Basically, you've posted "Engineering" verbage or best practices terminology on how things might be "generally" constructed...not true facts or evidence. Yet throughout this thread are facts and photos refuting things you've posted so far. Then you took it up a notch and reposted into a 4 yr old thread which included the same engineering verbage you did here. You are working with "theories" and not necessarily reality. I prefer to work from facts and visual observations of the actual drums. Fwiw, my 30 yr work history is in Nuclear Engineering, Combustion Engineering, and Operations Engineering. I know a little bit about engineering.
Once again, you're incorrect that Yamaha has nothing in their original documents about these DA drums having mixed ply shells. Here are 3 OEM examples stating otherwise. A link to the Yamaha 1978 drum catalog. You can find them on drumarchive.com. I will quote from the 1978 catalog here:
Yamaha 1978 drum catalog
Page 23 of 48: description of their ET900D series concert toms. And they state shells of "birch and Philippine mahogany." These are the same shells and 900 series drums that came with my 1982 Tour Series concert tom 8000 kit....same shells on concert toms and the floor tom/kick drum. Yup, mixed ply shells despite being called a 900 series. Proof positive that 900 series shells are not always all birch.
Link to 1981 Yamaha drum catalog
Go to page 10 of the 1981 catalog. You will find a table on the lower right giving 2 distinct options for a 9000 series shell. Either "Birch OR Birch and Camelia." There it is in print. An option for any wood drum in a kit. Kzac's statements are in error.....Yamaha's written literature disputes Kzac in 3 distinct places over a 3 yr period. The 9000's were not always all birch....at least Yamaha says so....and the drum bearing edges say so too. You will also note that in the 1981 catalog pages for the 8000 Tour Series kits are the option for 900 series concert toms.
And now a quote from Yamaha's Drum Vault ID. Start by typing in "FT-916DA". It comes up with a shell made of "Camelia/Philippine mahogany." That's an observable fact for a 16x16 900 series 16 in floor tom with the DA variant. Why would this even appear in Yamaha literature if the mix ply option on a 9000 shell never existed?
Yamaha Drum Vault Identifier
And these 9000D real wood drums MIT ROC that I now own have XH date codes on the 13,16, and 22 inch drums. All made in January 1980. The 12 inch is dated a month earlier with PZ. "X" isn't supposed to be used for year dating per the Yamaha dating guide....only for the month. Here's proof they used both Q and X to denote the 1980 "zero" year. A drum with XX would be Oct 1980. I've seen one of those. My own drum badge photos follow.
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1978 pg 13 catalog Had only two series kits, either 9000 series or 7000. The 9000 series was full birch, while the 7000 is camellia outerply and phillipine mahogony inner plies.
Thanks for posting those photos. From that view the shells look very clean. Many of those have lots of "scars" in the finish from heavy handling/gigging. Can't really see the plies well on that 2nd photo. Head will need to come off. Did the drums come with floor tom legs and a bass drum tom mount? If you wanted to add a couple period correct stands for the kit, yours would have come with the gold label decals.....double braced (900 series) or single braced (700 series). Back then the hi hat stands and snare stands both tend to be single braced regardless of the model line. Both of those lines came with the small (and cool looking) mushroom shaped rubber feet. They are pretty available in the $30-$50 range for single braced. Great stands that will hold up. Gold labels ran until around 1980/81. Then the silver labels were in play from 1981-1985. Either would be fine since your bass drum and toms overlap both eras. The current purple line stands (1990's to date) are good too. Prices are similar for all of them when used.
Sorry if someone wrote this earlier, but didn't the early Yamaha 9000 have larger wing nuts on some of their hardware?
Thank You! the bass drum is unique to the kit, 10 lugs seems like overkill but makes tuning a breeze.. At 1st, I didn't care for the chrome bass drum hoops but now i kinda like it. The 3 toms appear to be born together.Wing nuts and wing bolts were basically the same size in the run of 9000's. The only changed I'm aware of is around 1980 when they went from a smooth finished wing bolt with rounded edges and incuse "yamaha"....to a more square shaped wing with sharper corners and a raised "yamaha." If you count the large "wishbone" wing bolts on the tom mount swivels (see Johnnydova's kit above) those were bigger and in production until 1980. Then Yamaha made everything more uniform utilizing the same sized wing bolts all around mounts and stands.
Great looking kit Johnnydova. The only thing I'd have expected were wood hoops on the bass drum. The metal hoops were used on the 7000 series drums. Yours appear to have a chrome insert on them....maybe from a chrome wrapped 7000 series bass drum? I guess it's also possible it could have been a special order or something done on day 2 at the selling music shop. Your bass drum came from the factory without T-style tension rods in the bottom 2 positions on each side. 1978 Yamaha catalog linked below which gives some nice close ups of hardware and drum details. Interesting too that Yamaha ignored the usual "made in USA" 8 lug convention on 20" bass drums and went with 10 lugs per side.
1978-1980 Yamaha catalog