kevin gilmore

Power supply can supply as much current as you want. Transistors can take up to 4 times as much bias if you can get rid of the heat. Best done on the off board heatsink versions.

No other changes. One version ago, lil-knight had me make the mounting holes for the heatsinks slightly larger.

There is a new version of both of the amp boards with jumpers for local or global feedback for the next round of boards when needed. I still like the global feedback version better.

I have no trouble soldering the heatsinks with my weller, but i'm using 50+ year old eutectic solder. And plan on doing so forever, or until my 30+ lbs of stock runs out.

Pretty sure that the input for maximum output is 2.8 volts peak to peak. Will try and find the datasheet later. You can always add a 3 or 6 db input attenuator.

B&O USA is about 3 miles from my house, i wandered over there one day and they let me buy a pair as spare parts for their speakers.

Boy are those speakers old. I would look carefully at the surround on the woofer before spending any money on amps to drive them. The B&O icepower things sound even better, and you can get them in a box with a power supply up to about 300 watts. Just wait till the batteries in the RWA amps start cracking and leaking acid jello due to their quality charging circuitry. Anyone that owns one and doesn't change the batteries every 1.5 years is looking for trouble.

Preamp board is 12.4 x 6 inches multi amp is 6.1 x 3.4 inches black hole is 3.5 x 3.62 inches

Absolutely i an do silver. The regular stuff is kind of soft, so i would have to be careful. There is some german silver that is drop forged, weighs about 30% more per unit volume and that stuff is really hard. I have some of that, but the form factor is wrong. If you don't coat the silver with something, then it is going to oxidize very fast, possibly with a rainbow. Might look cool that way. Denatured alcohol around these parts is sold in the drug stores, and is absolutely clear.

Its gonna be a busy spring and summer.

2 x 2 x 1.5 is the absolute minimum. Which is why i'm having trouble finding snakewood that is big enough in the "desired" direction. I do this on a monarch engine lathe with very sharp carbide tool bits. Step 1, use a bandsaw to make a roughly round blank. Step 2 use a pressure plate and a live center, and make the blank completely round. (pick from standard size that will fit perfectly into a collet) Step 3 insert round blank in collet, drill the hole for the shaft piece and use a boring bar to make the mounting area. Step 4,5,6 make the shaft piece which takes 3 steps on the lathe and then 3 more steps on a vertical mill. (center drill, drill, flip and countersink) drill holes thru the shaft piece into the wood and attach the wood screws. insert back into the lathe, and machine to proper dimensions insert into the NC lathe and do precision micro machining on the front and side. The knobs come out that shiny without any oil, varnish, or any finish of any kind. Takes about 3.5 hours per knob. Eventually i will make the shaft pieces completely NC and that will shorten stuff about 1 hour. There is no way to NC the prep work. The harder and more dense the wood is, the easier this is to do.

But wait... There should be 499 quotes... 500th episode is this sunday. Evidently there probably are more repeats than i expected.

What i need now is a better lens for taking pictures like this. The various lens distortions really show up, because i can assure you that things are absolutely 90 degrees and flat to less than .0001 inch. Really want a 300mm macro lens that focuses 1:1 at 2 feet or more from the front of the lens. As far as i know, no such item exists. Sure wish nikon would release a new version of the 200mm macro, i don't want to buy a 15 year old lens design. The reason for the longer lens is that it makes it easier to light things. Bocote next week. But i need to find something to coat it with to keep its yellow color, because as it sits in air, it continues to get darker and darker.

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

Actually our friendly monk is getting 2 knobs. And they are done too. I have enough depleted uranium to make a knob. And the appropriate carbide bits... Maybe the diamond tools would work better. Going to have to try it sometime. I would probably have to cast a lead container if i wanted to ship it... I can just imagine what would happen if the radiation detectors went off on fedex or UPS. The USPS people are probably too ignorant to notice.

Rumor has it a crazy monk is getting the next knob

I cast them. Learning as i go. The 3rd one came out perfect. The bubbles on the first one really look neat. I have enough material now to spin cast a couple into a mold. Figuring on about 250 grams each before final machining. Power hit trashed one of my two aluminum mounting spindles this morning. No power == no brake. with the feed on, took .125 down to .060 in 3 seconds

The 18k gold one is on the dynahi. Pictures many moons ago, will see if i can find it. Definitely leaving all the woods bare. I think they look better that way. here we go 121.6 grams http://gilmore.chem....du/dynaknob.jpg http://gilmore.chem....u/dynaknob2.jpg http://gilmore.chem....u/dynaknob3.jpg http://gilmore.chem....u/dynaknobj.jpg somewhere i have pictures of the 24k knob, its 151 grams, and i never mounted it on anything. This is years ago when gold was relatively cheap.

So the diamond tools came in today. And i have a chunk of marble and granite to try and turn into knobs. Should be fun. After that i'll go and find some fancy stone. The redheart is shrinking and the cracks probably won't be visible in about 2 weeks. Should be able to make a few aluminum mounts tomorrow. Need to change the title of the thread to just T2 knob turning since i've already done a titanium one, and a 18k gold one. one of these days .9999 fine platinum.

The tube is not pulling current, and you need to look at the cathode voltage to figure out why. Top of the batteries should be +200, you might want to look there too.

Q11,Q12,Q25 or a tube let loose is first best guess. Plate voltage on that tube is likely to be +500

http://gilmore.chem.northwestern.edu/woodies2.jpg The redheart started cracking about an hour after machining, including the original block. So this one needs to dry out a few years. The olivewood also started cracking, but much smaller cracks. And the bocote started out much lighter and is getting darker as it exposes to air. The bocote and the cocobolo should work out great.

Pictures later, the bicote really came out nice, so did the cocobolo. Not really liking the redheart, and the olivewood is so so.

http://gilmore.chem.northwestern.edu/woodies.jpg the bocote looks a bit dark, who knows...

The challenge will be to make the thing as easy as a kgsshv to put together and get to work. Still the voltages are a bit high so i'm going to add foolproof testpoints for adjustments.