We get a lot of questions about our process every week. We encourage you to read everything about what the process is and is not, and read, hear and watch real customers’ and real players’ reactions to our results. If you have a specific question that isn’t answered here, please email us.

Q. What is the AO1 process and how does it work?
A. In  2012, patent #8,134,064 was granted for the process.  In simple terms –  The AO1™ process “ages” the wood in a specific pattern, optimized to the unique sound-producing properties of a given instrument.

By changing the nature of the wood we are able to increase the resonant amplitude of the instrument, giving it more sustain, making it louder, more dynamically balanced, easier to play and more articulate.

For the detail-oriented, here is a full tech description of the AO1 process: 

When an instrument arrives at AAL, it is allowed to sit at room temperature overnight to reach equilibrium. A cursory visual and sonic evaluation of the instrument is implemented upon arrival. The instrument is allowed to sit for another 24 hours to ensure its temperature and moisture content have also equilibriated to our 72 degrees F and 50% RH lab conditions. These conditions are kept constant during the entire AAL Process.

The AO1 Process begins by a thorough visual inspection followed by sonic and tactile impressions made by one or more guitar techs and/or players. After the initial evaluation is completed, the instrument is placed in an anechoic chamber and a proprietary sensor system maps the input and output response of the primary sound forming surfaces of the instrument.   The I/O response is then used to establish unique process parameters that will be implemented on each individual instrument.  Just as no two instruments are the same, the AO1 process is custom calibrated for every instrument.

Once the process parameters are mapped, various locations of the instrument are targeted and then are, what might be referred to as -non-thermally annealed.  To accomplish this, high energy sonic waves of extremely specific energy levels are focused at similarly specificlocations on the instrument while simultaneous response measurements are made.

At various stages in the process, the instrument’s I/O response is measured and new sets of AO1 process parameters are incorporated until the instrument has reached approximately 90% of its ultimate capacity potential as determined by the technicians. The AO1 process is then stopped and final mapping of the I/O is made.  The instrument is played again by one or more guitar techs and their impressions are noted before the instrument is returned to the customer.

The AO1 process allows for symmetrical, properly located oscillations to occur in the sound forming surfaces of the instrument and manifests itself in greater volume/dynamic range, richer, more full sound, and more responsiveness to the player’s touch.  Over the course of the following 4-6 weeks, the instrument will continue to transform into its full 100% potential assisted by continual, intermittent playing.


Q. Do you change anything structural or cosmetic about the guitar?
A. No. There is no shaving, sanding, removal, or addition of material in any way or modifications to the bracing, saddle or any other part of the instrument. The changes are at a cellular level and are undetectable to physical observation.

Q. I’ve got a  custom, hand-built, small-batch guitar with an Adirondack top and select Brazilian Rosewood back & sides  that one of the best small luthiers in Vermont made for me personally. How can you say there’s something wrong with it?!
A. We don’t say that. We love and support luthiers. We’ve processed many guitars for them. There’s nothing wrong with it any more than there was anything “wrong” with a brand new Martin D-28 in 1932. Our process isn’t designed to “fix” something wrong with well-made guitars, it’s designed to take them to their fullest mature potential as intended by the masters who built them. Would it sound even better if you played it and cared for it for 75 years or so? Then our process can make it can sound that kind of better right now.

Q. I’ve seen other, similarly advertised procceses that say they work on solidbody guitars too. Why doesn’t yours?
A. Firstly, understand that the process is pure, science that “works” on wood, period. It will work on any and all wood. But the aspects of the top of an acoustic guitar, the section that it is generally agreed upon as having the most impact on the volume and performance and sustain of an acoustic instrument – is much different than that of a solidbody. An acoustic instrument’s top’s stiffness, and cellular structure directly affect the vibratory qualities that then create the sound of the guitar. A solidbody guitar produces sound much differently. The type of wood, density and other factors still affect the sound it produces, but in a completely different way that is then amplified by pick-ups. We’ve built our reputation on the DRAMATIC improvements we’ve achieved with acoustic instruments. The results on solid wood instruments are much less observable and less controllable.  Would it work? Yes. Would the guitar sound better? Not discernibly enough to warrant the expense or the effort due to the science and nature of it. In our opinion, anyone trying to sell the same results for acoustic instruments as solidbody ones is selling snake oil, not science. Our process is built around consistent, measurable results of the scientific method.

Q. What wood types are good candidates for the AO1 process? What about body shape/size? What about age?
A. As of yet, none of those factors have emerged as a pattern in how well a guitar does with our process. Stiffer, “overbuilt” guitars improve significantly more, but we’ve seen top-end results with several different wood combinations, ages and body sizes.

Q. You are making claims of +3db  and more volume gains. That’s more than doubling the output of a guitar. That seems crazy.
A. Crazy, no. Significant, yes. Every guitar’s results are different. We don’t claim to be able to take any guitar and increase its amplitude by “Xdb”. It WILL get louder, achieve more sustain, have a more balanced sound, and feel easier to play. Those are the areas that we affect. But because every guitar is different, every guitar’s processed results are different and they’re impossible to predict accurately enough to make promises from. On average, we’ve been seeing about +3db increase on the guitars we’ve processed. Recently, we had a guitar that achieved a +6db gain.

100% of the guitars we have processed have come up in volume. Across the board. Some more than others.
For many players, ANY volume gain is welcome.

Q. Is the process permanent or is it lost over time or when I change strings?
A. The process is permanent. Due to the physical nature of the process, your instrument will actually continue to improve for 4-6 weeks after it is returned to you. It will not dissipate with the changing of strings or anything else you choose to do to your guitar.

Q. What happens after the process when I get my guitar back?
A. Your instrument will continue to improve from the process for roughly 4-6  weeks after the process at a tapering rate before leveling out. A few notes about your Post-Process experience:

There is a  ‘burn in’ time of about three weeks where we suggest that you play the guitar in standard tuning for about 1-2 hours a day.

When we process the guitar, it takes the wood to a point as if it were played for many years. But it far surpasses the amount of those characteristics that one person could achieve with one playing style.  After the guitar has been processed, the ‘burn in’ time helps ‘set’ those characteristics in place much like when you apply pressure to two pieces of wood while you’re gluing them. The more pressure you apply via a clamp – the better the join will be. You create the “clamping” benefits by playing (the more aggressively, the better) for about 3 weeks after the initial process has been rendered.

Q. Will the process work on a composite material  instrument?
A. No. The process was designed around the natural polymer properties of  wooden instruments.

Q. If I like the results of the process, can I have it done a second or third time or more to get more out of my guitar?
A. Unnecessary. The process is a singular, permanent application and each instrument receives the fullest extent of what we are able to bring out of it.

Q. What stringed instruments will the process work on?
A. The process was initially conceived for guitars but came out of research that was carried out on multiple types of stringed instruments. AAL is now offering versions of our AO1 process for mandolins and violins with the same stellar results.

Q. Will my instrument be subjected to any harsh temperature or humidity changes.
A. No. Your instrument will be kept at controlled, normal ambient environmental conditions during its stay at our labs.

Q. Will it work with nylon string classical guitars?
A. Yes. The classical guitars we have processed have had some of the most dramatic improvements of any instruments that we have recorded thus far.

Q. I have a small crack in my guitar. Can it still get the process?
A. The process is intended for instruments in good structural condition. We would prefer that you have it professionally repaired before sending it to us.

Q. How long does the process take?
A. Depending on our waiting list/backlog, we will have your guitar for about  2-3 weeks and make every effort to get your instrument back to you quickly.

Q. I’ve got some trepidation about sending off my guitar.  Where is it going?  Who will receive it?
A. We have made arrangements with Hollowood Music to receive and send back the guitars through their shipping & receiving facility, and to process payments. Hollowood Music is a 45 year-old Pittsburgh based music store with a  sterling reputation. Your instrument will be professionally repacked, insured and sent back to you via overnight delivery service.

Q. Who else besides AAL can provide this process for my guitar?
A. The process uses sophisticated instrumentation and techniques. We have talked to several luthiers and guitar manufacturers about the possibility of licensing the process in the future.  For right now – we are the only facility that is authorized to perform the process for individuals.

Q. How can I be sure the process will work on my guitar?
A. The process has worked on every single instrument we have applied it to. That’s a 100% success rate across many instruments over a significant time period. Because every instrument is different, we cannot tell you exactly how much your guitar’s sound will improve before we do the process. We do inspect and analyze each instrument that comes to us and we are able to predict some of the areas that the guitar will improve in. The AO1 Process™ will work on any fine wooden stringed instrument but it will not be nearly as effective on low quality tone woods or poorly designed instruments for many reasons. If you own a well-made instrument, we can make it sound nearly priceless.

Feel free to email us and ask us about your instrument.

Q. Do you change anything structural or cosmetic about the guitar?
A. No. There is no shaving or sanding.  There is no removal or addition of material in any way or specific modifications to the bracing, saddle or any other part of the instrument. The changes are undetectable to the eye.