Review - New Headway EDB-2 Preamp

[almeriastrings]

The Headway EDB-1 has now been around a while, and has picked up some pretty high profile users, Ricky Skaggs being one name most will recognise. It is an extremely well-made and versatile unit, think of an L R Baggs Para-DI with an extra 'blend' channel, and then some. The quality and accuracy of the EQ and notch filtering on the Headway preamps is outstanding. Build quality is to full 'pro audio' engineering standards, rather than 'prosumer' grade. As of very recently, it has just got even better, as the EDB-1 is being retired and the updated EDB-2 introduced in its place. It has numerous features and options - too many to describe here in detail, but key elements include a high grade mic pre with +18v phantom power, a master 'mute' switch (with indicator!), a new 'standby' mode, phase reverse on Ch1 and Ch2, preset EQ ranges for violin/mandolin, guitar and bass, notch filter with variable Q for Ch1 or Ch 2 (with indicator LED), three input impedance options for Ch1 and Ch2 (Low-Active, High 5M and Hi+ 10M), EQ now assignable to Ch1, Ch2, or both, an AUX in on mini-jack for iPod practice/backing tracks, fully balanced output on XLR (of course), plus mono out on 1/4 jack, ground-lift, and operation on 2X 9v batteries - with low battery alert indicator. It will also operate from a separate PSU. It does not operate from +48v phantom power, but the presence on phantom on the outlet XLR will not cause any problems.

This is how it looks:





Panel control functions:



I have been testing out of of the very first units off the line over the last few days. I do not personally use a pickup in any of my mandolins, but I do have them in my Breedlove acoustic guitar, and there is a pair of ancient Barcus-Berry 'Hot Dots' in Bill Clifton's old D-35 - so I was able to test both active and passive transducers with those. My wife also has a transducer in her OM-42 and mountain dulcimer. As expected, it works very well indeed with all sources. The range of EQ available is superb, and the controls are very positive and precise. There was plenty of gain even for the very low output old 'Hot Dots'. Self-noise was imperceptible - another improvement is that available gain has increased and even lower noise components are used in this new version (though the older model was no slouch in this respect to begin with). It really is a very good sounding preamp. Clean, clear, lots of headroom and with exceptional EQ facilities. For passive transducers, it is a matter of selecting which input impedance sounds best - 5M or 10M - it can vary.

My prime interest in this unit, however, was how it would perform as a microphone preamp. Of of the drawbacks of using a compact mixer live is that even if you use ones with high-grade mic pres, you invariably sacrifice more extensive EQ options, usually being limited to just Low-Mid-High. A sweepable mid is great, but still falls short of what you can do on a large desk. My thought was that possibly, the EDB-2 might be a way around this limitation when using a microphone on acoustic instruments.

I therefore set about trying it with a range of microphones:

1) Shure SM-94 (cardiod, electret)
2) Audix VX-5 (hypercardiod, electret)
3 Rode M3 (cardiod, electret)
4) Beyer M-201 (hypercardiod, dynamic)
5) AKG D5 (hypercardiod, dynamic)
6) Shure Beta 27 (LD, hypercardiod, condenser)
7) Neumann KM-184 (SD, cardiod, condenser)
8) SE Electronics SE1A (SD, cardiod, condenser) - manual mentions incompatibility here
9) AT 4031 (SD, cardiod, electret)
10) ART M-One (budget LD, cardiod, condenser)
11) SE Electronics X-1 (budget LD, cardiod, condenser)

Key questions to be answered were how the +18v phantom supply affected things (not an issue on the electrets or dynamics, of course, but certainly so for the LD condensers), input gain performance, self-noise, headroom, etc. The manual specifically mentions problems with SE mics on the +18v supply....which is why I included a couple in this test.

To be continued...

[Mike Bunting]

Thanks, I'm looking forward to the conclusion. I wonder if it has enough improvements for me to consider upgrading from my EDB-1.

[mandotim1955]

If it's an improved version of the EDB-1, it's going to be sensational.

[Ben Milne]

Mmm, hole bunch of mics you've mentioned are listed as P48 in their respective specs. Not liking the chances on its of those, but standing by for report...

I think the original version is a great piece of kit for particular circumstances, but it looks like my two criticisms of it might remain, the size of the mute switch, and inability to power from P48. I find using two 9v batteries or a walwartPSU a bit inconvenient.

[foldedpath]

I don't know about most of the other mics on the list, other than spec requirements, but I know the KM184 likes to see 48v for best performance (full frequency response, low distortion, self-noise specs, etc.). It might work at 18v, but I'd be curious about whether it sounds the same as full voltage. I hope you'll be comparing against a 48v mixer or mic pre.

Otherwise, I like the specs of the EDB-2 preamp. It would work fine with the range of clip-on mini condenser mics we talk about here, because those don't need full phantom power.

[almeriastrings]

OK... Part Two.

First, a typo to correct. The Hi+ input impedance on the jack inputs is 20M, not 10M. The 'Low' impedance on those inputs is 1M, incidentally (not 50K as printed on page 13 of the manual - it is correct on page 25). The XLR input impedance is 2K

The Mic Pre

There are two unusual features. The first is that it only supplies +18V phantom power. There is absolutely no problem with this for most back-electret microphones, or most mics that are used as 'blenders' with pickups. The vast majority of these will be quite happy with +18v. So, in this little test, the SM94, Rode M3, and Audix VX-5 were fine (as expected). The manual does specifically warn that SE Electronics 'true condenser' mics are problematic with anything less than the full +48v, and I confirmed this. The SE1 refused to work at all, and I also tried an SE4400a - that too was completely dead. Similarly, the X-1. To be fair, these are specified as requiring +48v, so this is no real criticism of anyone. I also tried another mic, the ART M-ONE. This is an unusual, budget LD microphone that has a rather nifty looking blue LED built in for a 'glow in the dark' effect ! On a more serious note, it does draw rather more current than most condenser mics at the same time, so it was no surprise to see that while it produced some output, it was noisy and did not sound too great. I am not sure it would sound too great even with +48v, but I digress! The surprise performer on this meagerly +18v was the KM184. It really did sound very usable and acceptable. A close runner-up was the LD Shure Beta 27. That too sounded OK. The lesson here is that mics certainly vary greatly in how they perform with less than their specified phantom voltage. Some may not work at all, or sound very noisy and compressed, others may work fairly well. Obviously they all work a lot better when operated within specs!

Just to prove that, I turned off the +18v and inserted a good separate phantom power supply between the EDB-2 and the microphones. All of the mics that failed to work properly the first time around were now happy and delivered normal output. Those that did function earlier on less than specified voltage (KM184 and Shure Beta 27) delivered a higher output. There was no discernible difference in the performance of the electret mics. If you are planning on using microphones specified as needing +48v with this unit, then it is certainly a good idea to use a separate phantom power supply capable of delivering a full +48v between the Headway XLR and the microphone. This will require a short XLR-XLR patch cable. Turning the +18v Headway power off will also no doubt extend battery life considerably.

This unit was clearly intended for use with electret and clip-on mics that have modest power requirements and it indeed performs well with those. The above was intended as a bit of a 'stress test' just to see what happened, and to show that in any event, there is a practical work-around.

I mentioned two unusual features with the mic pre. The second is the gain available. This is quoted as +50db max on the XLR input. I did not measure this precisely, but I did directly compare to another preamp I have that has identical gain (a Presonus Digimax) and it was very close. This level of gain is quite a lot lower than what you will find on many desks and studio preamps, but will be adequate for higher output microphones. I found that with low-output microphones (both dynamics) it was necessary to bring the gain and master controls up quite high, to the point where self-noise became obvious. By contrast, the mic inputs on my Allen & Heath ZED R16 and Soundcraft EFX-8 mixers offered more gain (+60db) and subjectively lower self-noise. It is not easy to get ultra-low noise, high-gain performance from battery operated microphone preamps that also have to supply phantom power. This is one reason why those that do provide this can easily run to $1K per channel (Sound Devices, Audio Developments, etc). The available gain and cited noise performance (-84dB at 30db gain) is perfectly acceptable for higher output mics used in a live music setting, however. It is nonetheless a long way short of what really top class preamps can achieve (75db gain and -127db). Therefore, although fine for live and stage use, the 'microphone' channel here is not a 'studio' preamp. In practical use in a live situation, and with suitable microphones, self-noise is not intrusive or problematic, however. Mic choice is critical, however. You really do need fairly high output ('hot') microphones that (unless you are also running a separate phantom PSU) are also happy with the +18v available.

In most cases I found I could run the input gain around 2 O'Clock and the master in the same position. Once you advance the input gain much above 3 O'Clock some self-noise becomes evident.

In summary, I felt the EDB-2 is an excellent DI for transducer pickups, both passive and active. The EQ and notch filter facilities are highly versatile and perform superbly. The mic input is also absolutely fine for use with close-mic'd instruments and with fairly high output microphones operating within their specified power supply requirements. Low output mics can be a problem, however, and the self-noise performance ('noise floor') could be better. It is really a matter of selecting microphones that are well-matched to the unit. The DPA 4099, for example, is known to work very well with it.

If you already have an EDB-1, I would have thought that it is not worth the expense of upgrading unless you really need the 'new' facilities on offer. The EDB-1 is already a very solid performer.

[Mike Bunting]

If you already have an EDB-1, I would have thought that it is not worth the expense of upgrading unless you really need the 'new' facilities on offer. The EDB-1 is already a very solid performer.

I was thinking the same thing.

[foldedpath]

Good review, thanks for the info. It's not surprising that they built it to these specs for phantom power, considering the trade-offs with battery drain. I have a Tascam DR-680 field recorder that supports 48v on six channels, but that's from eight AA batteries, and the battery life is noticeably shorter when running phantom on all the channels. The design of the EDB-2 is obviously intended more for powering things like the clip-on mini condenser mics. Adding a 48v phantom power supply would just add an AC power cord, which defeats the purpose of a portable battery preamp like this.

I have to go off on one small rant about the way they label the EQ knobs. It's that "presence" label... ugh! I wish manufacturers of devices aimed mainly at acoustic instruments and general sound reinforcement would get away from using that term. It's just a dumb carry-over from early tube electric guitar amps, where it worked on the negative feedback loop to shape tone differently from the rest of the EQ bands.

Why not just label the 5 EQ bands on the EDB-2 as Bass, Low Mid, Mid, High Mid, and Treble? Or just list the center frequencies. We're not dummies, especially anyone interested in gear like this. We don't need to be coddled as if we're knuckle-dragging electric guitar players, who freak out if we see something that doesn't remind us of our old tube amps. Use the proper terms for these things. Bah, humbug!

But it looks like a useful little box anyway.

[Avi Ziv]

Why not just label the 5 EQ bands on the EDB-2 as Bass, Low Mid, Mid, High Mid, and Treble? Or just list the center frequencies. We're not dummies, especially anyone interested in gear like this. We don't need to be coddled as if we're knuckle-dragging electric guitar players, who freak out if we see something that doesn't remind us of our old tube amps. Use the proper terms for these things. Bah, humbug!

LOL! Love it

[ParcelOfRogue]

Hi Ben, I'm John from Headway who did the outline design of the EDB-1 & 2, as well as the much smaller EDM-1. I thought I might explain where we are on issues raised.

I play Mandolin, Octave Mandola, Mandocello and a bit of Electric Bouzouki, by the way.

The Multi -function EDB-1 or EDB-2 are far too power hungry to operate on the few milli-amps available on Phantom power from Mixers etc. We did try to make them operate in that way, but I don't believe that any such device with that level of functions could operate in that way.

However, the new, smaller, simpler, less power hungry EDM-1, will operate from Phantom power, if the supplied XLR to Jack Plug adapter is used. This is because the unit has less functions requiring power. Phantom on Mixers was designed for powering true Condenser Mics, but will cope with standard Di Boxes, which have low power requirements and don't operate many functions.

The EDB-2 has a much lower noise figure, especially on it's XLR Mic Input, than EDB-1. The general performance of EDB-1 offered less clarity and higher noise than EDB-2, which I believe people sometimes confused with the 18v Phantom to Mic Input aspect. While a tiny handful of true Condensers ( so far just by SE ) have failed to work on the 18v Phantom, most work fine and certainly good enough for live work.

On the size of the mute, we had to keep that small since the box is already cramming a quart into a pint pot at the very least and there is no room to include oversized switches or pots, otherwise, the box would be much larger, heavier, impossible to get into an instrument case, or mount on a belt.

The EDB-2 offers a Standby setting as well as a Mute. The Standby, was to encourage a 2 stage switch on, to cut the thump while the box is plugged in live to speakers. The Standby can also be used as a Mute, which gives you another chance to find it on a dark stage.

We have listened to what people liked about the EDB-1; which was a great deal; as well as the relatively few moans and we have taken as much as possible on board, which is so far going down very well. Players requests for additional features are likely to be taken into account in future products.

[ParcelOfRogue]

Hi almeriastrings, I am John Littler of Headway. Thank you very much for your detailed report on the EDB-2, which I have noted.

I thought I might offer an explanation to the readers regarding the noise levels.
Noise, or background hiss is generated by all electronic components, to a greater or lesser extent and in putting a multi-function unit together, clearly that would add more noise than a simple Pre-amp or Di Box with few functions. Of course, if you daisy chain several simpler units together to obtain similar functions, this would add noise and might be likely to be noisier.

In addition, in offering a unit that has a viable life with batteries, we are limited in terms of the choice of components used. If we were offering a unit with less functions or one which was powered purely via mains, or a mains powered AC-DC adapter, we could use lower noise components and offer a better figure.

However, we have reduced noise on EDB-2, compared to EDB-1, especially on the XLR Input Mic option and I believe you are correct in suggesting that it is fine for live, as it was mainly intended. If noise is an issue, such as in professional recording studios, you would probably be unlikely to be using a battery powered device. We are very pleased with the tone, EQ and noise figures on the new Pre-amps, including on the simpler
EDM-1 and I would suggest comparing the units next to closer competitor units, if anyone is unconvinced about their performance.

As to the differences between EDB-1 and 2, apart from noise, they are more than meets the eye. EDB-2 can offer 5 Band EQ to 1 or other channels, or both, Phase reverse can now be applied to either channel, there is both lower gain and higher gain on both channels, via dual gang pots, which cope better with very hot or very weak pickup systems and it has an XLR Output level which is more modest, to be better able to plug into XLR Mic Inputs on basic level Mixers.

Also, we believe we have achieved a clearer tone with better headroom and have tried to make the labelling easier, for the average non technical user to understand. We also put a lot of effort into improving the manual further, which had already received positive comment.

On notch filter, that can now be applied to either channel and the cut has been reduced to 12 dB from 15 dB. We have found this sufficient to cut feedback peaks, while making less of an unwanted hole in the sound. Of course, with notch filters, the point is to make some sort of reduction in sound in an unwanted area.

The switchable input impedance has been extended to a 3 way on Channel 2 and the On/off switch has the addition of a standby position, which if used to switch on slowly in 2 stages, will cut the clunk noise, if connected to live speakers.

However, we are grateful for your input and are likely to take your comments on board when producing future additional models.

[ParcelOfRogue]

Hi String 14, I am John of Headway and I'm grateful for your input. However, I thought I would comment on the Presence issue as there is quite a bit of uncertainty about what that term refers to.

It is true that Electric Guitar amps sometimes offered what they called Presence in addition to Treble. They usually referred to Presence as being the very top end control, operating at a higher frequency than Treble. Instead of taking our cue from that world, we decided to ally with the Pro Audio definition, which sites presence as a narrow area, centred between about 2.5 kHz and 3 kHz, which normally requires a smaller amount of cut and boost compared to the other controls. I recall the EDB-1/2 use about 7 dB cut and boost, instead of between 12-15 dB on other controls.

We find the Presence area a useful one to cut for many piezos, magnetic pickups and Electret Condenser Mics, as they often produce too much in that sometimes clunky low treble area, although much of this is subjective.

It is always difficult trying to pitch descriptions on product or in manuals, so that they are as understandable as possible to the non-technical, but also get the information over to the technically minded without sounding long winded or worse. Since a fair proportion of our customers play the Violin family and are not usually at all technical, we have to bear them in mind and I am sure that well informed players such as yourself will normally cope easily with the unit.

There are a lot of people who have been using EDB-1/2 in different ways and while most will not use the belt clip, it is there if required and that would not be practical with the Power Supply, but we also include the Power supply for those that require it.

We do listen to real customers and try to take their views into account in future products, when they are possible.

[Perry]

These units look very nice and as I am on a constant quest for better plugged in tone I am tempted.

There are two features on my ToneBone Pre-Z that I find very useful; the boost switch and the mute switch.

I suppose if the sound were far better on the Headway I can live without them. Also the fact that the Headway runs on batteries is a major plus.

Can anybody compare the Headway "sound" to that of the ToneBone Pre-z?

FWIW I am using my ToneBone with a Schertler/mandolin and K&K/guitar set-up.

Thanks

[mandotim1955]

I use a Headway EDB1, our guitar player uses a Tone Bone Pre-Z. To my ears, no contest; the Headway produces a far more natural sound, with less noise.

[almeriastrings]

I like the Headway very much. It offers a huge amount of control, with flexible routing and input/output options and a logical layout. The ability to create mic/pickup blends is a really key feature. It is an excellent sounding box.

The Radial is also a good quality unit, but entirely different in concept. It seems to me that it is more geared to those using pickups only and requiring more extensive pedal routings and 'live' switching between sources. I would say the Headway is much more "pure acoustic instrument" oriented, and is just about perfect for anyone working with both a mic and a pickup together. The EQ on the Headway also has the edge, in my opinion. As you can see above, the designers themselves are very approachable and clearly understand the needs of acoustic musicians.

The variable input impedances offered are a real life-saver when you have to cope with 'guest' musicians with various types of transducer.

[Perry]

I like the Headway very much. It offers a huge amount of control, with flexible routing and input/output options and a logical layout. The ability to create mic/pickup blends is a really key feature. It is an excellent sounding box.

The Radial is also a good quality unit, but entirely different in concept. It seems to me that it is more geared to those using pickups only and requiring more extensive pedal routings and 'live' switching between sources. I would say the Headway is much more "pure acoustic instrument" oriented, and is just about perfect for anyone working with both a mic and a pickup together. The EQ on the Headway also has the edge, in my opinion. As you can see above, the designers themselves are very approachable and clearly understand the needs of acoustic musicians.

The variable input impedances offered are a real life-saver when you have to cope with 'guest' musicians with various types of transducer.

Thanks for the input.

Interestingly enough even though the ToneBone Pre-Z is touted as being for two instruments it only has one set of EQs so what I end up doing is use just one channel and change the low pass filter when switching from mandolin to guitar. Not the best scenario but seems work good enough. I used to own a Pendulum SPS-1 and it truly was dual channel but was quite a complicated layout.

What appealed to me about the ToneBone is that it sounded good right out of the box with almost no adjustment.

The Headway's EQ is assignable to channel one or two or both BUT the notch filter can only be assigned to channel one or two or bypassed; but not both. As mentioned this unit seems to be more geared to a dual pick-up system.

I still may get one; can someone suggest US dealers?

[Perry]

p.s. there's a review of Headway 1 & 2 units is the current (Willie Nelson on cover) issue of Acoustic Guitar mag. I don't have it yet so can not comment on content.

[dang]

The Radial is also a good quality unit, but entirely different in concept. It seems to me that it is more geared to those using pickups only and requiring more extensive pedal routings and 'live' switching between sources. I would say the Headway is much more "pure acoustic instrument" oriented, and is just about perfect for anyone working with both a mic and a pickup together. The EQ on the Headway also has the edge, in my opinion. As you can see above, the designers themselves are very approachable and clearly understand the needs of acoustic musicians.

The variable input impedances offered are a real life-saver when you have to cope with 'guest' musicians with various types of transducer.

I have and use a Tonebone PZ-pre that I use with a NXT Double bass by Ned Steinberger. This is the budget version so I didn't realize how poor the polar pickups would sound going into a bass amp without a preamp. Got a tone bone PZ pre and problem solved...

It's got that PZB switch that "adds a class-A booster circuit and increased impedance for the piezo-electric element."
If I don't have that switch 'on' the NXT bass sounds terrible.

I have a Schertler Dyn-M on my mandolin that I regularly use (without any preamp), and I want to get the Headway EDB-2 as a multi-functional device, but what I am wondering is without that PZB booster circuit will I have the same quality of the sound for my NXT bass as I am currently getting with my tone bone?

...Or as you said above (Almeria), is this one of those situations where the headway can handle the "variable input impedances offered"?

[almeriastrings]

Hi Dang,

I have no direct experience at all with the Steinberg 'Polar' transducers (so take this with a pinch of salt), but from what I can infer from the somewhat sparse specifications they publish, it appears to be a multi-element piezo system. They specify a minimum preamp input impedance of 1M Ohms. That being so, then the 'Hi' switch on Input One of the EDB-2 should provide a satisfactory match (5M Ohms), however there is an alternative (Hi+) position that increases the input impedance to 10M Ohms - this is identical to the impedance of the Tonebone PZ with the PZB-2 switch engaged.

The PZ is a very nicely engineered pre/DI. I would not say the Headway was superior - simply different. The main difference is in how they handle microphone inputs .The EDB-2 will supply either a 'regular' format 18v phantom power source on the XLR, or A-B power (<10v) to directly power an electret mic via either tip or ring on the Ch. 1 TRS socket. So, as a preamp/EQ/DI with 'blending' in mind it is hugely flexible. If you do not need this kind of microphone handling, then there may be little advantage changing from another really high grade unit such as your Tonebone PZ. It does not have a 'boost' switch, either, and has no foot operated switches. You have to pre-set them by hand. In that sense, the Tonebone may be preferred by some users. They are both really excellent devices and both sound very good on a wide range of sources.

[dang]

Hi Dang,
...however there is an alternative (Hi+) position that increases the input impedance to 10M Ohms - this is identical to the impedance of the Tonebone PZ with the PZB-2 switch engaged.

Perfect, just what I was trying to understand!

The main difference is in how they handle microphone inputs .The EDB-2 will supply either a 'regular' format 18v phantom power source on the XLR, or A-B power (<10v) to directly power an electret mic via either tip or ring on the Ch. 1 TRS socket. So, as a preamp/EQ/DI with 'blending' in mind it is hugely flexible. If you do not need this kind of microphone handling, then there may be little advantage changing from another really high grade unit such as your Tonebone PZ. It does not have a 'boost' switch, either, and has no foot operated switches. You have to pre-set them by hand. In that sense, the Tonebone may be preferred by some users. They are both really excellent devices and both sound very good on a wide range of sources.

What I am really looking for is a preamp for my Schertler and AT Pro-35 which both have XLR inputs (rendering the tone bone useless) but the ability to cross over and use it for my NXT bass (and therefore have an option for a situation where I need to run on batteries) makes the Headway EDB-2 even more handy. THANKS!

Dan G.

[almeriastrings]

Right.

Well, you can actually run an AT PRO 35 straight from the Ch.1 jack socket, in fact. This means you can use the 'wireless' version (without the XLR 18-48 phantom to 5-10 volt A-B power converter). I use them like that to power AKG C411's, DPA's , Ovid system mics, AT's, Sony lav mics and various other back-electret elements and it is excellent. It is just a question of a bit of re-wiring in some cases, e,g., replacing the mini-XLR on the wireless versions with a TRS jack plug. I measured 7.5v on that input socket which is right in the middle of the 5-10v requirement of all of these designs.

I know people who successfully have used the DYN's into both channels of the Headway, but if into Ch. 1 you need an impedance converter. I would normally run one of those into the Ch. 2 XLR and reserve Ch 1 for electret mics that require the 5-10v A-B power.

[lloving]

Has anyone had any luck using the EDB-2 with a DPA 4099v using the 18v phantom power. I have tried that combination with no luck. I am using a QSC K8 powered speaker as the final output. 4099v to EDB-2 to the QSC. I get nothing but a pop when I go from Off to Standby on the EDB-2. Other testing has verified the 4099v and the QSC both are in working order.
Is my problem the 18v, do I need the full 48v for this setup to work?

Thanks for any replies.

LL

[foldedpath]

Has anyone had any luck using the EDB-2 with a DPA 4099v using the 18v phantom power. I have tried that combination with no luck. I am using a QSC K8 powered speaker as the final output. 4099v to EDB-2 to the QSC. I get nothing but a pop when I go from Off to Standby on the EDB-2. Other testing has verified the 4099v and the QSC both are in working order.
Is my problem the 18v, do I need the full 48v for this setup to work?

My guess would be that the DPA 4099's XLR barrel adapter/step-down transformer is looking for a nominal 48 volts to convert to the mic's 5-9v bias power. If it's seeing significantly less than 48v as a starting point, then the mic may not be getting enough juice.

A battery preamp like the EDP-2 that says it has "phantom power" at 18v is really just stating that some condenser mics will work with it, and it saves on battery drain. But it's not really the nominal spec for phantom power. The manual says it's enough to power "99% of condenser mics" and I think that's misleading. Some very good condenser mics don't perform well unless they get a full 48v, like Neumann KM-184's among others.

As a long shot, it might also be a problem with your XLR cable, so test that against other cables known to be working.

Edit to add: I just remembered that the DPA 4099 works fine with the 24v "phantom power" in the mic input of my little AER Alpha amp, which isn't that far off from 18v, but it could still be a consideration. Check your settings on the preamp, and check your cables.

[almeriastrings]

FP (as usual) is quite right. The little XLR 'adapters' that come with DPA's, AKG's, AT's etc., are built to expect a standard +48v phantom supply from a typical mixing desk. Some will work from +24v and a few from +18v... but it varies, because internally they use different circuits. Also, their current requirements vary in addition to their voltage requirements. To top off all those variables the actual mini-microphone elements themselves may work on anything from 3v to 11v! Performance will normally be reduced as voltages drop below the optimum, however.

This is the inside of an AKG Micromic III adapter:





Quite a sophisticated circuit using surface-mount components on those. Some are much simpler. I have noticed a lot of the lower cost adapters shamelessly copy the DPA circuit, but use lesser grade components!

Solutions:

1) If you do not want to do surgery on your DPA you can still use it into Ch. 2, but you may need to insert a separate phantom power
box capable of supplying a higher voltage and current first. You can then turn the phantom on the Headway Ch. 2 off. There are lots of these available. Some use mains (115 or 220v) via a adapter and others use batteries. From measurements I have done over the years, I can say that you will normally get very best performance from either a mains powered unit OR from a battery powered model that uses FOUR (not two) 9v batteries, though some that use 2X 9v batteries are absolutely fine. Quality on these things varies wildly. I would recommend avoiding the very cheap ones.

2) With a Headway EDB-2 (not EDB-1) you can do away with the XLR adapter and directly power the mic from the Ch.1 TRS jack. This means modifying the mic and voiding your warranty, however. Only try this if you know exactly what you are doing and have adequate electronics skills. If you get it wrong you could - potentially - cause serious damage. It does work very well, however. I often mod them by inserting a lockable mini-HICON connector in the cable, this then allows you to use either the original XLR adapter or a custom cable to the Ch.1 jack of the EDB-2.

As you can see... variables.. variables...

[lloving]

Thanks FP and Almariastrings. Very useful info. I think the picture is getting clearer at this end.