LR phono by Pete Millett build

MrEd

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I have been pondering this design for about a year now... let the games begin as the old saying goes. 😊
I have Pete's phono board and I am going use his power supply also.
My original plan was to use the Silent switcher from diyAudio but they have been unavailable for a while.

20220205_081832.jpg
The design info can be found here.
 
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MrEd

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Next decision is making an easy option for cartridge loading.
I don't intend to incorporate MC step up into this, but I want to be able to optimize capacitance loading.
My thoughts are to keep the 47k loading resistor and add a selector switch to choose between values that will parallel a cap on the board.
C2 and 4 on this schematic are the caps on the input.
InkedLR_sch_clip_LI.jpg
The value selected by Pete Millett is 150pf.
My thoughts are to place a value lower that this on the board and then use the next selection to equal 150 and have a couple option graiter than 150pf.
Anyone have thoughts on what values would be most useful?
 
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Wntrmute2

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I just tested his boards for regulated low voltage. Easy build and very stable. Easily gets 6.3VDC from the 6.3V transformer winding as he claimed.
 

Wntrmute2

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Filament supply for the driver tubes in my 3C24 build. The 3C24 will have it's filament lit by Rod Coleman's regs.
 

MrEd

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Today's progress. Sadly lacking some inductors...
It's just an R phono right now and my Digikey order with my power supply parts is in a snow storm... 😒
20220205_153836.jpg
I also decided to build a one chassis design today after much back and forthing, and ordered a chassis.
 
Chassis is from an eBay seiller here in Texas
That’s a real nice chassis- fit and finish looks great!

That’s not a bad price either. Shipping though, at 2/3rds the cost of the case, is disenfranchising. Part of modern reality though it seems.
 

Thermionics

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Thermionics

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I used a slightly modified version of the Millett bipolar power supply to build a PSU for a Hypnotoad AD797 HQMC phono stage. Very, very nice quality.
 

MrEd

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After looking at prices vs shipping cost, 2 chassis vs 1 this ended up the best.
It has lots of room to keep the two boards apart and add a patrtican to maybe help keep power supply noise out.
 
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Thermionics

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Yeah. I'd definitely add a partition. Are you planning on isolating signal grounds and grounding the PSU, or are you going to follow what Pete did in his original?

(personally, I lean towards the former, but it all depends on noise levels)
 

MrEd

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Yeah. I'd definitely add a partition. Are you planning on isolating signal grounds and grounding the PSU, or are you going to follow what Pete did in his original?

(personally, I lean towards the former, but it all depends on noise levels)
Still pondering that one but leaning towards isolating signal ground.
 
After looking at prices vs shipping cost, 2 chassis vs 1 this ended up the best.
It has lot room to keep the two boards apart and add a patrtican to maybe help keep power supply noise out.
It’s great. I’m just surprised at shipping costs in general these days.
 

MrEd

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Anyone have thoughts on best material to separate the halves with?
Aluminum, steel, copper, or maybe a sandwich ?
 
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