DIY mic pre based on Studer 169 (DOCUMENTS PUBLISHED FINALLY)
« on: November 20, 2009, 07:19:19 AM »
(Picture added as an attachement, so you must be logged in to see it. Google page creator has been discontinued and I am looking for an alternative place for hosting my files.)

The idea of this project was to copy the sound of the 169 mic pre as accurately a possible. A friend of mine bought two original channels from Ebay and I repaired them for him. It was so time consuming that I decided to built new ones when he needed some more. That was much cheaper alternative too.

In blind tests my friend or his colleagues couln't hear difference between the original and clone. In the test setup the output of the original channel was taken directly after the mic pre and buffered like in the clone.

All parts, except the transformer, are available from every electronics store, but finding the transformer is not as difficult as you may think. Neutrik NTM4 is exactly the same transformer as the original Studer 1.022.400.00. Neutrik has a global distribution network, so their products are available almost everywhere.
http://www.neutrik.com/fl/en/audio/210_205801/NTM4_detail.aspx

I redesigned the gain setting which originally had three steps of 13-14 dB. I changed it to four 10 dB steps. A balanced output stage was also added.

There was some extra space on PCB as well as unused switch sections, so I included LED indicators in the gain and filter switches (see the picture). Personally I don't like that kind of "decoration" but I know that some people do. Leave them out if you don't like them.

The rotary switch on the left is common for phase and phantom to save space.

My original version was made using 30 years old Feme switches that I got for free ( http://www.4most.co.uk/assets/Image/swt_04.jpg ). Since the Femes are no longer manufactured, I made another layout for Lorlin switches (to make this project available to the forum members).

As usual, I don't sell anything related to this project. If someone wants to manufacture boards or offer kits, no problem (but the price must be fair). All the information is provided "as is".


DOCUMENTS:

Schematic
https://docs.google.com/open?id=0B_XBYPfmG8pVWkFtYXhNNDZhb0k

Component designations
https://docs.google.com/open?id=0B_XBYPfmG8pVeGJqYU5qTEZkZTA

Components values
https://docs.google.com/open?id=0B_XBYPfmG8pVRmNoQzlfaHZ5eG8

Copper layer (for home etchers)
https://docs.google.com/open?id=0B_XBYPfmG8pVOXM2VE9mMGt2UUk



My other projects:

Neumann W492 EQ
http://www.groupdiy.com/index.php?topic=28332.0

Neumann OA10 discrete op-amp
http://www.groupdiy.com/index.php?topic=34105.0

Studer 169 EQ
http://www.groupdiy.com/index.php?topic=33996.0

Studer 169 EQ in API 500 format
http://www.groupdiy.com/index.php?topic=36522.0

Balanced 12 input summing amplifier
http://www.groupdiy.com/index.php?topic=29082.0

Balancing/unbalancing amplifier
http://www.groupdiy.com/index.php?topic=29333.0


« Last Edit: December 21, 2012, 03:12:14 PM by audiox »


okgb

Re: DIY mic pre based on Studer 169
« Reply #1 on: November 20, 2009, 07:32:12 AM »
I use them a fair bit
not sure that they are the cleanest clearest but i've never been unhappy
i'm in thanks
GKB Audio / Greg Boboski

hobiesound

Re: DIY mic pre based on Studer 169
« Reply #2 on: November 20, 2009, 11:09:48 AM »
mmmmmmmmmmmmmmore projects!!!!! cool

Re: DIY mic pre based on Studer 169
« Reply #3 on: November 20, 2009, 01:41:21 PM »
yes please!  is the pcb single sided?

Is that 0-10dB gain pot some sort of trim?


btw, OT you ever get to testing that neumann DOA?

mylesgm

Re: DIY mic pre based on Studer 169
« Reply #4 on: November 20, 2009, 06:09:36 PM »
ooh I'd love pcb/kit for these, been thinking about making a mixing desk (really scary) and modules like this make me think it'd be easier than I thought...
Thanks for a neat design!
m
Check my work at www.mylesmumford.com

Joechris

Re: DIY mic pre based on Studer 169
« Reply #5 on: November 20, 2009, 06:29:05 PM »
This looks like a new Audiox classic. This would have a huge potential as a 500 module as well.
I really like your down to the point style, no nonsens and simplicity.
j
« Last Edit: November 20, 2009, 06:35:04 PM by Joechris »
musicians vary +/-9dB depending on mood, drugs, and line-voltage. (PRR)

mpc3000limited

Re: DIY mic pre based on Studer 169
« Reply #6 on: November 20, 2009, 07:38:44 PM »
Nice! As with your other projects great ideas and nice job!

kambo

Re: DIY mic pre based on Studer 169
« Reply #7 on: November 20, 2009, 08:03:54 PM »
cool preamp :)

Re: DIY mic pre based on Studer 169
« Reply #8 on: November 20, 2009, 08:46:36 PM »
Audiox you are churning out the projects lately. I'll probably build one or two
Nick 'The Wandering Eye' Franklin

PRR

Re: DIY mic pre based on Studer 169
« Reply #9 on: November 20, 2009, 10:22:26 PM »
> looking for an alternative place for hosting my files.

http://tinypic.com/ is handy for forum-size images. Utterly free, they give you a URL to paste into a forum message.

Beyond casual use, I suggest registering for an account; otherwise if you lose the URL you can never find your picture again.

> Google page creator

If you need more elaborate project documenting tools, tinypic is probably not what you want.


shot

Re: DIY mic pre based on Studer 169
« Reply #10 on: November 21, 2009, 05:05:21 AM »
Man this is awesome!
Audiox, you're the man!
Respect!

doubleroger

Re: DIY mic pre based on Studer 169
« Reply #11 on: November 21, 2009, 06:54:27 AM »
Oh putain this is good. ;D

this (very cool) phase/phantom switch makes me believe polarity is switched at the input, right?
Please explain.
Arthur.

Re: DIY mic pre based on Studer 169
« Reply #12 on: November 22, 2009, 07:44:11 AM »
is the pcb single sided?

Double sided.

Is that 0-10dB gain pot some sort of trim?

The gain is adjustable from 20dB to 60dB. Four 10dB steps and 0-10dB continously variable.

btw, OT you ever get to testing that neumann DOA?

I published the documents, so you (or any other) can test it. I guess the question is not if it works but what it sounds in your application.
http://www.groupdiy.com/index.php?topic=34105.0

Re: DIY mic pre based on Studer 169
« Reply #13 on: November 22, 2009, 07:47:56 AM »
tinypic is probably not what you want.

The Google page creator allowed to upload all kind of documents (like pdf) but the new Google sites doesn't. Well, it was too good to last forever.

Re: DIY mic pre based on Studer 169
« Reply #14 on: November 22, 2009, 07:52:03 AM »
Oh putain this is good.

One of the 10-20 French words that I know. I am not sure if I should be proud of it...

this (very cool) phase/phantom switch makes me believe polarity is switched at the input, right?

Yes, like in the original circuit.

berre

Re: DIY mic pre based on Studer 169
« Reply #15 on: November 22, 2009, 08:28:39 AM »
Really cool new project!

Re: DIY mic pre based on Studer 169
« Reply #16 on: November 22, 2009, 08:50:59 AM »
is the pcb single sided?

Double sided.
cool, guess this is a good time to learn to etch double sided boards.
 
Quote
btw, OT you ever get to testing that neumann DOA?

I published the documents, so you (or any other) can test it. I guess the question is not if it works but what it sounds in your application.
http://www.groupdiy.com/index.php?topic=34105.0
Would you be willing to share the copper layers? I can see one layer on the compensation pdf, but if you don't mind posting the other that'd help.

ALSO, about sharing documents, maybe Picasa would work for you?  Never used it myself, but it's where the GSSL supersidechain docs were posted and they are still up after a year or more, so...

doubleroger

Re: DIY mic pre based on Studer 169
« Reply #17 on: November 22, 2009, 11:13:09 AM »
Oh putain this is good.

One of the 10-20 French words that I know. I am not sure if I should be proud of it...

Yeah I've been thinking lately that this place needs to work a tiny bit more on a multicultural angle.
Et VoilĂ !
Please explain.
Arthur.

Re: DIY mic pre based on Studer 169
« Reply #18 on: November 22, 2009, 10:28:00 PM »
Is gustav going to make boards for this bad boy? I can see it being quite popular.
Nick 'The Wandering Eye' Franklin

mylesgm

Re: DIY mic pre based on Studer 169
« Reply #19 on: July 04, 2010, 05:01:49 PM »
Is this project moving forward with PCB manufacture?  I'm keen to build...
M
Check my work at www.mylesmumford.com


 

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