Particular Parts
Ah... beautiful brand new parts. Shiny new copper bass strings and brand new Yamaha tuning pins. Why Yamaha tuning pins and not Diamond or some other American or German pin? Let me explain. First, a little background.
I've got a client who owns and runs Red Rock Studios in Miami. In the live room there's an older but nice Yamaha C7E. He called me in to get it ready for regular studio usage and one of my first recommendations was new bass strings. They sounded tubby and didn't have the harmonics that you really want in a recorded piano. Mapes is usually my first choice for piano wire but Yamaha does make their own strings so I called the California office and spoke to Dave Durbin, their technicial specialist.
To my surprise, bass strings for this Yamaha C7E are not stocked anymore by Yamaha. Dave suggested I call Mapes which is fine with me. I've know for a while that Yamaha makes tuning pins in half sizes and decided to ask Dave for his advice on choosing the right pin size.
(In case you aren't aware, a #2 pin is .275" or 7.0mm. Yamaha offers from 6.9mm (.271") to 7.3mm (.287") in .1 increments which would be #1.5, #2, #2.5, #3, and so on).
Dave explained that Yamaha pins it's pianos at the factory with 6.9mm pins which is the equivalent to a #1.5 pin. He then surprised me by recommending a #2 or 7.0mm pin size, not a #3 or 7.1mm. He explained that Yamaha pins blocks are made in such a way that the half pin sizes were necessary otherwise the pin torque would become extreme. I tested a 7.0mm pins on the lowest torque pin I could find on this particular C7E which was 60lbs. With the 7.0mm pin the torque went up to 110lbs. A 50lbs difference. Most of the other pins were in the 90-100lbs range which would put the finished restring at around 140-150lbs. Pretty good. I can only guesstimate that a 7.1mm pin would put the torque up to 200lbs which is definitely too much.I'm doing the install next week so they'll be a special report on the whole process.
If you've got stringing tips to share, send them in.