AT2020 + Audio Buddy

[danny.guitar]

I gave my friend my Audio Buddy when I got a DMP3, so he could start recording. He just recently received an AT2020 microphone and also an SM57.

I've always heard the Audio Buddy doesn't supply 48v phantom power. But the mic seems to operate and work fine.

On the specs of the AT2020 it says:

Phantom Power Requirements: 48V DC, 2 mA typical

Anyway, I was just curious about this.

 

[battleminnow]

Most Audio Buddy preamps don't supply a true 48v. Some do, but the QC is not great, and they don't advertise "48v", but instead tout "phantom power."

Mine works well with some mics, and not as well with others.

Pete

 

[mshilarious]

The AT2020 is an electret mic, which can often run on a very small amount of power, whether low voltage or low current. Probably AT didn't bother to cite that in their specs.

 

[danny.guitar]

Thanks, battleminnow. So I guess it's really a matter of QC luck, and luck with whatever microphone you try with it.

Very reassuring.

 

[danny.guitar]

The AT2020 is an electret mic, which can often run on a very small amount of power, whether low voltage or low current. Probably AT didn't bother to cite that in their specs.

Oh ok. That makes sense.

Anyone wanna go ahead and list a few mics they've tried with their Audio Buddy that didn't work? Just for future reference.

 

[warlock110]

Oh ok. That makes sense.

Anyone wanna go ahead and list a few mics they've tried with their Audio Buddy that didn't work? Just for future reference.

most mic don't need 48V, i think it ranges from 24-48V, as long as you keep 1 channel in the audio buddy plug you have ~ 40V, 2 channel both plug and it's not as good.

i can vouch, my MXL 990 works on the audio buddy.

the CAD M177 that i'm gonna get soon says that it only need 24V or 48 or 52V, i'm gonna try it and report back if it works.

 

[mshilarious]

Oh ok. That makes sense.

Anyone wanna go ahead and list a few mics they've tried with their Audio Buddy that didn't work? Just for future reference.

The MSH-4 would not work

 

[groovyisland]

some of the regulars at the harmony central boards used to recommend the audio buddy and they also had expensive preamps so they could compare it directly

 

[warlock110]

anyone know if the CAD M177 would work? or else i will cancel it.

 

[mshilarious]

anyone know if the CAD M177 would work? or else i will cancel it.

I don't know, but I would worry about it as it has an 8mA current draw. That is awfully thirsty. On the other hand it specs low voltage phantom (+24V), so you never know. It might work with reduced headroom or sensitivity or something.

 

[warlock110]

I don't know, but I would worry about it as it has an 8mA current draw. That is awfully thirsty. On the other hand it specs low voltage phantom (+24V), so you never know. It might work with reduced headroom or sensitivity or something.

man that's scary, i'm doing some search right now i'm sure someone have used this combo before.

 

[mshilarious]

man that's scary, i'm doing some search right now i'm sure someone have used this combo before.

Well see that's the tricky thing. You might plug it in and it works fine. That might be because it is fine, and it's up to spec. Or it might be because it works, but below spec, and the person using the mic wouldn't have known that.

On the other hand, do you really need it to work to full spec? That is, 143dBSPL handling, rated sensitivity, etc.

Also, since it is externally biased, a drop in capsule voltage could affect the frequency response of the mic. That could be a good or bad thing, depending on your preference and source.

So as you can see, it can be very difficult for a customer to really know these things. It would be nice if manufacturers were a bit more detailed in their specs (especially the preamp manufacturers, who know exactly what power their device supplies, but won't say), but that requires testing of nonstandard supplies, which is expensive and time consuming. So it's easiest to simply test and spec full +48V phantom power.

 

[warlock110]

Well see that's the tricky thing. You might plug it in and it works fine. That might be because it is fine, and it's up to spec. Or it might be because it works, but below spec, and the person using the mic wouldn't have known that.

On the other hand, do you really need it to work to full spec? That is, 143dBSPL handling, rated sensitivity, etc.

Also, since it is externally biased, a drop in capsule voltage could affect the frequency response of the mic. That could be a good or bad thing, depending on your preference and source.

So as you can see, it can be very difficult for a customer to really know these things. It would be nice if manufacturers were a bit more detailed in their specs (especially the preamp manufacturers, who know exactly what power their device supplies, but won't say), but that requires testing of nonstandard supplies, which is expensive and time consuming. So it's easiest to simply test and spec full +48V phantom power.

that's true, i have another pre (MIC 800 beringer), it sounds closely related to the audio buddy, and i think that one actually have 48V, it's a little more noisy but i can deal with that.

also it does work as this dude has the combo
https://homerecording.com/bbs/showpost.php?p=2541752&postcount=31

scares me there for a little . that dude uses 2 channel of the preamp, i think i'll be fine with 1 channel.

 

[warlock110]

here's the list of mic that people have use with the audio buddy, they seems to work
AT3035 11-52V DC, 3 mA typical
MXL v93m
C1 48V (2.5ma)
B1
Rode NT1
Oktava MK219
TLM-103 3ma @ 48V +-4
NT1000 6mA @ P48 (35V - 53V)

it's recorded at 41V +, so if the current hold up, i think it'll be fine. it actually was able to drive the NT1000 @ atleast 35V with 6mA, so it's not too bad.

the Naiant mic uses 8mA @ 48V, so i guess about 2X the power of the CAD M177, that's got to be the most needy mic i've seen, lol. after reading the spec on a bunch of mic, most of them @ 48+-4V only needs about 2-3 mA.

 

[omtayslick]

anyone know if the CAD M177 would work? or else i will cancel it.

Don't know if it will work, but here's an article that mentions that it is power hungry.

http://www.soundonsound.com/sos/Oct01/articles/cadmics.asp

 

[mshilarious]

the Naiant mic uses 8mA @ 48V, so i guess about 2X the power of the CAD M177, that's got to be the most needy mic i've seen, lol. after reading the spec on a bunch of mic, most of them @ 48+-4V only needs about 2-3 mA.

Well I have to drive the filament of a tube, so I have an excuse but if the CAD also draws 8mA at 48V, I don't see how I'm using twice the power.

Most mics do use 2-3mA, especially electrets, because they tend to use the same, rather efficient circuit. But a lot of designs are starting to use more, like the KSM44 at 5mA for example.

 

[warlock110]

Well I have to drive the filament of a tube, so I have an excuse but if the CAD also draws 8mA at 48V, I don't see how I'm using twice the power.

Most mics do use 2-3mA, especially electrets, because they tend to use the same, rather efficient circuit. But a lot of designs are starting to use more, like the KSM44 at 5mA for example.

it can power it at 24V too.

 

[mshilarious]

it can power it at 24V too.

At spec? Also, a +24V supply is usually across smaller value resistors. So in that case, current draw may be more than 8mA. Whether or not total power is the same, more, or less, I couldn't say without testing the mic and the preamp together.

 

[mshilarious]

Don't know if it will work, but here's an article that mentions that it is power hungry.

http://www.soundonsound.com/sos/Oct01/articles/cadmics.asp

Ah, I see, it uses an opamp. Opamps are great BUT they are hungry little beasts. I don't know which opamp CAD used, but figure 3 mA per amp, and if they ran a dual opamp for an electrically balanced output, there you go.

If you pull 8mA from a +48V phantom supply, you've dropped 27V across the phantom resistors. That leaves you with +21V to polarize the capsule (if you really had +48V to start with). If that isn't enough, you'd need a DC converter to step it up. With +24V supply, well there was a standard but I think it was dropped; I don't think you can assume any value for the resistors, but it seems likely that voltage at the capsule would be less than +20V. At some point, the capsule (or perhaps the DC converter, if there is one) is going to get unhappy. Opamps are also very particular about wanting their supply currents; fail to give it to them, and they will go on strike.

Then there is the effect on the other channels of the preamp; if the phantom rail drops significantly because of the draw from one mic, then a mic connected into the other channel that only needs say 2mA but really really wants +48V is going to be very disappointed.

 

[warlock110]

Ah, I see, it uses an opamp. Opamps are great BUT they are hungry little beasts. I don't know which opamp CAD used, but figure 3 mA per amp, and if they ran a dual opamp for an electrically balanced output, there you go.

If you pull 8mA from a +48V phantom supply, you've dropped 27V across the phantom resistors. That leaves you with +21V to polarize the capsule (if you really had +48V to start with). If that isn't enough, you'd need a DC converter to step it up. With +24V supply, well there was a standard but I think it was dropped; I don't think you can assume any value for the resistors, but it seems likely that voltage at the capsule would be less than +20V. At some point, the capsule (or perhaps the DC converter, if there is one) is going to get unhappy. Opamps are also very particular about wanting their supply currents; fail to give it to them, and they will go on strike.

Then there is the effect on the other channels of the preamp; if the phantom rail drops significantly because of the draw from one mic, then a mic connected into the other channel that only needs say 2mA but really really wants +48V is going to be very disappointed.

i'm only gonna use 1 channel of the buddy, let's hope it works, if not i'll try my MIC800 that actually does have 48V+, or i'll borrow a DMP3 from a friend of mine. Worst comes to worst, time to buy that VT1 i've been looking at lol.