My first ever experience with a blown cap - I’m going to consider it a badge of honor. I was in the other room for the first boom, and right over top of the amp for the second. Luckily I had the lid on. Just loud pops is all. That stuff is nasty and gets everywhere, but it at least wipes up somewhat easily. It also eats through inks... 
Attachments
If another batch of PCB's have wrong silkscreen then better Diyers check all polarisations
with the original article pictures https://www.firstwatt.com/pdf/art_diy_sony_vfet_pt1.pdf
with the original article pictures https://www.firstwatt.com/pdf/art_diy_sony_vfet_pt1.pdf
It also eats through inks...
Oh no... the ID of the Vfet is gone!!!! + handwriting of Nelson from the measurements!! Even worse!!!
At least, the Vfet should still have its soul & smoke inside..
Sorry about this.
It is obvious that as many as 8 boards from a prototype batch went out the door
with the rest. There is one difference - the polarity on the board of C1 is reversed.
If you have the C1+ mark on the edge of the board, then it is wrong. If the C1+
mark is on the bracket side, it is right.
The boards are otherwise OK, so you may need to rotate C1 when installing, or
pull it out and reverse it if you haven't already fired up the board.
If you have already put power to the board with a load, then you need a new
cap, and we will send them right out.
It is obvious that as many as 8 boards from a prototype batch went out the door
with the rest. There is one difference - the polarity on the board of C1 is reversed.
If you have the C1+ mark on the edge of the board, then it is wrong. If the C1+
mark is on the bracket side, it is right.
The boards are otherwise OK, so you may need to rotate C1 when installing, or
pull it out and reverse it if you haven't already fired up the board.
If you have already put power to the board with a load, then you need a new
cap, and we will send them right out.
You clearly see the trace on the PCB going to -O => negative pole of the cap should be connected here.
I think everybody is missing the silver lining - I have the coveted, ultra-rare prototype boards
In all seriousness though, I’m glad that we got this figured out early. After some consultation with Jim (and Nelson, indirectly) I got my backup pair of Rubycon in place and the amp is now making music! One thing I need to keep an eye on is the 20v measurement. The left channel fired right up where I left off, but I needed all of the pot on the right channel to get to 19.5v. I’m going to measure distortion, etc later and will report back.
In all seriousness though, I’m glad that we got this figured out early. After some consultation with Jim (and Nelson, indirectly) I got my backup pair of Rubycon
in place and the amp is now making music! One thing I need to keep an eye on is the 20v measurement. The left channel fired right up where I left off, but I needed all of the pot on the right channel to get to 19.5v. I’m going to measure distortion, etc later and will report back.Attachments
My first ever experience with a blown cap - I’m going to consider it a badge of honor. I was in the other room for the first boom, and right over top of the amp for the second. Luckily I had the lid on. Just loud pops is all. That stuff is nasty and gets everywhere, but it at least wipes up somewhat easily. It also eats through inks...
sorry to hear that, but imagine how many other builders you saved from the same trouble
I think everybody is missing the silver lining - I have the coveted, ultra-rare prototype boards
In all seriousness though, I’m glad that we got this figured out early. After some consultation with Jim (and Nelson, indirectly) I got my backup pair of Rubycon
Totally tangental, but what are the bookshelf speakers in your pic?