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Old 26th June 2003, 07:43 PM   #1
Boban is offline Boban  Canada
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Default Pearl - impression and question

Pearl - impressions and question

Hi,
I am living with the Pearl phono preamp for about 2 months now. It is a stock unit with some upgraded parts (output caps and input resistors are of better quality, I guess).
Separated power supply is connected to the preamp with the umbilical cable. Star gounding used to eliminate any noise.
For my low output cartridge I added Lundahl 9206 transformers. Silver wire is used as the internal wire.

I am not going to bother anyone with the construction details. It is a long process and it took me 2 months from start (ordering all parts) to finish. Sound is what matters, right?

First, there is no noise, and the unit is dead quiet. I have to turn up to 2-3 pm o'clock in order to hear some noise. Mind you that I never, ever, listened in that position, that would be too loud even for the neighbors. Sound is very detailed, and less grained than my previous preamp. Sound stage is very deep and wide. Acoustics music (guitars) is a pleasure to listen, vocals (female) sound like dream, sax sound like sax and organ like organ. The sound is very relaxed, warm and tube like.

Audio nirvana? No, not yet.

There is something what bothers me. I would like to have bit more punch, more dynamic sound as I have today. Right now I am sitting in a fifth or sixth row and I wanted to be in the first. Hope you understand what I trying to say. Sound is too polite and shy some time. I know that changing the resistor value (input) you can modify the dynamic of the sound, I did this part, can't go higher what I have, sibilance will jump right in.

What will happen with the sound if I use some other values for the output caps, other than suggested 10uF. Say 4.7uF or lower value.
Any other suggestions I can try to add more dynamic and punch to the sound? Anyone?
Or sell this one and build ONO?

Thanks
Boban

ps. my speaker cables (Cardas) are known to be on a warm side and speakers are lazy - 86dB. Is this a contributing factor as well?
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Old 27th June 2003, 09:01 PM   #2
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I would be willing to bet that the impression you are getting
is from an EQ curve losing a little more of the top end than
you like. I would consider adjusting it to lower the capacitance
or resistance of the topmost equalization pole, boosting the
highest frequencies a bit.

Of course its possible that the transformers are the reason
for this, and you might try the preamp without them. In any
case, you still can adjust the EQ curve to help make these
parts more complementary.
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Old 27th June 2003, 10:16 PM   #3
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Boban,

Wayne has a very neat modification which uses another set of JFets for a headamp in the Front which works very well, suggest you email him for the details, but not today.....he maybe having just a quiet ale here and there..

macka
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Old 29th June 2003, 01:13 AM   #4
Boban is offline Boban  Canada
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Nelson wrote:
>>
I would consider adjusting it to lower the capacitance
or resistance of the topmost equalization pole, boosting the
highest frequencies a bit.
Of course its possible that the transformers are the reason
for this, and you might try the preamp without them. In any
case, you still can adjust the EQ curve to help make these
parts more complementary.
<<

Nelson,
You are probably right with this. Is it possible to give me more information what to do as I don't know which parts are responsible for the topmost equalization pole?

And Macka wrote:
>>
Wayne has a very neat modification which uses another set of JFets for a headamp in the Front which works very well, suggest you email him for the details, but not today.....he maybe having just a quiet ale here and there..
<<

Macka,
Thanks for this tip, I will send Wayne an e-mail. I am always ready for any improvement I can do with this preamp. I am hardly wait to see what the sound is going to be later. Cigar is what I am after…..

Thanks
Boban
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Old 29th June 2003, 02:44 AM   #5
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Boban,

I have just done a quick search and pulled this post from a thread for you.

"On the subject of more gain for the Pearl Wayne (of Pass fame) has suggested to duplicate the 1st stage as a pre preamp and alter the gain."

"You could build the first gain stage of the pearl again for a pre preamp but use about 375 Ohms for a collector resistor instead of 1 K."

"This is what I propose to do, or alternatively you could make a BOSOZ stage following the Pearl for balanced output with additional gain."

Call or email Karen the DIY Diva for set of matched Jfets and your almost home.

The improvement over the Ortofon transformer I was using is quite noticable. With a good Mc cartridge you will then be extracting Hi end Nirvana for only a couple of hundred bucks.

I have searched and made oodles of riaa stages and pre preamps, this is certainly the best and is so simple and easy to make.

Wayne is very clever and has the knack of creating brilliance with simplicity. Know wonder Passlabs preamps have so many awards.

Enjoy

macka
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Old 30th June 2003, 07:31 PM   #6
Boban is offline Boban  Canada
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Macka,

Yes, I know about adding more gain to the first stage. I decided to go with Lundahl 9206 transformers as they were recommended in many places and there are some Pearl owners as well with this combination.
BTW, I listened some records yesterday (randomly picked, mostly pop and rock) and the sound is very much to my taste. There is that small thing I wanted to fix and that's it. From this prospective I can't justified (at least today) a big surgery, but rather small tweaking, something like Nelson suggested. Mind you, even if I don't do anything it is not end of the world. I am here for the music and to learn things or two and Pearl ig giving me 97% of what I want.

Boban
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