Roswell Pro Audio: Delphos Mic Review Roswell Pro Audio: Delphos Mic Review
There are certain microphones out there where the mere mention of their name inspires awe - is the new Roswell Delphos going to be... Roswell Pro Audio: Delphos Mic Review 4.5

Birth of a Legend

There are certain microphones out there where the mere mention of their name inspires awe. Neumann U47, M49, U47 FET, U67, M269c… AKG C12… Telefunken ELA M 251. For good reason, these microphones have been replicated over and over again, with some manufacturers offering affordable and current alternatives to these legendary options. This is a double-edged sword though, since there are so many replicas and clones that the original premise of these mic locker leviathans has gotten old. In my mind there are certain exceptions that get me pretty excited; microphones that are in the same ballpark as the OG classics yet are available to producers and engineers

everywhere for an almost unthinkable price. These mics actually innovate upon the tried and true, original formula. Roswell Pro Audio have come to the table with the Delphos – a microphone (conceived after the resounding success of their Mini K47) that they sell for an astonishing $299. Whilst the Mini K47 shares a similar capsule design to the U47 and U47 FET, as the name implies, the Delpho’s capsule is supposed to be voiced similarly to a U67 or U87 (both sharing the same capsule), with it being the new flagship of the new Roswell Pro Audio line. With the promise of both innovation and affordability (in comparison to the “brand name” option), I was excited to see if that promise was delivered upon.


In the world of microphones, transformer-less is almost viewed as a dirty word at times. When done correctly (just like microphone preamps), it yields a beautifully crisp frequency response with incredible transient response and clarity. When done poorly – well, it can sound shrill and/or lifeless. If you take some famous reissues of originally transformer-coupled microphones and compare them against their equivalent, latterly produced replicas, they often lack that ‘wow’ factor. That sense of life. That magic. In my case, I would much rather see a manufacturers design / build budget go towards higher quality components and capsules than toward a subpar transformer. This ‘path less traveled’ is the one Matt at Roswell took and, upon opening the small yet sturdy metal flight case the Delphos came in, it immediately felt and looked like a quality build. How it sounds is what is truly important at the end of the day though, so I spent the day at Grammy award winning producer, engineer, and musician Randy Kohr’s Slack Key Studio to start the process of giving this mic a run for its money.

“… upon opening the small yet sturdy metal flight case the Delphos came in, it immediately felt and looked like a quality build.”

Guitar Test

Since Randy owns something in the neighborhood of 56 guitars (including reso guitars, lap steels, etc), it was easy enough to set up the coveted, tweed Little Walter Tube Amps 50w with the matching 2×12 cab. As great of a guy as Matt is (as are the whole Roswell team) I had already decided not to go easy on anyone, so we put the Delphos up against the microphones it draws some inspiration from. I set up a Neumann U87AI and my prized Mic Rehab custom U67 and, to the sound of an Angel Choir got them situated as close to each other as possible in front of the cab, about 9 inches back. To see how it handled a classic transformer-coupled preamp, we set up our favorite preamps, RTZ Audio 9762s, for each microphone, which provides a Neve 1073-like sound while staying much more detailed and open sounding than the originals. The Delphos has a custom shock mount included that is cleverly flat as opposed to being rounded on the front, allowing you to press the mic directly against the grill cloth if you so wish – though that typically isn’t how it’s done at Slack Key. Starting with a beautiful, top-of-the-line lap steel, I had a couple of different styles laid down to showcase everything the microphone had to offer. From body, to transient response, to clarity. This was followed by a Baritone Strat to test the low-end response and detail, and then lastly I had some typical electric guitar laid down using a custom, hand built Les Paul to make sure all of the bases were covered.

“The Delphos has a custom shock mount included

Slack Key Studio Standard Electric Guitar (Mic Rehab Custom U67)
Slack Key Studio Standard Electric Guitar (Neumann U87 Ai)
Slack Key Studio Standard Electric Guitar (Roswell Pro Audio Delphos)
Slack Key Studio Baritone Electric (Mic Rehab Custom U67)
Slack Key Studio Baritone Electric (Neumann U87 Ai)
Slack Key Studio Baritone Electric (Roswell Pro Audio Delphos)

“I actually found the Delphos to be warmer sounding and heavier in the low mids than the U87.”

Purposely trying to lay down some riffs that really showcase the frequency and transient response for each microphone proved to be an effective method of getting some really telling baselines for each mic. As expected, the custom U67 tube mic was the thickest and warmest with the lowest output, which I personally really loved on the lap steel, though with the Les Paul I found myself yearning for a bit more clarity. That was about the only part of this test that went as expected though. I actually found the Delphos to be warmer sounding and heavier in the low mids than the U87 – and that blew my mind! I thought for sure that the U87 Ai and all of its transformer-laden goodness would have the edge in that category, but turns out that wasn’t the case. Maybe this is due to the psychoacoustic effect of the Delphos having slightly less high end, therefore making the low end seem more pronounced, but regardless, it sounds damn good.

Responsive Behavior

The Delphos did manage to maintain a very similar transient response and level of detail to the Neumann though, so you certainly aren’t sacrificing the clarity to achieve that extra level of warmth. It actually sounds as if it is closer to a vintage U87 than the modern U87 Ai, though the differences between the 87 and 87 Ai can be slight and vary depending on the particular example. But that wasn’t my only observation with the Delphos. It also seemed to impose more life upon the recording than the U87 Ai and whilst it still sounded great, in comparison the Neumann almost sounded 2D. There is a sentence I NEVER thought I would write. As always, the levels are set to unity gain within .1dB, which I had to double-check after listening back. I feel like you can really make all of this out with the cleaner guitar examples, though it was just as interesting seeing how each captured the distortion from the Little Walter and each microphone put its own spin on the track. For the lap steel, I can see the merits of having the flatter, perhaps more malleable U87 track if you were not quite sure how you wanted to meld it into the mix. Not that the Delphos really colors things all that much (if at all) in the first place, as you can tell by the audio examples. All microphones provided great, useable results with the Delphos really coming out of left field to easily stand head to toe with microphones costing many times the price.


A few days after this session, I arranged to have up-and-coming artist Ian Munsick join me to test what are probably the most popular uses for an 87 type microphone – vocals, acoustic guitar, and banjo. Due to popular request and the fact that this is an extremely popular microphone to own, we used a very similar Neumann TLM 103 instead of the U87 Ai again. For anyone who may not be familiar with the TLM 103, it is a microphone created by Neumann to be a somewhat affordable ($1,099-$1,299) yet authentic alternative to the U87 Ai, with a capsule that is supposed to be a cardioid only capsule derived from the K67 used in U87s. The other switches that are normally on the U87 were also forgone, leaving you with a no-frills, large diaphragm condenser microphone. With my U67 in the shop to have it tuned for a particular artist’s voice (cause Shannon at Mic Rehab is able to do that, which is awesome, it was between the TLM 103 and the Delphos for this round of tests. For starters, even with the TLM 103 having a higher sensitivity and output than the U87 Ai, the Delphos was SIGNIFICANTLY more sensitive than the TLM 103 still with an output that was hotter by about 7dB with no audible increase in noise floor whatsoever. This is spectacular if you want as clean of a recording as possible, since the microphone’s signal will stay purer as it doesn’t rely as heavily on the preamp. Besides the always-welcomed omni polar pattern (in addition to cardioid), the Delphos has a very transparent -10dB pad switch, much like the U87. This way, if you want to more easily drive your preamp and get more of that sound, you can hit the -10dB pad without worrying about altering the crisp detail and clarity. For this round of tests, I used my Audient ASP800 to see how each microphone would sound using an extremely clean, electronically balanced preamp of this nature. It always gives an example of a similar preamp that many home studio owners use.

Ian Munsick Strummed Acoustic Guitar (Roswell Pro Audio Delphos)
Ian Munsick Strummed Acoustic Guitar (Neumann TLM 103)
Ian Munsick Picked Acoustic Guitar (Roswell Pro Audio Delphos)
Ian Munsick Picked Acoustic Guitar (Neumann TLM 103)

“… the Delphos was SIGNIFICANTLY more sensitive than the TLM 103 still with an output that was hotter by about 7dB with no audible increase in noise floor…”

With Ian wielding his Martin D-28, I had him play both a picked and palm muted part as well as a more straight-forward strum pattern to gauge transient response / pick attack, richness, frequency response, and general usability within a mix. I just did a standard 12th fret mic placement which, whilst that and the Audient together cost the recording some low end, really focuses the tracks on the upper mid and high-end response. I also wanted to exaggerate a tiny bit of string buzz to see which microphone handled such a common occurrence with the most grace. With the TLM 103 sounding very similar to the U87 Ai, the results of the electric tests were pretty much a mirror image. On a sparser track with less overall elements and a greater focus on the acoustic guitar, the Delphos came off as thicker sounding with a rounder, fuller low end response whilst maintaining great pick definition and sparkle. That being said, the TLM 103 was brighter and airy as I expected, with an overall crisper sound that was not as apparent till these tests. This crisper sound I attribute to the fact that there was not nearly as much low end picked up, which causes your ears to fixate more on the mids and highs. For a dense, ultra full mix this may be a nice option, but I loved the sound of both and it is really a toss up to your tastes. I personally felt as though any string buzz would be put under a microscope with the TLM 103 in comparison though, adding another point to the Delphos tracks. Both could be used quite interchangeably with minimal EQing to get the desired results, but with the added 10dB pad and extra polar pattern, the Delphos seems like it could span a greater range of tonal options. Like most microphones in omni, you can add much more overall air to the recording with the Delphos if you so wish, or drive a preamp a bit with the -10dB pad to get some extra bite to fight its way through complex arrangements. Listening to the audio examples, I feel like this is going to be the one test where many of you are divided as far as your preference, since every time I go back to them I see the merits of each.

The Twang Test

I want to preface this next part by saying Ian is certainly no session banjo player. Unfortunately, Nashville’s high demand for twang ensured our go to banjo players were booked during testing, but I had him bring his Remo banjo over so we could at least get some insight into this extremely popular 87 application. Why does Ian own a banjo if he doesn’t even really play banjo, you may ask? Well, he’s from Wyoming, so he practically has a civic duty to have a banjo nearby at all times because of that. Again, you get a rounder, more balanced representation with the Delphos and a brighter, sharper representation with the TLM 103. Since Banjos can obviously come off as brash and shrill, and due to the fact I tend to like my recordings on the more neutral/darker side compared to them being brighter, I think the Delphos would be a perfect match. I would (almost) ALWAYS rather add high end back in later than try to surgically cut it out without overly dulling the source. With this particular recording, the TLM 103 produced a very accurate, exciting sounding result… though I feel like if a more seasoned banjo player really started shredding, things could come off as a tad harsh in the upper mids. The added richness and low mids from the Delphos did a stellar job of keeping everything balanced and helped prevent our ears from overly fixating on the higher registers of the banjo. This would save me the step of boosting them later on with an EQ and could even potentially save me from having to cut out some high mids or highs.

“… the Delphos did a stellar job of keeping everything balanced and helped prevent our ears from overly fixating on the higher registers of the banjo.”

Slack Key Studio Lap Steel (Mic Rehab Custom U67)
Slack Key Studio Lap Steel (Neumann U87 Ai)
Slack Key Studio Lap Steel (Roswell Pro Audio Delphos)
Ian Munsick Banjo (Neumann TLM 103)
Slack Key Studio Banjo (Roswell Pro Audio Delphos)

Vocal Balance

Last but certainly not least, we have my favorite test of the bunch… vocals. Ian has a lighter voice that can regularly come off as overly bright and piercing if the right microphone (and preamp to a lesser degree) isn’t chosen, which normally means he gets setup with a U47 or SM7B to be safe. This almost always entails adding a touch of high-end air back later though, with both microphones definitely being on the darker side of the spectrum. Because of this, whilst the Neumann was certainly a very present and modern sounding option, I can see it definitely getting “spitty” and harsh on his voice, just like it has a tendency to do on certain female vocals and tenor male vocals I have recorded in the past. This and the electric guitar recordings were the examples that I found the Delphos really, really shined on. You can hear a bit of sibilance cut through with the Neumann (though I had both microphones angled slightly down to avoid as much as possible, as I normally do), and while the Delphos wasn’t completely free of sibilance it was much more contained and would be significantly easier to automate, de-ess, or multiband compress out. I feel like for many vocals, the option of a very gradual high pass filter switch on the Delphos would really come in handy, and would make for a more traditional Neumann tonality that would come in handy on deeper male and female vocals. In this particular case, I felt like the balance was exceptional and all I would have to do EQ-wise is filter out the sub lows. Thinking about it some more… that would be an extra cool feature in this case since that way, whether you end up like the Delphos or Neumann audio examples more… you can get both with the Delphos. This is an easy change either in your DAW with an EQ plugin or hardware EQ though, and many people actually prefer to high pass filter anyways after the recording stage, which I myself do fairly often.

“The Delphos likely has more depth and warmth to it than any other transformer-less microphone I have ever heard, and I’ve heard a lot…”

Ian Munsick Male Vocals (Roswell Pro Audio Delphos)
Ian Munsick Male Vocals (Neumann TLM 103)


I attribute the surprisingly warm and rich sound of the Delphos that I have heard so far, to the NOS transistors that were used, which in a way makes it sound like it is actually incorporating a high end transformer in its design, which in the world of transformer-less microphones, is a rarity to say the least. I am sure the fact that much of the Delphos budget went towards a top notch capsule also helped, as about 90% of a microphones sound comes from its capsule – but the NOS transistors and high quality European and US made capacitors no doubt contributed brilliantly to the overall sound, which has exceeded every expectation I had. The Delphos likely has more depth and warmth to it than any other transformer-less microphone I have ever heard, and I’ve heard a lot… including the ones that cost thousands and thousands of dollars. In addition to all of the benefits that come with a transformer-less design, it still maintains that detail, sparkle, and overall balance of a U87 and even the U67 to a degree, which are the overall characteristics that made them so popular in the first place. Well, that and the fact that when U87s came out, they were marketed as a budget form of the U67, and sold like hot cakes, being incredibly affordable in comparison. Nothing about the Delphos sounds or feels like a budget microphone, though it maintains an incredibly attractive and achievable price point. My longing for a figure 8 polar pattern and high pass filter switch were quickly forgotten (and forgiven) after the top notch performance the Delphos gave throughout all of the tests, with a sound well above its modest price point. It is a classy looking microphone with a classy, clear, and balanced sound to match and it would legitimately earn its spot in my mic collection any day. The transient response, extremely low noise floor, ultra high sensitivity, and detail are the only evidence of this microphone being transformer-less, because the sound is anything but. The Delphos is undoubtedly a winner – no-brainer alternative to a U87 or any other microphone of that style. I didn’t want to send it back, to be honest. So much so, that I ended up purchasing the very demo unit I was sent for testing.

“I didn’t want to send it back, to be honest. So much so, that I ended up purchasing the very demo unit I was sent for testing.”

Price and Availability

The Roswell Delphos weighs in at an almost unbelievable $899 USD, €750 Euro + VAT

Find the dealer closest to you here

This is simply a transformer-less microphone done right. Cardioid, omni-directional, and -10dB pad options greatly increase the range of possible applications, with a great build quality throughout and an equally great price.
  • Smoother, richer & as detailed as U87 Ai and other similar mics
  • Omni and -10dB pad feature
  • High quality capsule, components and build quality
  • No figure 8 polar pattern
  • No high pass filter option

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Michael Frasinelli

Studio Owner, Audio Engineer, and Producer based in Nashville, TN, mentored by and working closely with Grammy Award winning Producer, Engineer, and Musician Randy Kohrs. Highly active analog gear habit, with a plugin hobby on the side. DIY audio enthusiast with an interest in all things circuitry.


Top Shelf Music Group
Slack Key Studios

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