The "normal" pF-area will have no impact on freq.response on a low impedance MC.
You´ll need a kapacitive load in the nanoFarads to get a hearable difference 😉
You do have to order the fuse drawer separately, but the cable gland should have it, mine did.
The beauty of DIY is you can put whatever resistors or capacitors you like in the DIP array.
Make the phono YOU want!!
😎
For the PS enclosure I had to be creative as it was impossible to find at toroidal at 26.3mm height. So with the shortest possible board stand offs and adding washers below the top lid, just to bring it aligned with the front plate, I managed to fit a 37.5mm one.
No challenges, no fun. 😉
Thanks..... Then I´m not worrying over my 36,5mm, I picked for the PSU.
That would be "plenty" of space according to you 😀
@Boydk Take 5mm stand-offs, trim them for 1 mm, then use 2-3mm washers or one hex nut between side panel and lid, and you will have the "enormous" amount of 1mm clearance between transformer and lid.
It just came to mind 🤣 🤣
I´m not using the "Group by" PSU. So the transformer will be mounted directly in the enclosure.
I took another approach. 2 x 18 volt torodial into @sachu888 PSU boards (had a couple on the shelf).
Adjust these to +- 19 volt DC out, and then into the Pearl-3. Gives the 7815/7915 4 volts above the regulated output,
which should be plenty. My guess would be even lower noise floor. We´ll see, how this pans out😉
@Boydk: Let me know how the 19 vdc works in the noise arena. The flexreg transformers from Randy can be adjusted from 14 to 22 vdc and if there is an advantage to 19 over 18 (or even higher) it is easy to accomodate.
Tried to go with a 1U enclosure on my first build but gave it up because of the Amphenol circ connector; it is a monster. But it allows for six 14 awg, finely stranded wires that will pass anything from 120vac to 20+vdc. Building these umbilicals is a pain but you do end up with 4 feet lines that will last forever.
The first P3 build I used two of the umbilical positions to pass the on/off switch from the PSU to the circuit board, thinking that the switch would be more convenient there and allow for the psu to be placed 4 feet away in the back. Does work and doesn't seem to add much noise (if any). For the dual psu build needed all 6 of the Amphenol positions for the two 18 vdc +/- lines and it has been, overall, better.
Tried to go with a 1U enclosure on my first build but gave it up because of the Amphenol circ connector; it is a monster. But it allows for six 14 awg, finely stranded wires that will pass anything from 120vac to 20+vdc. Building these umbilicals is a pain but you do end up with 4 feet lines that will last forever.
The first P3 build I used two of the umbilical positions to pass the on/off switch from the PSU to the circuit board, thinking that the switch would be more convenient there and allow for the psu to be placed 4 feet away in the back. Does work and doesn't seem to add much noise (if any). For the dual psu build needed all 6 of the Amphenol positions for the two 18 vdc +/- lines and it has been, overall, better.
Dual PSU will be the thing to do with my next Pearl-3 build. Seems one of my friends i grabbing this one,
even before it´s finished 😊
I would reconsider that setup. If I understand you correctly, you are passing a direct connection to line voltage to another chassis. Unless you are exactly correct with your safety grounding there are many situation where that could be lethal without any warning. I also believe even posting about such a design is against the posting guidelines. At minimum you would need an isolation transformer at the AC input to the PSU and still hope you have it wired correctly with all panels connected properly. Use this instead https://www.diyaudio.com/community/...ains-relay-includes-soft-start-h9kpxg.354971/
Need to order a PEM, Shurter has a couple of options for level of filtration. Is the DD12.8111.11 worth considering vs. DD12.9111.111?
Is the 1A (lowest filter range - 20db at 10khz) two stage filter DD14 (3-103-776) going to have any real benefit over the single stage DD12 (DD12.1121.111)?
There's no need for a 10A PEM right (DD12.9111.111)? I presume 1A is more than enough, but I'm often wrong.
There's no need for a 10A PEM right (DD12.9111.111)? I presume 1A is more than enough, but I'm often wrong.
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Generally the filtering is better if the rated load of the PEM is close to the actual load…
…but any filtered inlet is significantly better than an unfiltered.
…but any filtered inlet is significantly better than an unfiltered.
Except when you are dealing with SMPS converters which have "negative dynamic input impedance"!
https://www.omicron-lab.com/applica...dance-and-filter-stability-of-dcdc-converters
I am pretty sure there must be a way of using the hollow legs of an OPA socket that are then soldered on the board in place of the load resistor legs, and to use them so you can insert whatever load resistor you fancy into them.
You could either leave things like that with your favourite load resistor(s)... or for purist seeking for the best possible contact once the prefered load resistor is chosen, taking the socket legs out and solder the said fav resistor definitely in place...
Having said that it isn't that usual to change the load for MM, but then if you really want it that could be a way of doing it while having it reversible...
Just thinking out loud
Claude
You could either leave things like that with your favourite load resistor(s)... or for purist seeking for the best possible contact once the prefered load resistor is chosen, taking the socket legs out and solder the said fav resistor definitely in place...
Having said that it isn't that usual to change the load for MM, but then if you really want it that could be a way of doing it while having it reversible...
Just thinking out loud
Claude