some video/audio recordings of the spruce/maple qin:

1. Spring Thought
2. Journey to Hawaii
3. Wine Crazy

The first one is a recent recording in the "done" state and 2 and 3 were actually done before the top and bottom were glued together (and sides lacquered).   The unfinished state is interesting sound-wise.  In this case glue-up seems to have improved the sound but this remains a subjective judgement.  It is possible that the spruce top was simply a moving target and "opened up" a bit more.    

pics of "finished" spruce/maple qin

dragon moan - qin name (龍吟）

 There are various pics here of the spruce/maple qin.   The sound is very good and seems to be slowly improving presumably as the spruce opens up.   spruce/maple are good choices for qin I think.   As always it seems, there is more work to be done.  1. some buzziness under string around the hui 4/5 area.  I have improved it but it may be that we shall have to live with a toothpick under the string at the bridge.  Or make a new bridge (I haven't glued the bridge) which seems like too much trouble. At this point there don't seem to be buzzes elsewhere though. 2.some lacquer repair needed on the bottom due to too much sanding (actually due to spills on lacquering the sides which I should have wiped up but failed to spot.  relatively easy to fix.  3. need to lower the nut a bit.  1 mm. in general is about the right height above the top board.  This one is more like 1.5 mm at this time.  It is obvious at this point that the instrument maker learns about repair by making the instrument in the first place.  If you are lucky, two steps forward and one step back.  If you are unlucky the step back may kill the patient. 

back view

back view with rong kou out of the way

ready for playing on cedar table

bridge area on top

yuguzhai qinpu - what's wrong with it?

The yuguzhai and its author Zhu Fengjie are a bit of a mystery.   Probably the yuguzhai is a secret handbook in the "kongfu" sense - a few copies were made (not very many out there apparently) and given away to friends and students.   (I'm talking about the Yuguzhai itself and not its bastard stepson Qinxuerumen).  The section on qin-making does not necessarily represent a good approach or the common approach at the time.   It is possible that Zhu Fengjie did not build qin but had someone do it for him.   Here are a few grains of salt to keep in mind:

1. The section on string making as pointed out by Huang Shuzhi aka Wong Shuchee is wrong in the counts for "threads".   Apparently the counts in the book itself are based on the cycle of 5th.  In reality they are more of of a linear decrease from big to small.
2. The section on making the curvature of the top gives a method that is I suspect too simple.  The resulting top is more or less flat with curved sides.   I am referring to the use of the "forms", drilling down, and getting rid of the drilled sections on the side.   Zeng Chengwei just uses a plane and makes the wood chips fly.   I draw a circular form on the end (the nut side) and use a very big plane and a long meterstick to make sure I am doing things "straight".  In general the top should have more of a curve. 
3. It doesn't mention (I believe) the necessary concave curve (see this blog) on the top.   
4. The bottom board seems to be too thick and is never hollowed out in the real world.  You might do this though if you can't find a top board (on the order of 1 1/2 inches) that is thick enough.  
5. The lacquering section is over-simplified but on the other hand lacquering is non-trivial and takes a great deal of time and patience.  
6. Keep in mind the book is talking about building qin in S. China courtesy of 1850 or so.  Modern methods may vary (including finding wood ...)

Small update.   Been sick for quite awhile.  Maybe getting better.   The spruce/maple qin sounds good.  I'm working on finishing the lacquering of the sides.   Wood is chosen for two more.   opinion: use the best "local" wood you can find.   And not to worry too much about wood as used in China.   It also makes a lot of sense to use woods used in guitars, violin, cello, etc. in the US and Europe assuming you are in the US and Europe.   This all depends on what you can find of course.  Hunting for wood is an art in and of itself.   Possible top materials include:  spruce, western red cedar, redwood, maybe pine.  Possible bottoms might include walnut, maple, mahogany.   I'm not thrilled in general with catalpa as a bottom or as a material for providing resonance.   Easier to find on the east coast of the US anyway but not on the west coast.  I'm going to make a paulownia/maple qin and a cedar/walnut qin for my next outings and try and build my woodcrafting skill set a bit.   Eventually I want to do redwood/mahogany.  One other opinion is while I am hardly against using traditional lacquer - I am not thrilled about hiding beautiful wood and personally intend to use some form of "lacquer" that shows the grain. 

epoxy from rotdoctor is advised for "naked qin"

http://www.rotdoctor.com/products/landl.html

epoxy as a lacquer substitute?

http://www.resinresearch.net/

Is the answer. Or a possible answer. What is the question? The question is: what might we use in the US or "west" as opposed to traditional Asian lacquer from the tree or cashew lacquer which apparently is not available any more from Japan. Acc. to a friend who is a luthier of the bass making kind - especially fretless bass - the answer is some form of epoxy. Especially if it is engineered to be a bit tough in terms of UV radiation. A clear epoxy in particular is something to think about. So perhaps your guqin can double as a surfboard?

recent work on the spruce/maple qin

The spruce/maple qin is further along. At this point I have taken wood twice out of the insides and will probably do a bit more. It is not glued together yet. Sides are not done. It is held together by the strings more or less and some invisible doweling. The point now is to play it some and decide where or if more wood should be removed from the top. The tone is very clear. As usual open strings and harmonics sound good. The action overall is good. However one must remove the "correct" amount of wood. I have a hunch that is made trickier by the spruce top since spruce is said to open up slowly and needs a lot of play-in. I have been wondering where the wood came from actually and there is no way to tell. The spruce may have come from B.C. or Alaska probably. It is very nice to be able to see the grain.