Building a Pearl 2

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Thanks codyt.
I'm totally new to vinyl, and don't really have a cart in mind beside the newer AT-VM95 MM which are also 3.5-4mV MM, in which case I may reduce the gain as you mention.

For supporting gain for both MM and MC with the Pearl, I can think of 2 approaches:
1) Add a switch for R14 toggling between 2 resistors for 40db and 65db gain.
2) R14 fixed gain at 40db, with dual RCA inputs, adding a 1:10 SUT between the MC sockets and the boards. (a ~12.7K resistor would also be switched into R20, so that 100R is projected to the cart)

Has anyone tried this? Is a SUT "in-line" with the design philosophy of the Pearl even?
 
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I bet you’ll find that the Pearl will have enough gain for most MC, and is probably fine as-is for many MM carts too. Your first option would be perfectly fine IMO. In fact, all I’ve done is solder pin sockets in the R14 positions, so it’s just a matter of manually swapping resistors. That said, a switch like you described would be more elegant solution.

As 6L6 often mentions, you can probably get by without that 100pf loading cap too, since your cabling will have a fair amount. Or you could treat it the same way you do the gain selector.
 
I have an EPC205 with Jico SAS/B and it's good but the 881 with OEM stylus is better. I was able to do a back to back with both mounted on removable headshells in my EPA100. What is immediately noticeable is the separation of the 881 imaging and sound stage fills the room more, the only place the 205/SAS beats the 881 is surface noise is lower.

There is a guy on eBay goes by the handle cartridge_retipping-5, I have one of his D3000 retipped stylus and I can't pick the difference to my OEM D81. The D3000 is currently in use.

If you have the original stylus get it retipped. I haven't tried any of the aftermarket stylus for the Stanton so I can't comment first hand.


I nearly built the Pearl 2 until I found a guy in Germany selling Xono kits so I bought that instead. Pass Labs certainly know how to design great gear and kudos to NP for allowing the DIY community to build and enjoy these wonderful phono preamps...........


Was told ..best retipper for Stanton is expert stylus uk. . they are the the official one that is recommended by Stanton .might have a go at it

None of the replacement I bought sound right actually. As I have original to compare . It's really magical the old stuff
 
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Apologies if this was answered before but this and the other thread are quite long to follow.

The Audio-Technica MM carts spec asks for 100-220pF, although many state that FR is best in the 100pF region.

Given that tonearm wiring is about 25pF, and my interconnects (BJC LC-1) add another 25-36pF), would it be recommended to use something like 50pF, or none at all?

Thanks!
 
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Great, thanks for confirming.
So, omit C22 entirely?

I believe that would bring the total capacitance at less than 100pf, which is technically under the recommendation.. but based on this page, thats probably a good thing?
Hagerman Technology LLC: Cartridge Loading

My Grace F9 specs 220pf I think, but I’ve tried with and without and preferred nothing at C22. Add sockets if you want to try different values.
 
The Audio-Technica MM carts spec asks for 100-220pF, although many state that FR is best in the 100pF region...would it be recommended to use something like 50pF, or none at all?

I have an Audio Technica AT-150MLX MM cartridge with 5.0mV output. I rewired my tonearm with KAB SuperFlex Litz wire and replaced the original output cable with 1.0m of BlueJeans LC-1 cable. This resulted in total capacitance of of ~57pF for each channel. For me and my system, I felt this was a little bit too low, it sounded like it robbed treble. After listening for some time, I added 82pF in the Pearl 2 for a total of about 125pF per channel. This added the treble that I was looking for. I've had it this way for the past four years now and really enjoy it.

If you want more treble, add more capacitance. If you want less treble, add lesser amounts (or none) of capacitance in the Pearl 2. I really appreciate the ability to dial in the sound to my liking.
 
Great, thanks for confirming.
So, omit C22 entirely?

I believe that would bring the total capacitance at less than 100pf, which is technically under the recommendation.. but based on this page, thats probably a good thing?
Hagerman Technology LLC: Cartridge Loading

Some folks put Y-adapters on the turntable output cables. Then take RCA jacks and solder caps of various values across them. You can then add the desired jack to one end of the Y-cable to load the cartridge.
 
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I have been spending alot of time figuring out good layout.
I want to have short input wires, not too much of a rats nest and still allow for various input resistances for MM/MC (something like 100-470-47K), and allow for tweaking capacitance in case some cart needs more than minimal.

Attached is a sketch of how I would wire it, which addresses inputs, outputs, power and ground binding post.

I think I have an elegant solution for the capacitance loading by using pin headers and receptacles.
Connection between the header and the housing is very solid, much better than putting the thin capacitor leads directly in a socket.

For resistance loading to toggle between MM and MC, I am a considering a DPDT (on-off-on) next to each input, either above it or to the side. This will allow to toggle between 3 values (OFF = 47K).
 

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This has been on my mind too as I am gearing up to realize my Pearl (1) build. Here's my current thinking.

Unless one is intent on "playing" with cartridges and tonearms and 'tables a phono stage is more or less a set-and-forget in-line component. Vanity aside it can reside behind the deck and the preamp. So...

I'm planning to stack the boards on edge. Inputs on one end, outputs on the other and the power umbilical organized to feed the boards at or near the top of the case. The wiring would be short and well-separated.

One other wrinkle I'm considering was inspired by Tom Evans' Groove. The Groove has a reputation as a very quiet stage yet it is housed in an acrylic case. Evidently, the good performance is due in part to a (pseudo?) Faraday cage made out of copper-clad PCB material placed on either side of the signal board. I figured on stacking these with the Pearl boards and then finding a nice box to contain the assembly.

It's a plan. One plan.
 
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Attached is a sketch of how I would wire it, which addresses inputs, outputs, power and ground binding post.
.

I’m putting mine together (Doing the PSU now) and this is pretty much exactly how I’ve planned my wiring for the phono case. I was planning to take the output wires around the boards, but perhaps going underneath is a good idea!

I’m putting in a 2U Galaxy 330x280 chassis, yours looks to be a similar width.
 
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I'm planning to stack the boards on edge. Inputs on one end, outputs on the other and the power umbilical organized to feed the boards at or near the top of the case. The wiring would be short and well-separated.

I had considered this too. I like the the symmetrical wiring aspect and short power feed.

I ultimately decided not to do it because I prefer low profile.
Even with 25mm 10KuF caps and heatsinks, you can't use a 2" case.
I was also slightly concerned about heat from the regulators, not sure if thats an issue. Lastly, if I do plan to tweak the capacitance loading the way I mentioned, that would limit access to the lower board.

I agree that with your current cart its "set and forget", but I know that down the line I may want to play with other carts, MC, or whatever.. and I dont want to whip out my soldering iron and take the Pearl apart for that.
 
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I’m putting mine together (Doing the PSU now) and this is pretty much exactly how I’ve planned my wiring for the phono case. I was planning to take the output wires around the boards, but perhaps going underneath is a good idea!
I’m putting in a 2U Galaxy 330x280 chassis, yours looks to be a similar width.

Yes, pretty close. I'll be using a 12"x8" case.
One alternative wiring which is slightly cleaner is attached.

Is it OK to take the signal ground from the output instead of from the middle of the board?
 

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Those on-board capacitors do make things hard to finish up with a svelte unit!

The regulator heatsinks will be at the upper corner of the box and any generated heat can readily waft out the box leaving the rest relatively cool.

Are you including switches to adjust loading? Others have done this too.