Building a Pearl 2

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FormosaWest

Member
Joined 2013
AVWERK said:
Formosa
The Fidelity Research cart you are using is a very low .14 output and very old school. I have one of these also and temporarily used it to set my gain at first. You will get better sound out almost anything with slightly more output and certainly less hiss overall than this one.

Regards
David
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It sure needs a lot of gain doesn't it! Much more than a koetsu for example... Which id love one day, or maybe something else a little more in my price range. I hear the denon 103R is quite capble. i wonder how it would compare to the FR. Honestly though i really love the sound of the FR, old school as it is.
Im a young chap, and it was a present from my uncle who runs a koetsu black on his cotter b1 sp10 which i would say is better than the fr, but in many ways comparable. The higher gain of another cart would certainly give better signal to noise.

Cheers!

Andrew Formosa
 
W

Wellerman

Member
Joined 2011
FormosaWest said:
Im leaning toward this very same conclusion! Thanks for the advise on the gain influence. I think you may be right there. If the gain was lower im sure it would attenuate the hiss even more... If i move on to a higher output cart in the future i might up the resistance to 600 or 1000k. ... Once my make-before-break switch arrives ill be able to hot swap them, so im looking forward to experimenting with that and some other higher output carts to achieve even better signal to noise.

Does your pearl sound as great as mine is starting to? If not before im definitely convinced of the "burn-in" concept.
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I don't know about this burning in. I have not noticed sudden changes in sound signature and things like noise/hiss have been constant. I liked it when I first started it up, and still like it. Perceived changes could just as well be coming from getting accustomed to the sound of the Pearl.

A cartridge like a Goldring Eroica LX will give you much higher output and therefore better s/n ratio. You could then use 680 or 820 Ohm gain resistors. If the switch is not influencing the sound, it is a plus (I have to solder in a new resistor each time). Gain switchable 55/57.5/60/62.5 or something like that.
 
M

McQuaide

Member
Joined 2011
I'm late to this discussion, but my Pearl II has mild hiss with no record playing, and mild voltage fluctuation at times (~30mv either way). It's been running for over a year and sounds fantastic; it recently bested Heed Quasar and Phonomena stages in a H2H matchup.:D

So I too would advise buttoning it up and playing records:):)
 
F

FormosaWest

Member
Joined 2013
PKI said:
Any ideas what resistor I have to install to mach a Denon DL-301mkII (Denon DL-301 II cartridge,Denon DL 301 II cartridge,Denon DL301 II cartridge,Denon DL-301 II phono cartridge,Denon DL 301 II phono cartridge,Denon DL301 II phono cartridge,Denon DL-301 II MC cartridge,Denon DL 301 II MC cartridge,Denon DL301 II MC ca) load specs?
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Ive found the best performance from my Fidelity research cart has been when i give it 3 to 6x the specified load impedance. For weeks i couldn't understand why i liked loading R-user with a higher r value than what the FR cart specified in the data sheet.

I tried to like the specified 10 ohm, but found the bass too thin and overall it wasn't rich and full sounding as i thought it ought to be. This is a very high performance cart! Then i stumbled across a long and well written article about resistance loading mc cartridges. The author stated that loading the cart with a higher r value than specified wasn't just recommended, but required. The author stated that it was a common misconception that carts should be loaded with the value printed in the cart info sheets. He stipulated that this spec refers to output impedance of the cart, and not what the input impedance of the phono-stage ought to be. He argued that using the printed resistance value fails to load the coils correctly leading to thin bass and unbalanced frequency response. His recommendation was to give it 3 to 6 times the r value of what is printed in the sheet! I dont understand all of these things that well, but it offered an explanation to why i liked my cart better at 30 or 50ohms.

I thought, Eureka! And I realized i wasn't crazy - my ears where telling me it was right to use 30 or 50 ohms when my brain was trying to argue i use 10ohms.

My suggestion to you is to try 300 ohms. Your carts specifies minimum 100, so id give it 300 based on that guideline to use 3 to 6x.

I wish i could refer you to that article, but i cannot recall where i read it.
Solder in a 300ohm resistor in the r user slot and give it a listen. Id love to hear about it
 
F

FormosaWest

Member
Joined 2013
hifi-hospital said:
Hello FormosaWest,
How are you liking your Pearl? I'm still trying to get my boards clothed in a nice chassis. Your chassis is real nice looking. Where did you get it from? It looks expensive.:D

Thanks,
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Thanks!!
I absolutley LOVE the pearl 2. Im thrilled i managed to build onep and that it sounds so fantastic. Its only gotten better with time.
The cases are from HiFi2000.

Its an italian company. Their service is fantastic. They have several choices. The case is specifically called the "slimline" and it is the 2U height version. There is a 1u, 3u as well. The 2 unit one is the best heigh though. They have other cases as well. Different front panel choices are vaialable. I chose the 10mm front panel. I also got the interior base plate and the front fascade.
I used a regular bench top drill press, and regular quality titanium coated drill bits and bimetal hole saws to punch the holes. I used the slowest rpm setting on the drill press, and drilled patiently, clearing debris and lubing as needed to keep the bits sharp. I just used wd40 to wet/lube the drill bits. Square holes for the power input where drilled with a holes saw, and then filed square with a bastard file. I used a hand punch and hammer to start each drilling to prevent the bits from walking.

I used solid 24guage 99.999% silver for wiring, and stuffed it down teflon tubing. Woven Nylon expandable housing was used to protect the wiring and give it the pro look.

I highly recomend the hifi2000 cases. The company is fantastic, they have an english speaking representative, and delivery was actually fast.
 
H

hifi-hospital

Member
Joined 2004
Pearl Case

Thanks so much! The HiFi2000 cases are really nice looking! I'm anxious to listen to mine but have been too busy at my day job to get much done with the HiFi system. I'm still trying to work out how to incorporate two inputs since I have two tone arms on my turntable. I ordered some microvoltage latching relays. They are designed to handle very low voltage and current switching so they should add less distortion that a typical relay. I'm thinking latching relays also only have current in the coil when switching states. I've bread boarded a bistable multivibrator so that I could use one push button to switch between two inputs. I may just go with a momentary toggle switch to do the same thing.

Thanks again and Happy Listening!!
 
J

JOHNNYCR100

Member
Joined 2010

Hi 6l6, Hope you are well.

I have a capicator question:... on your build guide your layout follows the PCB stuffing guide nicely, however later on in the photos you appear to have a " extra-yellow ended capicator" which appears to be bypassing C13 (where C8 should be?)..i think?

Have you simpley bypassed C13 here- given its the last cap in the chain this may have an imporent influence on the sound?.. if so what value would that be?

I ask as i am about to order my components and would hate to miss anything here
http://i198.photobucket.com/albums/aa276/aeroplane_album/24vtest.jpg
Cheers
Johnny


http://i198.photobucket.com/albums/aa276/aeroplane_album/24vtest.jpghttp://i198.photobucket.com/albums/aa276/aeroplane_album/24vtest.jpg
 
6L6

6L6

Moderator
Joined 2010
Paid Member
Johnny,

The black and yellow cap you see is a 0.1uF film and foil that is mounted in the C8 position. This is a bypass to the main output coupling cap, C13, the 22uF Silmic.

The Silmic (C13) sets the tone, the film cap is optional, I used that specific one because I had it on hand.
 
R

Russellc

Member
Joined 2003
Paid Member
Tiny bit of progress on the easy part, the power supply. It is in its temporary home and generating proper voltages. Only need proper stand offs and some 4-40 screws and nuts to secure the other small barrier strip.
 

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Russellc

Member
Joined 2003
Paid Member
6L6 said:
Looking good!

The purple wire from the transformer is the shield. Attach it to the chassis.

What's the old chassis? It looks great!
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Its an old Dynaco Pat 5 case I bought from "Stereo Cost Cutters".....they bought all Dynacos parts, chassis, trnasformers etc when Dynaco folded back in the day. Had this thing for a long time! The faceplate is just a blank piece of brushed aluminum that came from the same place. I want to eventually put this power supply in one of the smaller store boxes, so it will match the store box I have for the Pearl 2 itself.

Russellc
 

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Russellc

Member
Joined 2003
Paid Member
6L6 said:
The rack handles look like 'industrial overkill' on the small chassis. I like it.

Keep the PSU in the PAT chassis, it looks fabulous, and anyway I'm going to have another project for you, so save the matching store chassis...

:) :) :)
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I got the rack handle for the Deluxe 5U box for the Turbo F-5, this looked to plain, so I added the handles. A box just like this but a couple of inches taller would be perfect for my Pumpkin Kit and boards, which are going to finally see a soldering gun, but not until Pearl2 and Turbo F-5 are done!

Russellc
 
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