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Old 3rd October 2012, 06:34 PM   #1
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Default help with phono stage circuit design

well I have a couple of questions that I hope someone with experience can help me with
I recently acquired a VIncent phono stage PH 8 which out of the box is a stellar performer (for the price 400 usd you get the phono and a separate really well built power supply). As all members here though, although very happy with its sound, I CANNOT LEAVE IT ALONE and I am plannig some basic mods (caps, and resistors specifically)

now my two questions
why the two sections of the phono stage use different resistors? one half uses 1/2 w and the other 1/4 w? the phono is an MM/MC design, but despite that I do not understand why use 2 different values for the two sections. And also can you from the pictures tell the type and brand of the ones in use?

I only use the MM section (which I assume is the one using the 1/4 w resistors) and I am planning to change things only in that section, if I change the capacitors only in the half section of the PS that powers the MM section will that have any unwanted consequences? I assume the two sections are totally separate, but I might be wrong

thxs for your help
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Old 3rd October 2012, 07:29 PM   #2
Mooly is offline Mooly  United Kingdom
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It does look very nicely made and I would say all of the parts are what I would call good commercial quality.

Could noise contribution be a factor in the larger resistors although any difference must be minimal. Maybe a marketing ploy... I don't know. Some of them seem a bit of an arkward fit too.

Its a nice unit... maybe enjoy it as it is
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Old 3rd October 2012, 07:46 PM   #3
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along with the external PS it does indeed make for a terrific value phono stage. We tested it with 5 others priced 1/2 to 6 times the price and with the exception of the audio note this was the clear winner.
based on its very very good performance and the same assessment of the parts usedgood commercial quality (good commercial quality) I definitely decided to push it to a different level, I already have several black gate caps to replace the panasonic FC used there, and even relatively cheap silmic II in the right places should improve things considerably.
I am replacing the 7812 rectifier with a belleson, and I am considering changing all the resistors with either takman metal or even TX2575, with a relative small investment 150 usd this is going to be an amazing unit, but given the fact that I do not use MC and do not plan to go that way I see no reason to spend the money on the MC section of the unit hence my questions
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Last edited by lightmaster; 3rd October 2012 at 08:01 PM.
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Old 3rd October 2012, 07:54 PM   #4
Mooly is offline Mooly  United Kingdom
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Good luck with all your mods, it sounds like you have thought it all through and not spending on the sections that aren't in use makes good sense too.

Now I'm not really the person to ask on specialist parts I'm afraid as I'm happy to stick to quality commercial stuff. I'm sure you'll end up with a terrific unit though. Let us know how it all goes.
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