Wind System
Last weekend I got the wind system pieced together enough that I was able to test the wind pressure. The previous owner said the pipes were voiced on 3", but the blower I have provided 4". I wanted to double check. I set the blower and reservoir on the floor and connected them using the PVC that came with the organ. I also needed to cover a few extra holes in the reservoir. I used a piece of 1-by lumber cut and hinged with black tape so I could fold the board, insert it into the reservoir, open it up and bolt it to a smaller board on the outside of the reservoir. I used a piece of rubber EPDM garden pond liner as a gasket. This is only a temporary fix, however. Before final installation I need to permanently repair these holes. I will be covering the 6" hole in the top and the 3" hole that I am now using to supply wind to the chests (I found that a modified 3"x2" PVC shower drain with a rubber gasket makes a great flange for attaching PVC to wood). I would welcome advice on how to properly and permanently cover these holes. An album of photos is linked below:
With the wind system patched I was ready to attach an off-set chest. The 8' octave of the gedeckt was handy and simplest in terms of wiring. I used a new (clean) shop-vac hose because it is flexible and fits perfectly into a 2" PVC fitting. I turned on the blower and found two leaks in the reservoir, each near some previous modification work. I will repair them later on, but neither is large- just noisy. Using my home-made manometer, the first pressure reading I took was 4", just as I expected. Note: the manometer is calibrated so you read one column from 0" up. One inch on a ruler equals two inches on the manometer.
I gathered some pipes- 2 or 3 from each rank at various ranges in the compass except the bass octaves. Basses are packed away pretty deeply and I have 7' ceilings in the basement- no head room any way. All pipes sounded and I didn't notice any out-of-place harmonics or other strange noises.
I was curious what would happen if I removed 2 of the 4 springs on the reservoir. The wind pressure dropped to about 2 7/8". I tried all the pipes again and I didn't notice a huge difference in the sound. Volume seemed about the same, maybe a hair quieter but hard to say (remember I have the blower and reservoir rumbling away in the same room). I will say the sound seemed gentler at the lower pressure- less harsh and edgy, 'warmer' and 'sweeter' maybe. I will probably test a few bass pipes by laying them horizontally on the floor. Hopefully they sound fine at this lower pressure, but we'll see. Since the organ was originally voiced on 3" and the sound is gentler, my plan at this point is to use the lower pressure with only two springs attached. If the lower pressure gives a better sound in an intimate space, I'm all for that!
Re your comments on less harsh & edgy sounds at the lower pressure (2-7/8"): My experience has been that "harsh & edgy" is needed in large venues, especially if pipes are in chambers. In a home setting, warmer & sweeter will definitely be in order, esp. if you don't have a 4+ second reverberation to mix the sounds. Other commentators will undoubtedly provide more details on this.
ReplyDeleteMac Hayes
Hello: I noted our website posted here thank you. btw the organ at St Andrews was "rebuilt" by our firm several years back. The original windchests by Vaughn were problematic and mostly not working. There are quite a few things that should be changed in the organ, but have not been discussed..The Pedal Reed should be replaced. Because of bugets in the past, some changes/alterations were never completed.
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