MC Stage for Pearl Phono - diyAudio
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Old 26th December 2003, 05:51 PM   #1
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Default MC Stage for Pearl Phono

Finished the cascode version. It seems quieter than the cap coupled 2SK170 circuit tried first.
Compared to my AN UK transformers the sound is cleaner and clearer. The bass is less, but much tighter. This may improve with more hours. The high end coupling caps used may take a 1000 hours of constant use to break in.

George
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Old 26th December 2003, 05:54 PM   #2
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Used a LC filter off Q3 to feed it with a real clean DC. The chokes are mounted close to the output stage.
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Old 26th December 2003, 05:57 PM   #3
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Default Pearl without MC

The chassis is mu-metal lined wood. The unit is very fine sounding. Thanks to Wayne and Nelson for sharing this with the masses.

George
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Old 5th November 2005, 09:05 PM   #4
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Default MC Stage for Pearl Phono

I'm about to build the Pearl and would like it to be able to run with lo output MC's as well.
Anybody got a superb solution ?
Perhaps The MASTER would throw us some crums ?

I run my current system with an MC with high output, but have a Van den hul (lo out) in my goodie box.
Would like to use it with the Pearl.

analogair
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Old 5th November 2005, 09:24 PM   #5
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Build the mc-stage of ONO.

Nick
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Old 5th November 2005, 09:47 PM   #6
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Default MC Stage for Pearl Phono

George,

Very nice work. Are you using Black Gates for coupling caps?
May I ask who makes the red & blue translucent flat wire?
Interesting that you are using mu-metal for shielding.

Jeff
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Old 5th November 2005, 10:06 PM   #7
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Default Re: MC Stage for Pearl Phono

Quote:
Originally posted by vinylkid58
George,

Very nice work. Are you using Black Gates for coupling caps?
May I ask who makes the red & blue translucent flat wire?
Interesting that you are using mu-metal for shielding.

Jeff

Those caps coupling the headamp to the Pearl are 25 cent Epcos/Seimens naked stacked films. 1 ufd 100v. Kidding about break in. The output caps on the Pearl are BG N series now.
That flat wire used to wire it up was DNM. It was given to me by a friend. Replaced it a couple months back with a three wire braid of 26.6 ga XLO. Much better. The DMN was worth what I paid for it.
If going with a headamp power it from C8 or R19. Used a 10 mH choke and a 1000 ufd cap to passive filter the headamp. It is dead silent.
For a circuit, use two 2SK170's, cascode with a ZTX450, stand the fet on 22 ohm resistors, and use the two 10K resistors on the cascode. It direct copy of the input stage used in the Pearl. Except it is two fets instead of four. Cap couple into the MM stage of the Pearl. Use whatever loading resistor works with your cartridge. I am using a 105 ohm measured value 1/4 watt AB carbon comp.
I have built a couple other phono's lately. Stock none are close to this Pearl. But the Pearl took months to get it sounding like it does now.

George
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Old 6th November 2005, 01:30 AM   #8
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Default MC Stage for Pearl Phono

George,

Thanks for the info. I was considering using the BG "N" type electrolytics instead of poly caps for coupling.
My Pearl is basically stock, as this is a learning experience for me (I don't have an electronics background). I really enjoy reading posts where someone has the ability to modify an existing design to suit their needs.
I don't require an extra gain stage at this point. My MC cart. has enough output as is.

Jeff
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