A Note on Open Box/Demo Amplifiers

For nearly 30 years, Dr. Z Amplifiers have been held to a strict price controlled, “no discount” policy. This year, we have decided to allow our dealers to discount open box, demo/floor models, returns, refurbished, and otherwise “used” amplifiers they may have, at their discretion. Discounted amps will be clearly marked as such and will not have a factory warranty. Hopefully this will encourage you to investigate our dealers’ current stock for a great deal on a Dr. Z Amp.

Again, there is one important caveat to this agreement: discounted amplifiers from our dealers will NOT be covered by a factory warranty. However, this does not mean our dealers will sell an amp in any sort of disrepair. All discounted Dr. Z Amps will be sold in fully operational condition. Please buy with confidence. Despite not carrying the factory warranty ascribed to new products, the Dr. Z repair dept. will gladly service, modify, or otherwise advise on any of our products, be it new, old, used, discounted, demo’ed, etc. Please take a look at our variety of modifications and services available for our product line here.


Happy playing,

Dr. Z

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100 Cures Shipped!




I would like to thank everyone who has purchased the new Cure amp. Since Jan. 2017, we have shipped over 100 Cures with 67 still in back order. This is an amazing honor for us. Not only have Cures sold at an incredible clip, they have been overwhelmingly accepted and raved about by their owners.

This amp just hits the spot; it has great clean and wonderful overdrive tones. It weighs only 33 lbs. and its level control works like the best attenuator ever built. A hand-built, American-made heirloom amplifier, at an import amp price, everyone needs the Cure to add to their stable of gear.  Either at home, in studio, at church, jam night, or on stage with a full band, the Cure will fit the bill.

Again, thank you to the 100+ players who have already purchased a Cure (some more than one!) and to those that have one on order, we will keep building them, you keep playing them.




Dr. Z

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Standby Switch



Standby Switch in Tube Guitar Amplifiers

The use and need of a standby switch is an issue that comes up from time to time. Let me say that a standby switch is a convenience supplied to guitar amps. Now not all guitar amps have standby switches. For example, the Carmen Ghia and its directly heated 5Y3 rectifier does not need a standby switch. By the time the 5Y3 conducts high voltage, the tubes are heated and ready to conduct. Extremely high quality tube stereo amps, like those made by McIntosh also don’t have standby switches. Remember that many stereo tube amp connoisseurs and audiophiles use these kinds of amps sans standby switches. I have never read an issue about the lack of standby switches on stereo tube amps.

So why do amps have standby switches? They are installed as a convenience for the operator. When a band would take a break, the standby switch was used as a “mute” switch for the amp. Once the break was over, the amp would be ready to play with the flick of a switch.

A few terms used to scare users into using standby switches:

Cathode Stripping: This term does not apply to the tubes used in guitar amps. This applies to cathode ray tubes, and only under limited applications.

Cathode Poisoning: In my 50 years of dealing with vacuum tubes I have never heard about this phenomenon. Cathodes only conduct electrons when the anode of the circuit has a high voltage potential to attract them. High voltage is present only when the standby switch is in “play mode”.

Here are some simple dos and don’ts when using a standby switch:

  • Always use a standby switch when dealing with a solid state rectified amp. The immediate surge of high voltage on a tube isn’t the best for its long-term life.
  • Power on your amp, then wait a minute or so and engage standby switch. This is the proper use of a standby switch.
  • Turn standby switch off if you are switching speaker cabs, engaging a half-power or triode/pentode mode on amps with these features.
  • Engage standby switch when taking a break.
  • When you power down your amp, just turn off power switch and leave standby switch on. This will safely drain high voltage from your transformer and filter caps for safe transportation.