andre tchmil

API 312 Thread!
« Reply #40 on: August 23, 2004, 07:56:42 AM »
thanks PRR.

Chrissugar.
what to do with the centertap, simply joining.
I'm gonna use the LL1636 in the 1:10 configuration (100ohm/10K) in the 312.
What do you think ?, suggestions?


smilinfu

API 312 Thread!
« Reply #41 on: August 23, 2004, 10:38:05 AM »
I used the 1636 at 1:10.  Seams to work fine, but have not really put it to serious work yet.  I do have to admit that I?m a newbie and this was a fairly arbitrary choice on my part, much of the group was using 1:5 so I thought I might learn more by doing the wrong thing first.  Haven?t noticed any problems (some noise issues, but I don't think they are related).  Next time around I may try 1:5 or even switch them just for comparison, but that is months away.

chrissugar

API 312 Thread!
« Reply #42 on: August 23, 2004, 03:26:18 PM »
Hi Andre

Look at the pdf:
http://www.lundahl.se/pdfs/datash/1636.pdf
At the last page you do it like configuration C on the right side and do not use the central tap. You do not need it.
Connect the primary and ground to the mic and if you need phantom power use the classic pair of 6.8k resistors but keep in mind that this is an amorphous core transformer and it do not like DC. The solution to minimize the DC that flows through the primary is to have the two 6.8k resistors of very close value. Buy a pair of precission, 0.1% rezistors or select from a bunch of 1% ones.

chrissugar

P.S. DO NOT FORGET THAT THE VIEW IN THE DATASHEET IS FROM PIN SIDE!
Christian Mike Sugar
        CMS-LAB

andre tchmil

API 312 Thread!
« Reply #43 on: August 23, 2004, 07:49:43 PM »
Chrissugar, I studied the PDF with all the possible connections.
So it is 1:10., right ?
But I'm hungry to learn, so can you explain why not to use the
connection as on C -Left ?

thanks.

andre tchmil

API 312 Thread!
« Reply #44 on: August 25, 2004, 11:02:02 AM »
Chrissugar, I studied the PDF with all the possible connections.
So it is 1:10., right ?
But I'm hungry to learn, so can you explain why not to use the
connection as on C -Left ?




Can someone check that for me please?
I want to finish my 312 and am still in doubt.

On the Lundahl page , you see all possible connections.
In the 1:10 configuration (fig. C) you have on the right , the one with the centertap , and on the left the one without.
Why should I use the configuration on the right as opposed to the one on the Left., Or doesn't it really matter ?

thanks

andre tchmil

API 312 Thread!
« Reply #45 on: August 26, 2004, 09:05:41 AM »
thanks :oops:

chrissugar

API 312 Thread!
« Reply #46 on: August 26, 2004, 05:22:07 PM »
Sorry Andre for the late response.

My 12 channels of API type preamps are wired this way and they work wonderfull for more than 10 month. I used these preamps on some major projects [ MTV Music Awards winner band last year for my country, other bands and some film sound recording] and people were amazed by the sound.
At least you can be sure that it will work good as long as it works here. I forget to say that this is only API topology but all the components are diferent , jfet based discrete opamp, Lundahl in and out transformer.

chrissugar
Christian Mike Sugar
        CMS-LAB

babyhead

API 312 Thread!
« Reply #47 on: August 27, 2004, 02:54:43 PM »
Check this out...I bought these with the intention of putting them into Fabio's 312 kit:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3832175223&ssPageName=STRK:MEWN:IT

I need to verify the ratios and phase...any ideas?

Could it be like a 2623?

Was this a score?

-Mark

Bauman

API 312 Thread!
« Reply #48 on: August 27, 2004, 03:09:58 PM »
Looks interesting Mark!
 I didn't check the model number but you can find the windings measuring the DC resistance. There're 4 windings so you just need to group the wires in pairs, look for low resistance. Use one pair for input and put other 2 in series to output.
I think you'll need a scopt to check for correct phase... or maybe someone here got some trick to do this other way...

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store

Bauman

API 312 Thread!
« Reply #49 on: September 28, 2004, 05:37:22 PM »
Hi,

Just to let you know that the last files for API312 boards, version3, are in here:

http://www.thediypill.phx.com.br/forumfiles/

under R312* names you got the partlist, the schematics and the board (component side and ready-to-transfer solder side).

I´ll post the PSU data to use with it soon...

ENJOY!

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store


Bauman

API 312 Thread!
« Reply #50 on: September 30, 2004, 10:42:52 AM »
:grin:

This is going to be a lot of fun!

http://www.thediypill.phx.com.br/r312_v3.htm

Warm up the soldering iron!!!

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store

owel

API 312 Thread!
« Reply #51 on: September 30, 2004, 10:59:00 AM »
alright!!!

Fabio, which on one of those 2520 is the real A*P*1 version?   The first one is the Melcor, I'm not sure about the 2nd and 3rd.

Bauman

API 312 Thread!
« Reply #52 on: September 30, 2004, 11:13:46 AM »
There are 2 original layouts: the PP*2*5*2*0 is one  Peter P. sent me on the last minute. The other 2 are also a work from Pete, but I did the component silk according to the schemo we have. I did 2 versions, the 2*5*2*0 is the ´real´one, with the original componets footprint (2Ns, TIS transistors) facing down and with long pins. The 2*5*2*2*0BC is a modified one with BCs/BDs transistors, facing up, and short pins...

btw many thanks to Mikkel MCS for the use of his gerberlizer! program :)

My goal with this work is to spread them all over the world so we can collect technical and musical impressions, compare to originals and so on.
Fun fun fun!

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store

Flatpicker

API 312 Thread!
« Reply #53 on: September 30, 2004, 11:40:50 AM »
Quote from: "Bauman"
There are 2 original layouts: the PP*2*5*2*0 is one  Peter P. sent me on the last minute. The other 2 are also a work from Pete, but I did the component silk according to the schemo we have...
Cool!  :thumb:
Got schematics?

owel

API 312 Thread!
« Reply #54 on: September 30, 2004, 04:03:37 PM »
When we get the PCBs, do we also get a sheet with the schematics, parts list, etc for the PSU, main board, and 2520?

Bauman

API 312 Thread!
« Reply #55 on: October 01, 2004, 10:30:35 AM »
Ruel, I choose to leave it online, here:

http://www.thediypill.phx.com.br/forumfiles/

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store

Bauman

API 312 Thread!
« Reply #56 on: October 27, 2004, 11:23:17 AM »
Hi,

I've  uploaded the opamps info today, link on the post above.
Let me know if something is missing.

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store

Bauman

API 312 Thread!
« Reply #57 on: November 10, 2004, 12:55:17 PM »
HEY!

Here are some pics of my API312 babies  :grin:



1 channel with CM75101APC and Profile 4804, all panel switches still to arive...

The big pics:

http://www.thediypill.phx.com.br/forumfiles/r312_1.jpg

http://www.thediypill.phx.com.br/forumfiles/r312_4.jpg

gonna pay visit to metalworks man on Sat.

cheers!
Fabio
cheers!
Fabio
_____________________
www.thediypill.com/store

Greg

API 312 Thread!
« Reply #58 on: November 10, 2004, 12:59:19 PM »
Excellent !!! Can't wait to get my boards...

Is that the Melcor 1731 op-amp in there?
Greg Stein
New Orleans, LA

robomatique

API 312 Thread!
« Reply #59 on: November 10, 2004, 01:25:38 PM »
Looks fantastic!!!   :razz:

How did you mount the opamp? DId you solder it in place in some way or did you have any type of sockets?

Thanks

Robert
"Trying is the first step towards failure."
-H. Simpson


 

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