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My CNC phono preamp build.

So I ran into a snag with this pbono pre build. The 10mh/160ma inductors aren't available anymore for the power supply. The ones I bought have thicker leads, .81mm, and the original Panisonic inductor used had .6mm thick leads with 5mm spacing. The thicker leads won't fit the smaller holes in the PCB. The obsolete Panisonic part number is ELC-11D103F. Mouser number 667-ELC-11D103F. I found another with .7mm diameter leads I think will work, but is rated for 130ma./ 160ma saturation. I just dont know if the lower current one will work here or not. Also, does anyone know if the 33pf caps at the input of the preamp board should be omitted? They weren't in the BOM.
 

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Lavane said:
So I ran into a snag with this pbono pre build. The 10mh/160ma inductors aren't available anymore for the power supply. The ones I bought have thicker leads, .81mm, and the original Panisonic inductor used had .6mm thick leads with 5mm spacing. The thicker leads won't fit the smaller holes in the PCB. The obsolete Panisonic part number is ELC-11D103F. Mouser number 667-ELC-11D103F. I found another with .7mm diameter leads I think will work, but is rated for 130ma./ 160ma saturation. I just dont know if the lower current one will work here or not. Also, does anyone know if the 33pf caps at the input of the preamp board should be omitted? They weren't in the BOM.
Click to expand...

Just use a small hand spun pin vice and drill out the PCB holes. I do it all the time. just make sure you can solder on the side the traces are to make a connection as the through hole sleeve may be removed by the drilling.

Athanasios
 
Nashou66 said:
Just use a small hand spun pin vice and drill out the PCB holes. I do it all the time. just make sure you can solder on the side the traces are to make a connection as the through hole sleeve may be removed by the drilling.

Athanasios
Click to expand...
I've done that also before. I'm just trying to keep from doing that if I can. The inductors I bought, and there aren't many in this value range had a 2mm wider spacing also. I'm hoping the 130ma ones I found earlier will work here. The original ones used were 160ma. The spacing is right for the 130ma coils, and the leads are just .7mm wide where the originals were .6mm. I'm hoping someone will know if the 130ma ones that saturate at 160ma will work. With 7mm diameter leads I can easily work with that.
 
Lavane said:
I've done that also before. I'm just trying to keep from doing that if I can. The inductors I bought, and there aren't many in this value range had a 2mm wider spacing also. I'm hoping the 130ma ones I found earlier will work here. The original ones used were 160ma. The spacing is right for the 130ma coils, and the leads are just .7mm wide where the originals were .6mm. I'm hoping someone will know if the 130ma ones that saturate at 160ma will work. With 7mm diameter leads I can easily work with that.
Click to expand...
I used these Inductors on my PS board from Sachin : Mouser# 542-RL875S-103K-RC
The 33pf caps are optional for adding capacitance. I originally had the 33pf caps installed but removed them due to too much capacitance. Played fine with HOMC carts but MM carts were "Muffled". After removing the 33pf caps all was fine. I'm limited with my DIY skill sets as a disclosure, just sharing a recent experience.

Cheers
 
tjste said:
I used these Inductors on my PS board from Sachin : Mouser# 542-RL875S-103K-RC
The 33pf caps are optional for adding capacitance. I originally had the 33pf caps installed but removed them due to too much capacitance. Played fine with HOMC carts but MM carts were "Muffled". After removing the 33pf caps all was fine. I'm limited with my DIY skill sets as a disclosure, just sharing a recent experience.

Cheers
Click to expand...
Thanks! I'll look those up. Its the last piece of the puzzle.
 
Well,, then just try em with your board and see if they work,,, Then you can see about fitting them...
Maybe put a small piece of solid wire in the hole (think turret!!) instead of drilling bigger if ya want to keep the board stock??
 
Lavane said:
I just went and ordered the Bourns inductors.
Click to expand...
The board I put together ran at 15.2v per and silent. It was a project for a friend returning to vinyl. I placed them in an inexpensive plastic enclosure.. nothing as elaborate and impressive as your project, that's for sure! I have limited experience, so I'm watching your build closely.
 

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tjste said:
The board I put together ran at 15.2v per and silent. It was a project for a friend returning to vinyl. I placed them in an inexpensive plastic enclosure.. nothing as elaborate and impressive as your project, that's for sure! I have limited experience, so I'm watching your build closely.
Click to expand...
Good to hear it's quiet. I'm using a 1.5 amp 120v-12v AC wall wart to drive the power supply. I ordered the inductors you used, they should be here by next Wednesday or Thursday. That's all I need to finish up the boards. I bought a panel mount jack like you used to connect the wall wart step down trany and installed it on the back.
 

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I finished up the preamp today. I had got a couple dud Op-amps, so ordered 4 more from Digikey. I then got sound, but had a hum. After a quick grounding fix its dead quiet. So far I really like this preamp. Thanks to all that helped me find a few bits I needed, suggestions, and answering my questions in a few PM's.
I'm calling this one done. I burned it in with some AC/DC at my bench. :rockon:
Build thread here if anyone is interested.
https://audiokarma.org/forums/index.php?threads/passive-pre-input-selector-build.1025777/
 

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dlucy said:
@Lavane which opamps did you try? Which did you end up using?
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I settled on two OPA2134's. I tried a pair of NE5532's first.
The NE5532's sounded good, and are still widely used in a lot of consumer gear. But the OP2134's had a noticable difference for the better.
Maybe because the OP2134's have JFET's instead of BJT's?
There is a big price difference between the two.
I payed 69 cents each for the NE5532's, and $6.96 or the OP2134's.
Still, that's pretty cheap.
 
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