Originally Posted by kevin gilmore
It sounds absolutely wonderful. Dead quiet too. I'm going to have to build
at least one more.
I certainly know how to do a DHT based electrostatic amp. I even know
how to do a grounded grid version. The amount of additional iron necessary
to pull that off however requires a power supply that would be absolutely
gigantic. Or high frequency switchers for the fully isolated filament voltages
which i really don't want to do. Or car batteries, which i also don't want
You can always use another Blue Hawaii
I find that the SR-007 needs an even more powerful amp then the BH so DHT's are the best way forward. Massive Japanese iron for the PSU is a necessity and massive film caps to compliment them. I'm going to throw something together to see if this is indeed the way to go. I've pretty much decided to use 845's for output duty as they are cheap and sound great. Everything else is hard as the drivers need to be massive so something like a SV572 would do the job but they are out of production and the prices are climbing. Still much cheaper then a 300b. I will probably have a single ended input stage with a transformer doing the phase splitting for the push pull output stage. I really want to try a transformer coupled amp for some insane reason.
Originally Posted by justin w.
The amp uses the same amount of power but the larger heatsinks outside of the chassis will do a much better job keeping the amp cool. The tubes' current sources are also new as you noticed.
The power supply is greatly improved, the tubes get 2 minutes to warm up and then the high voltage slowly comes on. This will be much easier on the amp and the power supply components
I built around 12 of the original Blue Hawaii and will be building 10 of the new KGBH SE (about half are reserved at the moment). I don't know how many are in the world, but I would guess it's around 25-30
The old version gets pretty warm but that's a good thing up here in the frozen north.
The delay on the HV line is a good move as the Chinese tubes don't last long in the old version. The Valve Arts you shipped with my amp were starting to show signs of wear after about a month but the Mullard XF2's are still perfect after 3 years.
There are no plans for a tube rectified PSU for the Blue Hawaii? That is pretty high on my to-do list after building a 845 based amp. It would definitely add a
different tone to the sound and the small caps make it even faster.
Btw. It's pretty cool that my amp is one of 12 made. How many were silver?
Originally Posted by Mindless
That's not too bad. I would expect it to be significantly more expensive. Guess that's excluding tubes? Getting a two pairs of matched EL34s might be kinda expensive...
EL34's can still be found dirt cheap, I've bought quite a few quads of Mullard XF2's for under 200$ each and you can't do much better. The new stuff is much cheaper. The difference in tubes is huge
and it's hard to stop using the Mullards after you've heard what they do.