luvdunhill

I enlarged the center hole for the input tube sockets to improve the fit. In looking at various pics, not everyone did this (did anyone?), so it's probably a personal preference. Regardless of what you do, they sit at a lower height than the output tubes. Don't forget to really tighten the center pin before soldering to make sure the two halves of the socket are firmly connected together.

Indeed!

nice! what's that massive green with yellow stripe wire for? Have you flipped it on yet?

ok, one more question that probably nobody cares about, but hey... Would it have been possible to locate the Stax jack and the hole for the volume shaft at the same vertical position? If the jack is about 1.125" tall and the RK50 is 27mm off the PCB, this looks like it should be possible. I'm trying to figure out why this wasn't done... to potentially avoid a mistake cutting my front panel I'm staring at the missing front panel on mine and it looks doable, but I'm not sure if I'm missing something.

I matched them at 6V and Ib = 3.5uA and used a 1M pot in series with a 1M resistor to set the current. Once the base current was set, I just read off the collector current and matched these values. Typically what I do is set a target collector current using the pot, then read off the base current and use this to calculate hfe, but this approach doesn't work well with high hfe devices. In this case, it's better to just fix the base current...

double

Bourbon Old Fashioned with Russell's Reserve

China typically.

You can even get zag sockets, but if you use standard .1" veroboard you'll have to do some tricks with the pins. But yeah, rotating is the trick. I'll take a pic for you tonite, and if anyone is interested I could colate the matching data and post that.

Second only to CRDs, but maybe i am the only one that matches those.. I recently matched a ton of 2sc3381 and those aren't really that hard. You need two meters, one that can do .1uA accuracy and a resistor and a pot... The key is making a jig that just requires you to pull the device out and rotate it so you don't have to duplicate the jig for the second side...

A few questions... Is CTR important? Is it better to let the base of the transistor float, or tie it to the opto? Looks like a good strategy for a 'stat amp...

Agreed. Look for 1.7v though, the 1.8v will result in a different operating point unless you adjust a few resistors. You'll probably have to buy a few different kinds and measure them. You may even have better luck with 3mm devices.

I've bought a lot of stuff from them, they are definitely legit.

Excellent! Please stop by mikeymad's place first though Free all those bottles from the needless slaying!

I haven't been able to get kümmel in Texas at all... Russian variety I'd assume would be even harder to find. I've had it overseas though, and i would imagine it would work well in cocktails..

WANT! Been on my list for quite a while.

Thanks! It's been great so far!

I'm not sure what it was called. I actually like it

A pint of Peroni with an ounce of Campari in South Padre.

A pair of Twentieth Century Cocktails

That was probably the most "meh" WWDC I've ever followed. No new hardware is no new excitement in my book.

Personally, I'd file Kevin's T2 build with his KGSS build, as a "special" one that doesn't require additional changes and then turn around and do the modifications to stabilize your build.

LOL

nice! With your loop, won't you have the input RC filter from the amp transferred to the other input? I would think this would have some unintended consequences... I think it's worthwhile to move the feedback resistor like Craig did. I noticed Kevin did this in the second board revision, so I'd assume that he would agree. If you don't have a scope, I'd also add the additional 5pF/1kV caps across the 100K resistors as well (IIRC, Craig ended up omitting these caps and the 2.2pF caps, but I wouldn't do this unless you can verify the results, including transient response). I'm not sure if Craig ever posted picture of the modification, but it's not too hard to imagine what he did. Also, has anyone else done the mod outlined below? If so, I'd be curious to see what your thoughts are. https://picasaweb.google.com/inuponken/T2#5566996623938911634

I really enjoy Plymouth, and a Plymouth G&T