How to Connect an External PSU for a Mic Pre?

[cpsmusic]

Hi,

In another post I inquired about a "transparent" mic pre. A few different ones were suggested which I'm interested in building. I was thinking that an external PSU that supplied phantom and operating power to the pres would be useful - something that I could just plug in. The diytubes Universal PSU seems to fit the bill. Just wondering what the best way to get the different voltages into the mic pre would be? Am I right in thinking that I'll need some kind of four-pin connector (48V, +-15V, Ground)? My father (who recently passed away) built a lot of tube HiFi gear and some was powered using what I think are Amphenol (?) connectors. I want to make sure that if I do this it's solid and safe!

Cheers,

Chris

 

[Whoops]

Hi Chris,
I dont really know if I understand what your question is but I will try to help you

Theres a lot of different PSU's that people around here use.

The SSL9K was popular one it used 78xx and 79xx regulators and one LM317 for the 48v
Other PSU's use LM317's and LM337 so that all voltages are variable
there's a lot of different options, look in the white market.

here is an example:
https://pcbgrinder.com/index.php?route=product/product&path=59_73&product_id=98

 

[cpsmusic]

Thanks, my question was how to physically connect the external PSU to the mic pre - i.e. what sort of cable and connector. I came across one example which uses a 5-pin XLR. Just wondering if there was any other connector that would be better?

 

[Whoops]

I normally use this type 5 pin "CB Radio" connectors:

http://www.dhresource.com/albu_292778247_00-1.0x0/5-pin-connector-for-cobra-uniden-ssb-cb-radio.jpg

http://www.vetco.net/catalog/product_info.php?products_id=6555

http://www.parts-express.com/cb-mic-plug-5-pin-female--090-540


I like to use them because they're cheaper than 5 Pin XLRs and I dont have any other equipment around the studio that uses these connectors for audio or other application, so I don't have a risk of being misused to connect to the wrong piece of equipment.

you can also use 5pin XLR, 5 Pin mini-XLRs, 5 Pin DIN:

https://proaudio.com/catalog/switchcraft-ta5fx-mini-5-pin-female-xlr-cable-connector.asp

http://www.allelectronics.com/make-a-store/item/din-5f/female-5-pin-din-connector-in-line-locking/1.html


I'm advising 5 Pin because you will need to connect the MiC pre case to the Earth Pin in the 3 prong power chord.
so you should have:
1) +15V
2) -15V
3) 0V (signal ground)
4) +48V
5) Chassis Ground

 

[cpsmusic]

The 5-pin CB connector looks perfect. Yes, I was mainly concerned that other types of connectors would accidentally get plugged into the wrong thing.

Cheers!

 

[Whoops]

It's hard because they have 5 pins so will not fit in a 3 pin connector .