kevin gilmore

what we need to do is find a massive stock of 1000uf/25v blackgate non-polarized caps. The only place that has them in stock wants $80 each and we need 35 per board.

http://gilmore.chem.northwestern.edu/bernhoftsbakari1.jpg http://gilmore.chem.northwestern.edu/bernhoftsbakari2.jpg http://gilmore.chem.northwestern.edu/bernhoftsbakari3.jpg Next year i will definitely need more

Tom should have received his present today

updated schematic and picture, have a look. very pathetic BOM in progress includes some of the power supply 1000uf 35v ls=5 dia=13mm 871-B41041A7108M000 35 0.47 16.45 .1uf 100v ls=5mm 80-R82EC3100DQ70J 14 0.32 4.48 4.7uf 63v wima 505-MKS24.7/63/5 7 4.33 30.31 470pf 500v ls 5.9mm 5982-15-500V470 4 2.28 9.12 39pf 500v ls 5.9mm 598-CD17ED390JO3 2 1.35 2.7 220pf 500v ls 5.9mm 598-CD15FD221JO3F 2 1.22 2.44 220uf 50v ls 5mm dia 10mm 647-UPW1H221MPD 4 0.58 2.32 4700uf 50v ls10mm 35 dia 598-SLP472M050C5P3 2 3.2 6.4 mjf15030 6 1.63 9.78 mjf15031 4 1.63 6.52 heatsink amp board 513102b02500g 8 1 8 mpsa56 19 0.12 2.28 mpsa06 23 0.32 7.36 lsk389 2 relay 653-g5v-2-h1-dc24 2 2.76 5.52 op27 digikey 4 6.01 24.04 Its about $137 not including the resistors and some of the other power supply components. So definitely under $250 with transformer and everything. Unless you go very nuts on the resistors.

Thanks, got all of them. Not sure yet about q27 collector cap. The 4.7uf caps are at birgir's idea. (also kind of expensive) evidently no amp is complete without some wima's. will post again when i get home.

please someone (everyone) verify the board vs the schematic http://gilmore.chem.northwestern.edu/ksa5.pdf http://gilmore.chem.northwestern.edu/ksa5.jpg

The picture says 500R. will check the detailed pictures later.

same compatible pinout.

stereo board http://gilmore.chem.northwestern.edu/ksa5stereo.jpg may put an alpha pot on it depending on what people want. 10 x 7.5 inches. Slightly smaller than the original.

mikhail's just awful hack job removed and correctly replaced http://gilmore.chem.northwestern.edu/dsc_0234.jpg

That is a hallicrafters. I have one that is almost identical. The different color top is on a hinge is a dead giveaway. http://www.google.com/imgres?imgurl=http://www.mbzponton.org/n2awa/radio_Hallicrafters_S40.jpg&imgrefurl=http://www.mbzponton.org/n2awa/hallicraftersS40.html&h=756&w=864&sz=161&tbnid=Pn7JInGUt_swMM:&tbnh=90&tbnw=103&zoom=1&usg=__mqGkTXJ4HNy7e3YmCywIMTKPndQ=&docid=G2a7_MaBCm1tdM&hl=en&sa=X&ei=WK24UKjGEoTs2AWbn4DQAg&sqi=2&ved=0CFAQ9QEwBg&dur=420

http://gilmore.chem....du/dsc_0177.jpg The blackgate caps and the dact are mikhail's handiwork. here are the schematics for the 2 power supplies. The first one is the original supply that tom owns. http://gilmore.chem.northwestern.edu/ksa5psschemold.pdf this is the newer version http://gilmore.chem.northwestern.edu/ksa5psschem.pdf I think we will be doing the new version. I'm sure they sound different.

power supply board should be done by the end of this weekend.

The real way to look at this is to calculate what the Rp of the tube does when the tube is hard on. For example for a 6ca7 in this kind of circuit, a 30k plate resistor on 600 volts ends up with about 70 volts at saturation across the tube. You can calculate what it is for different tubes. But the last 20 volts before saturation is highly non-linear, and with a 600v supply, and 30k i would be surprised if the peak to peak output voltage would be more than 300 volts with <1% thd. I'll calculate more when i can get to a real computer later. For mikhails es1 disaster with the output tubes already biased to -150v, and 50k plate loads, the maximum peak to peak voltage (stator to ground) was also less than 300v on a 800 volt power supply.

Lower value plate resistors saturate the output tubes in a hurry. Try it and you will see. Constant current sources way better And lots more parts

I have over 2000 vinyl... Problem is feedback from the speakers right thru the turntable. I would have to put the turntable in another room to get that to work. Too much trouble. ripping sacd's with ps3 very easy once you get all the software pieces in the right place. trouble is the ps3 is a cheap piece of crap, and once the dvd player dies, getting replacements is impossible. As is replacement power supplies.

you need better eyes... http://gilmore.chem....u/ksa5orig2.jpg the relays are output relays driven by a simple delay circuit. no real protection. there evidently was an issue with 24v relays used on 21v. Q14 is the Vbe multiplier thermally tied to Q23 for output stage bias.

Board files available to all

The people at diy audio where i just posted this seem to think that Todd Eichenbaum actually designed it. I don't know, none of the people i knew at krell are still there so i have no way to verify. As a speaker amp, you probably want the most efficient horns you can get. Not a good idea.

Both Birgir and I have wanted one of these for quite a while, and they never seem to show up. So with a little help from one of the members here we were able to reverse engineer this one. http://gilmore.chem....rn.edu/ksa5.pdf http://gilmore.chem....rn.edu/ksa5.jpg still have work to do on the power supply. All the parts are still available, but identical and compatible parts also available. mpsw06 and mpsw56 and lsk389 I think this one is fairly cheap to do. And easy to assemble. Single channel is 10 x 3.65 inches. Single ended not really a HE6 killer, but balanced, a HE6 heavyweight for sure. If you replace the servo opamp with opa445, then you can go up to +/-35v rails. Then its definitely a HE6 killer single ended. picture of the original http://gilmore.chem....du/ksa5orig.jpg single ended with +/-21 power supplies, it does 10 vrms into 4 ohms or more. balanced 20 vrms into 8 ohms or more. single ended with +/-35 power supplies, it does 16 vrms into 4 ohms or more. balanced 32 vrms into 8 ohms or more.

8g3 also fake date code. There is one other fake date code that will take me a bit to find.

yep, those are the identical date code (0e4) that were the fakes that birgir and I shoved up dalbani's ass. Darlington, and good for no more than 30 volts.

output dc on the tubes should be close to 0. 150v is not right

You need to measure the high voltage rails to know more. If they are 20% high, then what you really have is the transformer wired for 200v running on 240v. And then the transformer gets very hot.

see if you can buy 2sk389/2sj109 or the singles versions... i'll bet you get a few hundred quotes.