The ultimate DIY? A Stax SRM-T2!

[Craig Sawyers]

...and we have people complaining about it being too complex...

The amazing thing is that the active, signal-route part of the circuit, is four tubes and four FETs. Everything else is either current sources or voltage sources. Plus the servo, of course.

[luvdunhill]

I'm thinking about using 26 awg for everything except the heaters. Assuming appropriate voltage rating and temperature rating, would this be okay? Quick check of charts say 2.2A for chassis wiring and 361mA for transmission is rating for this size..

[spritzer]

The amazing thing is that the active, signal-route part of the circuit, is four tubes and four FETs. Everything else is either current sources or voltage sources. Plus the servo, of course.

Yup, that's what I tired to explain to them but I don't think they actually understood it. It's the same people who think opamp based designs are "simple". Sure my gainclone has very few components plus single chip per channel...

[kevin gilmore]

I used 20 gauge for everything except 18 for the ground.

That's the maximum size the amphenol connectors can take.

[Craig Sawyers]

I used 20 gauge for everything except 18 for the ground.

That's the maximum size the amphenol connectors can take.

The single large ground pin is specced at #16

[kevin gilmore]

finally back on track after 9 days of stomach flu...

http://gilmore.chem.northwestern.edu/woodknob1.jpg

30 minutes on the bandsaw, this stuff is tougher than aluminum.

Smells wonderful.

[kevin gilmore]

yep, i'm going overboard on this one

http://gilmore.chem.northwestern.edu/knob%20assy.pdf

I figure about 10 hours of labor on this.

The metal stuff will be non-magnetic stainless.

[Kerry]

That's really nice! Can't wait to see it completed.

[Craig Sawyers]

finally back on track after 9 days of stomach flu...

http://gilmore.chem.northwestern.edu/woodknob1.jpg

30 minutes on the bandsaw, this stuff is tougher than aluminum.

Smells wonderful.

Looks great Kevin - it is a bugger to work being so tough. But real Lignum Vitae has a wonderful perfume, doesn't it?

Really looking forward to seeing the final thing. You definitely need pilot holes for the screws though, or drill and tap - just as you would for metal. As you know I tried 1/4UNC and M6 with perfect results.

[MASantos]

That's quite a nice piece of wood you have there!

Any reason why you didn't work it on a lathe?

On a side note, there's a kitchen knife brand here in portugal that makes these really nice knives with Lingun Vitae handles. I've got a 30 year old one and it still looks like new!

[kevin gilmore]

Well i have to cut it up into a round shape before i stick it into the lathe...

Otherwise i waste an entire huge piece of EXPENSIVE wood just for one knob.

This way i'll get 4 knobs. And everyone knows what 4 knobs in the hand is worth...

holes for the screws will be drilled and tapped. Special screws designed

for woods like this.

Edited September 17, 2010 by kevin gilmore

[morphsci]

That is really nice. I love the smell of sawdust in the morning.

[kevin gilmore]

The smell of lignum vitae is like no other wood i've run across.

Even after aging of 20+ years.

[kevin gilmore]

http://gilmore.chem.northwestern.edu/woodknob2.jpg

This is completely unpolished. 45 minutes with a carbide point.

Took .01 of the top too.

[Craig Sawyers]

http://gilmore.chem.northwestern.edu/woodknob2.jpg

This is completely unpolished. 45 minutes with a carbide point.

Took .01 of the top too.

That, Kevin, looks outstanding!

[Dusty Chalk]

Mesmerizing.

"Look into my eye."

[Voltron]

Nice, but if you bored in from the side and sliced it just right, you could get the magic eye on the end of the knob! "This amplifier is truly hypnotizing..."

[Craig Sawyers]

the magic eye on the end of the knob

Only on Head Case

[kevin gilmore]

If i had any idea the eye was inside the piece of wood like that, i certainly would have done so.

There was no way of telling from the outside what the pattern on the inside was.

[luvdunhill]

If i had any idea the eye was inside the piece of wood like that, i certainly would have done so.

There was no way of telling from the outside what the pattern on the inside was.

no chance of an x-ray machine doing that? I understand it's wood, etc... just curious if it's possible at all.

[kevin gilmore]

my xray machines are designed to go ultra small. So even an ic chip is kind of big.

i know where to take it to do a standard film xray, will have to try it. Don't think the

resolution of film is going to work on this.

[Craig Sawyers]

no chance of an x-ray machine doing that? I understand it's wood, etc... just curious if it's possible at all.

The Zen-like cabinetmaking books by Krenov talk about the risks of cutting into a piece of wood. Even with his legendary intuition of reading a plank, he would often get it wrong. At one stage he almost paralysed himself with the fear of cutting or planing incorrectly and missing that perfect effect.

That is the risk and the joy of working with wood.

[Dusty Chalk]

MRI? Kidding (probably shouldn't say things like that out loud to Kevin).

If it's any consolation, I like the way it turned (ahem) out.

[Voltron]

I was just kidding of course. That knob will be stunning with polish.

[morphsci]

I don't think a contrast dye would penetrate any significant depth in lignum vitae. I say ultrasound as the best bet.