The Memphis 20 Blues Harp Amplifier


Congratulations for choosing the Memphis 20 amp!  We know you will love it:  the Memphis 20 has a big, full, colorful tone very similar to the tweed  amps of the 1950s.  It is one of the coolest sounds in all of blues music, a real vintage vibe.   Your amp is specifically tuned for blues harmonica, and it is suitable for practice, recording, or performing in any venue.

The Memphis 20 was designed with two goals in mind:  tone and value.  Every circuit component was judged for its tone.  The cab was chosen for its combination of sturdiness, appearance and value. We chose items that were economical, to be sure, but they deliver the tone and quality we were after.  Other amps like this cost twice as much, but we think they do not sound any better.  And the bottom line for any amp is the sound.

Minor cosmetic imperfections on the amp are normal and expected.   The Memphis 20 amp is a great tool for serious players.   It is gig- or studio-ready.


Save all the packing materials!

Connect your harp microphone to one of the input jacks on the top panel.  There are four jacks total:  two for the Normal channel and two for the Bright channel.   The jacks labelled “1” are High input and the jacks labelled “2” are Low input.   The Low jack will reduce your mic signal a bit compared to the High jacks.  The Low jacks may help fight feedback, while the High jacks may give you more volume.  I suggest you first try Normal channel jack 2.

One of the coolest features of the Memphis 20 amp (and others like it) is the ability to bridge the channels for a broader range of tonal voicing.  I’ve provide a jumper cable for this.   With your mic plugged into Normal channel jack 2, use the cable to bridge from Normal 1 to Bright 2.  Then you can adjust the volume of both channels to customize the amp’s voice.

I suggest setting all three controls (Normal volume, Bright volume, and Tone) to 50% to start.  From there you can experiment with using different input jacks, different bridge jacks, and different control settings. 

Note from Ronnie Shellist: “I get big fat tone that has just the right amount of break up.  I plug in to Normal 1 and use a jumper to bridge from Normal 2 to Bright 1.  Both channel levels on 5-6, tone on 4.  I can push it hard.  The M20 gets crunch like the Memphis Mini and big tone like a Bassman or Super Reverb.  The sound is right where it should be and the tone is awesome.”

The input jacks are ¼ inch phone plugs wired for high impedance.   If your harp microphone is wired for low impedance it will have a different connector and you will need a converter.  I use the Audix T-50K converter and I recommend it, but there are many other good products out there.

Switch the amp power on and wait a few seconds for the tubes to warm up.  Then switch the Standby to on.   Make sure the volume and tone controls are set low at first.  Increase the settings as needed after the amp is ready.


This is gigging amp, suitable for stage work in clubs.   It delivers great tone and strong volume in a compact cabinet.  When practicing at home I usually dial the volume and tone to 3.  When gigging I crank both channels up around 9 or 10 and adjust the tone to suit the room.  Your settings may vary a lot because of room acoustics and your personal tastes.

The Memphis 20 amp has a wonderful crunch when you attack with more than one reed.  Open your playing aperture a bit to allow adjacent reeds to play on a draw note.  Hit it a little harder on the attack and then quickly drop to normal pressure.  This is one way to get the crunch and color you hear in the example videos at the Memphis Blues Amps website.  This amp loves the overtones generated by multiple reeds!


All harp amps feed back at higher volumes.  Feedback has seldom been an issue with the Memphis 20 amp.  If you are playing in a small room with reflective surfaces the amp may begin to feed back.  Reduce the volume and tone.  Try pointing the amp away from you.  Work on your mic cupping technique to isolate the mic from the sound of the amp.  Move to a larger space.

If you are playing in a club and you hear feedback, try the solutions mentioned above and also consult the sound guy.  The most likely culprit is too much harp signal in the monitors.


Very little maintenance is required.  When you receive the amp it is a good idea to make sure the four screws securing the chassis are tight.  They can sometimes work loose during shipping.  Check to see if the speaker is solidly attached to the baffle.  Do NOT overtighten!  That could damage the speaker and/or strip the screw holes.  

The fuse is accessed at the top of amp.  It is a F2AL250V fuse. Fast acting 2 amp 250 volt.


The Memphis 20 amp comes with a limited warranty for the period of one year from the date of new shipment.  There is a 90 day limited warranty on tubes and speaker subject to approval.  Any modification to the amp or abuse will void the warranty.   Shipping for warranty is the responsibility of the buyer.

DO NOT return the amp unless you have first obtained an RMA (Return Merchandise Authorization).    No exceptions!  You may contact us three ways:

Call or text 530-408-6710, or


In the case of a return, shipping costs are not refundable.

Thank you again for choosing the Memphis 20 amp!  Please feel free to contact me with any comments or questions you may have. I’ve gigged the amp extensively for the last year.  It has delivered fantastic tone and dynamics every time, even when being used by different players in every set of a raucous blues jam.  I’ll be happy to help you get the most from this great little harp amp.


-Rick Davis
Sheridan Wyoming USA

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