Protect Your Investment

Mercury’s Amp-Saver™ technology controls the power flowing into your amp – so you can power up confidence every time. The patented microprocessor controlled Amp-Saver automatically works with your amp’s on/off switch – simply plug in, turn on and play.


Why do I need it?

By controlling the power flow from your outlet, Mercury’s Amp-Saver prevents destructive hard-starting so your amp doesn’t inhale anything harmful. Gentle start-ups are key to prolonging your amp’s life.

How does it work?

The microprocessor controlled Amp-Saver automatically works with your amp’s on/off switch – simply plug in, turn on, and play!  The Amp-Saver and included Copper-Tone Power cord are designed to work seamlessly with your existing setup and You’ll sleep better knowing your transformers, tubes, and especially TONE are being actively protected.

How is it different from other devices?

  • Unlike any other product on the market, Mercury’s Amp-Saver incorporates ‘smart’ circuitry to actively monitor the voltage and current at start-up. If something doesn’t look right, the Amp-Saver will go into ‘protect’ mode and save your amp from anything destructive. If no issues are detected, the power to your amp is slowly raised to diminish inrush currents in the mains transformer, filter caps, and tube filaments. The Amp-Saver also offers user-programmable ramp speed (how slow or fast the power is applied), and current sensitivity (offering the ability to fine-tune for your particular amp — more info below).
  • Other circuits use passive devices (resistors/thermistors) to blindly slow the inrush current at turn-on. Unfortunately this method adds heat and robs audio amplifiers of the power they need to work their best. Even more sophisticated relay/solid state switchers do not offer active protection if too much current is being pulled.

What is Ramp Time?

This controls how quickly or slowly the Amp-Saver ramps up the voltage and current to your amp. The Amp-Saver is designed to minimize the inrush current at any setting. From the factory, the ‘RAMP ADJ.’ is set to maximum (fully clockwise) which goes from zero to full power in about 5 seconds. This control can be adjusted to your application using a small flathead screwdriver- the minimum setting is 1 second (fully counter-clockwise).

As it ramps, the Amp-Saver status LED will flash a few times and then stay lit green, indicating your amp has been safely started without any detected issues.

What is Current Sense and how do I set it up for my Amp? (Advanced users)

When you switch your tube amp on, the Amp-Saver monitors the power flowing from the outlet into your amp. If the tube amp is in trouble and is drawing more power than it should, Mercury’s Amp-Saver will go into protect mode and shut off the power (indicated by a flashing red status LED).

From the factory, the Amp-Saver ships with ‘SENSE’ set to maximum (fully clockwise). This setting will work for tube amps up to 300 Watts RMS. For advanced users who want to customize the protection for their particular amp, the Amp-Saver Sense control can be adjusted to customize the current protection for your particular amp.  The process outlined below requires you to start with a properly working tube amp – Mercury is happy to recommend an Amp Technician in your area if you require assistance.

As a rough guide, use the table below to match the wattage of your amp to the Amp-Saver ‘SENSE’ setting with a small flathead screwdriver. Using this starting point, switch your amp on and and verify that the Amp-Saver status LED stays lit green after ramping up the power. Some trial and error may be necessary to fine-tune this sensitivity as it needs to be set to a point just above the ‘protect’ mode. If the LED does not settle on green but instead flashes red, the Amp-Saver will need to be reset by unplugging it from your power outlet and the Current Sensitivity control will need to be increased (turned clockwise).

Approximate settings by Amp Wattage:

Amp Wattage (RMS)
Current Sense
0.1-5 0-10%
5-20 25%
20-50 50%
50-100 75%
100-300 100% (fully clockwise)

Next, with your amp turned off, lower the ‘SENSE’ control slightly (counter clockwise), switch your amp on, and watch for the solid green Amp-Saver status LED. Repeat this process until the Amp-Saver LED flashes red – at this point, with your amp turned off, and after resetting the Amp-Saver by unplugging it from your power outlet, raise the Current Sense back up slightly, and watch for the solid green Amp-Saver status LED. At this point, the Amp-Saver offers maximum protection for your tube amp and can give you advance notice if components start to fail.

My tube amp won’t turn on using the Amp-Saver. What happened?

  • If the Amp-Saver light won’t turn on at all it is likely not getting power – try a different 120VAC outlet. If the Amp-Saver doesn’t light up using known working outlet, check the fuse (inside the Amp-Saver’s IEC power inlet). Note: fuses don’t usually blow for no reason – this is a good time to double check your setup for faults . Replace only with a 5A Slo-Blo 5 x 20mm fuse – there is an extra fuse held in the fuse tray.
  • If the Amp-Saver light is blinking red, it has gone into ‘protect’ mode and something may be wrong with your amp. Double check your setup and see the ‘Current Sense’ section above for more information. Mercury is happy to recommend an Amp Technician in your area if you require assistance.

AMP-SAVER Consultation Services

If you are a large Manufacturer or Boutique Amp Builder with a custom AMP-SAVER application in mind, let Mercury’s Engineering team bring your idea to reality. Our experienced team is the right choice to meet your precise power flow control needs.

© Mercury Magnetics
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