nattonrice

There are some general themes established throughout the thread (in no particular order) which if followed seem to lead to success more often than not. -> You can use (correctly rated) wanky resistors anywhere except the 700v batteries: these must be the specified Xicon part and should be raised off the board surface (for memory they are slightly inductive which adds a stabilising factor and stops a particularly annoying type of noise on the output). -> As a (possibly unique to me) extension of this: the dividers at the output of the regulators should be Xicon and raised (in my case the PRP units were leaking and causing the voltage to swing all over the place which is bad). -> At the minimum adjust all pots to the middle of their resistance/travel: Inu suggested middle for the 10k, max resistance for the 2k (this worked for me). -> Don't risk using possibly shitty nos 6922's: try for matched triodes as well as matched pairs (as an example, everything I've had from tubedepot has been good). -> Check your transformer voltages (at load if possible) before connecting them to any terminal blocks: never trust that things are as the spec sheet says. -> Fire up the psu BEFORE connecting it to the amp and check the voltages: load test if you can. -> Check all LEDs discarding ones that either don't work or have odd Vf: saves un-needed hassle and annoyance. -> Don't use fake parts: they are shit and cause various failure modes, none of which are good. -> If you have some form of tester then test all the sand: past basic sanity checks on the bjt's I didn't, this was a bit reckless and ymmv. -> Use teflon sheafed test points (digikey for example) on the batteries and only ever use one hand when moving probes (preferably you right one): this is basic practice, don't fuck it up. Apart from that there really is nothing else except to take a lot of care that you put the correct things in the right places. The great thing about the t2 is all of the leds in almost every major circuit component. Any time a bunch of them come on but others don't it really triangulates the fault. If you get the batteries into the right ranges then every led should be lit to some extent, if any are completely dark then that's your first place to start hunting for problems.

Nice to see that my spray-n-pray method was your biggest take away from the thread The build looks great!

Granted, they don't roll off a fancy German assembly line, but I've been shocked at the shitty internals on *some* modern production tubes. I guess we should be thankful there's still a market at all?

John beat me to it! I really feel for Justin and others that need to source these oft faked parts in small commercial quantities. The whole situation blows.

What they won't do is cover the cost for re-annodizing if this was something you had done on the cocked up batch. Sucks ass when that happens.

I'm in on this bus, I'll take 100 of 2SA1486 if available.

I know Kerry was working on something to-this-end but I'm not sure if he got to the panelisation stage (it was on BB).

A 211 stat amp would be a complete pita to sit in front of from a glare point of view

The New Fractal Dynahi, now shipping from Head-Case.

Since the current source boards I gave you need to be air wired you can put them most anywhere within reason. For memory Kerry put a pair of 1kv wima caps on them too (HT decoupling like the t2, kgsshv, etc). I'm looking forward to what you do!

Mine arrived today! Hand drawn instructions ftw =D

I grabbed the biggest squeeze'y tube of plain white silicone grease I could find. It's this one: http://www.jaycar.com.au/productView.asp?ID=NM2012 Seems to do the job. Just watch out because, kinda like yogurt and whey, the oil separates to the top of the package and will go everywhere if your not careful. You can literally track where I've worked on the t2 and bhse over the last year

Thanks Todd! A life saver =D

I ended up pulling all prp in the batteries and replacing with xircon. I was going to try lifting but... The problem in the psu turned out to be the upper resistor in the servo divider on the -500v rail. I tried raising it thinking it was just leaking to ground but with the same weird behavior. With out any test equipment (so talking outta my ass) it seems prp internally do funny things when near their 500v rating. Well at least that one did. I just decided that rather than stuff around chasing noise issues I'd just use the known quantity. At the very least, people now know where to look for the innovative win. When I can be bothered I want to move the 62k to back side of the board. I didn't use the 6.55v trick (just alternate adjustment to settle at +200/-540 and then do it by ear for noise and hum). However I did start with both rv1 and rv2 centered. In the future it would be nice to have another way of doing it.

Thanks guys =) Uuuuurrrrrggggg teaching on 3hr sleep really blows.

I humbly but proudly submit myself to the "well thank fuck for that" club If only about a year and a half late! I finally sat down 2 weeks ago with some good time to ruminate over the power supply problem (of all things) I was having. Three calculations in and I slam my forehead into the desk as hard as humanly possible. Fast forward to today where all the extra crap to finish the amp came in... it works flawlessly first power up! I did almost shit myself when I thought I could "hear" a tube starting to arc... it turns out that arcing noises are a great indicator that YOU'RE DOING IT WRONG. Both channels pingponged and settled really quickly once I figured out what in the hell I was doing. Being dead silent with 8 tubes and bazzilions of gain is really cool. I just listened to some tunes and, well I think there's been enough ol'English in this thread already Truly magnificent, it's like a bhse on steroids. Tomorrow I'll bolt it all together and make it pretty. Before I go to bed (it's 4am) here's some pics of it not blowing up. All of my sources have excellent volume control and, since I never plan on selling this, direct wired works for me. I filled the knob hole with a nice mini white led indicator fed off the 12v line. Since it's good to have places to hook multiple ground connections (be it a meter or input etc) I've got two solid core 16awg loops, one on each side. Apart from that it's red and blue. Thanks Kevin and everyone who participated in the thread and left a great body of work to follow!

That looks wicked

I love that thread. It's a shame that CW isn't around anymore, for memory he had easy access to the same washi that Feastrex use.

Morphine - Candy

That looks wicked! I just watched the youtube videos of your engraver, way cool

The guy is a self important arrogant prick. At least we saved the photos.

DAMN IT! Kevin beat me to it. I thought I was being so witty... Edit: this is what I get for reading HF before coming here, I deserve to be slapped.

It does exactly that, delay the HT transformer for about 55s give or take. It's the same circuit that Kevin put on the t2 psu board but with a small 12v regulator on it for power. If you don't have two separate transformers then I guess you'd have to relay the secondaries... which makes me nervous for some reason. Is it ill founded worry? (serious question)

You can map your basement man cave. That mini bar of yours will add some fantastic colour

This is exactly what came to mind with one in particular.