Double Bass XLR Adaptor

[gypsydjango]

I have a condenser mic--xlr. I want to use a xlr adaptor to 1/4" jack to plug into a
pre-amp to mix the mic with a magnetic pickup--1/4" jack. Would there be any signal loss on the condenser mic?

 

[Joeywhat]

Does your condenser need phantom power? A lot of them do, and if so no you cannot do that.

Also be aware that mic pre amps often only work through XLR, and if it's a combo jack the 1/4" input will assume you're plugging an instrument in, not a mic.

 

[DoubleMIDI]

Every condenser mic needs power. Typically provided via phantom power that is only available via XLR.
If you have an electret, they sometimes can be powered via a battery on the mic or in an external powering box.
TS cannot deliver phantom power, TRS could, but typically doesn‘t.

So you need a phantom powering device before you can apply an XLR to TS adapter.

But you better should get a mic preamp that can deliver phantom power. That way you get a better level for an amp.
There are cheap ones from ART. The quality is OK for the price.

So you need two preamps, one for the mic and one for mixing.
Or you get one that can mix and has a mic input with phantom power like one of the Headway preamps. A reduced phantom power like the 18 volts results in a higher noise floor but in most cases works with condensers (almost always with electrets).

 

[gypsydjango]

Many thanks for your knowledge. Much appreciated.

 

[bassically_eli]

TS cannot deliver phantom power, TRS could, but typically doesn‘t.

That's not true. TS can deliver phantom power over the tip. Some electret condensers can work this way. Some preamps offer this are the Headway preamps (they have multiple options for PP), the EBS Stanley Clarke preamp, and the LR Baggs Mixpro and Gigpro. Typically this is very low voltage (5v-11v).

That said, I agree that since the OP has a mic with an XLR connection, he'd be better off with a preamp with XLR and phantom power.

 

[DoubleMIDI]

Phantom power by definition is always delivered on the signal AND inverted signal lines, so any instability in the phantom power gets evened out.

If power is only delivered on the signal (without having an inverted one at all) this is an older method. I don‘t know the English term, but in German it is called „Tonaderspeisung“.
This method is not compatible with phantom power and currently only used with electrets using a specialized battery adapter or preamp. Therefor the voltage is typically lower than the 48 volts phantom power that needs to power the membrane. It is typically 9 to 12 volts, but can work down to 1.5 volts because it only powers the JFET (similar to a piezo impedance buffer). It works with such a low voltage because mic signals have a much lower amplitude than piezos.

So I was right. „Tonaderspeisung“ is different from phantom power (because of definition and incompability).
A condenser with an XLR connector always needs phantom power (even if it is an electret which may work with a lower voltage than 48 volts).
Mics with „Tonaderspeisung“ only use two connections, are unbalanced (even if very old mics with a DIN 3-pole connector look like they have three connections but haven‘t, but there are some that use three and are compatible with phantom power), use lower voltage than phantom power and need a special powering, typically with a special powering adaptor or preamp. It is not standardized like phantom power.

 

[bassically_eli]

Phantom power by definition is always delivered on the signal AND inverted signal lines, so any instability in the phantom power gets evened out.

If power is only delivered on the signal (without having an inverted one at all) this is an older method. I don‘t know the English term, but in German it is called „Tonaderspeisung“.
This method is not compatible with phantom power and currently only used with electrets using a specialized battery adapter or preamp. Therefor the voltage is typically lower than the 48 volts phantom power that needs to power the membrane. It is typically 9 to 12 volts, but can work down to 1.5 volts because it only powers the JFET (similar to a piezo impedance buffer). It works with such a low voltage because mic signals have a much lower amplitude than piezos.

So I was right. „Tonaderspeisung“ is different from phantom power (because of definition and incompability).
A condenser with an XLR connector always needs phantom power (even if it is an electret which may work with a lower voltage than 48 volts).
Mics with „Tonaderspeisung“ only use two connections, are unbalanced (even if very old mics with a DIN 3-pole connector look like they have three connections but haven‘t, but there are some that use three and are compatible with phantom power), use lower voltage than phantom power and need a special powering, typically with a special powering adaptor or preamp. It is not standardized like phantom power.

LR Baggs and Headway both refer to the unbalanced power as phantom power in their documentation (and on the actual device on my EDB-2 H.E.), but perhaps there is a better term that I am not aware of. It would be useful to use a different term as there always seems to be confusion around this topic.

My Prodipe mic can actually work with either type of power. It comes with an adapter to go from XLR to mini-XLR. the signal on the XLR side is balanced, but as you described, the signal on the mini-XLR side actually only uses two connections even though there are 3-pins. I took some measurements a while back and found that it converts 48V to 5V, and 9V to 1.5V. I didn't notice any audible change in noise level, but the 9V power seemed to provide just enough signal to work with--it needed a lot of gain.

As for the unbalanced connection, I was able to use a 1/4" to XLR cable from my Mixpro (providing 9 volts), but it involved some tinkering and resulted in an unbalanced signal (*hence the asterisk above). So it's not really a solution I would recommend to others, but I enjoy tinkering and it allowed me to blend an electret mic and a pick up with a nothing but a belt-clip preamp attached to the bass.

Edit: I tried a similar scheme with the AKG C411 PP, but it will not work without balanced phantom power.

 

[Wasnex]

Phantom power by definition is always delivered on the signal AND inverted signal lines, so any instability in the phantom power gets evened out.

If power is only delivered on the signal (without having an inverted one at all) this is an older method. I don‘t know the English term, but in German it is called „Tonaderspeisung“.
This method is not compatible with phantom power and currently only used with electrets using a specialized battery adapter or preamp. Therefor the voltage is typically lower than the 48 volts phantom power that needs to power the membrane. It is typically 9 to 12 volts, but can work down to 1.5 volts because it only powers the JFET (similar to a piezo impedance buffer). It works with such a low voltage because mic signals have a much lower amplitude than piezos.

So I was right. „Tonaderspeisung“ is different from phantom power (because of definition and incompability).
A condenser with an XLR connector always needs phantom power (even if it is an electret which may work with a lower voltage than 48 volts).
Mics with „Tonaderspeisung“ only use two connections, are unbalanced (even if very old mics with a DIN 3-pole connector look like they have three connections but haven‘t, but there are some that use three and are compatible with phantom power), use lower voltage than phantom power and need a special powering, typically with a special powering adaptor or preamp. It is not standardized like phantom power.

I don't think the typical way phantom is delivered has anything to do with evening it out. AFAIK, it's primarily done this way so the AC signal is differential, but the DC is not. Not a good idea to apply 48V across the voice coil of a mic element. Also, I believe any noise on the DC should cancel out...I guess you could say "evening out the noise," and I would know what you were trying to say.

While German has a separate word "Tonaderspeisung," I am not aware of such a specific word in English. There may be a specific word in certain technical circles, but AFAIK lay people don't know or use it. AFAIK, we still call it phantom power.

I tried a translation web site and the result was tonader feeder. No English word for Tonader. However, "ton" translates to volume and "ader" translate to vein. I guess volume, vein, feeder sort of makes sense.

 

[bassically_eli]

Well, according to Google "Tonaderspeisung" is Swedish for "tuna stew"

"Der" is "the" in German (der, die, and das), so I think a closer translation is something like 'the sound feed,' 'sound supply,' or 'supply of (for?) the sound.' But I like tuna stew better, so I say we make that the industry standard term

 

[Happy Steve]

I have heard of this referred to as 'T-power' in the context of unbalanced electrets..
Powering microphones

 

[Wasnex]

I have heard of this referred to as 'T-power' in the context of unbalanced electrets..
Powering microphones

Yes, T-Power appears to be short for Tonaderspeisung as suggested by @DoubleMIDI . The references I have reviewed say it is also called A-B Powering and T12 (described in DIN 45595). Apparently, it is/was common in the film industry. I have seen several preamp OMs refer to it as Phantom. Although this appears to be incorrect, it is what I remember seeing.

Since T12 is not something I have ever used, it's possible I have seen it referred to by one of its correct labels, and just don't remember.

 

[Wasnex]

Well, according to Google "Tonaderspeisung" is Swedish for "tuna stew"

"Der" is "the" in German (der, die, and das), so I think a closer translation is something like 'the sound feed,' 'sound supply,' or 'supply of (for?) the sound.' But I like tuna stew better, so I say we make that the industry standard term

German frequently smashes a bunch of words together to form new words. I don't think articles like "Der" are typically part of the new compound word. AFAIK, the article remains separate. Perhaps there are exceptions.

Ref: German Compound Words Explained With Examples (thoughtco.com)

 

[Ryan in PDX]

@gypsydjango if you tell us what the mic and preamp(s) in question are, we should be able to tell you what will work best.

 

[Povl Carstensen]

I am happy with my Rolls phantom power supply, and then straight into my Quilter BB amplifier with a XLR - jack cord. Enough headroom, and I do not miss the extra controls and gain staging of dedicated preamps

 

[DoubleMIDI]

@Wasnex was right that „unbalanced microphone powering“ (my idea, since phantom power is balanced) is bad if applied to dynamic mics and that was a much stronger reason to invent the balanced phantom powering scheme.
If you have a board with switchable unbalanced mic power, you might destroy dynamic mic coils or capsules if you forget to switch off the power. 48 volts may break down a bit, but it can still burn the coil wire or excite the Membran too much (because it acts like a speaker then).

And yes, the German article “der” is never part of a compound word.

BTW, it is Ton-Ader-Speisung which I would more or less literally translate to sound-line-supply. The power gets on the hot line and ground on the shield.
A capacitor is needed to block the DC towards the board/amp and a resistor from voltage source to hot line to let the signal superimpose the DC voltage.

The mic of the OP must be an electret (there are LDC electrets too and they are not necessarily bad, even though very cheap capsules that are not great exist).
It seems that the adapter divides the delivered phantom power for unbalanced mic power not reduced by regulation to a certain voltage level (which is the simpler and cheaper solution).
Since unbalanced mic power is not a single common standard norm (at least if you have very cheap electrets), even though norms exist, the expected voltage and the delivered one should be compatible.

AKG uses a tiny XLR-like connector for the C411L and many other electret mics that is exclusively used (by AKG) to power the electrets with an unbalanced two-line connection (typically used with their wireless transmitter boxes too). They built mics and preamps/wireless transmitters that only share that connector type and supply voltage as a company standard so you can mix them as needed.

My Audio Technica AT-35 (the old one) has the same connector as the AKG to fit to the battery adapter/preamp, but I’m not sure if they are compatible.

My old AKG C411 has a mini-TS plug, so also two-line and from the three contact of the mini-XLR, only two are used. So, if I want, I could change that old C411 to a C411L by replacing the mini-TS with a mini-XLR.