kevin gilmore

I'm definitely liking the 6bl7 as it is a dual triode. So we could do an amp that is 3 octals per channel. Slightly bigger than i want, but ok if the tubes are cheap. Looking into 6p14 now.

So there is absolutely NO way we are going to do an A10 board due to all the issues we know about. But it would be nice to do something simple that anyone can build. So i'm looking for tubes that can handle at least 500 volts, anything there is bunches of that does not have stupid pricetags attached. And its not going to be SRPP either, because done right, you need at least 5 seperate filament supplies. 6s4's don't seem to be in plentiful supply any more. Otherwise its a circuit board that is bigger than it should be with multiple 6ca7's... Any ideas?

2 people asked for the gerber files, so here they are. this still needs checking for errors. http://gilmore.chem.northwestern.edu/ll.zip

I have both of you beat. Over 1200 sq feet in my basement just filled with electronic antiques.

Very close to done now, stuffable many different ways, mosfet/bipolar current source transistor/led stacked current source/single high voltage current source resistors/zener 400v/450v/500v http://gilmore.chem....edu/srm323s.jpg and .5 inch smaller in vertical direction than kgsshv which is what birgir wanted. Deepak, you asked for it, you got it. and here is the schematic which needs a bit of editing to show the rest of the options http://gilmore.chem....srm323splus.pdf And we now have an official name for the thing. Ljóstrandi leiftur I like it.

One of the women i work with is full up kosher. 2 of everything in the kitchen. Full up religious too. But when she goes out for dinner she will have ribs or things with bacon in them. I find this a massive contradiction. So i don't keep kosher. Besides which you usually cannot get kosher prime beef.

http://gilmore.chem....edu/srm323s.jpg you can use non-isolated mosfets if you want. you should use the bipolar listed for +/-400V you can use the 2sc4686a and the 2sa1486 in place of the ksa1156 and then go to +/-500V +/-15 volt supply not needed. Will add the LED current source option soon. Same exact size and hole placement as the kgsshv board

I should stop watching the cooking channel. matzoh balls wrapped in bacon. Going to have to try this.

Stone knobs coming soon. First some italian black specked marble Hopefully this week.

The LL is not any cheaper than the KGSSHV. In fact, done right, its slightly more expensive.

So do we do a circuit board that is identical to the LL production version, or do we do a modified version thats better? Off board or on board heatsinks version. Really, taking the kgsshv board layout, the last 2 stages are identical, so changing the front end it pretty trivial. And the kgsshv power supply works great at +/-400 volts with only 2 resistor changes. And its not a rummage sale... its a rubbish sale. Especially the rudistor clones.

And i get bottles of the black death in return. And goodies from birgir's bakery, whose version of fruit cake is just amazing. (not what we think of as fruit cake in the usa which is generally useful for pounding nails and not much else) Birgir calls the stuff "stolen" but stolen here is not anything like that. Its a great deal. Testing indicates that to get the same distortion levels as the kgsshv does at 18 watts per channel, you have to go to 38 watts per channel on alex's fet design. Or lower the power and suffer significant THD at higher frequencies. I completely expected this. All parts now ordered for the preamp and blackhole. Mouser must love me.

The connectors are on .2 inch centers. But i can certainly change it for production. There are right angle plugable connectors that work great, its the kind of connectors that crestron uses on just about all their products. Will look tomorrow.

The parts situation is a royal pain in the ass for sure, unless you had the foresight to buy lots of stock of stuff a few years ago. Which some of us did. The idea is to have all the parts sourceable from mouser. On my kgsshv power supply, the ksc5026 replaces the 2sc3840 directly The ksc1156 can replace the 2sa1486 with an added zener on the drive transistor, but a better solution is the pin compatible (you have to flip it) Fqp3p50 The lt1021 is a digikey only part. For the amplifiers, when the 2sc4686a parts dry up, the 2sc4686 parts will still be available, or you can use the same ixys ixta3n120 alex uses which is a special order part. Or the fqpf8n90c at +/-450 the lsk389 or the singles are available at another distributor and are standard production parts. The 600 volt pnp is available as a 2sa1807 which is surface mount only, and the adapter boards will be needed. Or the 2sa1413 which may be discontinued. Alex's design is all mouser parts except for the 2sj74 which is discontinued but still largely available. At some point these will not be available anymore and then linear systems will really HAVE TO GET OFF THEIR FUCKING ASSES and deliver the p-channel parts. The bipolar version of my kgsshv is twice as fast (250khz -3db) than the fet version (130khz -3db) due to significant gate capacitance of the output fets. The n-channel input part is 30% faster than the equvalent p-channel input part. Although you can go bipolar here too. It all sucks i tell ya. Unless you are Nelson Pass and can pay stupid money for custom Static Induction Transistors which are n-channel only.

I believe he had to sleep on the couch a couple of days!

I'll do up the power supply later. I don't think much of the power supply. The amp part has 30db less THD than the exstata. Way better. about -80db second harmonic distortion across the full frequency range, and a rising third harmonic that is -70db at 20khz. Peak to Peak voltage really is close to 1350. Some people are going to like the mosfet sound better than the bipolar of the kgsshv. Nothing stops you from building the kgsshv with mosfets however, other than the fact that the parts are not isolated, they are a direct drop in for the 2sc4686a

Inu still holds the record for attempting to do powder coating in his old kitchen stove.

Not sure what you mean, for the terminal strips, they make 45 degree versions. For balanced its definitely stacked boards on top of each other. I already see a silkscreen error, so there will be for sure a couple of very minor changes for the production version.

Wow, alex actually does exhibit some learning after the exstata debacle. Well at least he knows better now where to acquire working schematics. http://gilmore.chem.northwestern.edu/liquidlightning.pdf For those that don't recognize it, its none other than a stax srm323 with mosfets in stage 2 and 3, and cavalli style current sources, and a stacked current source in stage 2. But for $4k+ ?? AH well the price of progress. Now alex needs to go back to the liquid fire, remove the tubes, replace them with jfets, just like the schematic he borrowed from about 1981.

Well you want 2 for balanced.

Well the critical stuff fits. http://gilmore.chem.northwestern.edu/kgitsojc.jpg

http://gilmore.chem.northwestern.edu/blackholebd.jpg The critical stuff fits. Now on to massive parts ordering binge.

Sorry, i'm tired and could not be much more creative.

Yeah Team. Boards at the post office , will pick up tomorrow. prototypes of the multiamp,blackhole and preamp. Will be sending justin his knob tomorrow also, i had better see pictures of it mounted.

Those are the top output transistors, and you can't measure them in circuit that way and get reliable results.