eggil

Congratulations!

http://www.trendsetter.com/product-p/lsk389c%20to-71%206l.htm

Thanks John. I had read the article before. He used for a heat spreader ether a 25x25 mm aluminum rod or an aluminum sheet with a thickness of 10 mm. I guess an L shaped flat aluminum piece is as good as a cuboid shape. No discussion of this in Westhost.

What would work better for heat transfer to the heat sink?: a. L shaped aluminum piece like the one shown above b. solid aluminum cuboid/rectangular piece

This is the way I am thinking about offboarding the transistor. I haven't done it since still waiting for the chassis with the external heat sinks

Gilmoretron

go buy yourself a pair of Bose and everything will be OK

EDIT: I should have listened to luvdunhill earlier: This is what he mentioned before about removing heatsinks: 1. remove the device 2. use a heat gun and heat up the heat sink. Use a heat shield to avoid the PCB. Get 'em hot 3. thread a piece of string through the hole so you have something to pull 4. Use Chip Quik 5. pull They pop right off I struggled removing the first 2 heatsinks, then I remembered I had some Chip Quik and the next 2 heat sinks popped without difficulty. I used a regular solder gun, but still worked great. That stuff is magic! My PSU is now ready for bigger heatsinks. And in case anybody is wondering how to connect an external pot, here are some pics.

My most sincere Thank You for all these wonderful designs. Go Kevin!!!

Don't know yet. Spritzer, you mean just use offboard heatsinks inside the chassis? I guess a real big one would work :)I haven't found a chassis I like

OK then. Now to buy a chassis with a big external heatsink to offboard the transistors after removing the 4 small heat sinks, similar to the offboard KGSSHV built, using aluminum brackets.

Mine has no imbalance.

Just changed the resistors from 1K to 1.5K. (Thank God for the Hakko 808). Everything works but won't be able to leave it on long enough to measure temperature tonight. CORRECTION: With the 1.5 K resistors: temperature in the mid 80's after 1 hour of listening. With the 1 K resistor: 91 degrees! It is still too high.

I guess it may be easier to replace the 1.5K with 1K than offboarding the 8N80's.

Victor, I used 1K resistors. I think I will modify the PSU per RiStaR's idea: 1- removing the heatsinks, 2- bending the transistors back, and 3-using an aluminum bracket, connect them to larger off-board heat sinks, 4-plus making sure there are large vents in the case. http://www.ebay.com/itm/171015163803?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

May be a second. No more. Currently measuring 85 degrees in one of the heatsinks.

88 degrees Celsius on the heatsinks seems a bit excessive. Anybody else has measured the temperature of the heatsinks? I don't know how accurate these cheap Radio Shack IR thermometers are.

And another Megatron comes to life! Bach sounds glorious Many thanks to Kevin for this wonderful design, to Birgir for preventing a major disaster with the PSU, and to RiStar and Victor for their much needed assistance.

DC Offset is staying around 4V for both channels. I am concerned however that the heat sinks for the 8N80C's are a toasty 80 degrees Celsius. I know there is more current than the KGSSHV because the 3904's are not installed, but isn't this a bit too much? My KGSSHV's were in the 60 degrees range.

Almost to the point I can hear music. Perhaps today. The casing though.... that will take time

You are quite right. I remember now

Oh my goodness! They are so beautiful! I can now see why people like tubes! My wife is in Finland with my camera. iPhone pics.

Here is first power up. All LED's turned on. The 2 closest to the tubes not as bright as the other 2. Tubes got warm but did not see any glow. Where is the glow?? Got cold feet after a couple of minutes and turned it off. Thumping heart rate @ 140 per minute. Nothing exploded.

There is a Canadian guy at headfi who did this. Can't remember his name. It may have been ujamerstand

I haven't had the pleasure of listening to these phones. Hopefully they will make it to a meet stateside someday.