kevin gilmore

What you really want is solid marble pillars (the real stuff not synthetic)

Actually if you set the pots pretty close before you solder them in, and you don't have any shorts and everything is in the right place, it powers up just fine the first time.

Yep once you turn 40 you are toast. They used to make tv alignment tools which had a recessed blade inside a plastic tube. Put it over the pot and it stays in place. various politically incorrect name for those tools.

Actually someone is pressuring me to come up with a new otl amp. Its going to be called the Rock Lobster.

Could be, i ran it off bench supplies. The idea for this thing, and stuff like it is to get rid of the nasty output cap. You can do pretty much exactly the same thing for a singlepower extreme. And with all OTL direct coupled tube amps, you absolutely have to have output short circuit protection. Most people consider 6as7's to be expensive fuses.

If you completely recondition it, including belt and brake shoes its a very nice although quirky machine. Servo drives the capstain. First 30 seconds it usually wow's and flutters like crazy. Also sticktion in the tapes themselves will throw off the servo. Wonderful machine. Some even have the dolby-b option. Don't even bother trying to get recorded tapes, 99% are trash. Use for live 2 channel recording. B700 is a much better machine.

mostly due to layout. BHSE has 2 heatsinks 12 inches long. plus heatsinks inside the power supply. T2 amplifier has 2 heatsinks same height 17 inches long. T2 power supply has 2 heatsinks same height 17 inches long. (it really does not need this much, but it will look better when sitting under the amplifier.)

teflon sockets only it is. Actually looks a bit better this way. Anyone that can build a dynahi can build this. If you stuff all the parts in the right place and can do a really good job of soldering it should be a snap. http://gilmore.chem.northwestern.edu/staxt2connexonlyrev0-2.bmp ground plane removed for picture otherwise it wipes everything away, components that don't look like they have a lead connected are connected to ground http://gilmore.chem.northwestern.edu/staxt2rev0power-6.bmp i even have a bill of materials. (first time ever) so i have a clue how much its gonna cost, and how many more parts to buy. 231 semiconductors makes this the most complicated headphone amp ever.

Things are coming along, current board has layout for standard (i.e. cheap) and the teflon sockets, i'm thinking of going with the teflon sockets only. Any opinions on this... Definitely going to be less than $2000 in parts not including chassis. even with the teflon sockets and the SumR transformers.

Spritzers bakery is 175 years old this weekend. Time to make the donuts.

power supply coming along. http://gilmore.chem.northwestern.edu/staxt2rev0power-2.bmp Need +/-12 and high voltage delay circuit. have the one of the supplies on the bench for testing, works great. Initial quote for the transformers is 3.7 OD, 1.8 High. Plenty of room in the box for 3 of them.

And its mirror cousin. Fixed those two... thanks.. the npn on the power schematic is actually a 2sc3340 and the reference will be a ref102 because its less than half the price for the same thing.

They say so, but in any case i'm going to put 2 in parallel at 50 ma each just to make absolutely sure. Amp as is runs 80ma.

proposed power supply for high voltages http://gilmore.chem.northwestern.edu/staxt2multips.jpg There will be at least 5 of them. +500, +250, -250,-500, -560 might be overkill for the bias. Way better than 1% regulation. Not dual tracking, that is a lot more work. and probably unnecessary due to the servo's already in the thing. Could do them as shunt regulated supplies, they would then dissipate a bunch more heat.

Thanks i just sent him an email. This is what happens when i try to help people for nothing..

$375... I thought $85 for just the connector was a good deal. Maybe the person who wants it may change their mind.

The kt77's will definitely fit horizontally. Sure looks like they will fit vertically too, otherwise just leave the top off. spritzer needs to punch a hole in his rack, and put in a quiet fan to push air from the bottom thru the top of the thing. the reason the T2 may be a little bit light in the bass could be that the tubes are only running at 5 watts each, and i definitely would not turn up the power any higher in that chassis. The BHSE runs the tubes at about 10 watts. The diy T2 will have lots more heatsink and it will be easy to dial up the power.

So i've been dealing with fischerusa for the last 6 weeks. i agreed to make a he60 to he90 plug so that one person can use his he60's on a hev90. 5 weeks later after promising the male connector in 1 week or less, i'm back on the waiting list from the factory, 12 weeks for one fucking connector. And two of the sales people i've been dealing with in that time have "left the company" and the purchase order keeps getting dumped in the bit bucket. What a way to run a company. Justin: where is my BHSE... estimate a 4 week time frame including the year please.

62C == 144F yes hot enough to cook eggs Even the krell does not get that hot. listen to some great music and cook dinner at the same time. I did not get the red JJ coating on those things either.

Time for a bigger equipment rack. Might as well get it now, you will need it later anyway. The power supply is quite a dense brick at 35 lbs.

The problem with mikhail's tube sockets is that the plating on the metal pins comes off real easy, then all you are left with is regular steel which gets rust on it and the contact quality degrades very fast. There are plenty of other sockets just like that that are made better. Everything said about teflon is true, but if you use the solder mount sockets and have everything perfectly aligned, nothing ever moves. In fact if i could get the tulip pins by themselves i would not even need the rest of the socket. Except then you have to pay real attention to the way the octal tube gets inserted.

I don't know what you paid, and don't really want to know, but you got a real good deal. a REAL good deal. Obviously the next step is to build the same thing with 6C33's running at full power. Then after that i have some very large and low voltage EIMAC's that really like to run at a few amperes...

If bigir finds me another T2 floating around for sale from a reputable dealer/person i would buy it just to add it to the collection of other things. I can do a better job 25 years later. But justin class chassis's are a whole bunch of work. At least i'm very now well familiar with the 3D milling machines and the software, so i can make a chassis with all sorts of pretty holes pretty easily And even go for completely custom one piece heatsinks. Then ship the stuff out for anodizing. Should cost about $1k for the chassis. Assuming the labor is free. The arlon circuit board makes no difference as the lower capacitance is definitely not necessary, and it probably would have to be much thicker to hold off the 1kv floating around. This is pretty close now after about 18 hours of work. http://gilmore.chem.northwestern.edu/staxt2rev0.bmp at least all the obvious errors are gone, and the ground plane has about 95% coverage once i add it.

3 days ! So if i'm an amateur what do you call mikhail...

The 6dj8's in the back next to the pot are the cascoded input stage.