kevin gilmore

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.

That is a rough question, and if you ask 3 different people you should get at least 5 answers. Here is my short list of resistors that are NOT critical. R99,100,101,102 R88,89,90,91 R80,81,82,83 R84,85 The multi-watt resistors in the amp section definitely are important. Some may consider the other parts of the servo's to be unimportant, but i think that everything that touches any of the audio signal would be important.

There was one bottle of the Don Julio Tequilla in all of chicago, and i ordered it, just went to pick it up and it was damaged and they would not sell it to me. I was told to stay away from the other 2 high priced versions which were evidently based more on the name than anything else. But this spoke to me, so i bought it instead. Binny's Beverage Depot - Wine, Spirits & Beer Since 1947 - Product Detail there was only one bottle of this in all of chicago too... The scotch collection had very little that seemed interesting... May drive to the algonquin store to see what else they have. If there is any reason, i can bring an insulated bucket of dry ice...

Can anyone find suitable teflon tubing for the power supply modification at mouser? My mind is drawing a blank... I've been using the stuff for 40 years and just can't find the right keywords.

whether or not the material is magnetic is only part of the equation. Any precision resistor that is spiral cut to set the resistance is going to act like a coil. Way back when when i was designing stuff i had a list of the military resitors that now reside in my basement, that listed the approximate number of turns for each of the resistors in the stack. I would usually design for minimum inductance. Or build in the inductance coupled with the capacitance to make filters out of single components. Stax did this with one of the servo feedback loops.

found a wiring error on the main board, and added .5 inch resistors over the surface mount, so it can now be built either way. can't post anything till power is restored to my servers.

I would be real careful with that. Blow a germainum transistor and its game over. Chances of finding any replacements is pretty much zero. "Oliver Tex Germanium" charges stupid amounts of money for germanium output transistors.

No reason to remove it. No reason to hide anything. Put it back if you wish.

Standard power supply caps are 50mm... So if you pick the ones in stock now that are 63mm then it isn't going to fit into a 3 inch high case. (vertically)

Yep F1. At least i think its the F1. I have a real nelson pass unit around here somewhere. Same as Recstar has. All of my speakers are way to hungry to run with something like that, so its really just a balanced output headphone amp. And i like the dynafet better for that purpose.

Yes its going to be very tight in that case. Also remember you need input and output jacks, and an input power jack. If you push the power supply all the way to the transformer, move the transformer up a bit, use the thinnest ac input jack you can find, you should have enough room on the other side for xlr jacks.

Have the top end one from about 2 years ago, stopped using it because it did a lousy job. Have the one specifically made for garages, the mechanics got so dirty inside after about 4 months that it completely crapped out, sent it back for repair, got a second one that lasted only another 4 months. Expensive toys.

First watt is a current source. Sounds absolutely fantastic with some speakers and headphones. Sounds horrible with lots of other stuff. Highly inductive speakers for example typically blow the fuses.

silly boy... http://gilmore.chem.northwestern.edu/melos.jpg

there are so many design flaws in that thing i don't know where to start. but the biggest one is using the filaments as the current source for the output stage. Once you hack that out, and run the tubes the normal way, and use a real resistor for the current source, lots of problems go away.

I sure hope there is going to be enough booze for the people showing up...

I'm sure there are payment plans. There will be one extra chassis in the final batch, which i won't have polished or anodized till the beginning of january. Its really nothing compared to the pile of parts.

tobacco does evil things to audio gear. especially the high voltage stuff.

http://gilmore.chem.northwestern.edu/su7300.pdf

found the exact schematic. The 3 amp fuse is in fact the input power fuse and is a fast blow. The 3.3 amp fuses are slow blow and are the amplifier output fuses. So anything <= works fine. xba1f30nu100 is the 3 amp powr source fuse xbas1a3301 is the 3.3 amp output fuses