Warm Audio WA-67 - Teardown

[Whoops]

For instance, how do I know the person designing the PCB for those high impedance circuits really understood the challenges and made sure the manufacturer got things right?

You buy from a trusted seller, that proved already that he is selling a good PCB. You check others feedback

And once it's built I can't just send test tones from my DAW through the mic and look at the response.

Yes you can, it works fine

You need an anechoic chamber and really good measuring equipment to fully understand what is going on with the mic, don't you?

You can measure it without any anechoic chamber, we don't need the same level of precision approach as a company that is developing product. You can also go a studio that has a dead room if you want, and it would be good enough.
This is DIY if you build it correctly with good quality parts, it will sound pretty good and maybe no need to do any measuring at all.
Just record with it and have fun

Anyway, I wish you all good, but let's not hijack the thread...

 

[living sounds]

Anyway, I wish you all good, but let's not hijack the thread...

Sorry!

 

[Ricardus]

Thanks! I've DIYed mics before, but feel this is an area where expertise and proper testing equipment are vital. It's not as easy to get right as a compressor or preamp, as evidenced by all the lousy to mediocre sounding mics out there, even those made by commercial outlets.

Juding from these comparisons I think the Advanced Audio version doesn't do the Neumann thing either, unfortunately:

Start with something more simple than a tube mic build. Maybe start with their U87. I built two. Fantastic.

But you're you're looking for mic advice, I am a HUGE fan of Shure's LDCs. I own a pair of KSM44s and a pair of KSM27s (now called the SM27) and for $300 I don't think you'll find a better mic than the SM27. The KSM44 clock in at about $999 these days, but if you didn't have any high end German mics in your studio, and only had KSM44's you'd do fine. It can handle anything.

 

[kingkorg]

But you're you're looking for mic advice, I am a HUGE fan of Shure's LDCs. I own a pair of KSM44s and a pair of KSM27s (now called the SM27) and for $300 I don't think you'll find a better mic than the SM27. The KSM44 clock in at about $999 these days, but if you didn't have any high end German mics in your studio, and only had KSM44's you'd do fine. It can handle anything.

+ 1.000.000. Ksm line is insane. Ksm32 has the vintage Neumann vibe.

 

[12strings2hands]

You can listen to comparisons between the wa-67 and the Neumann reissue here:

https://www.amazona.de/test-warm-audio-wa-67-grossmembran-roehrenmikrofon/
To my ears these sound very different and the Neumann is very obviously a far better sounding mic.

Here the same reviewer compares the modern U67 vs a vintage one:

https://www.amazona.de/test-neumann-u-67/

Could almost be the same mic

 

[kingkorg]

Almost the same mic? Frequency deviation is huge, shown in the graphs on that page for every polar pattern. Curves are vastly different so not a linear level deviation which could be adjusted by tweaking the circuit. According to the graphs these mics have nothing in common.

Screenshots you attached show they are recorded in the same space, besides that i see no similarity.

If these tests are done right, and they seem to be, wa67 is anything but a faithful replica, and non surprisingly shows the capsule and it's surroundings are to blame. HF curve shape of Neumanns capsule is notoriously hard to match and it shows yet again. Different headbasked doesn't help.

 

[living sounds]

Start with something more simple than a tube mic build. Maybe start with their U87. I built two. Fantastic.

But you're you're looking for mic advice, I am a HUGE fan of Shure's LDCs. I own a pair of KSM44s and a pair of KSM27s (now called the SM27) and for $300 I don't think you'll find a better mic than the SM27. The KSM44 clock in at about $999 these days, but if you didn't have any high end German mics in your studio, and only had KSM44's you'd do fine. It can handle anything.

Thanks, I'll check the Shure mics out. I only knew them as a manufacturer of dynamic mics.

I have built mics before myself, even a tube mic (see above). They're great. But like I wrote, I think it's not that easy to get a mic to sound as great as a Neumann U67.

 

[12strings2hands]

Could almost be the same mic

Almost the same mic? Frequency deviation is huge, shown in the graphs on that page for every polar pattern. Curves are vastly different so not a linear level deviation which could be adjusted by tweaking the circuit. According to the graphs these mics have nothing in common.

Screenshots you attached show they are recorded in the same space, besides that i see no similarity.

If these tests are done right, and they seem to be, wa67 is anything but a faithful replica, and non surprisingly shows the capsule and it's surroundings are to blame. HF curve shape of Neumanns capsule is notoriously hard to match and it shows yet again. Different headbasked doesn't help.

I should have explained more...each of the 3 graphs shows a different polar pattern. In each polar pattern graph the 2 microphones are superimposed on each other. The frequency response of one mic to the other mic is, to my eye, as exact as could be given the difficulty in maintaining correct position for the compared mics.
Are you saying that the graphs of the mics are hugely different? Because I couldn't get even run a test of 2 matched mics on hand here and get a graph that close.

 

[kingkorg]

The u67 is shown as 0db flat line in the graph. Which means it is used as reference. Yellow line is wa67's deviation from u67. The difference, which is +-5db, total of about 10db in difference. In my book they couldn't be more different.

When it comes to your screenshot graphs what you see as common are huge peaks and dips which come from surroundings. Not from the mics. Naturally they look the same as you are recording in the same space. However you are missing the details where they differ and deviate from each other. And they differ a lot!

Do a 1/3 smoothing on those graphs and you will see what i'm talking about. Or use something like curveEQ to show you the difference between the two responses.

You are also using 10+db per division, which is not helping.

Edit:
Nevermind, i did it for you. The CurveEQ image below shows the difference between the two with cardioid strumming example. I hope you get the point.

 

[pinchemotherloaf]

Soldering Comparison

Neumann vintage U67 (solder on both sides)

View attachment 88474

Reissue Neumann U67 (Solder on both sides)

View attachment 88475

Warm Audio WA-67 (Soldering only on one side, it saves time and saves money on solder, less toxic solder fumes and it looks great also)

View attachment 88476

I was a mil-spec solder-smith in early eighties producing mainframe cards for Intel. Neumann's solder joints are excessive except for the C3 joint in both original and reissue. In Warm Audio's case I see only one joint (out of twenty) that passes, in the middle below the cap. Neumann used leaded solder on the original, pre RoHS, making the joints shinier. From what I can say, and know, solder can create it's own noise problems in microphones (near capsule) meaning sometimes less is better but should be sufficient.

 

[CJ]

did anybody ever follow Stephen Paul's work as to capsule construction?

 

[gyraf]

did anybody ever follow Stephen Paul's work as to capsule construction?

..I tried to for a very long time, but found that he was very much into pouring out smokescreen over every thinkable technical detail. To the degree that most of the clear advice he ever gave out on capsule construction turned out to be decidedly wrong. I got the feeling that he was very afraid of helping any competition..

Sorta like the opposite of you..

/Jakob E.

 

[Tim Campbell]

Well as I mentioned before Stephen and I became friends before he died to the point of him offering me a job. However we totally disagreed about capsule properties. I pursued this thin film idea a bit but found the benefits negligible and the mechanic problems over time too great

 

[living sounds]

From what I can say, and know, solder can create it's own noise problems in microphones (near capsule) meaning sometimes less is better but should be sufficient.

Interesting, thanks! This is the level of detail necessary to get right building mics that makes me hesitate to DIY.

 

[abbey road d enfer]

. From what I can say, and know, solder can create it's own noise problems in microphones (near capsule) meaning sometimes less is better but should be sufficient.

Actually, it's not the. solder, it's the flux residues that amalgamate dirt and humidity.

 

[xeawr]

I never had a good feeling about the Warm Audio products, but things can be worse!
What to think about this 'construction'? (Golden Age Project)
I would take a lot of creativity to make it worse than this...

In 2018 they sold this 'thing' for €1499 including VAT...

well if it sounds good it is good, no?

 

[RuudNL]

well if it sounds good it is good, no?

https://www.soundonsound.com/reviews/golden-age-premier-ga-47
" Pros: Excellent build quality and styling."

HAHAHAHA!!!!

 

[12strings2hands]

The u67 is shown as 0db flat line in the graph. Which means it is used as reference. Yellow line is wa67's deviation from u67. The difference, which is +-5db, total of about 10db in difference. In my book they couldn't be more different.

When it comes to your screenshot graphs what you see as common are huge peaks and dips which come from surroundings. Not from the mics. Naturally they look the same as you are recording in the same space. However you are missing the details where they differ and deviate from each other. And they differ a lot!

Do a 1/3 smoothing on those graphs and you will see what i'm talking about. Or use something like curveEQ to show you the difference between the two responses.

You are also using 10+db per division, which is not helping.

Edit:
Nevermind, i did it for you. The CurveEQ image below shows the difference between the two with cardioid strumming example. I hope you get the point.

Thanks for that. I feel a little stupid, but this is really useful info.

 

[bo108]

Dear all,
I happened to see the comments on the Golden Age Premier GA-47 MKI. The MKI has been replaced by a MKII version that has a much more tidy interior, check out the pictures. It uses an expensive Rogers circuit board.
Both versions has received a lot of great feedback from many users, also professional ones, but as always, sound character and performance is always a matter of taste. I do believe though the mics in the GAP Premier line offers good value for the money.
In case you are interested, find more info here: Golden Age Premier (Product list) [Golden Age Music AB]
Wishing everyone all the best for 2022!
Bo, Golden Age Project, Sweden

 

[soliloqueen]

..I tried to for a very long time, but found that he was very much into pouring out smokescreen over every thinkable technical detail. To the degree that most of the clear advice he ever gave out on capsule construction turned out to be decidedly wrong. I got the feeling that he was very afraid of helping any competition..

Sorta like the opposite of you..

/Jakob E.

This seems to be an ongoing problem with capsule making. People are very protective over 100-year-old information and regularly employ smoke screens. I understand a lot of people make capsules for money so they want to maintain a sense of mystery and exclusivity, because on some level they're afraid that sales will go down if more people know how to make capsules. That fear is only founded if people are buying capsules for practical reasons, but people don't buy boutique capsules or microphones for practical reasons. They do it to support an artist. I wish people would be less insecure about their capsules. More people learning to paint doesn't devalue any specific artist's work.