c12mech Posted July 16, 2012 Report Posted July 16, 2012 Justin, I would imagine that my only needing 8 of the 2sk216 and 4 of 2 sj79 would not be very practical on your end unless you have another use for them or could sell them on your site. I'm always looking for a better price for these things but there seems to be nothing cheap about this amp which is fine with me. Next up is coming up with a suitable enclosure that looks really good. I would love to have gotten one of the originals that KG did but that's not going to happen.
c12mech Posted August 3, 2012 Report Posted August 3, 2012 My boards showed up today. These things are freaking huge. I like it!!!! I opened the package at my wife's office and her first comment was "That looks like it is going to cost a lot to put all the parts on it." My reply was "Yes, it will." I already told her I want some 009's for my birthday(40th) next year. I may have it done by then. I plan to buy the parts for this in small doses. That way I don't see what I really spend on it.
nattonrice Posted August 6, 2012 Report Posted August 6, 2012 (edited) 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! Edited August 6, 2012 by nattonrice 1
livewire Posted August 6, 2012 Report Posted August 6, 2012 Most excellent! Two thumbs - way up! ! ! ! ! ! ! ! ! !
nattonrice Posted August 7, 2012 Report Posted August 7, 2012 Thanks guys =) Uuuuurrrrrggggg teaching on 3hr sleep really blows.
eggil Posted August 7, 2012 Report Posted August 7, 2012 That is in a word : beautiful. Congratulations !
deepak Posted August 7, 2012 Report Posted August 7, 2012 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! Nice work! What was the power supply problem/solution?
spritzer Posted August 7, 2012 Author Report Posted August 7, 2012 It's a lovely sight when one of these springs to life.
luvdunhill Posted August 7, 2012 Report Posted August 7, 2012 Did you end up replacing the PRP resistors in the batteries, or elevating them? I cannot tell from the picture
justin Posted August 7, 2012 Report Posted August 7, 2012 2SK216/2SJ79 FETs have been end of lifed. trying to get as many as i can.
c12mech Posted August 7, 2012 Report Posted August 7, 2012 Thanks for that info Justin. I guess I should go ahead and get those parts if nothing else for my T2 build.
justin Posted August 7, 2012 Report Posted August 7, 2012 i dont have the BOM in front of me for the T2, but here is what I know that may affect builds: input JFETs: 2SK389 - discontinued years ago 2SK170 singles - now discontinued Linear Systems LSK389 - only available matched pair Nearly all Toshiba thru-hole npn/pnp transistors have been end-of-lifed or discontinued Same for the high-voltage parts 2SC3675 and 2SA1968 Unsure what the status is of the thru-hole NEC 2SA1486
deepak Posted August 7, 2012 Report Posted August 7, 2012 Did you end up replacing the PRP resistors in the batteries, or elevating them? I cannot tell from the picture The batteries look like they have Xicons to me.
luvdunhill Posted August 7, 2012 Report Posted August 7, 2012 The batteries look like they have Xicons to me. heh. I thought one thing and asked another. Really. My real question is, did you try elevating the PRP resistors before putting the Xicons in (which you clearly did)... yeah, that's the ticket.
nattonrice Posted August 7, 2012 Report Posted August 7, 2012 (edited) 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. Edited August 7, 2012 by nattonrice
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