Famed for their bowlback construction (from synthetic Lyrachord), Ovations are immediately recognisable electro-acoustic instruments. Their unconventional appearance and construction can arouse strong feelings (both for and against), from acoustic guitar players, who tend to be very conservative and suspicious of 'innovations'. The idea behind the bowlback shape is simple; the intention is to reflect all string sound out to the front of the guitar. Since you've read this far, I take it that you are an Ovation enthusiast (or at least intruiged by them). So, here's a step-by-step guide to these unconventional guitars.
First, the construction. Ovations come in
Deep Bowl - the best acoustic sounding Ovations. They're loud and project their sound well (often well above the volume of other guitars played alongside). I have a deep-bowl 6 and 12 string.
Medium Bowl - similar to the above. The bowl makes for a comfortable playing experience in the eyes of many players, although if you have (or are developing) a 'bowl' of your own between chest and belt area, then this can be an issue in terms of keeping a hold on the guitar when sitting down.
Shallow Bowl - now we are getting into the realm of pure electro-acoustics, where the guitar sounds better amplified (and is intended to played this way, rather than a simple acoustic). Acoustically, these guitars can sound thin
Supershallow Bowl - again, similar to the above. These tend to be designed as out-and-out stage instruments. A few Ovations with SS Bowls buck this trend, but these need to have top-flight tonewood tops to compensate for the bowl construction. The 1984 Collectors is a good example of an acoustically great-sounding SS bowl.
So, overall, it's simple. The bigger the bowl, the better the acoustic sound in general terms. Shallow bowls can be easier to play (especially if you are a little bowl-shaped yourself). Most bowl depths have the choice of cutaway and non-cutaway models (although the latter are definately in the minority).
Electronics - When amplified, all Ovations sound great. Ovation pioneered the electroacoustic concept, and still are at the forefront of this field. The best current Ovations include notch filters to control feedback, and have built-in graphic equalisers and tuners.
The Model Range
Applause - These are the intro level Ovations. Laminated wood tops, often with simplified electronics. Made in China, previously in Korea. The very first Applause guitars (up to around 1978 with an aluminium fretboard and resin foam neck) were USA made. These are an entirely different animal to the subsequent range.
Celebrity - Mid-range instruments. Badged as 'Ovation', but with 'CC' model numbers. Again, from the East, although the quality can be impressive (especially with older Celebrities). Mostly laminated wood tops, although some newer Celebrities now have solid spruce tops. Can be nice players, with increasingly sophisticated electronics.
Ovation - USA made and the quality difference from the above ranges is marked (and worth the expenditure). Basic models are Balladeer, Legend and Elite, then Custom Elite and Custom Legend as the current top of the range. The Elite range features shoulder-mounted multiple 'epaulette' soundholes.Solid wood (usually spruce) tops on almost all, with fancy binding, abalone inlays and ebony fingerboards on many of the more expensive models. Some have Koa, Redwood or Maple tops. Mid- and Upper-range models have five-piece laminated necks for strength. All are very well made indeed, with low action and good volume projection; these can be an excellent buy if you shop around. Perfect for players used to the feel of a good electric. Ovation 12 strings are probably amongst the best in the business; the necks rarely give problems, and they tolerate being strung to concert pitch in the long term without difficulty. Ovation produce an (almost) yearly Collector's Series Limited Edition; these tend to feature exotic tops and innovative features. USA-made Ovations are very good value for money indeed compared to other acoustics of comparable tonewood (on the top at least!). Buy with a fitted Ovation case if you can; these are also top quality, and are moulded to the guitar exactly, providing much better protection than all but the very best alternative cases. Apparently Ovation ship their guitars tuned to concert pitch, such is their confidence in the protection afforded by their hard cases.
Adamas - these are really an entirely different guitar, with a composite graphite and birch top. Very high quality and accordingly priced.
Best USA Ovation Models - This is somewhat a matter of personal taste, but the Elite T1778 (value for the construction), the non-cutaway 1718 (for acoustic sound), the supershallow 1984 Collectors (best SS bowl acoustically) and the Custom Legend (beautiful top of the line) all have their die-hard advocates. There are others too...
And all Adamas models as well.
Watch for - Cracked soundboards (common). These are fixable, but have a cosmetic impact. Also missing 'ears' from headstocks; these can be a pricy repair.
Be careful with - the 'MOB' model with the 'surfboard' soundholes. Not to all tastes (even for Ovation fans), this USA-made guitar was recently discontinued. The 'Tangent' is another model of minority appeal. Bear in mind when bidding. That said, there could be some bargains out there...
All Ovations are currently attractive price-wise with the £/$ exchange rate. Importing a guitar from the USA (new or second-hand) makes great financial sense at the moment, even allowing for shipping and customs duties/taxes. You can easily save 50% on the price of an equivalent example in a UK outlet. There's also the issue of choice: Ovations are not sold in huge numbers here in the UK, so the more unusual models may only be available from overseas.