21 January 1900
Revised :


" .. I didn't think I'd be in a position to 'review' the enhancer so soon, but its effect is surprisingly clear and in the case of the four lovely acoustics Russ Wootton has made for me, very positive indeed.

They are all significantly more responsive, particularly in the lower midrange after only a few hours with the enhancer at setting 3.

I am now moving on to my other acoustics to see what the results are like before borrowing a couple of old Gibson mandolins to see what happens there! .."

" .. I put the 'Enhancer' on my Picado classical, which was finished in July, for three days. I must say both the Sobell and Picado are the same beasts, but are more open, with more sustain and more resonance, basically more oomph!!

This is the best gadget you could buy - I could not put my Sobell down yesterday evening and found I was falling in love with it again (even though we never fell out). As most of us are striving for that ultimate guitar and acoustic sound, this Enhancer could help you on your way."

Unsolicited comment from the Acoustic Magazine forum - thanks to editor Ben Cooper.


I'd buy an Enhancer for Mandolin without reservation.  I've set up a “Giggle Stand” in the garage (it hums), and rotate my instruments through the process on a continuous schedule of a week or two each.  David prices them in British Pounds, but it turns out to be $150 USD. This is an especially good investment for those of us with two or three or five mandos, or retailers who serve a relatively sophisticated buyer who can hear “belly”—the difference after treatment probably increases appeal (open, deeper tones)  by 50%. (from Canada)

Acoustic Enhancer

for Mandolin or Guitar


The Enhancer has a detachable base so it will work on violins, violas, cellos and double basses by simply adding the appropriate base.


It's based on the same principle of gentle vibration to develop resonance in a new, budget or rested acoustic / folk guitar or mandolin. It works particularly well where the wood used is not of great merit. It won't help with electric instruments which do not rely on the resonance of the wood in the production of tone.


If you regularly play your guitars or mandolins the Acoustic Enhancer may not be of much interest, but otherwise it will help. It does not age or mature the wood, but it does improve the acoustic response. I have noticed a marked increase in the harmonic content of the open strings in violins and in guitars and mandolins. They are much more readily excited sympathetically by stopped notes.


Just as the human body or a car engine benefits from exercise, so does a stringed instrument.


The theory behind the Acoustic Enhancer is gentle vibration through the bridge for 3-7 days (or longer).



I first read about this vibration theory in A Treatise on the Structure and Preservation of the Violin by Jacob Augustus Otto 1848 (published by William Reeves, London) where he writes about having bought a well-used but very ordinary violin …

which, although every judge knew it to be a trade instrument, was not inferior in tone to an Italian one … This led me to imagine that constant vibration shakes the resinous particles out of the wood, whereby rendering it more porous and better adapted for producing a good tone, than it otherwise is.


There are two connected units. The power unit plugs in to the mains (90-230v 50/60Hz) and produces a selectable and safe DC voltage of between 6 and 12 (<300mA). The other unit – the vibration head - has a special pad on the base which grips the strings near the bridge or on the bridge of mandolins.. The unit is secured by a Velcro strap(s) under the bridge and over the unit.

To allow the guitar or mandolin to vibrate as freely as possible, it’s best not left in its case. Laying it on a hard surface is ideal. With the Enhancer secured by a strap it is also possible to suspend the guitar by the scroll (vertically) so it is completely free to vibrate. The instrument should be strung, tuned and therefore under normal playing tension.



Results of measurements on violins can be read HERE

The Acoustic Enhancer for Guitar or Mandolin needs a vibrator and appropriate base.

Bases for bowed strings are available HERE.



Within UK, including 1st Class post


Outside UK, including delivery by International Tracked/Signed

Vibrator only



Base for Guitar
Acoustic / Folk



Base for Mandolin




Sit the vibration head to the bridge with the connecting lead on the 6th string side. Place the loose pad(s) beneath the strings and secure with the strap(s). Set the voltage by the slider on the front of the power unit (or the yellow dial on the inside, depending on the power unit) to minimum and plug in to the mains. Increase the voltage until you feel vibration throughout the instrument. Settings between 6 and 7.5 seem to work well. If the vibration sounds raucous, back off until a steady hum is resumed. The settings will differ between instruments and even on the same instrument may change over a period of time. The unit is quite safe up to the maximum setting but is working most efficiently before it starts to sound lumpy. If you hear an unusual vibration check that the lead connecting the two units is not touching the body of the instrument.


Just as a car battery will discharge if not used, the violin will revert to its previous state unless it’s played or exercised occasionally by the VAE.


If you have a number of instruments, the Acoustic Enhancer could be used on them in rotation. Play the instrument after 3 days and again after 7 days and note any changes.


Ordering information

Order by email or post, specifying violin, viola, cello or double bass (different sized units for each instrument). Prices include tracked postage.

Payment via

a) Credit/Debit card (see below).

PayPal account NOT required.
b) PayPal to david@violinman.co.uk.
c) Sterling cheque payable to David Andrews and posted to the address on the Contact page.
d) BACS transfer to Sort Code 07-01-16 Account 40552891 with your name as reference (otherwise I won't know where the money has come from!)


Outside UK you will need a mains adapter to convert the UK three pin power supply (90-230v 50/60Hz) to your system.


This is now included free.

Guitar and Mandolin


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