DIY mic pre based on Studer 169 (DOCUMENTS PUBLISHED FINALLY)

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dirtyhanfri said:
I'm wondering if it's like in Green pre or Tac Scorpion preamp,  just a jumper in a ferrite core?

i've been trying to find out as well. studer original bom and schematics don't report those values (oh and btw, studer original has another L post trafo pre amp stage and a double L pre trafo). from audiox's component layout values pdf it looks like it's marked as FER, so i'd guess a ferrite bead. a friend of mine has one and i'll try in the next couple of days to take a look and get a measure.
 
Spino said:
dirtyhanfri said:
I'm wondering if it's like in Green pre or Tac Scorpion preamp,  just a jumper in a ferrite core?

i've been trying to find out as well. studer original bom and schematics don't report those values (oh and btw, studer original has another L post trafo pre amp stage and a double L pre trafo). from audiox's component layout values pdf it looks like it's marked as FER, so i'd guess a ferrite bead. a friend of mine has one and i'll try in the next couple of days to take a look and get a measure.

Do you have any news on the L1?
Anyone? ???
 
darkcharly said:
Do you have any news on the L1?
Anyone? ???

ooops, totally missed this one, sorry.

yes, original L where Philips p/n 62.01.0115. they can be changed with TDK p/n B82114-R-A4.
in italy, they can be found at Distrelec with code 350214.

as for the original common mode choke before the original trafo (parts L1A and L1B on the original studer schem) each single coil measures about 240 mH, and ferrite is indicated as 3E3. no ideas on the wiring though, and no idea of what could come close to that.

hope it helps. any further infos would be great!



 
Spino said:
darkcharly said:
Do you have any news on the L1?
Anyone? ???

ooops, totally missed this one, sorry.

yes, original L where Philips p/n 62.01.0115. they can be changed with TDK p/n B82114-R-A4.
in italy, they can be found at Distrelec with code 350214.

as for the original common mode choke before the original trafo (parts L1A and L1B on the original studer schem) each single coil measures about 240 mH, and ferrite is indicated as 3E3. no ideas on the wiring though, and no idea of what could come close to that.

hope it helps. any further infos would be great!

Spino: Of course it helps! Thank you very much for the info!
 
I went to re-read this thread. Maybe considering doing it.

I'm confused on one thing. Audiox wrote it's a double-sided board, but in the build documents there's only one-sided pcb copper mirror. Is this copper mirror okay? PCB is one-sided etch, yes?

Difficult part seems to be L1 choke. Does anyone know what is the value of this inductor in henries?
I found TDK B82114-R-A4 on Mouser, but Mouser is very expensive in my country. Too expensive if I want to order just few pieces. I may try to find substitute that I can get locally.
 
shot said:
Audiox wrote it's a double-sided board, but in the build documents there's only one-sided pcb copper mirror.

The first layout version was double-sided, the final single-sided.

shot said:
Difficult part seems to be L1 choke. Does anyone know what is the value of this inductor in henries?

Almost any ferrite bead should be fine. In the unlikely case of oscillation, add turns.
 
Awesome pre! If anybody would be up to transforming this into a 500 series pre I'd surely offer them a beer or two.?

Or should i just go ahead and order that protopcb from AML. :)

Anyways excellent work Audiox and the 169 Eq is next on my building list.  Don't know how to thank you enough so thumbs up!

-Forever lurking

EDIT:
For anyone interested there's a new thread:
http://groupdiy.com/index.php?topic=59616.msg756998#msg756998
 
Hi,
could somebody post their voltages? I'm having trouble with my self etched board. Probably a bad connection but can't seem to find it. Voltages would help a lot. Thanks
 
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