Where are Dr. Z Amps made?

All Dr. Z amps are made in Cleveland, Ohio. The amps are all hand-wired right here at our shop. All cabs are assembled and loaded here too. We bench-test and play-test each amp and cab before it ships to one of our fine dealers.

Do you sell direct?

No. We have an excellent network of dealers that are very knowledgeable on our line.

Click here for a list of our dealers.

Do you sell unloaded cabs?

No. All of our cabs are play-tested before leaving the shop.  If they don’t have a speaker in them we can’t do our job!

Do you retolex amps?


Do you sell grill cloth?


Do you repair used Dr. Z Amps?

Yes, we are happy to bring your used Z amp up to current specs and give it a once over. Email repairs@drzamps.com for details.

Are you ETL Certified?

Yes, we are officially “ETL Listed to UL 60065” certified for the USA and Canada. We are also CE certified for the rest of the world. The certification process was done by Intertek/ETL which is an independent third party lab. We believe we are the only boutique amp manufacturer with models that are “ETL Listed to UL 60065” certified. This was a very lengthy and expensive process. We are very proud to build amps for our customers that are certified for safety, reliability, and durability.

Many tests were performed and documented. We are spot inspected 4 times a year by ETL to insure we are using building methods and materials outlined in the report. Click here to view the full report.

Are you in compliance with California Proposition 65?

As a small business with under 10 employees we are legally exempt from CA Prop 65, and our products are not required to carry any labeling. Read more about Proposition 65 by clicking here.

I bought a used/open box/demo/floor model amp from a dealer at a discounted rate. Does this amp include a warranty?

No, but we offer repairs and updates to all models at a fair rate. Please email repairs@drzamps.com to schedule service on your amp.

Where can I get new tubes for my Dr. Z Amp?

We have a list of recommended tubes listed for each of our amplifiers here. You can purchased the recommended tubes for your amp from The Tube Store.

How do I bias my amp?

Most of our line is cathode biased and does not require re-biasing after replacing the power tubes. Amplifiers that are fixed biased should be re-biased by a knowledgeable technician. The bias information for all Dr. Z amps is located here.

I have an amp that is no longer listed in your product line. Do you still support these amps?

Yes, amplifiers that we have ceased production on are still supported by Dr. Z amps as Legacy Models. You can find information on them here or the Z-Talk Forum. If you need service on your Legacy amplifier, please contact repairs@drzamps.com.

Do you have an artist program?

Not at this time.  Our artist program has been suspended.  Our production is limited and we appreciate all players supporting our network of dealers.  You will get excellent information and service from any of the fine dealers listed here.

Where can I get slip covers for my amp?

While there are many fine amp cover makers out there Dr Z Amps recommends Studio Slips. Studio Slips are made in the USA and feature outstanding craftsmanship and are an excellent value. We include Studio Slips on our Z-Wreck combo and the Z-Wreck quantum silver set.

How should I use my stand-by switch?

Dr. Z covers the do’s and don’t’s of the stand-by switch in this blog.

How do I run an extension cab with my combo or hook up 2 speaker cabs to my head?

This is an easy procedure.  First thing to do is get a quality Y Cable like the ones offered by Procables N Sound.  These cables are available in series or parallel wiring.  Always match the ohm rating of the extension cab to the ohm rating of your combo speaker.  The same goes for running 2 cabs.

Here’s an example for parallel (the most common) connection:

  1. Disconnect your 8 ohm combo speaker from the back of the amp chassis and plug it into the Y cable.
  2. Plug the extension cab into the Y cable.  You now have two 8 ohm loads in parallel to make a 4 ohm load.
  3. Plug the Y cable into the 4 ohm speaker out on the rear of your amp.

Series connection is the same except that two 8 ohm loads make a 16 ohm load.  Not all Z amps have 16 ohm speaker outs so be sure to check your specific amp.


Dr. Z has made an instructional video to complement this written guide. When troubleshooting be sure to have a speaker load always connected before powering your amplifier on. 

WARNING: Make sure you unplug the amp when changing fuses, and do not touch the metal pins of the tube sockets with your fingers.

NOTE: Do not assume that new tubes are good tubes. Many new production tubes are bad out of the box. Try to have tubes you know to be good for these troubleshooting procedures.

Part 1: Fuses

  1. Remove ALL tubes from the amp.
  2. Install new fuses.
  3. Turn amp power on, and standby on.
  4. Turn off and check fuses.

If the fuses are ok, your power transformer is OK.
Move on to part 2.

Part 2: Rectifier

  1. Install rectifier tube.
  2. Turn amp power on, and standby on.
  3. Observe rectifier for signs of arcing.
  4. Turn off and check fuses.

If the fuses are OK, and the tube does not arc/spark your rectifier is OK.
Move on to part 3.

If a fuse is blown or your rectifier is arcing replace the rectifier and fuse with equivalent replacements and repeat part 2 of troubleshooting procedure.

Part 3: Power Tubes

  1. Install power tubes.
  2. Turn amp power on, and standby on.
  3. Observe rectifier and power tubes for arcing or red plating for about 30 to 45s.
    Arcing will most likely occur immediately, but red plating may take a few seconds.
  4. Turn off and check fuses.

If the fuses are ok, and none of the tubes are arcing or red plating the output tubes are OK.
Move on to part 4.

If a fuse is blown or your output tubes are arcing or red plating or your rectifier is arcing, replace output tubes, rectifier, and fuse with equivalent replacements and repeat part 3 of troubleshooting procedure.

Part 4: Preamp Tubes

  1. Install preamp tubes.
  2. Turn amp power on, and standby on.
  3. Test amp for sound or noise.
  4. Remove each preamp tube one at a time and replace with a known good tube.

If amp works again or noise goes away, mark or discard problem tube and continuing rocking and/or rolling.
If there is still no sound or the problem did not go away, contact repairs@drzamps.com for further instructions.

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