kevin gilmore

Well the TEC at the time cost me $4500. Completely stainless steel guaranteed not to rust. They lied. The only way to send it back to the factory was to take it apart, because no standard shipping company would have taken it in one piece. And all the screws and a lot of the stainless was rusted pretty bad, so there was no way to take it apart. Went into the trash can. Only some of the parts had the 20 year warranty, so it would have likely come back with a $2k bill. Never again.

I never did the parts kits. Never will either, not enough time. All current chassis are spoken for. There is actually one extra chassis, but no board set to go with it. I just don't see me doing another chassis run. Some other fool would have to take that on.

Before i had the weber, i had a TEC. Way expensive. Was supposed to last 20 years. Firebox and ceramics cracked after 9 years, then i found out that they can't sell replacement parts because the ceramics were wrapped with an asbestos like compound and then inserted into the firebox. So even though it had a 20 year warranty i would have had to send the thing back somehow to the factory. That was not going to happen. Moral of the story, nothing lasts forever. If you don't run the thing at 11, it should last 10 to 15 years. But it is made of clay/ceramic/who knows what. And if you drop it, or if it falls over due to wind (kind of hard to do as its pretty damm heavy) it might break.

My boss has one of these things, (the bigest size one) and absolutely loves the thing. I've had some food from it, and it sure is tasty. It can do things my gas fed weber cannot do.

For those interested here are the prices. It really only makes sense if i do another 20 piece board run. power supply board quantity 5 $157 each quantity 10 $97 each quantity 20 $61 each amp board quantity 5 $242 each quantity 10 $166 each quantity 20 $102 each so prices did go up ever so slightly due to increase in sales tax. which makes a set of boards quantity 5 $399 quantity 10 $263 quantity 20 $163

I like some of those pics. maybe an armagnac this time. The reason for binnys is that there is a store less than a mile from my house I like the 70 year old stuff too, but that is going to have to be for a very special occasion

power supply fix pictures courtesy of Inu http://gilmore.chem.northwestern.edu/noise%20fix1.jpg http://gilmore.chem.northwestern.edu/noise%20fix2.jpg But if you don't want to cut the land, you can put the ref chip up on a pair of sockets with a resistor in the middle. Picture on that later.

I should have said that the booze has to be at least 80 proof. And something interesting.

And now i get from another distributor that the 2sa1968LS has been discontinued and i have to order from them NOW... This is getting real old real fast. Glad the board is designed for both. Was going to modify the power supply board for the 2sa1968ls because justin likes the led's... But...

It may be a plastic package on that part, but its not insulated, collector is on the bottom.

Consider arm broken. Still have lots of booze left... But i'm in the mood for something fancy too. Someone go to the binny's website and find something in the $400 to $500 range that is in stock. (a single bottle of something) Then let me know what to buy. Since all of the toys on my to buy list are still vaporware, i have to spend some money on something.

There is a reasonable distributor, i think in england that ships worldwide and has reasonable prices. Don't remember which one, its buried in the T2 thread somewhere.

updated bom. also this which is real sweet, but needs a slight bit more work and then some testing. The only shuntregulator i know of that won't blow up without a load. http://gilmore.chem.northwestern.edu/shuntregulator.pdf

looks like about $350 in parts with the transformer. plus the circuit boards much better version of the bom, still missing the other parts of the thermal washers and part numbers for those http://gilmore.chem.northwestern.edu/kgsshvbomas.xlsx you would need to add input connectors and a pot. If someone wants to do a group buy on all the transistors, and someplace else other than the usual place, i'm sure we can get the price down somewhat.

I want to see pictures of the insides first. I use OCXO's all the time, they are a $500 part. At least the good ones are that much. I don't see how you can put a $500 part inside a $3500 retail priced unit. Poorly done non PID temperature control would be just as bad as no temperature control whatsoever. Still, kind of silly as the only thing it does is stabilize at a specific frequency, and unless the thing is actually powered on all the time, it would do more harm than good. TCXO's are a much better idea, and cheaper and stabilize quicker. Analog volume control is definitely the right way to do this.

Had not thought about that. Will have to look into it.

but then how do you prevent the coconut shell from touching the speaker... can't allow the vibrations from the speaker to influence the capacitor. Actually patrick might have a product for that one.

I have finally figured out the discrepancy in my spice simulator on the power supply vs ltspice. Although they still don't entirely agree. The explanation would take 3 or 4 pages, so i'll omit that. Back to the 20 year old software.

Original design can run on +/-600 volts and absolutely requires T2 style heatsinking. Which puts the chassis at about triple the cost of the rest of the parts combined. Maybe more. I don't think that is what people want. This is supposed to be an everyman kind of thing. If you want nuts, go and build a T2. Or you have to be someone like luvdunhill or n_maher with the equipment at home to do the chassis. Or even kerry which manages to do that kind of stuff on a balcony overlooking central park. Even i don't do chassis like that at home and i have all the right machine tools. Getting the heatsink interface right pretty much requires a NC machine. Or a whole bunch of patience. I'm working on yet a third power supply design. Shunt regulator. Sure, why not. Except my version does not blow up without a load, it uses the ixys parts as the current source, and i measure the current thru the shunt, and if its too much, i shut down the amount the current source supplies. Sort of the best of both worlds.

There is also an alternative power supply board, cheaper than the T2 style, its pretty much identical to the BH power supply board, at 450 or 500 volts. No reference, opamp or 2sc3675 needed, and 2 less heatsinks. http://gilmore.chem.northwestern.edu/kgsshvps2.jpg option for 2nd pass fet and heatsink for better heat spreading. amp schematic updated. I've tried having someone else order the boards. But if i pay for them even if they ship out of state, they still charge me tax. For boards i buy for nwu with the tax exempt number, i still have to go over it with them every single time. A real pain. But they are the best boards i have ever seen.

The resistor may not be necessary as the output impedance of the reference is about 1k. In which case the cap would need to be 1uf. I have not tried this. Also instead of cutting a trace, you can put the reference up on a pair of sockets stacked together with the resistor in the middle. Picture on this at some point.

exactly the same crap as walker links High Definition Links but cheaper. Nothing but a capacitor. Takes a bit off the top. Causes instability in some high slew rate amplifiers.

OK, the holdup for the last 5 weeks was trying to supply 2sa1968LS at a rational price. ($7.13 each is not rational) I was told by the person that should know that they should be 70 cents each. So after contacting various unsavory ic parts companies only to be told that my offer of $1.29 (mouser price on the ixtp compatible part) was WAY too low, i just gave up and decided to modify the layout of the board to incorporate both current sources. Literally 10 minutes after i uploaded the files below, i get an email with a quote from a british distributor, and guess what... 70 cents each. (plus or minus due to exchange rate) Since lots of things have been changed or moved around, lots of checking needs to be done. also apparent discrepancies on the power supply schematic vs the amp board are due to the differences in voltage. If you go with the 2sa1968ls which i think sounds ever so slightly sweeter, the power supply rails have to be +/-450 volts. If you go with the ixtp01n100d, then you can go with +/-500 volt rails. http://gilmore.chem.northwestern.edu/kgsshvproduction.pdf http://gilmore.chem.northwestern.edu/kgsshvproduction.jpg http://gilmore.chem.northwestern.edu/kgsshvpowerproduction.pdf http://gilmore.chem.northwestern.edu/kgsshvpowerproduction.jpg The amp board is 8.25 x 6.25 inches with 240 holes. you need 2 The power supply board is 9 x 7.5 with 374 holes. The single transformer is going to be 4.5 inches in diameter and about 2.5 inches high. (if you go with the SumR) If i do the board run and do 20 sets, because i'm in illinois and so is imagineering... the price increases by 9.5% due to sales tax. Which would make a complete board set $71.46. plus shipping. If someone else wants to do the board run that's ok too, gerber files will be posted once people verify that there are no mistakes. Digikey is the only one with the 2.5 inch version of the aavid heatsink, mouser only stocks the 2 inch version. 2.5 inch version highly recommended. BOM now needs serious work. I'm not doing chassis on this one. (well except for my nelson pass style chassis which is for me only) Put it in a hifi2000 box, or hammond box, or a wood box. But plenty of top and bottom holes.

First things first. Then i will read upward later. The power supply problem is fixed. Verified by Inu. Took about 5 tries. Will have pictures soon. Power supply total noise is 26 millivolts at load. Under the noise of the tubes. Which is still very quiet. schematic updated with the fix. For those that want to play... http://gilmore.chem.northwestern.edu/T2PSfix3.asc get a copy of ltspice which is free. Simulate and put the probe on the output. Cut one of the wires to C3 (but not C3) and simulate again. ltspice likes to rearrange nodes sometimes for no apparent reason, so if things look screwy, delete the trace and put the probe back on. I still cannot get my spice machine which has never failed in the past to do what this does. But with the added parts, the optimization still comes out the same. I can't play any more for 2 days due to the labor day power shutdown. Lt spice completely fails with the same spice models on the amplifier schematic. 8 chassis have been delivered to the polisher. I expect them to be back in about 3 more weeks, then 4 go for anodizing. This is strictly a logistics problem now. All of the machining of every single part (except for more stax jacks because i keep selling those on the side) is finished before the increase in price of machine time on sept 1. When the chassis arrive from the polisher i will ask for payment on the next 4 chassis. Many who missed out on this want another run. Justin has a brand new heatsink that is 5 inches high. (like this thing isn't big enough already) the 5 inches combined with the 16.2 inch length of the heatsink means that i cannot machine the front and back holes. I would like to find a machine shop that would do the entire job. If someone knows a shop capable, i would like to know. Would have to be a featurecam supported shop, or have machines that i have a G code optimizer for already (i have most of them). The price on the chassis would definitely go up a bunch. Or people can do what luvdunhill is doing, which overall is a massive amount of work. On the current chassis, all pieces, there is 12 hours of machine time. That is just machine time, does not count the added load and unload cycles, or the cleaning of the goo afterwards. $700 of the chassis was machine time. But if people still want another board run, that can be done. All fixes have been applied to any future board run.

i'm having no luck... don't know what to stick (the spice model for the 2sc3675) and where to stick it, or how to get it to simulate what Inu see's... Then i'll get around to figuring out how to add/chance component values... Time for an early dinner.