Bonsai (Andrew Russel) has a very good article on his website re. grounding:
For the Ground Loops presentation and the rest of the Hifisonix projects, visit https://hifisonix.com/
For the Ground Loops presentation and the rest of the Hifisonix projects, visit https://hifisonix.com/
Just a quick follow up to those building a Pearl 3.
This phono stage will most likely tell you new things about your favorite records. Some may fall out of favor as a consequence, others may rise in your esteem. It can be a bit shocking tbh, at least I've felt that way. There are a few platters I have been afraid to play.
This phono stage will most likely tell you new things about your favorite records. Some may fall out of favor as a consequence, others may rise in your esteem. It can be a bit shocking tbh, at least I've felt that way. There are a few platters I have been afraid to play.
I am no longer getting notified of new posts for this thread for some unknown reason, so late answering this.
My PS board is grounded with a wire to the chassis. Unlike when I make audio signal cables, I didn't tie the shield and ground together at the supply end - the shield is floating at both ends. From there, it's just the three power supply cables going to the RIAA board in it's own box. It is extremely quiet.
<https://www.hypex.nl/media/fa/d8/a3/1682342122/The G word.pdf> really gets into G theory in a practical paper..
@brianco
Looking at Figure 21, that's what I've been considering as the ideal.
So, if the ground post in the signal box is a "shield" connection -- mixed as it might be at the cartridge end -- and considering that we have a bridge in the PSU that "breaks" signal and safety/shield grounds...
Shouldn't the PCB grounds not be attached to the ground post but instead run back through the umbilical to the bridge (or rely on the PSU grounds?)
And if it is not reasonable to rely on the umbilical shield (maybe because there isn't one) then there should be a dedicated shield conductor to connect the signal chassis to the PSU chassis at the earth side of the bridge.
The Morrison drawing is nice but where's the bridge? And the separate PSU chassis?
And a lot depends on how the traces run on the circuit boards, I guess. The schematic didn't distinguish signal and power grounds.
Back in the day I grounded my Leach preamp (similar configuration) using a belts and suspenders approach. The circuit boards were grounded via the standoffs and wires back through the umbilical to the PSU board, also grounded to the chassis. It seemed to work.
But maybe it coulda worked better...
Looking at Figure 21, that's what I've been considering as the ideal.
So, if the ground post in the signal box is a "shield" connection -- mixed as it might be at the cartridge end -- and considering that we have a bridge in the PSU that "breaks" signal and safety/shield grounds...
Shouldn't the PCB grounds not be attached to the ground post but instead run back through the umbilical to the bridge (or rely on the PSU grounds?)
And if it is not reasonable to rely on the umbilical shield (maybe because there isn't one) then there should be a dedicated shield conductor to connect the signal chassis to the PSU chassis at the earth side of the bridge.
The Morrison drawing is nice but where's the bridge? And the separate PSU chassis?
And a lot depends on how the traces run on the circuit boards, I guess. The schematic didn't distinguish signal and power grounds.
Back in the day I grounded my Leach preamp (similar configuration) using a belts and suspenders approach. The circuit boards were grounded via the standoffs and wires back through the umbilical to the PSU board, also grounded to the chassis. It seemed to work.
But maybe it coulda worked better...
Pearl 3 pioneer kits are now available for purchase:
https://diyaudiostore.com/collectio...front-end/products/pearl-3-phono-preamplifier
https://diyaudiostore.com/collectio...front-end/products/pearl-3-phono-preamplifier