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48 v phantom power supply units. Difference in sound?
Old 15th September 2015
  #1
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Freddie Flame's Avatar
 

48 v phantom power supply units. Difference in sound?

Will a expensive (ca 300USD) phantom power supply unit make my Neumann tlm 103 sound better than a cheap one (ca 50USD)?
Old 15th September 2015
  #2
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nosebleedaudio's Avatar
 

Quote:
Originally Posted by Freddie Flame View Post
Will a expensive (ca 300USD) phantom power supply unit make my Neumann tlm 103 sound better than a cheap one (ca 50USD)?
It IS possible, because after the fact Phantom power use Caps in series with the mic input...
The best IMHO is to be part of the Mic pre design with superior decoupling and a ramp up like I use...Reduces the pop when phantom is turned on..
Phantom needs to be VERY clean and a solid +48V, +- 4V...
Old 15th September 2015
  #3
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The answer to your question resides in the quality and design of your pre amp or desk providing the phantom power. In my studio the ADL600 and UA 4-710d pres along with my UFX are all very clean power sources as is the QU16 we use for live performance. Many years ago I had a Mackie VLZ that was not capable of powering up the condensers we needed for our Bluegrass band. I dumped it and bought a 2800 series Allen & Heath that was a much better desk with MUCH BETTER POWER RAILS & Phantom Power.
Old 15th September 2015
  #4
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In theory there will be little or no change in the performance of your mic introduced with a decently designed phantom power supply.

However, cheaper units often have less filtering (smaller caps) in the power supply and that can allow hum and unwanted noise to enter the circuit.
The other difference is that the cheaper phantom supplies can only supply enough current to run a single or small number of mics.
What happens is that a mic (or several mics) with a larger current draw has/have a higher voltage demand and if the power supply struggles or sags their will be a dip in the voltage.
What this translates to is a reduction in the headroom of the mic.

So, you can operate a condenser mic with less than the full 48V, but the mic's headroom will be diminished and if the voltage falls too far the mic's internal pre amplifier won't work at all.
The voltage has to drop pretty far before the later happens.

In your case, a single TLM103 isn't going to cause a cheap phantom supply to sag or run out of juice, but I wouldn't think the power supply filtering would be as good on the cheaper unit.
All this being said, a phantom power supply is not a complicated circuit.
I have built my own phantom supplies in the past when my console didn't have an internal supply.
Old 15th September 2015
  #5
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Freddie Flame's Avatar
 

Thanx for your replies guys!
So, I have a Neve 1073LB in an older API lunchbox that has no Phantom power, and my main mic will be the tlm103. Do you think a better (more expensive) +48 psu will be worth it, or may I be just as good with a cheaper one?
Old 15th September 2015
  #6
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Brent Hahn's Avatar
 

Quote:
Originally Posted by Freddie Flame View Post
Will a expensive (ca 300USD) phantom power supply unit make my Neumann tlm 103 sound better than a cheap one (ca 50USD)?
Are you sure you're asking the right question? Is it possible that you simply don't care for the mic?
Old 15th September 2015
  #7
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Quote:
Originally Posted by Freddie Flame View Post
Thanx for your replies guys!
So, I have a Neve 1073LB in an older API lunchbox that has no Phantom power, and my main mic will be the tlm103. Do you think a better (more expensive) +48 psu will be worth it, or may I be just as good with a cheaper one?
How old is the Lunch Box, don't ever remember seeing one with out phantom.. Older than mid 80's??
Maybe I just never sold one with out phantom...
Old 15th September 2015
  #8
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Never thought about it before, but is phantom power generated by the lunchbox itself, or by the individual modules?
Old 15th September 2015
  #9
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Quote:
Originally Posted by Brent Hahn View Post
Never thought about it before, but is phantom power generated by the lunchbox itself, or by the individual modules?
Lunchbox in the ones I've seen. Lunchbox provides +/-16V and +48V rails to each module.
Old 15th September 2015
  #10
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Quote:
Originally Posted by Brent Hahn View Post
Never thought about it before, but is phantom power generated by the lunchbox itself, or by the individual modules?
Comes from the main power supply then goes to each module connector.

Last edited by nosebleedaudio; 15th September 2015 at 04:26 PM..
Old 15th September 2015
  #11
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John Willett's Avatar
 

Quote:
Originally Posted by nosebleedaudio View Post
Phantom needs to be VERY clean and a solid +48V, +- 4V...
And capable of providing 10mA to every mic. (many do not).
Old 15th September 2015
  #12
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Quote:
Originally Posted by John Willett View Post
And capable of providing 10mA to every mic. (many do not).
5mA is on the highside, if a mic really pulled 10mA there would only be around 14volts left for the mic to use...not much...
Old 15th September 2015
  #13
Quote:
Originally Posted by nosebleedaudio View Post
5mA is on the highside, if a mic really pulled 10mA there would only be around 14volts left for the mic to use...not much...
Does the milliamp rating typically refer to the overall reserve for all mics in a multi-channel phantom powering device? For example, the Rolls rack mount unit is rated at 14mA, has six channels, and has a street price of around $150.
Old 15th September 2015
  #14
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Quote:
Originally Posted by nosebleedaudio View Post
5mA is on the highside, if a mic really pulled 10mA there would only be around 14volts left for the mic to use...not much...
But the spec. states that 10mA is required.

I know most mics only draw 2mA, 3mA or 4mA, but I have seen some at 6mA - which is why the spec. states 10mA is required.
Old 15th September 2015
  #15
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Quote:
Originally Posted by Aural Endeavors View Post
Does the milliamp rating typically refer to the overall reserve for all mics in a multi-channel phantom powering device? For example, the Rolls rack mount unit is rated at 14mA, has six channels, and has a street price of around $150.
specs state 14mA per channel.
the mic will draw what ever it needs...
Old 15th September 2015
  #16
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kafka's Avatar
Quote:
Originally Posted by nosebleedaudio View Post
How old is the Lunch Box, don't ever remember seeing one with out phantom.. Older than mid 80's??
Maybe I just never sold one with out phantom...
I thought the BAE was available without 48v until recently, unless I have it mistaken for another brand. But I do know I saw a new one in the past couple of years.
Old 16th September 2015
  #17
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Quote:
Originally Posted by nosebleedaudio View Post
5mA is on the highside, if a mic really pulled 10mA there would only be around 14volts left for the mic to use...not much...
It's been years since I've measured it, but from what I recall, that's just about exactly what voltage is on each leg to ground for a C414EB when its fed from a standard 48V supply.

Total draw would be about 7 mA on each leg (14 total) into a dead short.

If you apply the 48V to the primary side of a transformer, you don't need to have any capacitors in the circuit. Just two [carefully) matched resistors. Of course, transformers have their own sonic issues.

Geoff
Old 16th September 2015
  #18
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Freddie Flame's Avatar
 

Quote:
Originally Posted by nosebleedaudio View Post
How old is the Lunch Box, don't ever remember seeing one with out phantom.. Older than mid 80's??
Maybe I just never sold one with out phantom...
Don´t know how old it is but it looks OLD! Got it recently.
I heard it was built in the beginning of the lunchbox era when the idea was to use only api eq and maybe compressor in it. Not to be used for micpres.
Old 16th September 2015
  #19
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Quote:
Originally Posted by Freddie Flame View Post
Don´t know how old it is but it looks OLD! Got it recently.
I heard it was built in the beginning of the lunchbox era when the idea was to use only api eq and maybe compressor in it. Not to be used for micpres.
Does it have 1/4" & TT's on the back?
4 Space?
So, you have tested to make sure there is no +48V on Pin 15, Pin on the bottom..

Found some old Power supply schematics (1981) & Lit and the Lit for the Lunch Box does state: Optional +48V.
Which also was when Pin 15 was still being used for Direct out on 560a's & 560b's...
Too bad your so far from me, I have 9- 6 space Lunch Boxes...All modified...

Note: The supply schematic I have from 1981 does NOT have +48V...

If it was me, I would get a newer Lunch Box with +48V...

Last edited by nosebleedaudio; 16th September 2015 at 01:05 PM..
Old 17th September 2015
  #20
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Freddie Flame's Avatar
 

Quote:
Originally Posted by nosebleedaudio View Post
Does it have 1/4" & TT's on the back?
4 Space?
So, you have tested to make sure there is no +48V on Pin 15, Pin on the bottom..

Found some old Power supply schematics (1981) & Lit and the Lit for the Lunch Box does state: Optional +48V.
Which also was when Pin 15 was still being used for Direct out on 560a's & 560b's...
Too bad your so far from me, I have 9- 6 space Lunch Boxes...All modified...

Note: The supply schematic I have from 1981 does NOT have +48V...

If it was me, I would get a newer Lunch Box with +48V...
Yep, that´s the one I´ve got.
I thought I´d save some money on just getting a 48v supply. If it does not degrade the sound I will be happy with that. But if I need the enxpensive ones I might as well get another lunchbox.
Old 17th September 2015
  #21
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Quote:
Originally Posted by Freddie Flame View Post
Yep, that´s the one I´ve got.
I thought I´d save some money on just getting a 48v supply. If it does not degrade the sound I will be happy with that. But if I need the enxpensive ones I might as well get another lunchbox.
I would HIGHLY suggest the 6 space with XLR's, the one with a linear supply...
These are found on ebay, and are not the newest ones...
Using an outboard phantom will be fine, just a pain to keep up with, plus the extra cables needed...
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