kevin gilmore

Without a precision mill, and some carbide bits, this is next to impossible. Taps are very hard and very brittle. If you have access to an ultrasonic cell disruptor, those have been known to loosen broken tap bits.

new version of board should be idiot proof for next time.

actually the + mark is the mark for the capacitor since once you stuff it, the + mark under the cap is now hidden. the plus mark on the diode bridge is towards the edge of the board, where the angle mark is. I will move the + mark for the cap. and add a + mark for the diode bridge.

mikhail had a version that looked just like that, and did in fact fit the teflon sockets, and it was threaded. So go looking for some russian junk and you should be able to find them. Or spotweld the nuts onto the frame. Or use female threaded inserts of the right size, a star washer and a brass washer and solder to hold things in place. edit: i tried some pems nuts and they work great if you have the right size, and something to use as a bench press to put them in straight.

Actually because the load is not a constant impedance with frequency the term SRPP does not apply anyway. It degenerates into a simple current source. And solid state seems to be a much better idea for this.

If you do SRPP you end up in the same troubles as the ray samuels A10. Same sort of thing as mikhail's original disaster. Voltage swing on the top tube is rail to rail. Which means that unless you want 4 seperate filament supplies for each of the top tubes you quickly exceed the cathode to filament voltage specifications. Which in additon means seperate tubes for the outputs. 8 in all. Gets big and complicated in a hurry.

could be relabeled 2sa1413 which are 400 volt parts.

This is strictly the obvious fake test. If a k216 tests at 130 volts you know you are going to be in trouble. When a 2sa1968ls tests at 180 volts, you know you are in trouble. You need a real curve tracer to do real tests. So far all the fakes are so obvious, there is no reason to get to step 2.

How much were they at 3000 each? But if its another fuckjob like DALBANI who refuses to stand behind their product, probably not interested. Speaking of which, birgir now has verfied fake K216's also from DALBANI. Here is how to test the fets For the K216 Make an adapter that ties the gate pin to the source pin which goes to the emitter pin in the socket, and the drain goes to the collector. Then test as a NPN. The real ones test at 230 volts, The fakes test much less.

I could probably do that. When i don't know.

Don't forget to order this tool. Its absolutely required. http://www.amazon.com/Who-Doctor-Sonic-Screwdriver-Replica/dp/B003FHXMDC

10m90s on a heatsink is WAY better than any resistor. Good for 900 volts. Other versions good for more than 1kv. If a tube ever shorts, nothing bad happens. If you use the resistor plate load and a tube shorts, fireworks. Anything more than about 20 ma will push the output tubes too hard. blubliss has a gilmore schematic fully modified singlepower with the ixys parts you can ask him how much better it sounds than the original.

i have a solution for that

The purpose of the cross coupled thing is to increase gain. This is not an easy thing to do. You need at least 70 db of open loop gain, and that has to be at 20khz. Mikhail's versions without modifications suffered greatly from this which is why there were severe channel to channel imbalances.

for $20 with shipping i had to buy it. The thing i had been using got flakey, its 50+ years old.

i'm running way behind for various reasons. To do the simple zener version, make the zener string a total of 450 volts. (3 x 150v zeners) Do not populate the following (this is for the top supply, the bottom supply is the same) Q5,Q6,Q3,Q4,Q7, lt1021 R10,R4,R7,R6,R5,R29 C16 make R25 10k to 100k. (need to test this for lowest noise) put a jumper wire between the emitter and collector of the empty Q7 Which you can also do between the 2 ends of the missing 240k resistors like this http://gilmore.chem.northwestern.edu/pszeneronly.jpg next board run i'll add a 2 pin jumper.

I have the 200 wpc heathkit power amp in the basement, i use it ocassionally to drive a subwoofer. All NPN output stage. Cross between the bose power amp and the crown. Built lots of the RC gear for boats,planes in the day, the servo's were about half the price of the identical kraft units. Their TV's were pretty good at the time, but all the boards came pre-stuffed, so all you did was the wiring harness and adjust the tube. The NBS accurate clock was and still is one of the best things of its kind ever, and about 10% of the price of the Truetime. (i have both) The test gear was pretty pathetic. The speakers were just awful.

liar liar pants on fire. amp board is 16.00 inches x 11.950 (406.4 x 303.53 ) power supply board is 11.950 x 10.00 inches

When i shipped the T2 boards, i first took 2 x fedex priority envelopes, and put them on each end of the boards. Then i bought some padded foam envelopes from one of the business supply stores, put it in there, and shipped them. No problems, all of them got there in one piece.

here you go http://gilmore.chem....du/dsc_2289.jpg http://gilmore.chem.northwestern.edu/dsc_2290.jpg by the way, the lead free is a fucking lie too.

speaking of fakes... WARNING TO ALL... http://gilmore.chem....du/dsc_2288.jpg The one on the left is real, the one on the right is fake, and breaks down at 200 volts. birgir and i got nailed on this, about half of the ones i bought were fake, and most of birgir's (if not all of them) are fake. Evidently there are also 2sa1486 fakes out there, i don't have any pictures of the fakes. Get yourself one of these http://www.ebay.com/...=item1c1d98666e and test all the high voltage transistors before you put them in.

WARNING TO ALL... http://gilmore.chem.northwestern.edu/dsc_2288.jpg The one on the left is real, the one on the right is fake, and breaks down at 200 volts. birgir and i got nailed on this, about half of the ones i bought were fake, and most of birgir's (if not all of them) are fake. Evidently there are also 2sa1486 fakes out there, i don't have any pictures of the fakes. Get yourself one of these http://www.ebay.com/itm/DY294-Transistor-Semiconductor-Parameter-Tester-Meter-/120755611246?pt=LH_DefaultDomain_0&hash=item1c1d98666e and test all the high voltage transistors before you put them in. This includes the T2 !

RK50 to control the attenuator. I kind of like that idea. The RK50 should be available in mono, so not as much as you might think. Stereo with dual shafts might be nice, one for volume, the other for balance. The digital encoders are a way better idea.

schematics for the dynamic boards. I think these are the ones that match the boards. http://gilmore.chem....fetschembal.pdf http://gilmore.chem....ipowerschem.pdf http://gilmore.chem.northwestern.edu/dynahiver2a.pdf

mcm electronics had real 2sk216, but now out of stock, 81 days delivery. they don't stock the 2sj79