kevin gilmore

So here is my comment on the "fake" parts. I've been stocking up on lifetime supplies of the semiconductors i may need in the future. When you get them in large bags, the bags have a label on them that says where they were diffused, and where they were packaged. The diffused is always japan, and the packaging is taiwan,korea,china... So the parts could be the real silicon, but just packaged inside of less than adequate lead frames.

there seems to be a growing interest in the phono section... http://gilmore.chem.northwestern.edu/kgphonoservo.pdf not counting the power supply, this is no more than $50 in parts if you use the lsk389, a lot less if you use 2sk170's... With the servo, matching is virtually unnecessary. I'm trying to find the moving coil schematic i did way back when...

Erno was one of the masters for sure. here is that article http://www.tkhifi.com/div/Erno_Borbely_fet_articel_2.pdf and part 1 http://www.tkhifi.com/div/Erno_Borbely_fet_articel_1.pdf

I think that andy's remaining problem is that the entire chassis is not fully grounded together in one piece, and a couple of star washers should fix that problem. But it does make music.

So here is a little historical fun. Back in 1975 and 1976 while in college i was building and selling world class phono sections and preamps. (sound familiar...) Virtually all of which are still in use today. So while some things like good circuit design seem to be timeless, other things like double sided circuit boards with heavy ground coverage are new. These days i would add a servo to the thing to make sure there was no DC on the output, something that really did not matter back then, as there were no fully DC coupled power amplifiers. I don't actually remember which of the riaa sections i ended up with, there were at least 3, so i showed the one from Robert Linsey Hood The original fets were ct134, which i replaced with 2sk170 in this schematic. http://gilmore.chem.northwestern.edu/kgphono.pdf this was one of the first boards without a solder mask. http://gilmore.chem.northwestern.edu/opampfront.jpg http://gilmore.chem.northwestern.edu/opampback.jpg

Well yes, but show me another audio product that uses this scheme. Then again, there would be virtually no reason most audio products would need to do something like this. Old tube Tek scopes did this in a few places mixing solid state and tubes.

Added an extra mounting hole for the power supply board. May add one or two more if i move a few parts around. The turn on thump is mostly due to the size of the transformer. The T2 actually pulls a bunch more power, but since there are 2 transformers, the thump only lasts about .5 second.

i've tried to get information on the tubes before. did not get anything useful. On my unit which by now has at least 800 hours on it, i have 2 6dj8's that went massively noisy. One happened at cj. But i am using old stock tubes pulled from tek scopes. The two tubes that went bad, i put on the side and recently put one of them back in, and sure enough it was definitely toast. But it still tests good on the tube tester. I'm still on the same set of output tubes, the chinese junk that i put in at CJ. On some of the original production T2's, stax put shields connected to ground around the tubes. Birgir's had the shields. I have a picture of another unit without the shields. The center pin of the tube socket is connected to ground, and the chassis is ground, so it should be easy to make tube shields. The T2 uses the input tubes in a way that i have never seen before, and i'll never likely see it again.

i'm sure c11 and c14 are correct. Q16 and Q14 may be in backwards, will look at that soon. D3 and D4 are 1n4746 which are 18v zeners D1 and D2 are 1n4737 which are 7.5v zeners This version has to run as a moving coil unit. Reason, the .1uf 1% cap and 750 ohm resistor at the output of the first part are one of the 3 riaa filters. Another version has the input resistor and pot replaced with a 47k resistor, and then the gain of the input stage reduced by 20db or so by changing around a bunch of resistors. a couple of other things fixed too.

try again 6 Band Resistor Color Codes or 5 Band Resistor Color Code Calculator

Brown Black Black Yellow Brown Red ==== 1 Meg 1% 50ppm ??

I love it when a plan comes together.

The important fets are super glued together back to back. I don't want to mess with it and risk destroying it because there are no replacements. The others have no markings on them other than the part number and that typically means the BL... It sure seems that each and every unit had different resistors to adjust gain and DC balance. I may have found suitable replacement parts, but i have to build and test... But first i have to order a bunch of them. The klyne are an all opamp design with the opamps made from discrete parts. Really the same thing as the vendetta, and many others. Only way to get the noise down is with discrete parts.

First power supply working and tests at a total of noise of 300 nanovolts peak to peak. (under slightly more than full load of 200ma) I was hoping for better, but this is measured outside of a screen room, so it may actually be lower.

I predict that blubliss should be listening to a wonderful staxmass very soon. Both channels now adjusted to the right numbers. (servo's are a wonderful thing when they work)

A pair of lm317 3 terminal regulators feeding fets as current sources feeding pass fets. Cheap and effective. $20k blowtorch does exactly the same thing. You can certainly do much better these days including tracking regulators to reduce the pumping of the servo's. And much lower noise. I saw a schematic for the klyne a while back, no idea if it was accurate or not, the modules are just discrete fet opamps. The sutherland is an expensive joke. The ayre is much more my style these days

fixed... If you are building it yourself, the xono is going to be easier. But the xono has coupling capacitors between the stages and at the output. So if you want DC coupling... (required riaa network is always going to require capacitors) Its a shame no one has done the input stage as balanced. Makes all the sense in the world for reducing hum.

this should raise a few eyebrows a christmas present for all head-casers... taken from an actual device, so if i did it right, it should be 100% correct, and the only known complete schematic (not including a pair of lm317 pre-regulators) http://gilmore.chem.northwestern.edu/vendetta.pdf

I should have a working "supersillious" power supply for this thing in the next couple of days. Hybrid voltage controlled current source feeding a dual tracking shunt regulator.

just got an email from mouser that the 5pf caps are 1 year away... will find another one soon. A friend found a source for glass infused peek screws... I think i have to buy 500 of them minimum, but they are only $1 each.

blubliss goes to confession... Gotta love current limited power supplies !!! And one channel survived completely intact anyway. Pretty strong circuit design.

one channel works, the other does not. pretty sure that the tops of the batteries on the channel that does not work are about 10 or 20 volts and should be 200. Will know more once i know the cathode and grid voltages of U2. Could be that the servo is messed up. Actually all the sources are on at the same time. About 5kw total source power.

Well its the amount of flux, and the size of the beam that is of the most importance. So for all these new drugs we are working on, where you can only grow pure crystals that are 50 microns in diameter, these new sources generate much more accurate data, and a bunch quicker. I grow tomatoes at home, very nice tomatoes. With special fertilizer that i mix up from the good stuff. I'm trying to figure out if blubliss has a problem in one channel, or a balance issue. If its a balance issue, the circuit ping-pongs till both batteries in a channel are close enough. Pretty much the same way with the BHSE.

This is why i have been so drop dead exhausted for the last 3 weeks. Almost done now. http://gilmore.chem.northwestern.edu/xrayduo.jpg http://gilmore.chem.northwestern.edu/xraytriumph.jpg http://gilmore.chem.northwestern.edu/xrayprospector.jpg http://gilmore.chem.northwestern.edu/xrayfamily.jpg Seems that we have risen to the top of the food chain, at least in the USA (poor MIT) Should be getting back into audio design in a big way soon.

I have chips in my kyocera ceramic knives just from the knife hitting pieces of beef or chicken bones. They do break. The macor i use (machinable glass ceramic) works great in compression mode, but absolutely horrible in the other direction.