Topic: Smallest Pre-amp with 48v Phantom Power

[cashandkerouac]

I'm looking for a good quality pre-amp that will supply 48v phantom power.  Right now the Aerco MP-2 is the front-runner, but I'd prefer something that is more similar in size and closer in price to the Naiant Tinybox.  Any suggestions?  Can the Tinybox be custom ordered with 48v rather than 12v phantom power?  Thanks. 

[willndmb]

the tinybox does not do 48, but the littlebox can
prob roughly the same size as aerco but much less in cost, custom made for you, ships faster

[Todd R]

In the way of small preamps, there are (including historical and current models) the Aerco, the Beyer MV100, Sonosax sxm2, EAA/Aeta PSP2, Aeta PSP3, Sound Devices MP2 and MixPre, and the Naiant littlebox.

I'm sure this list isn't all of them, just some I can think of off the top of my head.  I don't think any are smaller than the Aerco MP2 though.  Beyond that, they're all probably pretty much in the same ballpark for size.

The tinybox does not do 48v phantom, and can't be configured to since the blocking capacitors needed to block the 48v DC are too large to fit in the tinybox case.  I'd imagine this would be the case for any 48v preamp attempting to be that small, so I'd doubt there are any 48v preamps the size of the tinybox out there.

Not to re-open your mic question, but the smallest solutions are probably to use the tinybox with schoeps caps and schoeps CMR cables (and no bodies), or similarly to use the Beyer ck930 caps and cables with a custom made tinybox (again with no bodies). There are some threads with pictures on these options.

Short of that, getting a pair of mics that can run on 12v phantom like the Milab vm44-link and pairing them with a tinybox also yields a pretty small solution.

I'm curious if there are any 48v phantom preamps out there smaller than the Aerco for use with any 48v mics (thus not including the schoeps nbox solution).  I can't recall any options though smaller than than those on the list above.

[jbell]

What's the cost on a new Aerco MP2? 

[H₂O]

Although it's not just a recorder - the Sonosax mini-r82 is a little bigger then a Korg MR-1, runs off 4 AA's and not only provides 48V but also is a 8 track recorder.


A little pricy at $5K USD but it's Swiss made!  Perfect recorder for the Rolex Submariner waring taper.

[page]

I'm curious if there are any 48v phantom preamps out there smaller than the Aerco for use with any 48v mics (thus not including the schoeps nbox solution).  I can't recall any options though smaller than than those on the list above.

Bingo. I almost listed an abreviated form, but realized that while I think the sax is sort of small when I hold it, it's not as small as the aerco, and if size is important, it's not going to beat the mp-2. The littlebox gets a good mention because it's comparatively cheap so a small hit on space may be worth it.

Although it's not just a recorder - the Sonosax mini-r82 is a little bigger then a Korg MR-1, runs off 4 AA's and not only provides 48V but also is a 8 track recorder.


A little pricy at $5K USD but it's Swiss made!  Perfect recorder for the Rolex Submariner waring taper.

touche

the r82 will fit the bill if price isn't a problem and you're willing to ditch your recorder as well. 

[OFOTD]

A little pricy at $5K USD but it's Swiss made!  Perfect recorder for the Rolex Submariner waring taper.

the r82 will fit the bill if price isn't a problem and you're willing to ditch your recorder as well. 

At least you'd still have a sweet Submariner on your wrist.   

[jbell]

A wendt X2 and there is one in the YS! 

http://taperssection.com/index.php?topic=141314.0

[sunjan]

I put the dimensions of gear mentioned into a spreadsheet.
Turns out the Aerco is one of the the smallest pre, at 18 cu.inch, even compared to all-in-one recorders.
The only P48 device smaller than that is the Denecke PS-2 (15 cu.in), but it doesn't come with any gain.

Other contenders and their cubic footprint:
Sonosax MiniR82   77 16.4
Aerco MP-2           16 18
Core Sound Mic2496  23
Zoom H4n           23
Littlebox                   25
Tascam DR-100   27
PSP 3                       27
MV100                     30
SX-M2                      30
Mixpre                     35
SD MP-2                   35
USBPre2                   47
Echo Audiofire 4   49
Graham-Patten DMic-20/24  56
Wendt X2            58

(edited, sorry got some figures wrong)

[cashandkerouac]

What's the cost on a new Aerco MP2?

$750

[H₂O]

What's the cost on a new Aerco MP2?

$750

and 6 months of your life 

[H₂O]

Sonosax MiniR82   77

I don't think it's that big - I actual have one (temporarily) right now and it's much smaller than I thought - maybe an optical illusion or something (a swiss mind game).


I'll post some comparison photos soon but it looks to be about the size of a sony M1.

[Todd R]

Yeah, good point.  From what I've seen, the miniR82 is 4.75" x 3.15" x 1.1", putting it at 16.4 cubic inches.  Considering it includes the recorder as well, definitely the smallest solution.

[willndmb]

I put the dimensions of gear mentioned into a spreadsheet.
Turns out the Aerco is really the smallest, at 16 cu.inch, even compared to all-in-one recorders.
The only P48 device smaller than that is the Denecke PS-2 (15 cu.in), but it doesn't come with any gain.

Other contenders and their cubic footprint:
Aerco MP-2   16
Core Sound Mic2496   23
Zoom H4n   23
Littlebox   25
Tascam DR-100   27
USBPre2   47
Echo Audiofire 4   49
Graham-Patten DMic-20/24 (disc.)   56
Wendt X2    58
...
Sonosax MiniR82   77

guess i don't understand how to come up with cubic inch
the lb is .2"x.1x.7 inch bigger then the aerco
how does that come out to 9 cubic inch bigger?
isn't a cubic inch equal to a cube thats sides are all 1"

[sunjan]

Todd is right, I goofed on the MiniR82 dimensions.

Will, the cubic footprint is simply the W x D x H multiplied.
As an example, Littlebox specs are:
"Case size, standard: 4.7" x 3.1" x 1.7" (120mm x 78mm x 43mm)"

4.7 x 3.1 x 1.7 = 24.769

[willndmb]

Todd is right, I goofed on the MiniR82 dimensions.

Will, the cubic footprint is simply the W x D x H multiplied.
As an example, Littlebox specs are:
"Case size, standard: 4.7" x 3.1" x 1.7" (120mm x 78mm x 43mm)"

4.7 x 3.1 x 1.7 = 24.769

gotcha

the aerco is 18 then
4x3x1.5

[jbell]

could you do an extended case version with aa or 9v sled? 

[jbell]

Just a thought the Aerco uses 9v batteries.

Extended tinybox?  No, that would be a littlebox.  Those battery trays aren't exactly small you know . . .

[Todd R]

It's possible to design a P48 tinybox but it would lack an internal battery.  I don't think that's a very compelling product, but if enough people think otherwise . . .

Possible to do a 48v tinybox with 1:1 microtransformers to block the 48v DC instead of the larger blocking capacitors?  Of course, this assumes the tranfos are smaller than the caps, but I thought they were.  Aiming of course to still keep the battery inside.

[Chuck]

I built a 5 x 9v NiMH littlebox (kit) into a Hammond 1590BB enclosure.

http://taperssection.com/index.php?topic=123658.0

I *think* it's the same enclosure as the Aerco. It's very small and sounds great!

[willndmb]

how would one power the tiny box if it was 48v?
external power?? to me that would defeat the purpose

i like not needing tools to change the battery, ie lb vs aerco

[page]

how would one power the tiny box if it was 48v?
external power?? to me that would defeat the purpose

i like not needing tools to change the battery, ie lb vs aerco

conversely, I'd rather have a removable 9v for the (polarization 48v tinybox), even if it meant removing the case each evening to change it. I'd use it so little that the internal l-ion would have to be removed/changed before I really got a good use out of it. I guess in some ways if a removable 9v isn't an option down the road, I'd gaffer tape it to the bottom of the box and wire a connector going inside somewhere. Ugly as sin, but it would allow me to change the battery. I've gotten burned twice on hard to remove l-ion units already so I'm weary of them. ymmv

[willndmb]

i agree
a 48v where you had to remove the case would be better imo then nothing at all
akg actives are better then a 48v tinybox too

[page]

You can have a 9V tinybox now, you just have to request it.  You need to be a bit careful with closing the case as the screws are steel but the case is aluminum.  If you overtorque the screws you'll strip the case.

oooo, aaaaaaa. shiney. thanks for the info.

[Roger Gustavsson]

P48 or P12, but I think many microphones do not take the full advantage of P48. Many are specified for 9-52 V. Maybe some are doing fine on P12? It is up to which microphones are going to be used.


Roger

[willndmb]

P48 or P12, but I think many microphones do not take the full advantage of P48. Many are specified for 9-52 V. Maybe some are doing fine on P12? It is up to which microphones are going to be used.


Roger

doing fine and full potential are different too
in the end it comes down to your ears imo
if you have mics that can run at 12v but sound better at 48v you may or may not care for the 12v sound

[page]

P48 or P12, but I think many microphones do not take the full advantage of P48. Many are specified for 9-52 V. Maybe some are doing fine on P12? It is up to which microphones are going to be used.


Roger

doing fine and full potential are different too
in the end it comes down to your ears imo
if you have mics that can run at 12v but sound better at 48v you may or may not care for the 12v sound

has anyone actually done testing on this? I'd honestly be surprised if schoeps, beyer, and akg all advertised compatibility at P12 and sounded "better" at P48. That seems like an engineering flaw to me.

[Roger Gustavsson]

The tradional Schoeps circuitry supplies the same voltage to the impedance convertering stage with P12 or P48. The buffer stage will probably have a higher maximum swing while running on P48. How many are really running their microphones at that high SPL to explore the difference? Normally we do not have 125+ dB in concerts, have we? I think we can find the figures in the specifications of some microphones.

Roger

[dactylus]

Short of that, getting a pair of mics that can run on 12v phantom like the Milab vm44-link and pairing them with a tinybox also yields a pretty small solution.

^
Has anyone out there with a pair of Milab VM44-Links gone the 12v phantom route pairing them with a tinybox?  If so I'd love to hear the results as I'd like to have that option available for myself.

[page]

The tradional Schoeps circuitry supplies the same voltage to the impedance convertering stage with P12 or P48. The buffer stage will probably have a higher maximum swing while running on P48. How many are really running their microphones at that high SPL to explore the difference? Normally we do not have 125+ dB in concerts, have we? I think we can find the figures in the specifications of some microphones.

Roger

Correct, we normally don't. I've only had 2 instances where I came close (mathematically the second one came out to just under 125 and I didn't measure the other) and both were cramped stage lip/onstage environments.

[DSatz]

page, there are many different circuit arrangements for condenser microphones, so I can't say how they all behave. Furthermore there is no standard for "9 - 52 Volt phantom powering" so any manufacturer who lists such a specification may seem to be doing the customers a big favor, but in fact any reference to an established powering standard is being evaded in that way.

In general, most microphones that can accept "9 - 52 Volts" are something like a 12-Volt phantom microphone that is designed to physically tolerate 52 Volts. They either are electret ("pre-polarized") microphones, or else they use a DC/DC converter internally so that the capsule is polarized at the intended voltage no matter what you supply them with (within their range, of course). Whether the audio output circuitry benefits from a higher supply voltage than the minimum would vary with the particular circuit design.

Schoeps CMC 6 and CCM microphones have come up in this discussion, and it's worth mentioning that they are something of an exception to the above. They use DC/DC converters, but instead of designing for the lowest allowable voltage and then throwing away what they don't need (i.e. converting it to heat inside the amplifer), they actually sense the incoming voltage and switch the converters to one of two specific modes. As a result they can (and do) conform to both ISO standard 12-Volt and ISO standard 48-Volt phantom powering, with identical audio performance, including maximum SPL.

But when they run at 12 Volts the DC conversion is more efficient, so for battery-powered recording, that would be the preferred mode if you have a choice. (48 V at 5 mA = 240 mW, while 12 V at 10 mA is only 120 mW.)

--best regards

[su6oxone]

A little pricy at $5K USD but it's Swiss made!  Perfect recorder for the Rolex Submariner waring taper.

the r82 will fit the bill if price isn't a problem and you're willing to ditch your recorder as well. 

At least you'd still have a sweet Submariner on your wrist.   

I'm partial to the Turn-O-Graph myself.

[Roger Gustavsson]

I think it is misleading with "phantom power". It seems that some believe there is power involved, that something is amplified and that is rarely the case. Phantom power supply or phantom powering is more appropriate.

Roger

[OFOTD]

I'm partial to the Turn-O-Graph myself.

I love that SS Date-Just.  Not very many Turn-O-Graph DJ's around that's for sure.    Great looking timepiece. 

Personally I am partial to the LV Submariner (LV16610)   

[su6oxone]

Personally I am partial to the LV Submariner (LV16610)   

Oh, that's nice... I like the green bezel.

[OFOTD]

Personally I am partial to the LV Submariner (LV16610)   

Oh, that's nice... I like the green bezel.

Me too.  The green bezel was the big selling point for me.  Only the 50th Anniversary Subs have the green bezel.  Unlike other Submariners they also have the maxi dial. There is a new one 'the hulk' that has the green bezel AND a green dial.   A little too much green for me on that one.   

I wish they had a a 48v version though...     ^^ sorry for the hijack

[Church-Audio]

I am going to develop a preamp, we are already working on the phantom supply circuit that will be the size of the 9100 preamp with FULL 48 volts and operate on 2 AA batteries or 9V we have yet to determine this. The preamp will have a single gain control with 6-12 steps and a simple vu meter. I will have this finished by the end of this year. This will be one of the smallest preamps in existence for stealth work. There will be other features that I cant speak of at the moment but its coming. When it does we will allow one to be lent out on the loaner section with a security deposit for evaluation. I am also in the works of opening up a Church Audio USA for emergency service of this preamp and for future designs / products all existing Church Audio products will be sold in Canada.. All preamps including the new line will still be shipped from Canada and be hand built by me. This preamp will be stereo.

[Chuck]

That's great Chris.

[jbell]

That's great Chris.

[page]

today is like christmas in july for folks after small gear.

Need a vote on feature set though, here are two options:

If you are just asking between the two options, maybe create a poll? dunno if that would be better or not.

[acidjack]

OK then, I can't let a core product line go, I'll have long tinybox with P48 out by the end of March . . . that is 0.9" x 2.1" x 4.7", or 9 cu. in.  I'll try and see if I can keep the design to 4" deep and cut the case, that case is easier to lop off than the others, that will keep it to 7.5 cu. in.

Need a vote on feature set though, here are two options:

- All front panel controls:  6-pin mini-XLR, three-position gain switch, high-current minijack out, on/off switch, dual green/red LED for on/peak/low battery.  Basically the same as tinybox but with P48.

- Rear panel input:  2x 3-pin mini-XLRs on rear; front panel:  minijack PIP input, three-position gain switch, high-current minijack out, low/off/high power switch, dual green/red LED for on/peak/low battery.  This is a littlebox in an extended tinybox case.r

I'd think for what you are doing, all front panel controls would be better....

[notlance]

Need a vote on feature set though, here are two options:

- All front panel controls:  6-pin mini-XLR, three-position gain switch, high-current minijack out, on/off switch, dual green/red LED for on/peak/low battery.  Basically the same as tinybox but with P48.

- Rear panel input:  2x 3-pin mini-XLRs on rear; front panel:  minijack PIP input, three-position gain switch, high-current minijack out, low/off/high power switch, dual green/red LED for on/peak/low battery.  This is a littlebox in an extended tinybox case.r

I vote for the second option with rear panel inputs.  I never run out of a bag so I don't need the front inputs, and since I have a SD 788t I already have the 3-pin mini XLR to XLR adaptors already built.  Selfish reasons all.

[page]

I vote for the second option with rear panel inputs.  I never run out of a bag so I don't need the front inputs, and since I have a SD 788t I already have the 3-pin mini XLR to XLR adaptors already built.  Selfish reasons all.

Exactly, open taping, I'd probably go for the 2x 3pin for similar reasons, but if I was stealthing, that single 6pin on the front with nothing on the back looks mighty appealing...

[Napo]

Even with stealthing I would go for front and rear panels.

Soldering a six-pin cable may be a bitch and not very durable.

BTW, Chris, Jon; you are my champions for stealth situations (the only option in 99% of cases in Italy). I will end up buying both 

[jbell]

I'd vote for the 2 mini xlrs too!

[page]

Even with stealthing I would go for front and rear panels.

Soldering a six-pin cable may be a bitch and not very durable.

Ah, I just have someone else I trust do that. 

The bummer in my experience on that is the mini-xlrs don't work well as either stubbies or right angles, otherwise I'd be more open to the idea of stuff on both panels.

[sunjan]

...the size of the 9100 preamp with FULL 48 volts and operate on 2 AA batteries or 9V we have yet to determine this.

Chris, Jon, I'm thrilled to hear about both projects.
What kind of runtime are you aiming at? Chris, if you're toying with the idea of 2 x AA, this would have to be primary Lithiums in order to crank up the voltage to P48??? Or is it really feasible to do this with 2 x 1,5V NiMH?

[Chimney Top]

Awesome - C.A. and Naiant

[cashandkerouac]

 

sounds like great news all around!!!

[su6oxone]

Need a vote on feature set though, here are two options:

- All front panel controls:  6-pin mini-XLR, three-position gain switch, high-current minijack out, on/off switch, dual green/red LED for on/peak/low battery.  Basically the same as tinybox but with P48.

- Rear panel input:  2x 3-pin mini-XLRs on rear; front panel:  minijack PIP input, three-position gain switch, high-current minijack out, low/off/high power switch, dual green/red LED for on/peak/low battery.  This is a littlebox in an extended tinybox case.r

As a Tinybox owner, I definitely like having all the inputs on the front panel.  More convenient for running stealth of course, but I prefer that for running out of a bag also. 

Sound great though, kudos to both Church and Naiant -- what would we do without these great entrepreneurs? 

[dactylus]

sounds like great news all around!!!

[drewloo]

...the size of the 9100 preamp with FULL 48 volts and operate on 2 AA batteries or 9V we have yet to determine this.

 Or is it really feasible to do this with 2 x 1,5V NiMH?

Sound Devices MP-2 can do it, so it's doable. 

[ashevillain]

Or is it really feasible to do this with 2 x 1,5V NiMH?

AA NiMH are only 1.2v

AA Alkaline or Lithium are 1.5v

[Erick del Valle]

Maybe expensive, but is a beauty

http://www.audioroot.fr/portable-battery-powered-stereo-microphone-preamp.html

Saludos!
Erick del Valle
Santiago de Chile

[willndmb]

how does the stereo xlr work?
split into a dual

[Roger Gustavsson]

Ground/screen is common for left and right channels, as it use to be. The other 4 pins gives you two differential/balanced channels. It can be split in two 3 pin XLRs.

Roger

[Erick del Valle]

Are You talking about the uPRE? the uPRE has unbalanced out in one 3 pin mini xlr (groud, left and right).

Saludos!
Erick del Valle
Santiago de Chile

[Roger Gustavsson]

Sorry, did not see that it has unbalanced outputs! The outputs can be impedance balanced. You will need to know (or measure) the impedance of the outputs. It is not a must or necessary to use a balanced interconnect. What do you want to connect it to?

Roger

[willndmb]

i don't want it, i was just wondering
i see it has dual 3pin xlr in and 1 3pin stereo xlr out

[Erick del Valle]

(I guess I have to change my avatar)

[willndmb]

(I guess I have to change my avatar)

lol
i stole it from you
i'll change mine if its an problem

[Erick del Valle]

no, not really, no problem

Saludos!
Erick del Valle
Santiago de Chile

[hi and lo]

That uPre really does have a nice form factor. Would love to hear more about its sonic qualities!