Input buffer for LuDEF, SissySIT and similar amplifiers

I am putting the buffer together , however a bit confused about the orientation of c6 and c7.
The marking on the pcb does not seem to match with the orientation of those elco's on
the photo's on the first posts.
Or should I take break and come back when my brain is recharged...

thanks
Leo
 
I finished my first two and they seem to work ok and will be used in my audio shortly. Looking forward to that!
However, having ordered 10 boards I want to built more of them. But the OPA551F now seems to be out of stock everywhere and the sites tell that it could be a YEAR before new stock arrives. Any possibilities for an alternative for this part?
 
Unfortunately, no possible alternate parts. Only option would be to rework supply section. Just consider yourself lucky to get parts for one pair build.
It is not only OPA551FA missing. OPA828 joined the list and there were thousands available.

Never taught it would come to this: old exotic parts, almost unobtanium, are in better supply-demand position than common, mass produced parts. :rofl:
Whatever I design with available parts, days after publishing is a DOA project. 😡
 
no, i ordered the16 OPA551f from Win Source about a week ago and this morning got the message they were out of stock and they would refund me....
They had two SKU numbers. Maybe other SKU number is available.
Octopart search still lists 2 versions as being available 4 days ago.
Other option is that some big company pulled them all, hopefully Mouser or Digikey.
 
HI Everyone,

I don't know where OPA511 can be found, but Digikey is showing OPA828ID in stock:

https://www.digikey.com/en/products/detail/texas-instruments/OPA828ID/9858342

I just bought four, since there's a delay in my build, due to a REALLY stupid mistake... Having soldered the resistors, OPA551FA and LME, I got a third board from the ones I had done at JLCPCB, and carefully checked the orientation of the OPA828. This was much easier on an empty board, since the resistors were covering up the board markings on the stuffed boards. DMM at hand I checked, and double-checked, and then soldered the OPA828 to the wrong board... so I now have a stuffed board (except for caps), one that is pristine except for one (beautifully soldered!) OPA828, and one that is lacking an OPA828, since I only bought two... :headbash:

Still debating what to do. This was my first SMD soldering in a while, and I had some trouble with the first OPA511 with solder bridges across the leads, needing to be sucked/wicked off. Heating several times to get that done left me uncomfrotable; I hope it's OK. The others all went just fine, but I was planning on using solder paste and a hotplate next time. How easy would it be to get the OP828 off the otherwise empty board with a hotplate, I can resolder it where it belongs? If I leave it on there would I risk damaging it if I use a hotplate and solder paste to solder three OPA511 and LME onto the board? Thoughts?

Best

Nigel
 
Being an electronics tech where I work, if someone were to hand me this board and say "see if you can get this part off without damaging anything..." I would probably put this tip in my Pace soldering station, then apply liberal flux and some quick heating of all pins quickly at the same time and flick the part off. Clean up pins / pads then reinstall. Probably not on a Monday morning as Murphy is usually standing behind me with a sly grin....
 

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Being an electronics tech where I work, if someone were to hand me this board and say "see if you can get this part off without damaging anything..." I would probably put this tip in my Pace soldering station, then apply liberal flux and some quick heating of all pins quickly at the same time and flick the part off. Clean up pins / pads then reinstall. Probably not on a Monday morning as Murphy is usually standing behind me with a sly grin....
That's a pretty cool looking tip! Needless to say I don't have one, but maybe can borrow... hhmmm... Is the gap the right width for an SOIC opamp? Or do you have a set of these in various sizes?