Ultra-high performance low-buck phono preamp (DIY project!)

Okay!

Long delayed update (Machine shop was slammed over the holidays) but my face plate is done! (well, machining is done- lots more to get to completion).

What do you guys think? As of now, I'm planning to fill all engraving with black lacquer, and the beveled edges of the copper will be polished, with the face being "brushed". Aluminum face will be "brushed" as well.

I have silver buttons for the four push buttons, but I also have black ones, with the top chamfer polished aluminum. Leaning that way now, but I'll mock it up and see how it looks.

I re-flowed all the SMDs and it's graveyard-quiet now. I need to address the pan pot, since there is no clear wiring diagram, but I guess I only have nine choices, so I should be able to get it...
Phono Pre face plate.jpg

The other copper plates are extras; well, the WP-2 one is for my headphone amp. Also Wyn's design, with a stepped attenuator it sounds... like nothing. Just how I like it. Since I am forced to use headphones or nothing these days, It's getting a lot of use and there is zero fatigue with it and tons of headroom (I bet it could drive speakers). I was considering one of the Krell KSA-5 headphone amps from eBay but no way.
 
J!m said:
Okay!

Long delayed update (Machine shop was slammed over the holidays) but my face plate is done! (well, machining is done- lots more to get to completion).

What do you guys think? As of now, I'm planning to fill all engraving with black lacquer, and the beveled edges of the copper will be polished, with the face being "brushed". Aluminum face will be "brushed" as well.

I have silver buttons for the four push buttons, but I also have black ones, with the top chamfer polished aluminum. Leaning that way now, but I'll mock it up and see how it looks.

I re-flowed all the SMDs and it's graveyard-quiet now. I need to address the pan pot, since there is no clear wiring diagram, but I guess I only have nine choices, so I should be able to get it...
View attachment 60387

The other copper plates are extras; well, the WP-2 one is for my headphone amp. Also Wyn's design, with a stepped attenuator it sounds... like nothing. Just how I like it. Since I am forced to use headphones or nothing these days, It's getting a lot of use and there is zero fatigue with it and tons of headroom (I bet it could drive speakers). I was considering one of the Krell KSA-5 headphone amps from eBay but no way.
Click to expand...
Wow….just WOW, beautiful.
Black will look classic and be easier to read. Dark blue or dark red would also look good and be a little different but pretty much any dark color will look great just because of your killer design.
 
J!m said:
Another update.

Again with the wrong relays… these are/were the same relay, just with bent legs for SM. I straightened them carefully and found:

They don’t fit.

After three failed attempts to get a fucking pair of relays, I MADE them fit.
View attachment 56216View attachment 56217

One side I got through the board; the other side is surface mount. I flowed enough solder to see it in the holes on the other side so, DONE.
Click to expand...


This is going to be "High Performance"?

Gotta stick around for this.

Where's the KABOOM

:)
 
I messed with the balance pot a bit today and I think I narrowed it down to 50-50.

I was unable to get right or left to ohm out, but I did find one pin has continuity to ground, so that’s my wiper. It’s either right now, or backwards. I’ll know later I think…

And I collect my parts tomorrow. They’ll be making the bezel for the power switch and level for the Rega too. Spent some quality time designing that (about five times over) but I think it’s done. (Not a lot of space in the corner with the larger platter)
 
WOPL Sniffer said:
This is going to be "High Performance"?

Gotta stick around for this.

Where's the KABOOM

:)
Click to expand...

Ill post the specs, which are impressive, but more importantly, it has been in use for about two years with the designer and friends of his. It sounds as good as anything else out there.

And it could run off batteries if that’s your thing.
 
"and level for the Rega too. Spent some quality time designing that (about five times over) but I think it’s done. (Not a lot of space in the corner with the larger platter)"

Jim, I like thinking out of the box too..... You could have mounted a mini bubble level in a Nickle, and mounted it to the tone arm like in the olden days.
 
I saw one of those tiny levels recently. But I have a good arm/cartridge set up and I don’t want to mess with that!

I have one floating around on the Rega anyway when it’s in use. I’m just going to mount it nicely so it doesn’t slide around and get caught under the dust cover…
 
J!m said:
I saw one of those tiny levels recently. But I have a good arm/cartridge set up and I don’t want to mess with that!

I have one floating around on the Rega anyway when it’s in use. I’m just going to mount it nicely so it doesn’t slide around and get caught under the dust cover…
Click to expand...


I say.. I say That was a joke son.... (spoken in a Foghorn Leghorn voice)
 
I think they might help with azimuth adjustment but once you get that, take it off and reset tracking force.

That’s assuming the platter is level…
 
Dude, the mini bubble level mounted on a nickle was a joke and a throwback to the old days where we put coins on our tone arms so the shitty records wouldn't skip..... Take a breath.... :)
 
I put Pennies on the counterweight of my JC Penney system! Deftly secured with electrical tape. Serious.

And I have to breathe too? Like I’ve got time for that!!!
 
J!m said:
I put Pennies on the counterweight of my JC Penney system! Deftly secured with electrical tape. Serious.

And I have to breathe too? Like I’ve got time for that!!!
Click to expand...


Gotta use a Penny on the JC Penney systems :)
 
Exactly. Might have been three of them… that was a while ago!
 
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