Pass kit

[giuz0]

I'm tempted to do the PCB by my self, is the first time that I try to print a PCB, but I think I will be able to do it.

Anyway, is possible to use the pearl phono 1 with a normal MM cartridge without add the XONO PCB, for example, just updating some component to change the gain level?

[wayne]

I checked and we have plenty of Pearl Two boards in stock.
Just send Sherlyn an email to order.

[royville]

Hi guys, please forgive my intrusion, I'm looking for advice regarding the Pearl.

I built a Pearl 1 about 12 months back, but I haven't had much success with it. Initially, I had lots of buzzing caused by grounding and psu issues which I eventually sorted with the help of some kind folks on this forum. But Ive never properly sorted out an oscillation problem I have. I am using it with Dynavector 10x4 high output moving coil cartridge and the result is a weak, wishy-washy sound accompanied by a kind of hf whistling (rather like the old am radio stations sounded as they drifted in and out of tune).

I'd like to ask a couple of questions if I may.

Mr Colburn, I was wondering if you've come across this before?

I would be interested to know if any one else has experienced anything like this, and how they cured it.
Is anyone else usung a Dynavector 10x4 with a Pearl 1 successfully?

I'm thinking of building a Pearl 2. Apart from being able to handle low output M/C's, how else is it different from the Pearl1, would it be more suitable for my 10x4 and would it be worth ditching my Pearl 1 for?

Hoping you can help
Thanks
Roy

[6L6]

First of all, you do need to get your Pearl working properly! Do you have another cartridge? Does the Pearl work well with a different cart? Do you have another phono stage to determine if the problem is your 10X4? Just basic troubleshooting.

As for differences between the Pearl and the Pearl 2, in terms of ultimate sound quality they are very much alike. (No surprise, as they are very similar circuits.) The biggest difference is the amount of gain. I like them both, very much.

[royville]

Hi 6L6,
Thanks for your response. Ive been playing about with it for a while now and I have tried all that you mentioned.
I have a Dual 505 as a spare t/t which has the standard m/m cart it came with, and it works fine with that.
I also have nad 3020 and Dennon PMA 250-se amplifiers both with phono inputs and they both work fine with the Dual, and my Dynavector setup (Linn LP12/Ittok/10x4).
I also borrowed a friends 'Reson Mica' m/m cart to try in the Linn setup and that worked fine also.

So I hope you can see my problem now which seems to indicate that the Dynavector has problems with the Pearl or vice verca. I am at a loss.

I have read your thread on the 'Pearl Phono' and was re-assured to find that your layout and grounding is exactly the same as mine. All the voltages measure ok too.

Just to be sure I wasnt imagining the problem, I fetched my scope in from the shed recently and verified there was indeed oscillation at the output of the Pearl (both channels). I cant remember what the amplitude was but the period was roughly 2.5 uSec.
Regards
Roy

[wayne]

Try a 1000pF cap in series with 680 Ohms across the input.

[royville]

Hi Wayne,

Thank you for your posting. I did as you suggested and now its working flawlessly. It's dead quiet with just a slight hiss at max volume.

What can I say - wow! and thank you so much.

Wayne, If/when I come to change my cartridge in the future, should I leave the 'mod' on the pearl or remove it?

I'm off to listen to my record collection now, - I may be a while...

Kind regards to all
Roy.

[wayne]

I have not seen a situation where it caused any harm so you could leave it in.