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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: Popmarter on November 06, 2019, 03:45:52 AM

Title: ISO: Smallest 48k powersupply
Post by: Popmarter on November 06, 2019, 03:45:52 AM
I love my Sony A10 and is ability to use an app for setting levels. In case you need too, you can hook all things on and put it on, way before a show starts and there is no need to doublecheck it all.

with that i would like to use it with a pair of 48v mics. what options do i have for a small powersupply? Denecke PS2? 3 hour batterylife will do.
Title: Re: ISO: Smallest 48k powersupply
Post by: if_then_else on November 06, 2019, 06:40:27 AM
JuicedLink RM222. It supports 12V/48V of phantom power, runs off a single 9V Li-ion battery for > 3.5 hours.
It's discontinued now, but I still have an unused one at home as a backup unit, if there's any interest.

Otherwise, check out the ones made by Kortwich, though you might need some external batteries.
Title: Re: ISO: Smallest 48k powersupply
Post by: aaronji on November 06, 2019, 06:49:55 AM
I've never used one, but Core Sound sells a P48 battery box. The 2Phant (http://www.core-sound.com/2Phant/1.php)...
Title: Re: ISO: Smallest 48k powersupply
Post by: pohaku on November 06, 2019, 12:37:58 PM
There are some in line power supplies as well, but you would need 2 of them.  They are relatively small.
Title: Re: ISO: Smallest 48k powersupply
Post by: yug du nord on November 06, 2019, 01:44:45 PM
I haven't seen any in-line P48 supplies...  but if it's within your budget, consider a small-ish preamp instead of a dedicated P48 supply.  I think small preamps are about the same size as most external P48 supplies.  And the preamp most likely would be higher quality than the A10 preamps.
But an external preamp would most likely be more expensive.

But then again, you would probably have to keep an eye on the external preamp...  so my suggestion might be worthless.   :facepalm:
Title: Re: ISO: Smallest 48k powersupply
Post by: if_then_else on November 06, 2019, 03:15:21 PM
I actually mean the Kortwich M2-mini which is intended for some pro cameras (like the Arri Alexa).
But the device can be customized...

The caveat is that you'd need an external battery and an Hirose adapter.

https://www.shop-ftt.de/de/vcp-m2-mini-arri-alex (https://www.shop-ftt.de/de/vcp-m2-mini-arri-alex)

This is the RM-222 (in comparison to the Line Audio CM3 mics)

https://www.dropbox.com/s/aed4hf23cbxuphg/line_audio-cm3.jpg?dl=0 (https://www.dropbox.com/s/aed4hf23cbxuphg/line_audio-cm3.jpg?dl=0)
Title: Re: ISO: Smallest 48-Volt power supply
Post by: DSatz on November 08, 2019, 07:15:06 PM
Nearly all microphones that require 48-Volt phantom powering also have balanced outputs, while your recorder has unbalanced inputs. Thus, you need more than just a 48-Volt phantom power supply; you also need a way to unbalance the signals from your microphones. As a third (but very important) item, the 48 Volts from the supply must be blocked from reaching the inputs of your recorder.

I'll give my reasons in a moment, but I think that the best choice for someone in this situation is often a good, small preamp that has phantom powering built in. Classic examples include the Sound Devices MP-2, Beyer MV-100 and Sonosax SX-M2; other people around here have other favorites as well.

Here's the thing: Phantom powering is standardized, but output circuits for microphones are not. If I spell this all out, it will go on for several paragraphs, but the essence of the situation is that there is not, and _can never be_, a passive adapter that will work with all different types of balanced microphones to send their signals to the input of your recorder. The most commonly used passive approaches will fail to work with, and may actually damage, microphones that they weren't designed to work with. There is no standard for how to take the output of a balanced microphone and connect it to an unbalanced input. The entire world of audio standards is based on never connecting professional (balanced) and consumer (unbalanced) equipment to each other.

So if you work out a solution for the particular microphones that you have today, then when you want to try some other type of microphones, you may find that you also have to get different adapters wired up to connect your power supply to your recorder. You will not have that problem if you use an outboard preamp (as long as it has balanced inputs and unbalanced outputs, or at least a consistent way to connect its outputs to unbalanced inputs).

A battery-run phantom power supply must have a certain minimum size, mainly because of its batteries and connectors. The minimum size for a battery-run preamp with phantom powering is nearly the same--the preamp-specific components don't usually take up much room. But nearly all preamps with phantom powering have balanced inputs, so you can connect any balanced microphone to those inputs without worrying about any special details about the microphones. That, after all, is what standards are for.

--best regards
Title: Re: ISO: Smallest 48k powersupply
Post by: gormenghast on November 08, 2019, 08:15:20 PM
Neumann BS48i2 is pretty small.  There was one for sale cheap for quite a while here.  I don't know if it sold.  They sold new around $1100. 

"The BS48i2 will operate up to 20 hours on a single 9-volt battery."
Title: Re: ISO: Smallest 48k powersupply
Post by: jerryfreak on November 08, 2019, 08:27:32 PM
re: Dsatz's psot

https://circuitswiring.com/balanced-unbalanced-converter-for-audio-work/
Title: Re: ISO: Smallest 48k powersupply
Post by: Popmarter on November 09, 2019, 06:43:29 AM
Thanks guys for all the comments, very usefull. Love this community!

I was lucky to have found a Beyer for cheap, which i hope to receive in the next few weeks. See how that works.
Title: Re: ISO: Smallest 48k powersupply
Post by: jerryfreak on December 23, 2019, 08:57:12 PM
saw this, looks like it fits

https://www.mozegear.com/phantom-power
Title: Re: ISO: Smallest 48k powersupply
Post by: rigpimp on December 23, 2019, 11:49:33 PM
Neumann BS48i2 is pretty small.  There was one for sale cheap for quite a while here.  I don't know if it sold.  They sold new around $1100. 

"The BS48i2 will operate up to 20 hours on a single 9-volt battery."

I have a really nice one of these I would let go of.  I have not used it in many many years.  I even have extra breakout cables for it.
Title: Re: ISO: Smallest 48k powersupply
Post by: willndmb on December 24, 2019, 09:10:31 AM
I haven't seen any in-line P48 supplies...  but if it's within your budget, consider a small-ish preamp instead of a dedicated P48 supply.  I think small preamps are about the same size as most external P48 supplies.  And the preamp most likely would be higher quality than the A10 preamps.
But an external preamp would most likely be more expensive.

But then again, you would probably have to keep an eye on the external preamp...  so my suggestion might be worthless.   :facepalm:
100%
You can get a tinybox that is prob the smallest 48v and a pre all in one
Title: Re: ISO: Smallest 48k powersupply
Post by: DSatz on December 30, 2019, 09:10:25 PM
The Neumann BS 48 i2 will power two P48 microphones, but how long the battery will last depends greatly on what type of battery it is and how much current is drawn by the mikes. You may find that you get only 90 minutes or possibly even less before you have to change.

Also, if you're considering buying a used BS 48 (either the single-channel or the stereo version) be sure to get a money-back guarantee. I've bought several of these on eBay and had the usual 50%-or-higher rate of duds. One supply put out 37 Volts; two were really most sincerely dead. These had to be abandoned. They are extremely expensive to repair, since what usually goes bad is the module containing the DC/DC converter, and that part costs several hundred dollars, not to mention unsoldering the old one and soldering in the new one.

--best regards
Title: Re: ISO: Smallest 48k powersupply
Post by: Len Moskowitz (Core Sound) on December 30, 2019, 10:53:39 PM
Core Sound 2Phant. Runs forever on two hot-swappable 9 Volt batteries:

www.core-sound.com/2Phant/1.php
Title: Re: ISO: Smallest 48k powersupply
Post by: EmRR on December 30, 2019, 11:12:59 PM
re: Dsatz's psot

https://circuitswiring.com/balanced-unbalanced-converter-for-audio-work/

even smaller, use a THAT 1200 series chip.  One example:

https://www.digikey.com/product-detail/en/sparkfun-electronics/BOB-14002/1568-1574-ND/7033192
Title: Re: ISO: Smallest 48k powersupply
Post by: gewwang on December 31, 2019, 08:48:49 AM
i ran the sonosax sx-m2 to power my dpas in front of the a10 until the d10 came out. now i just use the d10 as an all-in-one for stealthing and it’s been my only stealth rig since.
Title: Re: ISO: Smallest 48k powersupply
Post by: weroflu on January 08, 2020, 12:34:45 PM
I made this pre about 2 years ago. That 1510 chips. Afaik it's the smallest phantom powered mic pre, though not available for sale. Two balanced mini jack inputs, one minijack stereo unbalanced output. 10 way mini grayhill volume switches, 48v switchable phantom per channel.  I figured since really good all in one recorders like the dr100mkiii came out this thing would not have utility but who knows. No noise measurements but it sounded dead quiet and great. Mint tin case, so it's not built like a tank. No protruding switches are plus and minus, you have to get inside to set gain and switches but also it would be less prone to any of the switches breaking.

It would be a fun side project to break out the iron and sell some but I don't want to run a company or deal with any bureaucratic tape.
Title: Re: ISO: Smallest 48k powersupply
Post by: willndmb on January 13, 2020, 08:48:37 AM
I made this pre about 2 years ago. That 1510 chips. Afaik it's the smallest phantom powered mic pre, though not available for sale. Two balanced mini jack inputs, one minijack stereo unbalanced output. 10 way mini grayhill volume switches, 48v switchable phantom per channel.  I figured since really good all in one recorders like the dr100mkiii came out this thing would not have utility but who knows. No noise measurements but it sounded dead quiet and great. Mint tin case, so it's not built like a tank. No protruding switches are plus and minus, you have to get inside to set gain and switches but also it would be less prone to any of the switches breaking.

It would be a fun side project to break out the iron and sell some but I don't want to run a company or deal with any bureaucratic tape.
how long on average can it run two mics at 48v off a 9v?
Title: Re: ISO: Smallest 48k powersupply
Post by: jerryfreak on January 13, 2020, 06:44:47 PM
nobody mentioned tinybox. P48 was the one feature that didnt make it from the TB to the IPA
Title: Re: ISO: Smallest 48k powersupply
Post by: willndmb on January 13, 2020, 09:54:58 PM
nobody mentioned tinybox. P48 was the one feature that didnt make it from the TB to the IPA
i did
By far the smallest and best overall option imo
Title: Re: ISO: Smallest 48k powersupply
Post by: jerryfreak on January 14, 2020, 12:50:20 AM
my bad!
Title: Re: ISO: Smallest 48k powersupply
Post by: spyder9 on January 14, 2020, 01:13:38 PM
Denecke PS-2.

And it sounds great too!  :)