone warm, add compression without pre-amp distortion and really sound chimey like the best tube amps from days gone by. When power scaling down, the signal to the output stage has to be reduced by the volume control of the channel being used to achieve the amount of drive for the best sound. Experimenting with the volume and scale alone until the various sweet spots relative to the warmth / breakup factor and desired volume, is a good 5-10 minutes well spent.
2. Cut control:
Some guitars may sound overly bright, depending on the pickup configurations and other factors. The cut control can be used as an auxiliary tone control to put it simply. Adjust it fully counter clockwise to yield max bass, while fully clockwise yields the most treble. Thus the cut works against our intuition; rolling back, not forward activates.
3. Gain control:
The gain control is unique in the way it is effectively utilized in the circuit. Firstly, it is only active when the Boost is engaged. It is not designed to be maxed out in order to deliver the most pre-amp distortion, but rather it is designed more as a harmonic enhancer that really helps eventuate the even order harmonics coming out of the output stage, where the real tone lies. Adjusting the gain past 12 o’clock will yield high compression ratios, which can result in fuzzy tone on the lower strings. If more pre-amp gain is desired, a good overdrive pedal can be added and works very well. The amp loves pedals!
4. Cream Channel:
This channel utilizes a 5879 pentode tube with volume control and a four-position tone control rotary pot used to select four levels of capacitance within the circuit. Position 1 yields the least breakup and the brightest while the wide open 4th position delivers more mids and bass response and provides significant dynamic range from the guitar volume. Great circuit, with simple elegant control!
5. Clean / Boost Channel:
Triode clean channel with TMB equalization and switchable additional gain stage and gain control (see above) for low output guitars. This channel consists of a low gain preamp that delivers a full clean tone with smooth response but can be pedalled up for more drive.
The boost section switches in an additional gain stage (either by pulling on the Gain (Boost) control or with the foot switch) that is primarily used for low output pickups or to provide a bit of drive to the signal. The guitar volume can then be rolled down to clean the signal up. This can be used as a bit of a lead boost but not when the amp is power scaled down as the drive signal would be too hot in the boost position. When using pedals in the clean channel the boost should ideally be off.
This channel provides both a bright, clean tone that is perfect as a blank canvas on which the guitarist can develop their signature tone as well as an overdriven (boost) channel that delivers that mild gain and wonderful even order harmonics.
6. Input Jacks:
Both channels have independent input jacks, which allows the channels to be pedalled up individually and then accessed with an a/b switch.
36W Ozone Series
The Ozone 36 is a players amp based on the iconic 59 Bassman/ JTM 45/ Plexi. The power platform can be biased for KT66/6L6/EL34 output tubes and this in conjunction with a preamp circuit that, depending on the gain of the preamp tube used and the master volume function, allows the player to voice this amp to their own preference.
Essentially a tone control that can be adjusted to boost the upper mid-range frequencies to make the sound of the guitar seem more “present”.
2. Master Volume:
In a very basic sense, the idea behind the master volume is to be able to adjust the preamp and the power amp volumes independently of each other, thus giving a player the ability to control how much the amp is “breaking up” or overdriving while still keeping the volume at a respectable level. If a player wants to push the amp a little harder they can increase the “normal” volume and back off on the “master” volume and the amp will now be able to be pushed into overdrive without the much added volume. The reason for this is that by increasing the “normal volume” the amp’s preamp is producing more gain, but since the power section “master volume” is set lower, the signal is not being amplified as much.
3. EQ Section:
The EQ section has the classic cathode driven TMB controls that in conjunction with the classic/modern switch allow the response of this amp to range from classic tweed through bluesbreaker to blackface
4. Classic / Modern Switch:
This switch is used to vary the band width to deliver different tonal options. With the switch in the Classic position the amp produces a wider bottom end response delivering tone that is reminiscent of the vintage JTM45’s or 59 Bassman. With the switch in the Modern position the bottom end band width is narrowed delivering more of a Plexi sound.
5. High / Low Input:
Allows the player to select input based on the guitar being used. The low input provides a 6dB reduction for hotter pickups.