Carr Amplifiers Mercury FAQ
Answers to frequently asked questions about the Mercury.
- Can I get shimmering clean tones with my Mercury?
- Can I hear the Mercury in a live situation or at 8 watts is it only practical for home use?
- What tubes are used in the Mercury?
The General FAQ on the Support page addresses additional questions about tubes, speakers, purchasing a Carr amp, and more.
Can I get shimmering clean tones with my Mercury?
The Mercury is primarily a distortion amp, but gets some very nice clean tones at lower volumes. It's has a 3-position rotary switch Boost feature that adds grit to your basic tone setting. The Mercury's versatility is its attenuation switch, allowing for 8 watts, 2 watts, 1/2 watt, and 1/10 watt, all of which can get good clean tones by keeping the volume lower and the Boost off.
Can I hear the Mercury in a live situation or at 8 watts is it only practical for home use?
The Mercury is fortissimo for 8 watts, is fine for live gigs, and usually can be heard clearly in full band situations. Steve Carr uses a Mercury in his 5-piece rock band with his Les Paul Custom and never seems to need to mic it. Sometimes he puts it up on a chair or something else to get it off the floor, but it can also be mic-ed to great effect, if needed.
What tubes are used in the Mercury?
We refer to the tubes and their positions in the amp as V1, V2, etc. for preamp tubes and P1, P2, etc. for power tubes. The number indicates the position of the tube as counted from right to left when looking at the back of the amplifier. The right to left progression follows the circuit from input to output.
| P1 | V3 | V2 | V1 | |
|---|---|---|---|---|
| Type | E34L | 12AX7 | 12AT7 | 12AX7 |
| Manufacturer | JJ | Groove Tubes | Electro-Harmonix | Electro-Harmonix |
| Function | Single-ended power stage | Reverb return and mix | Reverb send | Initial gain stage, post tone-stack recovery |
The Mercury is a fixed bias amplifier and requires a bias adjustment any time the power tube is changed. See the Mercury Owner's Manual for more information on adjusting the bias. The amplifier has been optimized for the EL34 tube (the JJ E34L is their premium EL34-type tube), but the following tube types are also compatible with the Mercury: KT66, 6L6, KT88, 6550. Do not use a 6V6 power tube in the Mercury. The voltages and current levels are not compatible with 6V6s.
Carr Amplifiers selects and tests the finest current production tubes specifically for each amplifier model. Caution should be used when buying replacement tubes from any dealer who does not have a return policy as all tubes can have problems (NOS tubes are susceptible to microphonics and failure too).