kevin gilmore

So 26 volts peak to peak is about 9 vrms, which into hd800's results in a maximum volume level of a bit over 110 db spl. Dangerously loud. Ray samuels loud.

I would love to buy some ceramic screws. Where do i get #4-40 x .75?

I have no doubt that the sr71b is actually ray's best amplifier ever. And that includes all of his expensive stuff. Pretty sad that it is just a balanced meta42. In balanced mode, since the buf634 really does not like to drive less than 50 ohms (100 ohms balanced) i don't see it as a good match for low impedance headphones. I'm going to work up the numbers shortly, but at a minimum of 1.5 ma per buffer, at 30 volts nominal power supply the no audio standing power is 180 milliwatts. Not counting the switching power supply, and the other opamps. So i think even 16 hours actually making music is a bit optimistic.

well at least ray is now a head-fi sponsor. I'll bet jude gave him a great deal. Virtually identical ibasso product comming soon for about half the price. How many people are actually interested in a device like this that is going to eat batteries alive?

No its 4 individual diodes, so the quantity is correct. Any 1200 volt fast recovery diode works. Actually any 1000 volt to220 diode works. Used to be the st parts, those are out of stock too there are new versions of the st parts in stock. updated bom with a couple of fixes. alternate 680uf cap in stock is 667-eet-uq2w681ea definitely fits. like the T2, some parts were on backorder. Just spent 2 hours stuffing resistors. somehow forgot to order 3 values. more parts stuffing later today.

My boss bought me an aeron chair because of my back trouble. Makes a huge difference. He bought them from a store in northfield illinois, i don't rememeber the name, but all the chairs had slight blemishes, and they were about $500 with all the extra goodies. Still overpriced, but if you have to spend more than 4 hours a day in one, worth it. Also built like a tank with lots of cast aluminum pieces. And repairable if you should manage to tear the fabric.

Thats the first small prototype run, hence the increased cost. Someone else made them, not me. Its the reason why i'm not going to do another T2 board run.

more than 1600V p-p probably closer to 1700V p-p even more if you use the ixys parts for the current sources.

500 ohms is the correct value. Actually either one works, 500 ohms puts a bit more current into the 3rd stage.

Trouble with corvettes is all the standby current used by the alarm and onstar, so batteries don't last as long as they should. updated bom http://gilmore.chem.northwestern.edu/kgsshv.xlsx

Just noticed the silkscreen legend is missing... Will fix that later today. Will add the .47 caps to the bom later too. Had to stop by the car dealer for a new battery yesterday. 4.5 years is way more than most people get. And had the serpentine belts replaced because they were squeeking.

schematics, missing the 5pf caps. http://gilmore.chem.northwestern.edu/kgsshvproduction.pdf http://gilmore.chem.northwestern.edu/kgsshvpower3.pdf

I'll fix the led quantity thing much later today. There were 7 or 8 other errors i found and fixed yesterday as i was ordering parts. I've ordered all the parts i can from mouser, should be in by friday. Will order the rest of the parts from digikey. Those are the latest schematics, the only part that does not show up should be the 5 pf caps. Something else i will fix later.

15mm or 22.5 mm pitch for those caps.

jacob has some really nice knives... appropirately sharp too.

got here no problem and then got stuck in mike's driveway. http://gilmore.chem.northwestern.edu/chiliquifi1.jpg

Is it possible that we might actually have too much booze for the amount of people? Someone put mypasswordis on a plane real quick...

http://gilmore.chem.northwestern.edu/kgsshv.xlsx

make that 2 BR2,BR3 BRIDGE made up of 4 high voltage diodes each 1 BR1

Got a message that jim is not going to be able to make it. So i don't have to hand deliver the T2 chassis. So more room in the trunk for other stuff like laptop and camera.

I'm picking up the boards from the post office in about 2 hours, so time to post the corrected parts list which need to be applied to the bom Heat sink part numbers later. Amplifier board first, There are 2, so double all of this Resistors --------- 2 R1,R2 25 6 R3,R4,R13,R18, 1K R44,R45 2 R5,R6 180 6 R7,R10,R11,R14, 175K R29,R30 2 R8,R9 500 2 R12,R19 1200 4 R15,R16,R35,R37 100 1 R17 20K 1 R26 2k 2 R27,R28 5.1k 4 R31-R34 100K 1 R36 6.8K 2 R38,R39 200K 2 R40,R41 50K 2 R42,R51 10k 1 R43 3.3K 2 R46,R47 200 2 R48,R49 500k 1 R50 300 Transistors ----------- 6 Q1-Q4,Q9,Q10 2sc4686a either 2 x 2sa1968, or 2 x ixtp01n100d 2 Q5,Q6 2sa1968 2 Q7,Q8 ixtp01n100d 2 Q11,Q12 2sc2705 2 Q13,Q14 2sc2240 2 Q15,Q16 2sa1486 2 Q17,Q18 2sa970 Q19 is a Linear systems lsk389 or a pair of 2sk170 1 Q19 k389 1 Q20 2SC1815 Diodes ------ 4 D1,D2,D10,D13 LED 2 D11,D12 1N914 Miscellaneous ------------- 1 RV1 1k 1 RV2 2k Standard current source is Q6,Q5,R8,D2,R9,R10,R11 optional current source is Q8,Q9,R12,R13,R18,R19 power supply board QTY PART-REFS VALUE --- --------- ----- Resistors --------- 3 R1,R9,R39 3000 4 R2,R3,R20,R21 15/2W 4 R4,R6,R22,R25 400k 4 R5,R10,R24,R29 300k 2 R7,R26 62k 8 R8,R11,R14,R16,R27, 820K R30,R33,R35 2 R12,R31 20k 2 R13,R32 280K/1W 4 R15,R17,R34,R36 460k 4 R18,R19,R37,R38 100 4 R40-R42,R44 100k 2 R43,R45 5M Capacitors ---------- 4 C1,C3,C6,C8 680uf 6 C2,C4,C7,C9,C12,C14 100uF 2 C5,C10 .1uF 2 C11,C13 4700uF 4 C17-C20 .1uF/1000v Integrated Circuits ------------------- 1 U3 7815 1 U4 7915 Transistors ----------- 4 Q1,Q2,Q9,Q10 fqpf8n80c 2 Q3,Q11 2sc4686a 8 Q4-Q7,Q12-Q15 2sa1486 2 Q8,Q16 10m90s 2 Q8A,B,Q16A,B 2sc3381 1 Q17 ixys10m90s Diodes ------ 2 D1,D3 24V or 30 volt zeners 4 D2,D4-D6 1N4007 3 D7,D8,D10 150v zener 1 D9 130v zener Miscellaneous ------------- 2 BR1,BR3 BRIDGE made up of 4 high voltage diodes each 2 BR2 2 REF1,REF2 LM4040-10 2 RV1,RV2 2k

you assemble the tab transistors onto the angle brackets, add a couple of extra screws then align everything and tighten, then solder. The filament wires should be twisted in the umbilical, and between the bulkhead connector and the solder points on the board.

I should have my boards by the end of the week. Its going to be a great december...

here are kerry's spice files for people to play with. http://gilmore.chem.northwestern.edu/t2-ltspice.zip and this is why i've been so busy lately http://gilmore.chem.northwestern.edu/prospector1.jpg http://gilmore.chem.northwestern.edu/prospector2.jpg http://gilmore.chem.northwestern.edu/prospector3.jpg The bad boy in the 3rd picture has the equivalent flux of 10% of the APS Argonne Labs Beam line. i.e. about the same as 20 watt laser. Cuts thru flesh if you are stupid enough to get in the beam. And while there is no smoke (at least there had better not be any smoke) it is in fact all done with mirrors. Runs at 50kv and a little less than 1ma. The one next week is a dual source. And a triumph monochrometer the end of this week. Many thanks for funding from the State of Illinois.

The test circuit at 740 volts and 5 ma shows a base current of 49.9 microamps. So my guess is that at the operating point the 2sc3675 is running at an hfe of about 80. So its likely that the minimum hfe of 30 at 10ma is likely 60 or more at 5ma, and that typical parts are in the 80 to 100 range.