Woden Shrike Build

[Cal Weldon]

Where on Earth did you dig that shot up from Cal?

Here:
http://www.diyaudio.com/forums/tubes-valves/136909-wikipedia-article-tube-sound-3.html#post4643152

 

[Bob Brines]

I put a pair of CAT5 wires in a 1" clear vinyl tube and covered it with nylon mesh. Took then to LSAF one year. Nobody even mentioned them!

Bob

 

[Cal Weldon]

A sheep in wolf's clothing?

 

[jdrouin]

By the time I saw those crazy cables, all I had was a python joke, so why not start the actual build?

Made the cuts today. They're not perfect, but pretty accurate, and will probably have to be squared up a little bit. Any advice on how to do that?

I've got an orbital sander with pads of various grit and small hand plane.

As you can see from the scorching, I'm not a whiz with the table saw yet. I wouldn't do this without a partner again. The table itself is small and has a bit of friction, which makes handling the workpieces awkward.

Pics show the pieces loosely assembled to assess fit. Definitely workable, but needless to say I've invested in a flush trim bit.

IMG_4124 by jeffdrouin, on Flickr

IMG_4143 by jeffdrouin, on Flickr

IMG_4145 by jeffdrouin, on Flickr

IMG_4132 by jeffdrouin, on Flickr

IMG_4146 by jeffdrouin, on Flickr

 

[jdrouin]

Today I cut and chamfered the driver holes (they turned out really well), drilled the binding post holes, and started gluing things together. I measured, used L squares, and drew out where each piece should fit. However, during the gluing, a couple of the manifolds shifted under the clamps, so some of the internal measurements are a bit off. In one case the bottom of the first manifold is nearly 1/4" too close to the front baffle, while the top of it is spaced properly at 5". I have to imagine this will negatively affect the sound.

Part of the problem is the lack of square edges that were caused by an imperfectly aligned rip fence and blade wobble on the table saw. When I looked more closely at the saw yesterday, I noticed some sawdust stuck under the lip on the rip fence, which made it protrude slightly and caused long pieces of wood to feed at about 1-2 degrees off. I removed the sawdust and then clamped the lip for 24 hours; it is now straight again.

Also, because I was pushing so hard against the fence to keep the wood from wandering, I think I was actually causing the far end of the fence to move a little, which contributed to errors in the long sides as well as warping on the end grain due to the blade being pulled out of true.

I might complete this project as-is, if only to hear how the imperfections affect the sound. But I’m more inclined to start over with the following changes:

* Cut the wood with a partner who can help pull the pieces through the table saw

* Clamp the far end of the rip fence to prevent it from wandering

* Use a biscuit jointer to ensure that manifolds and sides line up properly and don’t wander under clamping

* Make inserts to place between the sides to ensure that they remain square under clamping.

It would have been a good idea to mock up the entire project in cheap construction plywood first, or even just do something simpler like make a small box. I would have made all the same mistakes and learned from them before using up this expensive plywood.

Oh well. If you have any beginners' tips and tricks that are appropriate here, I'd much appreciate them.

Thanks to all of you for your help so far.

Here are some pics of today's work, though I didn't get a chance to photograph the manifolds.

Untitled by jeffdrouin, on Flickr

Untitled by jeffdrouin, on Flickr

IMG_4195 by jeffdrouin, on Flickr

IMG_4200 by jeffdrouin, on Flickr

IMG_4203 by jeffdrouin, on Flickr

 

[xrk971]

Last year I borrowed a biscuit jointer to make speaker stands and liked it. For the Shrike build, I was thinking biscuits would help to keep the external walls from wandering and internal baffles at right angles. I'll try butt joints for this build but will probably use biscuits if/when I go for the Vampyr.

Regarding front baffle beveling: If I were to try it, is it best to bevel the edges before gluing up, or could one use a chamfer bit and do it after assembly?

Another neat trick that is basically "woodwork sinning" as GregB puts it, after applying the Titebond or whatever glue you use, add a few beads of hot melt glue internally where you won't see it while holding it by hand to align the pieces. The hot melt will tack the pieces together and prevent them from creeping around as you apply clamp pressure. Like liquid biscuits.

 

[jdrouin]

Another neat trick that is basically "woodwork sinning" as GregB puts it, after applying the Titebond or whatever glue you use, add a few beads of hot melt glue internally where you won't see it while holding it by hand to align the pieces. The hot melt will tack the pieces together and prevent them from creeping around as you apply clamp pressure. Like liquid biscuits.

Huh. Thanks. Maybe I'll try that down the line, but for now I'm going to go with what I know, and that's biscuits.

I didn't use the biscuit jointer because my friend who owns it moved away. Didn't buy a new one because I wanted to keep the budget small on this first project. I've learned all over again that it doesn't pay to skimp on tools.

Looking over the glued up enclosures, they aren't all that bad. I have enough damping material to do another pair of Shrike, so I think I'll finish this for the sake of following the project through, and then reassess. Maybe I'll do a Solo 103 for FE103-SOL.

Untitled by jeffdrouin, on Flickr

Untitled by jeffdrouin, on Flickr

Untitled by jeffdrouin, on Flickr

 

[zman01]

Nice work Jeff.

 

[Jerms]

It looks like those will clean up nicely. Maybe paint the carcase but finish the fronts in clear showing the plies?

 

[xrk971]

Looks great - nice work! FWIW, the amount of internal damping is something that's critical to the final sound. The designer already has recommendations of the atuffing and damping - but if there was someway you can temporarily use weather stripping gasket and clamp one side on (with wood screws) and listen /measure and adjust that would be ideal. On my TL I aimed for a critical damping that squashed the double resonance peak to almost a single hump. I found that this produced some of the cleanest and tightest bass ever. It takes iteration to do it though so if you seal it up you get what you get. Some small adjustment on the last leg possible via the terminus.

 

[pcgab]

Looks great indeed. I totally agree with X, clamp the last side on and test the stuffing/damping.

 

[paul burchell]

Or build with removable back panel

 

[Nanook]

Really?

These are what I take when I go on the road.

You speaker dork! I thought you only overcompensated with the size of your speakers, but not your cables. You just never know ...
... connected to a 3/4 watt/ch, flea-powered, scandium enclosed, yak p_i_s_s infused, liquid cooled amplifier from 1917 or some such thing no doubt

Sorry to intrude.

 

[chrisb]

Or build with removable back panel

I think it'd be hard to adjust damping in the individual folds of a design like this one - a removable bottom might make it easier?

 

[xrk971]

One way is to overstuff with polyfill and then use clothes hangar hooks to remove to taste (or to measurement). Easier to take out then put in.

Removable bottom could work - or temporary clamped on sides like I suggest. Glue shut when done.

 

[picowallspeaker]

... connected to a 3/4 watt/ch, flea-powered, scandium enclosed, yak p_i_s_s infused, liquid cooled amplifier from 1917 or some such thing no doubt

Sorry to intrude.

...remember that Cal owns a Bybee quantum purifier

 

[Cal Weldon]

shifted under the clamps

Cleats allow for perfect alignment and they don't take very long to install.

because I was pushing so hard against the fence to keep the wood from wandering

You have to be comfortable with your saw. You can actually tread very lightly with it if you relax, stand in the correct location and practice some cuts to get a handle on it. Too many people want to muscle their way through the job.
It looks like you paused near the end of each cut while you grabbed your push stick to finish the job. Not to worry, this will all come easier with a little practice.

* Cut the wood with a partner who can help pull the pieces through the table saw

Not necessary and can cause more problems.

* Clamp the far end of the rip fence to prevent it from wandering

If your fence cannot be tightened then sometimes this is necessary.

* Use a biscuit jointer to ensure that manifolds and sides line up properly and don’t wander under clamping

I use full length cleats. I only use a couple clamps because I like to use a finish nailer once it's clamped and move on to the next panel. That way the box is assembled lickety split.

* Make inserts to place between the sides to ensure that they remain square under clamping.

If your baffle fits inside the other pieces then when you clamp the top, bottom and sides, the baffles can be loose fitted to ensure all is square.

I would have made all the same mistakes and learned from them before using up this expensive plywood.

Yup, and you're the only person in the entire world who has ever done that.

 

[Cal Weldon]

...remember that Cal owns a Bybee quantum purifier

Cal owns 2. Or at least he did before they were sent half way around the universe and ended up in a small black hole in the SY galaxy, never to be seen again.

 

[jdrouin]

Thanks for the compliments and the helpful advice everyone.

They're done, and sounding lovely. Full, rich, very satisfying bass extension. I notice a very slight tinniness in the tone, which is probably due to the insides being a little off. The drivers only have about 50 hours on them, so I'll listen for at least another 350 while a make a tube phono preamp.

Taped gluing edges to protect from spray contact cement for the damping material.

IMG_4215 by jeffdrouin, on Flickr

IMG_4220 by jeffdrouin, on Flickr

IMG_4228 by jeffdrouin, on Flickr

IMG_4231 by jeffdrouin, on Flickr

The router with flush trim bit is my new favorite tool combo.

Before:

IMG_4247 by jeffdrouin, on Flickr

After:

IMG_4252 by jeffdrouin, on Flickr

IMG_4271 by jeffdrouin, on Flickr

IMG_4273 by jeffdrouin, on Flickr

Note the hi-tech hockey puck isolation feet. You would not believe how difficult it is to find hockey pucks in Tulsa, Oklahoma.

IMG_4284 by jeffdrouin, on Flickr

IMG_4303 by jeffdrouin, on Flickr

And here they are singing with my modified Tubelab SE 300B:

https://vimeo.com/159562051

Thank you so much Scott and Planet 10 for the plans! Very empowering!

 

[jdrouin]

Oops: let me be clear. When I wrote about "the insides being a little off," I meant as the result of my own construction techniques, NOT the design.

I listened for about two hours last night and really enjoyed them. They're very sensitive to the dynamics of the music, and very revealing.

This week I'll figure out how to use the measuring microphone I ordered from Madisound and will post some frequency response numbers.