Doppler Audio provides a huge range of quality vintage instrument and amplifier repairs. Whether you have a tonewheel Hammond Organ, Fender Rhodes, Wurlitzer Electric Piano, or a vintage guitar amplifier, we’ve got you covered.

  • Hammond Tone Generator Repairs
  • Pre-amplifier Service
  • Leslie Connection & Switching
  • Leslie Speaker Repairs
  • Full Restorations
  • Rhodes and Wurli Tuning & Voicing
  • Pickup & Tine Repairs
  • Key Rebushing & Action
  • Modifications
  • Suitcase Pre-amp & Amp Repairs
  • Guitar Amp Servicing & Re-Capping
  • Valve/Tube Replacement
  • Modification & Tweaks
  • Troubleshooting Weirdness
  • Full Restorations
Hammond Organ

Hammond Services


Tone Generator Repairs

Squawking bearings, faulty run motor or start motor, bad tonewheel filter networks and even bad tonewheel pickups can be repaired or replaced. 

To avoid tone generator removal and repair, missing tones can be replaced with installation of Trek II Generator Note Replacement modules.


Pre-amplifier Service

Hums, pops, crackles, weak channel volume and many other symptoms can be related to  pre-amplifier faults. Servicing your preamp can range from minor fettling to full restoration as required.

A quick chat over the phone will usually help identify whether you have a problem in the preamp or elsewhere in the organ. Feel free to call.


Percussion and Vibrato/Chorus

If your percussion tones have gone missing, or simply won’t decay, it will need  troubleshooting and repairing. It’s usually a single cause, but not always!

Similarly with the electromechanical vibrato/chorus system in a Hammond, when things start to sound bad there are several possible causes. Taking a methodical approach to finding the problem is essential, and is usually solved on a service call.  


Keyboard & Drawbar problems

Some Hammonds have had an easy life, others have keys that feel dead or clack. Keyboards can be refurbished with new felts and keys polished if required. Other keying faults can arise from vigorous playing (shout out to Lachy Doley!) in early models! Keying can be scratchy or ciphers can appear with very worn key contact/busbars too. Busbar shifting & cleaning services are offered along with repairs.

Drawbars can sound scratchy, intermittent or lose sound altogether. A common repair is to replace the nichrome resistance wire that tends to break off inside the drawbar assembly – this restores the ‘continuous’ sound of a drawbar when pulled out slowly.


Leslie Speakers

Leslie Speaker Services


Leslie Connection & Switching

Depending which model Hammond you want to connect to which model Leslie, the connection type will vary.  Most combinations can be catered to, including blending the organ’s reverb into the Leslie output. Likewise your preference for switching by hand or foot can be catered to.


Leslie Speaker Repairs

Some Leslies purchased secondhand will work perfectly well, but not very many of them! They are normally over 40 years old and regular servicing has often been neglected. 

Being an electromechanical device for animating the sound in a room, Leslies need attention to motors, speakers, amplifiers, crossovers, and even reinforcement of cabinet joinery in some cases. Doppler Audio offers the full range of Leslie servicing and stocks parts accordingly. 


Leslie Modifications

Some players like to get ‘a bit more’ out of their traditional valve Leslie in a live situation, or avoid mechanical clicking of the switching relay when recording for example. Minor modification such as a more efficient horn driver or a solid state motor relay can make all the difference. Other modifications are available upon request.


Combo Preamp Pedals

Some Leslie models such as the 147, 760, 910, 925 were originally available with Combo Preamp Pedals to allow for playing keyboard, guitar, mic or other instruments through the Leslie. Servicing the Combo Preamp pedals has come more necessary as they age and with simple wear and tear! Most parts are still available so these units are regularly returned to life at gigs or in studios.

Fender Rhodes

Fender Rhodes Services


Fender Rhodes Harps

Rhodes harps consist of tone generator assemblies, including a tine and tonebar pair mounted on springs with isolating rubber grommets held in place by screws. As the rubber goes hard or perishes and screws bend, the note tends to lose sustain and is more difficult to voice for good tone.

Harp servicing can range from simple tine replacement & tuning to full refurbishment including replacement of all screws & rubber grommets, full voicing according to player’s taste and replacement of any tines that have fatigued over time.


Rhodes Pickups

Rhodes pianos sometimes have one key that sounds much quieter than its neighbours. This is not just a need to adjust the pickup closer to the tine, it’s actually a dead pickup. The reason you can still hear the note is because the neighbouring pickups are hearing the tine.

Pickup replacement is often needed for a piano that has been stored in a damp garage, or one that has lived by the coast! Atmospheric moisture eats away at the thin pickup wire near where it is soldered to the output lug. Sometimes they can be repaired but it’s often more economical to just have new pickups installed as they are now available again at a reasonable price.


Rhodes Actions

Some Rhodes actions feel heavy, or clunky, or sludgy to play. Particularly when the key bushings are worn, hammer centre pins worn or broken, or if ‘lubricant’ powders have contaminated the hammer cam area.

All of these problems can be addressed – keys rebushed, re-felted, hammer cams polished and the action geometry improved with various modifications. 


Rhodes Suitcase Electronics

There were several generations of Rhodes Suitcase models using preamps with vibrato and power amps in the 4-speaker cabinets the piano sat on. Whilst generally reliable these systems are now approaching middle age and respond well to a bit of TLC.

Typical problems include loss of one channel, noisy preamps, distortion in power amps and blown amps or speakers.

Rebuilds of preamps, power amps and power supplies are normally done in the workshop but minor repairs can be done on site if your suitcase piano is giving you a bit of grief! 

Wurlitzer Electric Pianos

Wurlitzer EP Services


Wurlitzer Piano Harps

Unlike Hammond organs and Rhodes pianos, which use magnetic pickup coils, Wurlitzer Electronic Pianos rely on an electrostatic pickup bar charged to 150v static charge.

The tiny 0.006″ gap between a vibrating steel reed and pickup bar means harp hygiene is essential to avoid nasty pops, crackles and fizzing noises resulting from particles shorting across this tiny gap. 

When tuning, voicing and replacing reeds, we take care to clean reed gaps across the harp to reduce the chance of unwanted noises appearing when you least expect it! Apart from getting the harp to play evenly across the range, more ‘custom’ voicing can be done to suit the player’s preference.


Hums & Hisses

Depending on the model, there are several possible sources of hum and hiss that can be addressed when your Wurlitzer is serviced. Extra shielding, grounding and improved component quality can all make a difference to the ‘noise floor’ of your piano. 


Wurlitzer Keyboard & Action

Wurlitzer actions have many components in common with small acoustic pianos, and therefore need to be serviced and regulated correctly in order to maintain a light and fast playing action.  similar to a small spinet piano action.

During service, the action is removed from the piano and  either ‘freed up’ or disassembled and overhauled with new action centres, jack springs, felts, hammer tips etc. as required. Once back in the piano, full regulation is undertaken to ensure the piano will respond evenly to  very light playing through to rock ‘n roll. Wurli stuff. 

Keyboards have to be checked for bushing wear, rusty key pins, keys eased as required etc. Full keyboard servicing is available from simple key-easing and levelling to key re-bushing, re-pinning, and key capping for badly cracked key tops.


Wurlitzer Electronics

Wurlitzer amplifiers are getting older and often under-performing. When servicing these amps it’s important to get it right, including correct biasing of the output stage to avoid distorted output before full volume.

Vibrato (tremolo actually, but they called it vibrato) is a feature than can also give trouble and must be ‘tweaked’ on each piano, especially if it has been converted from a ‘student’ model.  

Our Work

Leslie Combo Preamp Pedal

  • Converted from 115v to  230v operation
  • For operating 145/147 Leslies
  • Bought on eBay USA by a local customer 
  • Now usable in Australia
  • Play guitar, vocals, anything through a vintage Leslie!


Echoplex EP-2 Tape Echo Sound-on-Sound


  • Converted from 115v/60Hz to  240v/50Hz operation
  • Fresh Pinch Rollers, Tape
  • Last of the tube models
  • Warm & quiet preamp
  • Super rare Sound-on-Sound


Testimonials … not again …

I am the best in the world. There is no one who is greater than I. I am really good. Look at me, I’m doing amazing things. I do amazing things and stuff because I am amazing. Just Look at me. Please.

John Smith

My Rhodes was suffering from a severe case of Airborne Syphillis. After Dr. Geoff got the smell off, then he took to it with a mystical anti-biotic spell and that seemed to do the trick. Just wish I knew how to play the piano. Impeach!

Barney McAll

I found a bunch of Wurli’s in a cow paddock this one time when I was having dinner at a steak house that was closing down. That was 23 years ago and Geoff is still working on them. They were bad then and now look even worse.  I’m gonna throw them onto his funeral pyre.

Kim Kelaart


Frequent Questions 


Will my Hammond Organ blow up?

Probably. They were built a long time ago and need special care and attention. If you are a complete fuck wit, then you probably shouldn’t have one in the first place. It’s most likely that you are an idiot and you don’t deserve to play a beautiful instrument like the Hammond Organ.


Am I a gig slut?

The simple and short answer is YES! If you play the Hammond Organ, you are more likely to get laid and die because you are a gig slut. At the very least, you’ll probably get herpes. You should get tested. And don’t forget to wipe down your organ after a long, hard, sweaty session.


Why does my Leslie Speaker suck?

Probably again because you are a fuck wit. There’s nothing wrong with the Leslie Speaker. Did you plug it in? Have you switched the organ on? Is the volume knob on zero? These are all factors that can hinder the beautiful tones of a truly amazingly beautiful Leslie Speaker. Invented by Don Leslie.


I can't play very well. Will I get better?

If you don’t practice for 23 hours a day, you will never make it as a Hammond Organ player, and you probably shouldn’t own one. There are plenty of people that deserve them, and you are just getting in the way. Shame on you. Let someone else have it. You should give it away immediately.

5 + 8 =


216 Old Thorpdale Road
Mirboo North, VIC, 3871


0408 682 172