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Hello Karen,
I have finally finished my pearl phono stage. Before building
the pearl I owned a couple of smaller MC-stages based on operational amplifiers. In comparison to
those the sound of the pearl phono is an enormous improvement and in my current system it just sounds
great. It costs only a little more than my former phone stages and in addition was fun building it.
I started listening with my Ortofon MC 25 FL cartridge. The
output voltage of the MC 25 is specified with 500 µV. For some more quiet records I had to turn up
the volume control of my Brinkmann Vollverstaerker almost up to full. Still the sound was great with
the MC 25, being airy with a wide and deep stereo image, but sometimes I got the feeling that there
was a slight lack of dynamics. Recently I purchased a Benz Ace M with an output voltage of 800 µV.
This cartridge in combination with the Pearl Phono is a dream. I am fully satisfied with the sound. It
is natural, warm and dynamic with a deep controlled bass. As mentioned before the sound stage is wide
and deep. Listening to records like Norah Jones „Come away with me" gives you the feeling, that
Norah is sitting in your living room.
To the build-up. I used two separate housings for the power
supply and amplifier boards. The power supply PCB was manufactured using a milling machine from LPKF
Laser & Electronics AG (Germany). The power supply is unregulated and has two 10000 µF
electrolytic caps per channel (Panasonic) and an additional 3,3 µF polypropylene cap per channel (Solen).
I used ultra fast diodes (BYV 28/200) in the rectifier which do not produce any spikes. Thus bridging
caps are not necessary. In my first set-up I used only one electrolytic without a PP-cap. In
comparison to this older power supply version the sound seems to have improved. But this is a very
subjective judgement since I was not able to directly compare the two versions. I could not find any
supplier in Germany for the Aeon 10 µF coupling capacitor in the second gain stage of the Pearl, so I
used Solens. The phono stage is very quiet.
Many thanks to your team, especially to Wayne Colburn for
sharing his ideas and to you, Karen for your support. After all getting all the parts to Germany was
not so easy. I have attached some pictures of my Pearl Phono.
Best regards and a Happy New Year
Marc <mailto:mh.hueske@web.de
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