Kerry

To Birgir's point, I always modify the PS for the intended use. For a 350v supply you can remove half the capacitors and the associated resistors. I like the performance of the design though it has a very high drop-out voltage. You can certainly get away with the 300V 100VA transformer, but you need to tweak the zener string. I find you need at least 20V higher on the pre-regulated voltage over the output voltage plus you want another 20 or so volts over that coming from the transformer. Problem is that the zener string moves 10 - 15 or so volts from cold to warm-up. I use the Antek 350V 100VA transformer on my KGST, but I run the output at 400V. The power is not an issue. Runs silent.

If you use the KGSSHV PS you should set the pre-reg zener string to about 400v. You'll need some head room above that so the transformers should produce a peak voltage of at least 430v. I'd use the 330v tap on the transformer.

Happy 52nd birthday Al!

Thanks for the compliments guys! It is a nice looking amp and has all the sound of Blue Hawaii

I believe it is a similar design to Justin's. I simply modified the current source for the output stage. Otherwise it is identical to the original Blue Hawaii design. I'm flattered by the post

Really nice! What finish did you use on the face plate?

That really looks nice! Great work.

Yes. What Sam said

Nice Eggil. You could also consider putting in blind taps for the standoffs.

Nice

The resistors in the batteries were the ones that were leaking. Make sure whatever you use are well insulated and are lifted off of the board. I originally used the red PRP and had them lifted, but they still caused problems. EDIT: Looks nice so far

^Yes indeed. Enjoy

The Darlington pair should be high hfe. No need to match within the pair. That's all I can think of at the moment.

I'd go for the higher hfe and get them as close as you can.

That knob really does make that amp stand out

Welcome to a wonderful hobby and great community. We apologize in advance to your wallet

Really nice work Craig

Wow. Very nice! Can't wait for your impressions once you get it running.

Nice design Geoff. It really looks beautiful

I think it sounds better upside down I see you did a lot of work on the board since last night. I love it I noticed the serial interface for the drivers. That really simplifies the board. This will fit perfectly in my build.

I've done the test fit for the amp section as well. Here's a better approximation of what it will look like. From underneath (Excuse the mess of wires. I'll fix those up once I'm happy with the fit)... Here's a shot from the top of the amp... I've just been listening for the past hour. Sounds great EDIT: PS. Happy New Year!

Thanks - and yes it does sound great. Kevin - Are you thinking of doing two columns and continuing to use both sides? Could be interesting. It would be nice if it could be soldered by hand too. Maybe trim down the control area a bit too.

I finally got the HV caps and the PS up and running. The voltages look good including bias and pre-reg voltages. I mounted the transformer and board to a temporary wood cutout that I milled. Fit looks good. The wiring is nice and neat... Here you can see the transformer in the steel case mounted to top plate (wood for now)... So far so good

The nice thing with the maxim driver is that I can set all of the pins low/high with one set instruction. It is programmable via a 3 bit address. I'm using an expander to control the address and set/reset. I've designed it so I can control two drivers with one expander, so two expanders and 4 drivers per channel. I've been setting one relay at a time, which is the same as I was doing with the original boards. I think I can get each channel to about 4" x 1.5". I'd like to see them mount one to the other. If we offset the relays this should work fine. Total dimension for balanced would be about 4" x 1.5" x 1".

I used two pins per coil. Here's the tech note I followed: http://www.maximintegrated.com/en/app-notes/index.mvp/id/3288 That's a lot of T2's in the wild