kevin gilmore

Yep, bizarre, but that is the way it works.

What better way to show the surface finish. Macro lens Paging Dr. Wood... Paging Dr. Wood...

birgir's knob http://gilmore.chem.northwestern.edu/birgirknob.jpg It is not polished at all, strictly micromachined. Even the fingerprints show up... Amazing stuff. 4.5 hours of actual machining time. 100 turns per .0001 inch. 2 passes front and side.

Well it is soldered in, so if there was an offset i got it right, but i did try it first, and it fit both ways. The output transformers are definitely offset and can't be put in backwards.

birgir's knob is done pictures later today when i get home.

lets try that again mje350 ECB across the plastic front.

The mains transformer can be put in backwards. So pay attention to the wiring of the transformer and compare to the board. Also the shield is soldered to a pin which really should go to circuit ground. too bad there aren't any connex 7 pin teflon sockets. very hard to tell the direction of the led's, so first test the led to make sure of direction, then look at the schematic to make sure you insert it right. I'm as far as i can go until the rest of the parts show up. Should take no more than 2 hours to fully stuff it. Cutting the holes in the back and front are going to take more time. as far as i can tell all of the mje350's are BCE across the plastic front...

I tested at 10% over maximum rated load (which is dc because its pure class A) out of the power supply with a stack of resistors. The leads out of the high voltage transformers are 14 inches long. And yes you have to tell them to do 600 vac wire for all of the transformer windings. Which SumR does anyway i think.

done and done...

C1 and C2 were always optional anyway, way back from the start. Never needed them before, hope not to need them now on the board, but might as well have a place for them if needed.

I don't believe the moisture content for one second. I have lots of lignum vitae here, after you take the wax off, it usually takes about 10 years for it to be usable and it shrinks well over 10%. My wonderful hardwoods store went out of business last year, so no more of the exotic stuff for me till i find some place else where i can look at the stuff first.

Not sure what happened with the stax jack. it may have been one of the first 3 that i did, and maybe i machined it a bit too fast. From now on i will test the fit before i ship any more stax jacks. The problem with teflon is that it likes to get out of the way of the end mills as it is being machined. Maybe i bumped the speed knob... It will be replaced. When i send birgir his "custom pure titanium" knob. Hopefully the material for that will be in the end of this week. Yep we are at the silly stage... Need to find a 2 inch cube of aged lignum vitae.

Birgir did get his chassis parts evidently i messed up on one of the stax jacks...

Fixed. new jpg and pdf for the amp board. keep the errors comming please, need it to be perfect the first time.

Well the ps board was not updated for some reason, all those should be fixed now. The wiper on the pot is the center pin, and as a two wire device it really does not matter which end its tied to ?? The connectons to ground are hard to see in the jpg's. here are the pdf's http://gilmore.chem.northwestern.edu/kgsshvamp3.pdf http://gilmore.chem.northwestern.edu/kgsshvps.pdf

At least someone is looking at it... Please check again for more errors.

475 volt windings... 2 of them, completely seperated. 39 watts each 30 volts center tapped 10va

oops just notice the mje350's were backordered. i think i have some original motorolas at work otherwise 2sa1156 or 2sa1486 would be identical and probably slightly better replacements.

Well pretty close. The shaft is machined single piece out of the knob material. Then there is a coupling right behind that to the extension shaft, and another coupling to the pot. Depending on which pot you get, the second coupling needs to be a different diameter on the pot end. The picture posted previously showed this. http://gilmore.chem.northwestern.edu/t2chassis29.jpg

Wow that came out great. Justin quality great. And slightly cheaper. Hey birgir, get your ass to the customs agent and pick up your package please. Then post some more pictures. Custom piece for Inu will be finished by next week. So will Birgirs one and only custom knob.

The delrin extension is what i had in stock. Aluminum works fine. The knob gets as hot as the rest of it. Its unlikely that people are going to listen to this thing 12 hours a day, and the anodizing is going to definitely get rid of the heat. On the original, the knob got very hot too. The 2sc3381's i have measure a diameter of .020 and i reamed the holes out to .0205 will go find some 2sj109's to measure.

Don't waste any 2sj109's. Not sure of the lead diamater on those, will measure when i get home. The 2sc3381's definitely fit, but are super tight. Which is why is reamed the holes a bit before shipping the boards.

need to figure out why the frequency labels don't show up... ? they do on the screen... this works http://gilmore.chem.northwestern.edu/eqgraph.jpg

i'm pretty sure this is correct. http://gilmore.chem.northwestern.edu/staxeq.pdf

dact mounting bracket (or other pot) http://gilmore.chem.northwestern.edu/dactmtg2.jpg