I agree, here the retail price does not alway guarantee a proportionate increase in quality or better microphone voicing. Here is the perspective from my view as a small microphone company.

The higher prices more often than not just means that more folks have their hands out along the way between you and the "real" microphone maker.

Take for example Neumann which is owned by Sennheiser. Neumann builds a U87 and sells it to Sennheiser who sells it to their distributor who sells it to the dealer who finally sells it to the end user.

A microphone that probably could be bought for $800 from the factory ends up costing the end user $3200. The electronic components in a U87 less the body and capsule are worth about $50.

Also, full page color adds in recording magazines are not cheap and you are certainly paying a lot of money for the Neumann branding. However, this is often a good thing when you want to re-sell.

The Neumann brand also guarantees a comfortable level of quality control while with China you must be always be upping the quality control and micro managing the manufacturing process.

A good technical background as a Pro Audio Tech and profession recording engineer is more useful toward building an affordable microphone with professional specs than marketing or used car salesman skills.

Recently, CAD dumbed down the fusing on their power supplies and we use the same supplier and it took me 6 supplies before I caught it.

Our circuit draws twice the current than the CAD circuit and if you turned on our supply when the AC voltage was near the extremes the fuse would blow on that odd occasion from the in-rush current.

The transformer looks like a dead short to until the power transformer is magnetized from the first cycle.

So, if the power supply was turned on when the voltage was near its highest which happens twice a cycle then the fuse would blow.
Once the transformer draws some current its impedance increases and current drops.

So, there was probably about a 1 in 10 chance of the fuse blowing at turn due to the a/c voltage being near its extremes.

I had to change out the fuses on 40-supplies even though we had spec'd them with higher fuses.

China figured they could save money by putting the same fuses in hundreds of supplies instead of stock two different size fuses or the ran out of the .5a fuses we use and substituted the 160ma slow blow?

However, big corporations are often profit motivated. A case in point... using a balanced IC circuit in the output of the Neumann M149 instead of a transformer. The spin is a more "state of the art".

But replacing the transformer with a IC balanced output circuit reduces the cost per microphone about $35-$40 which is huge for a bean counter.

However, someone at Neumann missed reading a 1971 AES paper that in a laboratory double blind fold test illuminated differences between tube, discrete and IC circuits.

This paper basically stated that in double blind listening tests at the onset of distortion the tube circuit could be pushed 20db before sounding "nasty". The discrete circuit 10db and the IC circuit just 5db.

In my "book" headroom coupled with a HiFi frequency response is EVERYTHING. The recording gear that always ends up be chosen as sounding best has the best headroom in my experience.

Case in point:-

The 1073 can produce an output level of +28dbm or +30dbu before the onset of distortion. Today the input of most A/D converters start to distort at +21dbu while the Radar A/D can handle +24dbu.

API, Ward Beck, ADM, MCI and other console makers in the 70's also produced products with this kind of headroom.

The UREI 1176 compressor could also produce +28dbm into 600 ohms before the onset of distortion.

The Neumann U47 microphone in good working condition will produce a maximum output of +14dbu but it would take a further 20db transient to make it sound "ugly".

This difference with headroom and circuit distortion considerations doesn't show up as much on a vocal BUT when you put the microphone in front of the bass amp as Grammy Award winning engineers do with our CM47SE the difference becomes more revealing. Our CM47SE tube microphones can produce an output level of +18dbu before the on-set of distortion from 20hz to 20khz.

So, the better the headroom in a microphone the better the circuit will be at reproducing all the details at high SPL's.

Having said that, the U87 can be more detailed on quite acoustic instruments because of slightly faster fet response and the larger bump of the K67 at 8-12khz.

But it will get a bit "nastier" and edgy as the SPL level increases at the microphone. For, example close miking a sax with a U87 will sound a bit edgier and more "ragged than with a U47.

Now, when recording DOA the 80's Vancouver Punk band the edgy U87 sound on the one saxophone solo would not be in poor taste and was the sound the producer was going for.

So, the U87 was not better for the job but its particular "edgyness" on loud sources was the "color" palette the producer was looking for.

The differences in sound between microphones with "correctly" built circuits will mostly result from the capsule and in a small degree to the head grill shape.

There are three basic LDC capsules. Now, there are Chinese variations of these capsules but the most common Chinese copy is the K67 but most of these use 2-3 micron diaphragms and sound "thinner".

However, I have seen edge fed capsules with 3 micron diaphragms and they also sound "tinnier" than those with 6 micron diaphragms.

The three capsule are:-

1)The K67 is very easy to mass produce and in cardiod with 6 micron diaphragms is flat through to about 5khz where it start to rise up 4-5db at 12khz. (this varies a bit from K67 to K67).
The economy Chinese makers use single sided/3 micron diaphragms which yield a thinner sound with often a slightly higher "Q" at 4khz.

2) The K47 capsule which has a random drill pattern in the single back-plate in cardiod produces a wider gentler rise in the 1-2khz range and a more gentle rise at 10khz than the K67 plus the K47 can take 2-3db more level than the K67. The K47 can really enhance the direct to throat sound. While the K67 can allow a vocal to cut more easily through a busy mix.

3) The C12 type edge fed capsule which has the most HiFi response because there is no center connection.

The original C12 just like the Tim Campbell CT12 is very complex to make probably one of the most complex hand assembled electronic transducers made in the late 50's through to early 60's.

A Tim Campbell CT12 cost $400 and there is a waiting period.

AKG sold just 2800 C12 microphones in 10 years so that's about one C12 capsule for each working day over the 10 year period.

The C12 in Cardiod is flat out to about 7.5khz where it gently rises and is up 4-5db at 14khz.

Now, I can easily sell 2-3 AK12 capsules a day either in our microphones or to folks upgrading Chinese microphones.

Several year ago John Peluso and Verner Ruvalds got together and designed an edge fed capsule based on the more easily manufactured K67 type capsule.

The result is the Peluso CEK12 and our AK12 capsule. These are edge fed dual diaphragm capsules with dual back-plates.

Verner increased the amount of holes drilled in the back-plates and almost half of the holes are drilled through into a common chamber between the two back-plates to garner the C12 response.

The result was a capsule with a C12 type response but that is easier to mass produce. Now these capsule cost 3 times as much in China as the capsules in a MA200 or the APEX 460.

They cost 4-5 times as much as the cardiod only capsules with 3 micron diaphragms used in the $100 cardiod only Chinese fet microphones.

The result is the the capsule is a bit more sensitive than the original C12 (more output level for the same polarization voltage).

However, the difference in response between it and the average C12 capsule is subtle at best as notated on Sessions with Slau.

Here is our CM12 with the C12 Edge fed capsule on a jazz vocal. Would this vocal sound any better with a CT12 capsule?

pulsaraudiolab.com/media/audio/mp3/Annette Leon Preview.mp3

In conclusion, the price of a microphone is related more to how many hands touch it before the end user gets it and how much more "hype" is put into economical Chinese made microphones than is put into quality components or the correct components.

I deal directly with the factory and engineers (through an interpreter) design and test our microphones here in our Summerland shop and studios before shipping directly to the end user.

If my $900 CM47SE had a NEUMANN badge even with all the same components it would sell to the end user for $6500 most likely but it would would have the Neumann LOGO and not the AA LOGO.

Now, the multi-level marketing game does feed a lot more folks along the way but I am not convinced that in todays economy where most of my friends are producers, engineers and musicians that they can afford to be quite this socialistic in the current condition of the music industry and be spreading around their hard earned dollars.

Cheers, Dave Thomas
[[url=http://[/URL]="http://www.aamicrop…"]Advanced Audio Microphones[/]="http://www.aamicrop…"]Advanced Audio Microphones[/]

Wow, you got to love that last post. Thanks Dave, that was very interesting!

This may be more suited to start as a new topic but... please tell me/ us what we can do with the MXL 2001-P and what it will sound similar to after your mod or variations of mods? Are there choices?

Hi Guys, I just finished upgrading an MXL 2001 so I will put together some notes and draw a circuit diagram of the changes.

The circuit I have of the MXL is not accurate and I will draw out the original circuit and my modified circuit that i used with our AK47 capsule.

It will sound closer to a UM70 with the AK47 because of the wedge head grill than a U47fet.

With our AK67 capsule it would more similar to a U87 in Cardiod or OMNI but the MXL2001 circuit has 6db more headroom than a U87.

I will try a draw up some circuit options.

Cheers, Dave

[[url=http://[/URL]="http://www.aamicrop…"]Advanced Audio Microphones[/]="http://www.aamicrop…"]Advanced Audio Microphones[/]

Hi Dave, while you're putting together the MXL 2001 mod info for us, I have more questions when you have time.
I have a new U87ai. Are you actually able to improve this as well? I understand the new U87 ai's aren't like the older U87's.

Cheers!

Late to the party, but I'll echo Chris' thoughts -

Thanks, Dave, for one of the most informative, exhaustive treatises on microphone construction I've ever seen!

I've always wondered about the true merits of mods and the guts of a mic (I'm more of a do-it-all, surface knowledge type guy), so this was really helpful.

MXL2001

Hi Guys, here is some more information on the MXL2001.

Now, there are probably several early versions of the MXL2001.

However, the 2001 that I just finished upgrading and other MXL2001 microphones I have seen have a hybrid circuit combining the U87 and the AKG414eb.

Even stock, the MXL2001 does not sound as harsh as the even cheaper transformerless Chinese microphones without any negative feedback and the same economical 3 micron K67 type capsule.

Now, in the U87 circuit only the head amp determines the final frequency response which is a result of the capacitance of the capsule and the cutoff frequency of the feedback network.

In the AKG circuit the output of the fet is coupled into a single silicon transistor running as an emitter follower to drive the output transformer but no negative feedback is incorporated.

The output capacitor and transformer can also determine the LF roll-off but this would be down in the bottom half of the lowest octave.

I noticed that in the MXL2001 the output capacitor was smaller than what we use in our CM47fet which has a similar circuit but has a 6.8 ufd tantalum and so the response at the very bottom is flatter for longer.

The advantage of the AKG output circuit is twofold:-

1) The microphone circuit will simply have more headroom as the output transistor can swing 40 volts dc and the U87's single fet can only swing 21 volts dc before the transformer.
So, the AKG circuit has 6db more headroom than the Neumann.

2) The output from the emitter of the silicon transistors has a much lower impedance (audio resistance) than the fet so a lower ratio transformer can be used.
In the U87 the output transformer with its 10:1 ratio is directly driven from the fet via a 1ufd capacitor and the final output swing is divided 10 times so the fet circuit much have more gain to compensate.
The U87 has a 16db greater loss in the transformer than the MXL2001 or the AKG 414. This means the fet needs 16db less gain and we again increase the headroom.

This difference is quite evident when putting an AKG 414 in close on a live drum compared to a U87. We also preferred our AKG 414eb in the Yamaha C7 over the U87's.

The U87 will still remain present but will get more "blurry" in high SPL situations compared to the AKG circuit.

The negative feedback in the first stage is what saves the day for the U87 as the K67 capsule has a response in cardiod is starting to rise at 5khz and is up 5db on average at 12khz and helps control the sibilance.

Some of the output is fed back into the input out of phase through a filter network designed to tame the rise in the HF response.

However, the AKG circuit does not have negative feedback and the C12 type capsule was flat to 7.5khz in Cardiod before it starts to rise and is up 5db on average at 14khz.

AKG choose to leave the high end rise as the circuit had the headroom to handle the HF transients. They left the recording engineer to deal with this rise which is often my choice as a microphone designer and user.

The thing folks love about the C12 is its flat through the mids and upper mids but is up 6db at 14khz which just adds sparkle and air to the vocal.

The C12 also has a dip at 2khz in the 180 degree response (back of the capsule) which reduces room sound and leakage from other sources or reflections from other surfaces into the rear of the microphone.

These differences in circuit topography make electronic sense as the condenser capsule is a capacitor and the original K67 had a capacitance according to Neumann of 50pf while the AKG C12 is upwards of 80pf.

Not counting the physical differences between the Neumann k67 and the AKG C12 which produce some of the difference in response the capacitance of the capsule and the negative feedback through the filter circuit will result in some major differences. In the later K67 used in the U87Ai the capacitance was higher and the filter circuit has slightly different capacitor values.

Here is the curve of the MXL 2010 in Cardiod that has no negative feedback to compensate for the rise in the capsule plus the 2010 has a transformerless Shoeps output circuit.

I have also include the response curve of our CM47fet in Card which has a 32mm/6 micron K67 type capsule. The CM47fet has a higher resolution as we didn't "photoshop" it to smooth out the curve.

In our CM414 we use the same circuit with our AK12 capsule and the negative feedback removed.

In our CM87 we also use the same circuit with our AK67 capsule and the negative feedback is removed.

Our CM87 is on average 2db brighter at 12.5 khz than the Neumann response after the negative feedback is applied.

It is quite easy to modify the MXL 2001 to fit an edge fed C12 capsule like our AK12 and take out the compensation or leave the compensation in and optimize it for a K67 type of capsule.

What I will do is draw out the circuit both ways once I decipher my notes. The circuit is quite similar to my CM47fet except some of the components have different part #'s and there are a couple of different values.

We changed R6 in the MXL 2001 to a 2k2 which will increase the headroom another 3db on average. We also increased the value of C8 to 16ufd although a 6.8 ufd would suffice.

The modification I just performed removed the feedback and added a OMNI/CARD option with our AK47 capsule which has a much flatter response than the AK67 used in the U87.

So, if you want a more vintage U87 sound from the MXL2001 then leave the feedback circuit and fit a K67 type capsule with 6 micron thick diaphragms.

If you want a AKG 414 like response then remove the feedback circuit which consists of 3 components and fit a C12 edge fed like capsule.

If you want a more U47fet/UM70 like response then remove the negative feedback and fit a K47 type capsule like the modification I just performed.

Best regards, Dave Thomas
[[url=http://[/URL]="http://www.aamicrop…"]Advanced Audio Microphones[/]="http://www.aamicrop…"]Advanced Audio Microphones[/]

Attached files

NT1A for me.. planing to get the NT2A too

Rode NT-1/NT2A

The Rode NT-1a and Rode NT-2a are both transformerless fet microphones with discrete output circuits and they use edge fed capsules but with 3 micron thick diaphragms.

Hence, the bump in the response between 3.5 & 4khz and another rise at 12khz in Cardiod.

My guess is the bump between 100 and 200 isn't really there but the response was plotted on a table top anechoic chamber which aren't accurate below 200hz.

Frequency Response

Cheers, Dave

Hey,

The MXL 2001 that Dave from Advanced Audio modded, belongs to me. I just got it back and decided I'd record a quick clip for those of you who are interested in hearing it in action. It's most likely going to be used on the song in the clip, but this isn't a vocal take that will make the final version, just a quick something for y'all to hear the mic.

[[url=http://[/URL]="http://snd.sc/n0eH7X"]Modded MXL 2001 Mic Sample [/]="http://snd.sc/n0eH7X"]Modded MXL 2001 Mic Sample [/]

the Avantone CV-12 $499.00 is a good mic for the price.

"For the price"...
A $500.00 Chinese condenser is a bargain?

SCRAM SPAM!!!!!!

Now now Mooney....I gotta tell ya...Superdigital is an Avantone dealer so I get to go hear these things....kick the tires....feel how they're made.....That mic is worth every penny they charge for it. seriously. Another new name in mics is the Miktek line. That stupid C-7 sounds as good as my original U87.......Gawd did I just say that!!!??? I have an Avantone CV14 ribbon. You should have one in YOUR great mic collection. Under $300 off the shelf in a nice box and a suspension mount. Blows the Cascade ribbons away. Ya know I wouldnt kid ya Brother....

NO, Dave, I believed you about the Avantone, and based on your recommendation, bought one from Full Rumpass, err Compass. Unfortunately, the mic was dead when I received it ; something was rattling around inside it. They (FC) were very nice about it and let me return it for credit. I decided to wait and get one of those new Royers. Oh well....
I'm sure that there are some very decent-sounding Chinese mics out there, and I take full stock of your assessment of the Avantone C-7. My real concern is long-term reliability - will it last as long as a Neumann? Components like cheap caps and trannies, these things tend to fail prematurely. Frankly, for $500 (OK, $550), I'd bet on an AT4047 over a Chinese LDC. But maybe I'm just wrong about that, wouldn'y be the first time.
And to be honest, my bitch about that post was simply that it looked like a "shameless plug" for their studio. I dunno...

Has anyone heard the Royer 101's yet? I thought John Dutton was going to try them but I don't remember a review. I'm going to get one of the Avantone ribbons on Dave's recommendation, but I just got the Royer SF12 and my wallet needs a recovery period.

Still in Yellowstone. Will return to civilization-such as it is-next week sometime.

TheJackAttack, post: 376641 wrote: Still in Yellowstone. Will return to civilization-such as it is-next week sometime.

I hope civilization is still around when you get back.....

I hear ya Moon. That would be a toss up for me too. I think the Miktek stuff is going to be the stuff to really get into. A few more ducketts but made in America of high quality stuff. Better get em now before the intro prices put em up where they belong.

I wish you'd got a solid shot at the Avantone though.........ahhh well........

Glad that you cleared that up regarding the Mitek. I wrote them off as another Asian wannabe. I should give them a closer look. I wanted a good LDC made in the USA, have only experienced the Lawson L47 which I liked...a lot.

I'll probably give the Avantone ribbon another try, I ended up using the Heil PR35 on the chickie that I wanted to try it on, and the client was fine with that.

CHINESE MICROPHONES

That's the rub. With the Chinese microphones it is important that the quality control is "micro-managed" by someone on this side of the pond.

Each one of our microphones are tested by us before shipping.

We are very specific with them about capacitors and transformers (but I have never seen even a cheap Chinese transformer fail prematurely???).

The capacitors used in the majority of Chinese microphones are better quality than those used back in the 50's & 60's.

Electrolytic capacitors in general fail sooner than other capacitors but we are talking 10-15 years under normal conditions.

The Neumann K67 capsules are notorious for failing as Neumann didn't use any binder to hold the gold onto the mylar diaphragm.

We have had quite a few Neumann U87's in here that have capsules that failed after 5 years of close vocal work.

My guess is the CV7 microphone was dropped during shipping and the capsule & mount were rattling around in the head grill as that's about all that can break loose???

The 4047 is a good microphone but a little pricey for a Cardiod only with a transformerless IC output circuit.

We get the same response with our CM47fet but it can be switched between Cardiod and OMNI plus has a -10db pad and internal LF roll-0ff and sells in the case with shock-mount for $289.

It uses high quality, tantalum capacitors in the audio chain, it has a discrete class "A" audio chain and has a transformer coupled output stage.

Cheers, Dave

[[url=http://[/URL]="http://www.aamicrop…"]Advanced Audio Microphones[/]="http://www.aamicrop…"]Advanced Audio Microphones[/]

moonbaby, post: 376576 wrote: NO, Dave, I believed you about the Avantone, and based on your recommendation, bought one from Full Rumpass, err Compass. Unfortunately, the mic was dead when I received it ; something was rattling around inside it. They (FC) were very nice about it and let me return it for credit. I decided to wait and get one of those new Royers. Oh well....
I'm sure that there are some very decent-sounding Chinese mics out there, and I take full stock of your assessment of the Avantone C-7. My real concern is long-term reliability - will it last as long as a Neumann? Components like cheap caps and trannies, these things tend to fail prematurely. Frankly, for $500 (OK, $550), I'd bet on an AT4047 over a Chinese LDC. But maybe I'm just wrong about that, wouldn'y be the first time.
And to be honest, my bitch about that post was simply that it looked like a "shameless plug" for their studio. I dunno...

MXL2001 schematic

Hi Guys, here is the schematic for the 2001 with a couple of my notes.

MXL2001 schematic

Hi Guys, here is the schematic for the 2001 with a couple of my notes.

I tried to attach the schematic but I get a note that the file is too large at 117kb???

Cheers, Dave

AT4021 is a great SDC.
SM57 is usually better than expected.