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Old 16th February 2012, 01:57 PM   #11
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Quote:
Originally Posted by TheShaman View Post
You could try Salas shunts as well.
I will most probably do that. I have a few boards on hand. I have to buy the parts and assemble but I'm sure it is a really good PSU.

I also have one AMB's o22 which is supposed to have lower then 12uVac @ 30V output and lower than 6uVac @ 12V output... These are really good numbers... It does not tell all the story and a listening session will be needed for all of them.

I'm also working with wolfsin on a more custom setup described above.

Ciao!
Do
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Old 16th February 2012, 02:56 PM   #12
Wolfsin is offline Wolfsin  United States
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Default Wow to the low noise, guyz

Wolfsin is sooooo thankful to have Do aboard this thread. Those noise numbers are amazingly better than the Kubota. I went in search of the Borbely article mentioned above but found only supplemental pcb patterns at the Audio Xpress site.

I now forsee a fair amount (re)plugging of regulators, a potentially error prone and costly activity during listening / testing. Are there suitable keyed connectors to reduce the risks?
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Old 16th February 2012, 03:31 PM   #13
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Please send your email id (Wofsin) by PM - I can email you the PDF article ( is in Public Domain and hence no issue using it to make your regulator if you wish) and way to get the PCB pattern as well. I have made that PS regulator from Erno' original kit-
I can even help you with K170/J74 matched pairs sellers. However I do not want many asking me!
Kannan
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Old 16th February 2012, 03:34 PM   #14
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Quote:
Originally Posted by Wolfsin View Post
I now forsee a fair amount (re)plugging of regulators, a potentially error prone and costly activity during listening / testing. Are there suitable keyed connectors to reduce the risks?
PS regulators and their connections to such high quality Preamps are sensitive to external noise/magnetic field - so keep the wiring minimal inside shielded enclosure if you want to evaluate them. It is a bit painful but worth all the trouble
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Old 16th February 2012, 06:49 PM   #15
Wolfsin is offline Wolfsin  United States
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Default + and - 30vDC @500ma to within .0003%

Specifications for the power requirements of the JC-80 may help limit the range of regulators to be considered. Dual rail 30vDC input to the cap multiplier must supply minimum 250ma per rail. The measured noise of the regulator output is present there but is further reduced by the cap multiplier.

The Kubota noise, at <.1mv, expressed as a percentage, is <(100).0001/30 or <.0003% so even if there are quieter circuits delivering 500ma per rail at 30v, the Kubota is pretty impressive. Moreover, the cap multipliers further reduce the noise.

When the kit price of $40 shipped is considered -- WoW!
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Old 16th February 2012, 09:11 PM   #16
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I just asked my friend (He's an audio engineer at a very well known high end audio company) to design me a Jung regulator with LM317 and 337 pre-regulation for the JC-80 preamp. Rectifier will not be onboard...

I need to know if anyone is interested so we could do a group buy.

The regulator and pre-reg would be on one PCB and have both positive and negative rails on it. LM317 and 337 would drop the voltage to 35Vdc then Super Jung to 30Vdc. The noise level should be around 2-4uVac but will be measured by their equipment.

Ciao!
Do
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Old 16th February 2012, 09:33 PM   #17
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Quote:
Originally Posted by pinnocchio View Post
I just asked my friend (He's an audio engineer at a very well known high end audio company) to design me a Jung regulator with LM317 and 337 pre-regulation for the JC-80 preamp. Rectifier will not be onboard...
Yeeeessss!
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Last edited by Wolfsin; 16th February 2012 at 09:39 PM.
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Old 16th February 2012, 09:55 PM   #18
Wolfsin is offline Wolfsin  United States
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We will be right on John's original prescription!

Quote:
Originally Posted by john curl View Post
The power supply does need a 337/317 DC regulator after the power supply caps, and the power transformer should be EI, or R core. The shunt regulator should not be necessary. High speed, soft recovery diodes are important, as well.
I was fixated on not doing a custom pcb but the wisdom of your approach is totally apparent with that kind of noise.
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Old 17th February 2012, 12:40 PM   #19
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Quote:
Originally Posted by pinnocchio View Post
I just asked my friend (He's an audio engineer at a very well known high end audio company) to design me a Jung regulator with LM317 and 337 pre-regulation for the JC-80 preamp. Rectifier will not be onboard...

I need to know if anyone is interested so we could do a group buy.

The regulator and pre-reg would be on one PCB and have both positive and negative rails on it. LM317 and 337 would drop the voltage to 35Vdc then Super Jung to 30Vdc. The noise level should be around 2-4uVac but will be measured by their equipment.

Ciao!
Do
What company and what's his name?? Just curious because it might be something I want to do.
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Old 17th February 2012, 12:58 PM   #20
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What company and what's his name?? Just curious because it might be something I want to do.
Unfortunately, I cannot disclose this information... He's not really supposed to be doing DIY stuff with his relation with the company...

Let's keep it quiet...

Don't worry, you know the company for sure. But now I'm just teasing you, am I?

He's just doing the PCBs and tests for me and does not want to get involved.

Ciao!
Do
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