Early Yamaha Kits
Yamaha built and offered drums in the 1970s through the early 90s in two formats, from information I have been able to glean from catalogs and actual observation...
1) American format
2) Japan and all other countries
The American format included (Mid 70s to 1980)
1) YD-9000 which is a birch shell drum that later became known as the Recording Custom, early versions had the separate lugs (taillight lugs) later found on the Tour Custom
2) YD-7000, sold in the USA was not the same as the YD 7000 sold elsewhere. The USA kits part numbers have a "D" suffex while the kits sold elsewhere in the world have a "G" suffix. The YD 7000 sold in the USA seems to be the YD 6000 shells with YD 5000 hardware (triangle lugs), YD-5000 tom holder (TH-70W) and metal BD hoops, however the BD was 10 lug and had the same spurs as the YD-9000. (advertised as Camilla and Meranti shells 10 ply for the BD and 9 ply for the TT). Due to the shell thickness these drums are heavy, a 5 pc kit weighs about 10-15 lbs more than the 96 Stage Custom with long lugs. These kits were short lived in the USA being replaced in 1980 with the Tour Custom series, therefore they are very difficult to find. They have a full/rich tom sound with lots of sustain. The BD drum sounds just alike a Recording Custom of the same period.... If you can find them they are the hidden treasure of drums....
Starting in 1980 the USA would have three kits: These kits would later include a "Power" version which had longer shells.
1) Recording (later called the Recording Custom) which is the YD-9000 sold elsewhere in the world (Birch Shells)
2) Tour Custom (which was the YD-7000 sold elsewhere with the early YD-9000 series lugs - taillight lugs) (Birch and Meranti shells)
3) Stage which was the YD-5000 kit sold elsewhere in the world (Meranti a various versions of inner shell material during their life time)
Japan and other countries had these kits during the same time period
1) YD-9000 (Birch shell kits called recording and later recording custom in the US)
2) YD-7000 (Same as the Tour Custom in the USA except with YD-5000 lugs) (Birch and Maranti Shells)
3) YD-6000 (later became the USA Stage Custom ... exactly the same) (Meranti shells with various versions of plies during their life time, and long lugs)
4) YD-5000 (which sold in the USA as the Stage and Stage II) (Meranti and a various versions of inner ply during their life time )
3) YD-3000 never sold in the USA (All Meranti shells)
Many people make the grave mistake of thinking Philippine Mahogany to be a softwood like fir or basswood, however that is completely false. Philippine Mahogany is a loose term for Meranti which is a hard wood with the same janka hardness as most Birch or Maple. Its an excellent wood for making drums and its sound is so close to Birch that it would be near impossible for anyone to tell the difference. Yamaha stated it had a deeper tone than Birch and in very close microphone recording that might be true.... In live performance however, I cannot hear a distinct difference between the two. I own both the Recording Custom and the YD-7000 (USA versions) ........my stage kit is a mixture of both
I think that drums constructed in the 60's through the early 90's were made for live performance, and drums constructed today are made for recording first and foremost (excluding entry level kits) I think that covers all manufacturers in existence today. The manufacturers probably discovered that live performance doesn't matter as much as how a drum sounds when its recorded in a studio. In live performance people will just hear a drum with or without microphones, distinct characteristics tend to get lost in the mix, especially in relation to rock, hip hop, funk, or country. In recording however the sound is far more distinct and measurable. I play older kits which were initially designed for live performance, I find the sound to be more distinct and specific than the later kits which are made specifically for recording activities..... Of course that's just my opinion and my personal preference.....