spritzer

I would install nylon washers on those screws as that is just an accident waiting to happen. The 1N4757 could be the culprit as the uneven PSU voltages could be causing your problems. The caps might also be damaged from the time it all went arcy sparky...

The voltages being off isn't a good sign. AC in is a bit high but that will only cause a bit more heat so nothing to worry about. What I'd check are the zener strings and measure each step against ground. Personally I'd just replace them to eliminate a possible cause for the voltage difference.

Not supposed to happen. What are the psu voltage readings?

Balanced is most definitely overrated in the general sense but I still fail to see why the bloody amp wasn't just made balanced through out. Team overkill would never have done something like this... The output impedance will be a factor in terms of SPL but only a bit. Easiest would be to just measure the output but it's a bit of a pain. The GS-X is a hell of an amp but it was just the only fully DC coupled discrete amp I could think of. The Luxman amps appear to have AC coupled outputs as there are some suspicious looking caps near the output.

Two gang volume control means it's only stereo. Why they took what is essentially a balanced input stage and then fed it through a stereo volume control and then onto a quad output stage is just odd. Why not go all the way and go balanced through out? As for the capacitor output, this is used to block the natural DC offset of the output stage. This is a common feature in Bryston designs so I'm not surprised but it only takes a few parts to make a servo which is completely transparent (certainly more so than a PSU capacitor) and means the output can be DC coupled. Amps like the GS-X do it like this so more transparent. I do agree with Ari that RCA inputs are often badly catered for but I've all but given up on them anyway. Why bother with them when one can go fully balanced...

There is special stage to do inverting after the volume control. My gripe is that they could just have married a balanced input buffer with a quad pot and had a fully balanced amp.

Is it just me or what's the point of this amp? Why on earth would anybody build something like this? So a fully balanced amp except it isn't since the input section is single ended and with only a two gang volume control which then feeds to two amp sections per channel. It's get better though as they capacitor couple the output so one gets to enjoy the sound of a quad of 4700uf/35V electrolytic caps. I truly don't understand this amp or the logic behind it.

That has to be the most powerful 30W amp in the world so I think he'll be just fine.

Sure, why not. Interesting to see if they claim the amp is truly balanced.

It does flow both ways and the shield is connected to ground on one end so it's really connected on both ends minus the miniscule resistance in the wire. I do file this tweak under the "won't hurt" category but feel free to use directional cables any way you want.

Not sure if you need to jailbrake first but I used to do this all the time on my 3GS. First you need tiny umbrella to act as a firewall by copying the tags from your ipad and thus allow you to install old revisions. It's pretty easy if you do it before the update.

594-VR37000004704JR5 is a good one and what I use. Tolerance doesn't matter with this stuff.

It's me who's holding up the Megatron as I'm waiting on more PCB designs before making a bulk order. Lack of time to make those but I'm getting close.

4M7 or 5M, it doesn't matter but do use one which is rated for 600V.

Happy belated!!!

I'm too tired to make any sense now but I believe the stock configuration runs at 6mA so it's a significant jump in current draw. There isn't another board run planned but the Gerber files have been posted in the thread and it's easy to just drop any fabhouse and email for a quote. Just ask how much a pair of amp boards and a PSU board would run you. Larger yields are cheaper though.

One has to remember that PCB's are nothing more than painted slabs of copper on a FR4 substrate. To rely on that paint for insulation wouldn't be the greatest idea.

It's not likely that the PCB is at fault but ever relying on the slikscreen for insulation is a bad call IMO. I always raise those caps just 1mm to make sure they can never short. Same goes for any and all top mounted traces and parts that pass over them. This is why we go to such great lengths of tracing everything at the bottom of the board.

Ain't that the truth. We rush from project to project as we keep coming up with something we like. We often loose track which is why we draw up PCB's now as we go along.

Separating the ground makes no sense to me and will likely only cause issues. Having a ground loop breaker on the earth makes sense for a commercial product but there are no problems here with it all star wired together.

400VA is indeed utter overkill and could cause issues with the unregulated voltage and thus causing the PSU to overheat. 200VA is plenty big. That should work just fine.

Try 5 minutes max....

Looks like I'll have to design a PCB this weekend. Ohh well...

Plenty of pots to go around so feel free to drop me a line. I plan to make my own PCB for them soon given how much I like my socket PCB but who knows when I'll get to it.

Looks awesome and the little Alpha pot is slowly but surely conquering the world!!! I just got another 100 so more for everybody.