kevin gilmore

Well at least its a better circuit board than rudistor. two open loop triode gain stages with cathode follower output. .001% thd at what output level? a nanowatt or two. more or less a singlepower extreme with a lot less power.

something in there other than snow otherwise the weight would flatten that car good.

40 kHz oscillator driving chip amp driving small transformer. same way craig does it. Easy, cheap and makes biasing much easier.

I still have dishnetwork because of all the scifi... I know its stupid expensive for what I watch.

here is an alternative which i'm doing in addition to everything else. a 1 meter dish pointed at amc21. and a satelliteav hd receiver. total cost about $250. plus installation. Tune it to pbs and have gobs of free programming forever. In very high bitrate mpeg4 which can't be broadcast at that speed. Nova and the like are just stunning eye candy. Add a usb hard drive for $50 and record the stuff for playback later. http://www.satelliteav.com/p/shop/?ws_pid=1593&ws_cat=446 http://www.lyngsat.com/AMC-21.html or add a motor, then more free tv to watch than you can possibly imagine.

i did not even know Phillips made a 2sc3675

so it turns out the hawksford already came up with the idea of cascading a current mirror (well sort of) http://www.essex.ac.uk/csee/research/audio_lab/malcolmspubdocs/J10%20Enhanced%20cascode.pdf it also turns out that the single ended version where you ground the input, and then drive the emitters makes an absolutely wonderful I/V converter for your favorite dac. also previously released in a simplified version by pedja rogic. http://gilmore.chem.northwestern.edu/privstage.pdf so the building blocks are now piling up. need a really sweet output stage (not the headphone kind) and this preamp should be able to compete with the big boys.

the stuff i used was custom made for the military and is pure silver. not going to try to buy more of that.

This is instead of the multiamp board. Input switching This board Pot of some kind Diamond buffer output There is nothing wrong with the multiamp, in fact it sounds great too. But the input impedance is lower due to supersymmetry. The idea on all of these is to eventually replace with jfets once they become available. As it is, this new board is without feedback of any kind, and is faster and more quiet. plus gain is a single resistor and compensation is unnecessary.

first cut at the board http://gilmore.chem.northwestern.edu/ubaltobald.jpg

Gore will happily make you anything you want. Minimum of 5000 feet. You will not like the price. I use 50 ohm cable.

updated schematic with servo http://gilmore.chem.northwestern.edu/kgsshvproductiondual.pdf

here is the unbalanced/balanced to balanced front end. http://gilmore.chem.northwestern.edu/ubaltobald.pdf really sweet sounding. 0 db of gain balanced, -6db of gain unbalanced. gain is controlled by R5,R32 so i could put a relay in that switches the gain to maintain 0db (or any other number) when you switch from unbalanced to balanced. still even better with the that340 replaced with jfets. mpsw06,mpsw56 replace 2sc2240/2sa970 when we can't get them.

i have known about this for a while. Its about 4000 sq feet of stuff. There is a few pieces i would be interested in, but very little of this stuff is actually useable these days. I would love a mint hammond organ with 2 tone cabinets and 2 leslies. (not sure how i would get it in the basement)

what i want is front end complementary jfets. Don't care if they are surface mount.

schematic http://gilmore.chem.northwestern.edu/kgsshvproductiondual.pdf you definitely want global on both, or local on both. and the output dc will drift a bit. i would use the jumper block you typically find on pc motherboards. .1 inch spacing. There should be miniature switches for pc mount that would also work. (remembering that the pointer works in the other direction) make sure they can handle 500 volts.

You populate all the resistors, there should actually be 2 more (I will look later) And then 2 x 3pin jumper blocks. Then you can switch between the two (not with the power on) There might be a schematic

the nitric acid blank (i used the cheap stuff) http://gilmore.chem.northwestern.edu/blanknitric.jpg the nitric acid blank over the sample http://gilmore.chem.northwestern.edu/full.jpg the expanded sample alone actually saturated the detector http://gilmore.chem.northwestern.edu/transistor.jpg Its so nice to have an ICPMS laying around

They are either liars, or completely incompetent or both. 4 years to make a p-channel jfet, yeah right. Or there are huge quantities of 2sk389 and 2sj109 somewhere that none of us have access to that are preventing lsj109 from being released. Ayre evidently has 10's of thousands of parts in stock, yet stax had to resort to glueing singles together recently. Even the singles are not available.

i sure wish some company (any company) could supply current manufacture complementary jfets. Then things would be so much easier.

That is what i want to acomplish.

The posted front end with a lower power output sage makes a kickass Unbalanced preamp. Still trying to match this performance in a fully balanced version

So this one kind of came out in the mix. http://gilmore.chem.northwestern.edu/nfd.pdf unbalanced in, unbalanced out, about 8 watts into he6 gain programable with a single resistor (use a really good one) and Thd < .01% seriously sweet sounding. will start on the board soon.

when i have time i will fix the ground plane issue around the caps.

wiring the transformer to the low voltage supplies with the center tap in the wrong place is definitely going to cause the caps to over voltage.