johnwmclean

Sorenb, congrats on your progressing build. I appreciate your detailed follow up post above, that is really helpful!

I really like this

Amphenol military grade connectors.

http://turbulentlabs.com/contact/

$2.00 a pc from China. They look the real deal to me, at least very similar to the bdent parts. I anticipated obvious fakes... What do you think?

I think you have 2K installed at the moment? You probably need 1.5K. Here’s a solution, parallel a ~6K resistor with already installed 2K resistor i.e. 1.5 = 2 X 6 / (6+2). You won’t have to take the amp and heatsink assembly apart to do this. Just ensure your soldering is nice and clean.

Thanks for the tips guys, I had time today to work on these brackets. Punching and using a centre drill bit worked a treat, as well as leaving the jig floating on the drill press, this also saved a crap load set-up time between holes. They’re fairly accurate... I’ve accounted for some margin off movement with the panels CamExpert are fabbing, but I won’t know for sure until I do a final fit.

Just some centre drill bits and an automatic centre punch nothing too exciting, my drill press is a Ryobi from Bunnings as well and it sure is quirky...

I'm after some help with my latest chassis design. It's an off board KGSSHV, in which Camexpert will be fabing all the panels and drilling the heatsinks. Which leaves me to create all the brackets, I've bought 16mm equal angle x 3mm x 1 metre lengths. Cutting is a no brainier, I've bought a little metal mitre box for this. It's the accurately positioning of the drill holes is where I may struggle, with my limited knowledge and tools, this is my plan... I have 100% accurate paper print outs of the drawings, which I'll use spray adhesive to stick on the brackets, the quick test I did last week proved to be a good technique for accurate hole location. I plan use a Stanley knife to cut a cross for the centre of the holes in the aluminum. Then using a automatic centre punch as starting point in the middle of the cut cross, which I'm hoping to find the exact centre by feel. This is where I start to get nervous, I bought several #2 centre drill bits to make a pilot hole using a drill press. From what I've read and watched, it's best not to clamp down the aluminum, instead it's best to let it float on the drill press and let the centre drill bit grab the metal and find the punch hole. Bearing in mind the spinning bit would be very close to punch proximity to enable this, doing an alignment beforehand. Then finally a pass through with the final drill bit size, an M3 or M4, again with the piece of aluminum floating on the drill press. That's the plan, sorry it's so long winded, am I on the right path?

My latest KGSSHV off board, sans volume pot is a ways off. I've completed the chassis design and have fpe files ready to go. I'm using HeatsinkUSA's 10inch profiles, which I'll get CamExpert to drill along with the other panels. The brackets are all going to be made my me, lots of cutting drilling and tapping to be done. I've been catching up on drilling technique for accurately positioned holes... I hate drilling period, but I've invested in some nice tools, so hopefully fingers crossed I'll get good results.

Congrats Michael! ^ This

Indeed. A killer of an amp, and another good reason to test under load and fully drain the caps. Edit: If you want to test the psu under load you need two resistors over each output to ground. I've used 2 x 4K 50W bolted to a large chunk of al, leave it on for 4 hrs or longer, use a fan over the whole set-up to keep things cool, the idea is to push/stress the components to maximum operating limits to expose any potential weakness.

Pars the spec looks good but the new smaller boards require an insulated package. Michael take a look at the schematic, you need a 500mW in those positions, also the voltage with the Xicon 271s is only 250V.

The recommended part (STTH512FP) is rated 1200V, so you’re like, you know, halfway there... I’ve had no problems using ST Micro diodes, their regulators I wouldn’t know.

Sufjan Stevens - Carrie & Lowell

I received a bunch of UTSource 4686s which look visually identical to the dbent parts. I happy to see they test good as well!

A decent digital volume control should make an RK50 redundant.

I’m going to use Cam-Expert for the panels. CE offer 10mm but only as a raw finish, I used it on my latest kgsshv onboard, I can see imperfections but it doesn’t bother me greatly. You could buff the panel if so inclined...

Will do! So far my search tells me anything custom fab is going to be waaaay too pricey being a one off small run, I may have to buckle and cut and tap myself. And yeah Julian at Conrad is notoriously bad at responding, especially if custom work is involved. On the other hand HeatsinkUSA have a cut to size length and tapping service, there’s a nice 10" profile that would suit this amp nicely. http://www.heatsinkusa.com/10-000/

Managed to get some time on my layout... It will be sans volume pot, using Conrad heatsinks, overall dimensions are 337mmW x 260mmD X 151.5mm H. The transformer will sit under the psu, taking avantage of the 151.5mm height. I plain to get the brackets fabed somewhere, I’ve seen a few online shops, it should be fairly straightforward. If anyone knows a good place I’d love to know!

Michael, My boards arrived today safely. Well packed and they look fabulous. Many thanks, John

Like this...

Double Post....

That’s correct 2 x 24V diodes for each rail. I’ve built the previous version 1.0 of this board, as far as I can tell the only differences between versions 1.0 and 1.1 is silkscreen, and a 300K resistor trace has been moved around a 1mm. Flip the switch already!

As a rule of thumb, check the unpopulated boards for shorts with the schematic.