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Old 28th May 2007, 09:17 PM   #21
diyAudio Member
Join Date: Mar 2004
Location: Albury NSW Australia
Hi AGain
I found this link on the forums
I will hand sketch a schematic of my grounds without the circuit.
Also i think i am getting noise from my 6v lm338k regulator boards.. i am increasing the filtration on that.. i will send you a readily available schematic for the lm338k (or at least a link.
I will get on to the grounding schematic this evening.. unfortunately i must go to work...yawn
Thanks again
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"Better to say nothing and keep them guessing than to speak and remove all doubt."
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Old 29th May 2007, 02:39 AM   #22
Sheldon is offline Sheldon  United States
diyAudio Member
Join Date: Dec 2003
Location: San Diego
Default Re: I could have cleaned the dust off them

Originally posted by duderduderini
They were clean 2 days ago!!
Heres both together
An easy thing to try is to move the power supply well away from the phone section. And, try rotating one or the other. I don't see MC transformers on the inputs (which can easily pick up stray mag fields), so this may not help - but it's a trivial test.

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Old 31st May 2007, 03:35 PM   #23
diyAudio Member
Join Date: Mar 2004
Location: Albury NSW Australia
Default Problem Solved.

Hi everyone.
Well I am a fan of happy endings and after a lot of thought i figured this might be dc heater supply noise. In essence the standard circuit provided by the lm338k manufacturers essentially stipulate a 0.1 uF on the input and a 1uF on the output.. I had a look at some other sites and i placed 2000uF on the input side with a 0.1uF tantalum and a 001uF disc capon the output. Problem fixed!!
Might I say this is a very lovely sounding phono stage and I would recommend Jims design and obvious ability. I settled in to listen to a night of LP's ...marvellous. After about one hour I got some motorboating in the right channel... well its 2 am here now and i will investigate this tommorow.
I would like to thank all of you for your interest, suggestions and kindness. The world becomes a different place when there is help around.
"Better to say nothing and keep them guessing than to speak and remove all doubt."
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