kevin gilmore

done

isolation between inputs may be an issue. feedthru does occur and for some of the switches, protection diodes will short the input to near ground with the power off.

That is a pretty accurate description of the differences.

our friendly monk has decided to build a second unit. One T2 is not enough

The ones that andy used were 50mm, and they just barely fit. You have to cut down the 3 front top screws to exactly .250 Better idea is to use the 45mm caps.

monastary off the northern coast of italy? was on 60 minutes recently.

The chrome jacks have to be machined down a bit otherwise the plug won't fit in all the way. Pictures were posted many moons ago. They are still slightly off size. My jacks are the exact right size, i will have to make more in the future. here is the print should someone want to make a bunch of them http://gilmore.chem.northwestern.edu/staxout3.pdf

Thats the things. Even better in carbide. Just about impossible to get those things to walk.

this is closer now, assumes the on board heatsinks http://gilmore.chem.northwestern.edu/kgsshv.xlsx

This is why GOD invented centering drills. Even with my NC machines good for .0005 inch positioning, without using the centering drills first, the wander is horrible even when clamped to within about .5 inch of the end of the drill bit. The problem with manual methods is first you have to use the centering drill on all the holes, then go back and actually drill them. Without a DRO, this takes a lot more time because you have to change the centering drill and the real drill bit for every hole unless you are confident enough in your positioning.

dynahi power supply board that fits on the side of a pesante case. redesign similar to sigma22 by Ti kan. current limiters, precision regulators, fixed 30 volt design, single center tapped transformer... http://gilmore.chem.northwestern.edu/dynahipowerschem.pdf http://gilmore.chem.northwestern.edu/dynapower2.jpg http://gilmore.chem.northwestern.edu/dynahipower2.zip

kerry's thing cannot do the kind of drilling and tapping necessary. On the other hand, nate has a desktop with DRO. Perfect for using a center drill on all the holes (required) and then drilling the holes. Tapping by hand is absolutely no problem as long as you have a chunk of metal at least 1 inch thick already drilled with the exact body size of the tap. Only way to keep the tap straight. And if you keep the tap straight, you won't snap it. I have a mill at home without a DRO, so i do it the old fashioned way and pay attention to the knobs. The NC machines just make it easy and fast.

Those heatsinks absolutely do have to be NC drilled and NC threaded. At a minimum a desktop manual mill preferably with digital readout. No way to use a hand drill. Its unlikely that the .5 inch spacing is going to line up with the fins, so no way to put nuts on the other side.

the hifi2000 case is instead of justin's heatsinks, not in addition. The 3U case should be big enough for one amplifier mounted to the side of each heatsink and the power supply board on the bottom. Two smaller power transformers or one bigger one. I'll be ordering one of these chassis soon. From birgirs dimensions, everything should just fit. But just barely. Justin's heatsinks would be used for a completely custom case, and this is a whole bunch of work i don't want to get involved in at the moment.

center tap is optional. and i have an even newer and slightly simpler high voltage supply coming soon. less parts, and the battery thing flipped upside down, and reference is now lt1021-10 because in fact it outperforms the lm4040-10 by a major amount. Long story on the lm4040 part...

My boards were 4 oz copper. Lil-knight's boards were 3.5 oz copper. A person here did in fact build the T2 as his first DIY project. And succeeded. But he had help from above. This thing is a whole bunch of work and even more if you are doing your own chassis.

http://gilmore.chem.northwestern.edu/kgsshvpower4.pdf http://gilmore.chem.northwestern.edu/kgsshvps7e.jpg http://gilmore.chem.northwestern.edu/kgsshvps7e.zip current limiters as suggested by doug, place for add on board for doug's regulator chip mounting hole size increased for #6-32 multiple build options including zeners only for simple and cheaper. (well cheap is a relative term) amplifier with on board heatsinks http://gilmore.chem.northwestern.edu/kgsshvampv6.jpg http://gilmore.chem.northwestern.edu/kgsshvampv6.zip amplifier for mounting to wall of the pesante case http://gilmore.chem.northwestern.edu/kgsshvampv7.jpg http://gilmore.chem.northwestern.edu/kgsshvampv7.zip

Power supply board with either simple zener option, or full regulator soon. Includes current limit to prevent the fets from blowing upon application of dead short.

At this point i will use any complementary j-fets that i can find regardless of package. But no match for the n-channel above. This is getting goofy.

A lot less than having to find an original T2 or build one. The sr-009 is just amazing on both the BHSE and the T2. You will see and hear soon enough.

I think you are now in the right place for a few of my new projects A 5uf cap after the 4.7M resistor is a BAD idea for O2's and most of the latest headphones. I'm sure you can find a distributor that will sell you parts and ship them to australia.

well you should use the 2sa1486 instead of the 2sa1413 if you are talking about the power supply. There are much better power supplies now. The 560pf caps are definitely the wrong compensation in the wrong place. Look at the latest kgsshv amplifier schematic here. http://gilmore.chem.northwestern.edu/kgsshvproduction.pdf what you want are the 5pf caps between the (in your version) collector of the 2sc3675 and the base of the 2sc2705.

i cannot figure out why the power supply is blowing up, mine still works great. However a current limit is a good idea and maybe a switch to doug's magic chip depending on price and real availibility.

i think you should handle the programming of this one. Whatever cpu you come up with just make sure it has an i2c output to drive the attenuator. gotta go watch Dr. Who premiere. will fix too small silkscreen tomorrow.

resistive! Nope, will not work behind plexiglass. Lets be serious here... resolution of one pixel. 320 x 240. Not gonna happen behind glass or plexiglass. You find me the apple display and touchscreen as a seperately purchasable item, and we will talk about it. This display and the cpu that drives it is a one piece item that is <$100. NOW MOAR MOAR BETTER. but 6 layers better idea for ground under the smt. http://gilmore.chem.northwestern.edu/attenuatorsmt18net.pdf kerry wanted the 1206 smt resistors in addition, and i found a way to cram those in too. So this should be it.