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-   -   Phono 3 noise issues (http://www.world-designs.co.uk/forum/showthread.php?t=8002)

Damien 7th March 2021 01:54 PM

Phono 3 noise issues
 
Hi All.

Iím new to the forum but realise from the wealth of experience out there it will be quicker to ask for advice than reinvent the wheel.

Iíve recently acquired a WD Phono3 & PSU 3.

It exhibits a lot of background noise even with no turntable connected. Not mains based but more like what you would hear with a poorly tuned radio station.

Iíve pulled it apart & the build quality leaves a lot to be desired so plan to rebuild as there are definitely some poor solder joints & some of the cabling is not well shielded.

Whilst Iím at it Iíd like to incorporate any recommended improvements for both units so would appreciate recommendations.

It currently has a pair of CED? G7LG7 & a J J ECC83S.

The caps & resistors all look to be pretty low spec & am happy to invest in better quality components.

Any suggestions would be welcome.

The phono stage is coupled to a Michel Gyrodeck SE with an SME V tone arm & Cartridge Man Music Maker 3 high output MM cartridge with an output of 4 mV & a loading requirement of 47k.

Thanks in advance.

Damien

bob orbell 7th March 2021 03:37 PM

Re: Phono 3 noise issues
 
Some pictures of both would help, with regard to the G7LG7, I cant find any reference to that number, ECC83 is what it was designed to run with, so that is what I recommend and use, the supplied capacitors in my opinion are good and I suggest you leave as was supplied but sort the bad construction out first, this is a good phono stage that can be made better, but, as said, sort the poor build out first, and pictures. Bob

Damien 7th March 2021 05:50 PM

Re: Phono 3 noise issues
 
Hi Bob.

Many thanks for your prompt response.

Having looked again the valves marked G7LG7 are also marked J J ECC83S on the other side so it appears all 3 are the same. Apologies for my ignorance on this one.

I 'll do as you suggest & re work both units initially so I have a good start point.

Are the original build instructions available as I didn't get them with the units?

Best Regards

Damien

Damien 7th March 2021 05:53 PM

Re: Phono 3 noise issues
 
Hi Bob

I'll get a few pictures of each & attempt to upload them.

Regards

Damien

Greg. 7th March 2021 06:00 PM

Re: Phono 3 noise issues
 
Hello Damien and welcome to the forum. Please PM me your email address and I can forward build instructions to you.

bob orbell 8th March 2021 07:14 AM

Re: Phono 3 noise issues
 
Thank you for attention for the build instructions Greg.

Damien 8th March 2021 10:36 AM

Re: Phono 3 noise issues
 
2 Attachment(s)
Hi Bob

Couple of pictures of the Phono 3 as requested.

Damien 8th March 2021 10:52 AM

Re: Phono 3 noise issues
 
2 Attachment(s)
Hi Bob

Please see attached images of PSU.

Best Regards

Damien

bob orbell 8th March 2021 02:01 PM

Re: Phono 3 noise issues
 
Thank you for the pictures Damien, both PSU and Phono are in fact series II, boards, but in the latest cases, no problem, but be careful if removing component from Phono as these boards are not the best, the tracks are very thin compared to the latest kit, I can see only a small amount of tidying up, but doubt if this will sort your problem, when you get the build instructions you will see the difference of the II to the III. Next you should test all voltages to ascertain all is well or not, we can guide you through this if you are troubled. Bob

Damien 8th March 2021 04:48 PM

Re: Phono 3 noise issues
 
Hi Bob

I'll have a look this evening & tidy them up.

I've no problem checking the voltages & will work through them & let you know. I'm assuming the info Greg has sent about the Phono 3 will still be relevant?

I had only intended to re solder rather than remove components for now, with the exception of a couple which aren't seated properly.

Will I need any different components in light of these being series II boards?

Regards

Damien


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