No. I made four traces cuts on the back of the board, all close to the regulator pins, and then jumpered the correct connections using solid tinned copper wire and teflon sleeving.
All three pins change so crossing the legs becomes unworkable.
I can post a photo if you like. I will try not to be self conscious about the workmanship.
So Jim, how did you work the connector and frame grounding wrt the signal grounding. There is only one lonely small ground connection on the board and I saw in one of your early photos that you had a bit of rats nest of connections to that point. How did you eventually resolve that?
Graeme
All three pins change so crossing the legs becomes unworkable.
I can post a photo if you like. I will try not to be self conscious about the workmanship.
So Jim, how did you work the connector and frame grounding wrt the signal grounding. There is only one lonely small ground connection on the board and I saw in one of your early photos that you had a bit of rats nest of connections to that point. How did you eventually resolve that?
Graeme
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I didn't.
The 1st version of the PCB had ground hum issues, the 2nd I could never get to stop oscillating. The 3rd version has addressed both those concerns, but I haven't bought a set of them yet.
The central point was rat's-nesty because I had a few things there for testing and clipping into, etc...
Here is my BOM if anyone is interested ...
As far as grounding, the build is on a single PCB, so there is no need for a separate ground since there are essentially no loops. I have no audible noise until about 1/2 volume but I only listen at about 1/3 volume. I do get hum when I touch the metal pot knob to adjust volume but that is it. I may change to a plastic knob to see if that addresses the issue.
As far as grounding, the build is on a single PCB, so there is no need for a separate ground since there are essentially no loops. I have no audible noise until about 1/2 volume but I only listen at about 1/3 volume. I do get hum when I touch the metal pot knob to adjust volume but that is it. I may change to a plastic knob to see if that addresses the issue.
I didn't.
The 1st version of the PCB had ground hum issues, the 2nd I could never get to stop oscillating. The 3rd version has addressed both those concerns, but I haven't bought a set of them yet.
The central point was rat's-nesty because I had a few things there for testing and clipping into, etc...
Thank you Jim.
I am going to get the board into the 1455 box first thing, then start working the connection issues. It's a bit of tight fit. The IEC connector on one end and the output connector on the other both have to be sort of centered in order to avoid physical interference problems. This is not where I'd prefer to put them for reasons of both appearance and hum pickup from the transformer and AC wiring. But we shall see.
I will start by connecting the earth ground to the chassis and the signal ground to that same point through back to back diodes or a low value resistor (or a cl60). I'm also going to isolate the input connectors and use ground isolation resistors there too. Maybe start with 10 ohms. I will report back. Suggestions are welcome.
Graeme
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Hello Wayne,
I assume I'm already very, very late but I am also interested in one PCB for this very pretending headphone amp. I appreaciate what you do for us here and it would be very pleasing if there are still some PCBs left, or if there is a second run for them.
Just wanted to let you know, that I've also sent a PM, but I'm just not sure which channel you prefer. Must be hard to track this amount of requests.
Have a great weekend.
Best, tom
I assume I'm already very, very late but I am also interested in one PCB for this very pretending headphone amp. I appreaciate what you do for us here and it would be very pleasing if there are still some PCBs left, or if there is a second run for them.
Just wanted to let you know, that I've also sent a PM, but I'm just not sure which channel you prefer. Must be hard to track this amount of requests.
Have a great weekend.
Best, tom