API 312 Thread!

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Hi these are just molex (brand) connectors. If you google "Molex KK" and look under images, you should see what they look like.  You don't have to use these of course, you can just wire things directly, it just makes things easier if you need to remove a channel for maintenance.  The Aux Molex is only necessary if you use the Aux out (for a VU, or maybe to make yourself a mixer like the 3124MB+ or whatever it's called.  But that's another can of worms. All the ones I've built so far have nothing connected to the Aux out.

Check this number at mouser : 538-22-23-2027  It's the two pin male header. There is a female part that the wire gets put into, and then attaches to the male.  First though there is a metal piece attached to the wire. That's what makes electrical conductivity between the wire and the PCB pad that the male molex is soldered to.

The vertical headers are only needed if you mount the small PCB on top of the larger one. But you can also just connect them with left over resistor leads or hookup wire, but again, you won't be able to take it apart as easily.

hope that helps!
 
Awesome thanks mitsos,
what pitch do you reccomend?,


Also, I was going to use 4 channels of cinemag 75101apc in put trafos,

not going to use zobel or load resistor,  do I need to bridge those points?

does the 75101apc just fit straight onto ur board like the EA2622?
 
laddie.music said:
Awesome thanks mitsos,
what pitch do you reccomend?,
I'm travelling right now so can't measure, but IIRC they are all 0.1" (2.54mm).

Also, I was going to use 4 channels of cinemag 75101apc in put trafos,

not going to use zobel or load resistor,  do I need to bridge those points?
NO!  That will short your secondary to ground!  Just leave them out.

does the 75101apc just fit straight onto ur board like the EA2622?
Yes, both of those have the same pinout, as does the Altran 3402, and a few other cinemags and jensens.

good luck!
 
It sounds good for sure, the difference is in the ratio, it's a 1:8, so a bit less gain than the 75101 (18 vs 20dB for the Cinemag). 
 
For the other end of the molex does it matter that the termination is crimp style, i haven't been able to find a solder termination style

http://www.mouser.com/Search/ProductDetail.aspx?R=10-11-2023virtualkey53810000virtualkey538-10-11-2023
 
no solder ones that I know of. You need the little metal insert, I think this is the one:

mouser#  538-08-50-0114

crimp it to the wire, and insert into the female plastic part.

You can generally use a generic crimper for these, or even needlenose pliers, it just takes a bit longer and is fiddly so buy a few extras in case of mess ups.  These take a bit longer to put together but are good to have in case of maintenance.  In all reality, you don't need them, you could just solder the wires directly, but I don't recommend it.
 
Cool thanks man,
You know I have a ton of terminal blocks like this spare in my collection from old boards,
like this
http://www.mouser.com/ProductDetail/Phoenix-Contact/1705469/?qs=qgZcrvoyHAeKr1p0qncEog%3d%3d

Can terminal blocks work with your stuff ever tried it?, they are also easy to use
 
well, the ones in the link have 5.08 mm pitch, which means 0.2", which is too wide for the boards.  Anything with 0.1" pitch should fit. check these out at mouser:
651-1725656
571-282834-2

never used them, but they say 2.54mm pitch, so they should fit. check datasheets and measure PCBs for proper clearance before you order.
 
thanks mitsos,
so is pitch the width of the holes on the board??,    that's why we buy 2.54mm pitch so the molex / terminal solder points fit the holes?

 
Hello

I'm looking for a PSU for 2 rackmount API 312 and have found this: http://fadisel.com/cebek-electronica/fuentes-alimentacion/fuente-simetrica-de-500-ma-cebek-fe-73_r_297_512.aspx

The price is really low and includes a 220V AC to 18V AC trafo... do you think that it could be suitable for this project?

Many thanks!!
 
laddie.music said:
thanks mitsos,
so is pitch the width of the holes on the board??,    that's why we buy 2.54mm pitch so the molex / terminal solder points fit the holes?
Exactly!
barry_es said:
Hello

I'm looking for a PSU for 2 rackmount API 312 and have found this: http://fadisel.com/cebek-electronica/fuentes-alimentacion/fuente-simetrica-de-500-ma-cebek-fe-73_r_297_512.aspx

The price is really low and includes a 220V AC to 18V AC trafo... do you think that it could be suitable for this project?

Many thanks!!
No schematic to see, but it looks like a common linear PSU. Should work, but it does not have a +48VDC for phantom power, not sure if you need that. 
 
barry_es said:
.. and includes a 220V AC to 18V AC trafo...
from the 'Technique information' more likeley a 230V to 36V center tapped EI-core (not toroidal) transformer.
The pic from the shop seems to show a different (single rail) psu.
As mitsos already pointed out, another rail voltage for phantom powered mics might be missing that could be fed by the same transformer and a voltage doubler or tripler circuit on a piece of perfboard, if so needed.
Mains transformer dimensions (93/53/55mm) won't fit in a 1HE enclosure, if this matters to you.

 
barry_es said:
Many thanks to both. I will try to find another option... any suggestion for a PSU kit?
1st define the whole pic of your requirements (might be more than two API312 cards), IE +/-max.operating voltage of opamp(s) used, +48V phantom power required, operating voltage/current of maybe wanted/needed relais for maybe a -20dB pad, polarity inversion, switchable hpf, peak/overload/vu-display, max.allowed size of your enclosure to fit a psu and transformer inside or keeping the supply external, preamp might be connected to different mains voltages when touring, ...
Updating your profile with your location data might better help us to help you.
 
You are rigth Harpo... More info needed:

There will be only two API 312 and The PSU inside an 1 U rackmount box. It will only work in a fixed location with 220V.The  opamps are EA 2520 from classic API. No DI, no led display... just phantom power,  Pad, phase change, gain and one power on led.
 
barry_es said:
There will be only two API 312 and The PSU inside an 1 U rackmount box. It will only work in a fixed location with 220V.The  opamps are EA 2520 from classic API. No DI, no led display... just phantom power,  Pad, phase change, gain and one power on led.
European sources could be JPKs 'PSL1' from Sound Sculptor or PPAs 'PSU2' from APP studio.
Other/non EUR sources might be the
Rocheys 'Uber PSU' from Expat Audio or mikefatoms 'ML12PSU' from Whistle Rock Audio,
all prementioned (probably missing some) psu pcbs or psu kits avail. thru the 'White Market' section of this forum, that could be set up for your probably gar2520 or SL-2520 DOAs (dunno a EA 2520).

Another source is Joes 'AC/DC' or 'Powerstation' from JLM Audio
...or just build one yourself on a piece of perfboard...
 
Many thanks Harpo!!

Many options, I will have to check them deeply, but... what do you think about using 78XX and 79XX regulators in Expat Audio 'Uber PSU'? I have heard that they are not very desirable for mic pres PSUs...

Thinking about a mix of them on a perfboard as you suggested...
 
Last question Mitsos!, hehe,

http://www.mouser.com/ProductDetail/Phoenix-Contact/1725698/?qs=Ul7CXFMnlWWqMaQ725FYXmzwK%252bHzU77o%2fz4Y0OOrB74%3d

Current Rating: 6 A
Voltage Rating: 63 V

Just wondering if those numbers are ok for the terminal blocks.
 
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