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Pearl phono PCBs Group Buy

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smario

smario

Member
Joined 2005
Re: OK

Alabama978 said:
I'll connect to the MM stage and try when I have it finished but have a few components to solder yet. I have not had too much time lately to work on it which makes me quite depressed as I would like to compare it to my existing Project Tube Box.

Best wishes for New Year:cheers:
Click to expand...

Just solder Rx (250 ohms up to 1K) and try. I think you will be satisfied. Your tube box will have a dificult time competing with pearl. In my case pearl won by miles over tube box, and in my friend case, Audio Research PH3 lost the battle with pearl.

Happy New Year
 
S

sts9fan

Member
Joined 2006
another grounding question

I am ready to start building my pearl/MC phono stage. I am still a bit confused on how to ground it.

Here is what I think I should do. Please correct me where I am wrong.

Connect all inputs and outputs to star ground. Can the ground lug be the star point? Then connect the boards to the star also. Which points from the Pearl and MC boards need to be connected to star?

Star is also connected to earth gnd through the umbilical? How do you ground the chassis of the amp stage? Do you run the grounds from the PS through the umbilical to the star and to chassis? So the gnd is connected to the PS chassis and the amp chassis?

I am confused.
Thanks for the help
Kris
 
Evaas

Evaas

Member
Joined 2001
Re: another grounding question

sts9fan said:
I am ready to start building my pearl/MC phono stage. I am still a bit confused on how to ground it.

Here is what I think I should do. Please correct me where I am wrong.

Connect all inputs and outputs to star ground. Can the ground lug be the star point? Then connect the boards to the star also. Which points from the Pearl and MC boards need to be connected to star?

Star is also connected to earth gnd through the umbilical? How do you ground the chassis of the amp stage? Do you run the grounds from the PS through the umbilical to the star and to chassis? So the gnd is connected to the PS chassis and the amp chassis?

I am confused.
Thanks for the help
Kris
Click to expand...

from the article on passdiy:
"The two isolated supplies will ultimately have their Grounds meet each
other, and the best place to accomplish this is at the output. If this
preamp is constructed with two channels in the chassis and an external
supply, then the grounds should meet at the output connectors. These
output connectors should be close together, and attach to chassis
ground at this point."
 
L

lordvader

Member
Joined 2002
That's my preamp in post #610 :)

And you're right, I did nothing special in regards to grounding. The PSU is dual mono, and at no point do the grounds come together, nor were there any star grounds.

My amps have star grounds though, so there is a point in the chain where the grounds come together (eg, my headphone amp has a star ground with all signal grounds going to that point, while my power amp has its 0V rails tied to safety earth via a thermistor).
 
S

sts9fan

Member
Joined 2006
ok then whats the deal with post #64 in this thread?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=78441&perpage=25&highlight=&pagenumber=3

where is the yellow wire connecting on the pcb? Why would he have two gnd lugs? This does not seem like the two channels ever meet. why?

I have a star gnd in my power amp and it is nice and quiet so maybe I do not need it here. It makes sence becuase they are all connected.
As for a gnd lug. IF I do not do full blown star gnd could I just connect the point where PS and signal meet on the pcb(C15?), the "star-star1" connection on the MC section and safety/chassis gnd to the lug?

Thanks for the help
Kris
 
A

Alabama978

Member
Joined 2008
Any more ideas on adjusting gain?

Further up this thread you will see my question regarding matching of my Benz Ace to the MC stage and Pearl board and my Amp. As Smario suggested I could add a resistor to the Pearl and dispense with the MC stage until I change my cart to a LO type in the future, then if necessary add the MC.

I am sure this will work OK but part of me thinks it would still be an advantage to use the MC stage now to allow fine tuning of the cartridge loading via the DIP switches.

Question is if I wish to do that what would I change to limit the gain to max of 66 dB because with the lowest setting on the MC stage jumpers I would have 60 + 14 = 74 dB way too much.

Any ideas?

I expect even if I use the easy method that Smario suggested then I'll add the MC stage now and disable it so that in the future there is no surgery required as I'll have forgotten about the technical detail by then :)
 
A

Alabama978

Member
Joined 2008
The two isolated supplies will ultimately have their Grounds meet each other, and the best place to accomplish this is at the output. If this preamp is constructed with two channels in the chassis and an external supply, then the grounds should meet at the output connectors. These output connectors should be close together, and attach to chassis ground at this point."
Click to expand...

Like STS9 I too found this confusing...

The two isolated supplies will ultimately have their Grounds meet each other, and the best place to accomplish this is at the output
Click to expand...

Output of what? The PSU?


If this preamp is constructed with two channels in the chassis and an external supply, then the grounds should meet at the output connectors. These output connectors should be close together, and attach to chassis ground at this point
Click to expand...

Are they talking about the phono stage grounds here? In my mind the above means that the boards are grounded at the output of the phono chassis and the PSU grounded where it leaves the case and the ground carries across via the umbilical power lead and meets the ground of the phono case?


Probably confused everyone now :)
 
R

royville

Member
Joined 2007
Hello Folks,

I have been interested in building the Pearl Phono for a while now. I contacted Passlabs but without much joy. I know I may be too late here, but I was wondering if any kits, or PCB's or any parts are still available any where?
I am in the UK so I could use some advise regarding cost (as well as shipping costs).
Regards
Roy.
 
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