Pass Pearl PCBs and related parts

[swt61]

That worked Marc. It's dialed in now.

[luvdunhill]

enjoy!

[swt61]

Can't wait to really listen once I change the necessary resistors in the Pearl. The Consonance PM-3 should arrive tomorrow.

[DigiPete]

New home for my Pearl PCBs:

Parmetal series 20 enclosure, 12"x8"x3", 0.18" thick clear anodize aluminum faceplate, black painted body, countersunk screws all the way around

$75 including shipping, not too shabby.

[swt61]

That should work great, and look even better.

[DigiPete]

Now I need to get all the bits and pieces to finish the job

[swt61]

You won't be disappointed. This is a very nice phono stage!

[DigiPete]

You won't be disappointed. This is a very nice phono stage!

I agree, I'd love to hear Luvdunhill's comparison of the Pearl with his Xono.

I've been listening to it uncased, but now its time to get it over with and case it up!

[Pars]

That should look really nice Pete. Have fun with your aluminum

[DigiPete]

That should look really nice Pete. Have fun with your aluminum

I decided to gut a computer psu to use for the offboard Pearl PSU case

[DigiPete]

So, I need some advice about grounding.

Phono inputs L-, R-, Gnd -- do these all ground to the case, or isolate?

Phono outputs L-, R- -- do these ground to case, or isolate?

DC supply voltage - does the (L-, R-) go to case ground? Where do the two DC supply grounds meet?

Thanks,

Pete

[luvdunhill]

So, I need some advice about grounding.

Phono inputs L-, R-, Gnd -- do these all ground to the case, or isolate?

Phono outputs L-, R- -- do these ground to case, or isolate?

DC supply voltage - does the (L-, R-) go to case ground? Where do the two DC supply grounds meet?

Thanks,

Pete

so, I don't really have a good recommendation on this one. I also used shielded cables, which adds another level of complexity.

I think theoretically, a star ground at the outputs would be best, with the output terminals being close together and use a star washer to maintain good ground to the case (i.e. around the RCA jacks). I'd isolate all the input grounds and connect the earth to the output star ground. Don't worry about the DC supply ground, just attach it to the board and you'll be fine.

Are you using 2 cases?

[DigiPete]

Are you using 2 cases?

Yes

[luvdunhill]

Yes

reread the PDF documentation, I think towards the end there is a note about grounding with 2 cases.

[DigiPete]

Yup, it looks like the signal grounds must be isolated from the enclosure (which is at DC ground). When they weren't, I was getting 60hz hum.

Worked good once I isolated the signal jacks from the enclosure. I tied the psu grounds together at the psu case output (per the directions).

[DigiPete]

Here are a few shots of the Pearl PSU (poor man's enclosure)

and the Pearl Preamp enclosure, so far...

[n_maher]

The painted par chassis really are the way to go, their anodizing is just way to sketchy. Are you having the front panel machined? If no, it may be touch and go with panel mounted components depending on what you're planning to have mounted on it. .18" is pretty, and pretty thick.

[DigiPete]

I am only drilling the front panel with a couple of led holes.

I will probably put a custom vinyl sticker on the front saying 'Pass Pearl Phono' or something like that.

Any ideas for an easy connector for the DC coming into the chassis? (need three conductor)

[n_maher]

Any ideas for an easy connector for the DC coming into the chassis? (need three conductor)

Neutrik Speakon works well and is pretty cheap. I used them on my PPA for exactly that purpose.

[DigiPete]

Neutrik Speakon works well and is pretty cheap. I used them on my PPA for exactly that purpose.

Those look nice. Thanks for the tip!

[n_maher]

Black is Speakon, Blue is Powercon, both I think have the option for 4 conductors so either should work for you. And if you look hard enough you might be able to find the gold-plated speakon connectors that Mikhail uses on the singlepower amps.

[swt61]

So I'm assuming that the other end of the PowerCon cable is a standard US three prong wall plug?

[n_maher]

So I'm assuming that the other end of the PowerCon cable is a standard US three prong wall plug?

That's the way I built it, yes.

[swt61]

Sweet! That's much more desirable to an IEC plug IMO.

[n_maher]

Sweet! That's much more desirable to an IEC plug IMO.

It is, provided that a) you don't care about the electric blue (only option IIRC) connectors and don't mind making your own power cords.