wa 47

[Papa Tango Charly]

This isn't a "mod" but rather my interpretation of the circuit. The main differences from the stock APX 460 are the tube, output cap, transformer and capsule, and you can get all the available info regarding these from the WA website. They don't spec a ratio for the transformer, but I'd bet an AMI 6:1 would do the trick.

Do you think that a 6.5:1 3U audio would do the job? thank you

 

[Papa Tango Charly]

This the ami version…?

 

[doqmemory]

Do you think that a 6.5:1 3U audio would do the job?

If you mean, "would it fit in an Apex 460?" then yes, but it is not right for the cathode follower circuit shown.

This thread is about the WA-47. It already has a nice AMI transformer in it, so why change it?

Are you trying to figure out how to make an Apex 460 (or similar, such as Alctron HST-11A) into a "WA-47 clone", then I would ask "Why?"

I have a WA-47, it sounds pretty good (especially after replacing the tube with an NOS GE 5751), but I would not want to clone it. The WA-47 is already supposed to be a "clone" of the classic Neumann U47, although the WA-47 circuit has almost nothing in common with the U47. The most you can say is that it has a similar capsule and a similar transformer, but everything I have read indicates the sound is not particularly close to a real U47 (disclaimer: I have only heard recordings of real U47). I have made several U47-style microphones based on the EF800 (and similar) tube. I like the sound of each of them better than the WA-47, but they have a higher noise floor (just by listening in headphones, not measured precisely).

The kind of changes that @Flatpicker found to the well-known Apex 460 circuit look similar to the "Fox mod" from Brian Fox. That is the best place to start when modifying an Apex 460 circuit. I still have my first (of very many) Apex 460 with the Fox mod with a 3U Audio M7 capsule. It sounds nice, but I never use it and plan to build something else with it eventually.

 

[Whoops]

I never traced this circuit, I just tried the mic one time, it was from a friend.

Capsule is a 3U Audio K47 capsule rated for 80V of polarization, it's not the standard 60V 3U Audio model.

I was able to take some photos when I tried the mic,
will post them here in case you find them useful

 

[Papa Tango Charly]

Si vous voulez dire, "est-ce que cela rentrerait dans un Apex 460 ?" alors oui, mais ce n'est pas bon pour le circuit suiveur de cathode illustré.

Ce fil concerne le WA-47. Il contient déjà un joli transformateur AMI, alors pourquoi le changer ?

Essayez-vous de comprendre comment transformer un Apex 460 (ou similaire, tel que Alctron HST-11A) en un "clone WA-47", alors je demanderais "Pourquoi?"

J'ai un WA-47, ça sonne plutôt bien (surtout après avoir remplacé le tube par un NOS GE 5751), mais je ne voudrais pas le cloner. Le WA-47 est déjà censé être un "clone" du Neumann U47 classique, bien que le circuit WA-47 n'ait presque rien en commun avec le U47. Tout au plus peut-on dire qu'il a une capsule similaire et un transformateur similaire, mais tout ce que j'ai lu indique que le son n'est pas particulièrement proche d'un vrai U47 (avertissement : je n'ai entendu que des enregistrements de vrai U47). J'ai fabriqué plusieurs microphones de style U47 basés sur le tube EF800 (et similaire). J'aime le son de chacun d'eux mieux que le WA-47, mais ils ont un bruit de fond plus élevé (juste en écoutant au casque, pas mesuré avec précision).

Le type de modifications que @Flatpicker a trouvées sur le célèbre circuit Apex 460 ressemble au " mod Fox " de Brian Fox. C'est le meilleur endroit pour commencer lors de la modification d'un circuit Apex 460. J'ai toujours mon premier (de très nombreux) Apex 460 avec le mod Fox avec une capsule 3U Audio M7. Cela semble bien, mais je ne l'utilise jamais et je prévois de construire quelque chose d'autre avec.

Je vois que je vais construire un vrai u47 à partir du kit audio VAMI. J'ai un Apex 460

 

[doqmemory]

Je vois que je vais construire un vrai u47 à partir du kit audio VAMI. J'ai un Apex 460

The 3U Audio G47 and the AMI T8 both are similar size and ratio, well suited for a U47-inspired build in an Apex 460 body. Suitable tubes are EF80/800/802, EC71/72, 5840, etc. Lots of designs floating around, such as the ones from Oliver Archut.

You need a bit of experience first, since tube mic power supplies are dangerous and the parts are not cheap.

The Fox mod I referred to, along with a 3U Audio M7 capsule, gets you as close as the WA-47 does to the U47.

 

[Papa Tango Charly]

Thank you

 

[Papa Tango Charly]

The 3U Audio G47 and the AMI T8 both are similar size and ratio, well suited for a U47-inspired build in an Apex 460 body. Suitable tubes are EF80/800/802, EC71/72, 5840, etc. Lots of designs floating around, such as the ones from Oliver Archut.

You need a bit of experience first, since tube mic power supplies are dangerous and the parts are not cheap.

The Fox mod I referred to, along with a 3U Audio M7 capsule, gets you as close as the WA-47 does to the U47.

I’m a beginner I have done shoeps, km84, repaired psu. I can change the diode of the Apex PSU. I have a 3U audio M7 Do ou thing I can do the Fox 460 Mod?

 

[Flatpicker]

If you mean, "would it fit in an Apex 460?" then yes, but it is not right for the cathode follower circuit shown...

I have a WA-47, it sounds pretty good (especially after replacing the tube with an NOS GE 5751)...

Yeah, I was thinking about the 12AY7/6072 CF when I said 6:1 (actually 6.5:1), but the 5751 CF is slightly higher impedance, so higher ratio transformer is better.

I had sort of blown off the idea of changing tubes because I figured the differences would be minimal, but you got me really wanting to try a NOS 5751 in my WA-47 now. How would you describe the difference in sound?

 

[doqmemory]

you got me really wanting to try a NOS 5751 in my WA-47 now. How would you describe the difference in sound?

It sounds smooth, without the original tube's brittleness. That's the best way to describe it. It still doesn't have the character of an EF800 based clone. (Apologies for the fuzzy descriptions. )

Well worth it.

 

[xeawr]

WA-47 owner here, I really like the sound and I'm really really picky. But yes - it's not a 47...
I have two and one had the tube replaced, not because it was noisy or broken, but I found the 5751 from another (third) WA-47 sounded a bit better. So I swapped tubes.
NOS 5751? Hmmm, I wonder where to get them, how much they cost and how they sound (in comparison). Tubes can be hit or miss sometimes...

 

[Flatpicker]

...NOS 5751? Hmmm, I wonder where to get them, how much they cost and how they sound (in comparison). Tubes can be hit or miss sometimes...

I don't know about what's available in Europe but the Tube Depot has some:
https://tubedepot.com/
The guy I mentioned in post #4 talks like the TAD 5751 makes a worth while improvement, but then again he's selling mods. I'm also curious about the 5751, Tung-Sol Reissue. Maybe either one might beat the stock JJ?

 

[Flatpicker]

Question for those of you that have the WA-47 and have taken it apart - Did you have any trouble putting the 3 screws back in that holds the sleeve in place? I could get 2 back in pretty easily, but the 3rd one was real pain. It seemed like it wasn't long enough and the threads wouldn't catch. I loosened the other screws slightly and finally got the 3rd one to thread into place (just barely) but took me a while.

 

[kingkorg]

Question for those of you that have the WA-47 and have taken it apart - Did you have any trouble putting the 3 screws back in that holds the sleeve in place? I could get 2 back in pretty easily, but the 3rd one was real pain. It seemed like it wasn't long enough and the threads wouldn't catch. I loosened the other screws slightly and finally got the 3rd one to thread into place (just barely) but took me a while.

Those bodies are mass produced in China, so not surprising (not bad by any means, just QC...). Thread carefully so you don't damage the finish.

 

[Whoops]

WA-47 owner here, I really like the sound and I'm really really picky. But yes - it's not a 47...

Personally I'm a bit confused or not really sure what is actually the sound of an U47, I don't know if you guys feel the same or not.

I've only tried 4 original U47s until now, the one I had in the studio I worked in had a Nuvistor tube it sounded good in his own way, then I had another from other studio with the original VF14 but that mic was not serviced for a long time and I was not sure if the tube was still up to the task, it sounded different than the U47 we had.
Then I used 2x U47s when I produced a record in Abbey Road Studio 3, I used them on top of the drum kit in a Glyn Johns 3 mic technique, they sounded good but I think any good LDC mics would work well for that application.

Then because the VF14M is long gone, all the many U47 clones I tried from different brands all of them have different tubes (than the VF14 and between them) and because of that the electronic circuit is also different than the original U47 circuit.
Most of them sound good to me but all sound different from each other.

So what is the U47 sound?
I really don't know

 

[doqmemory]

Most of them sound good to me but all sound different from each other.

So what is the U47 sound?
I really don't know

I think the moral of the story is, "If it sounds good and you can make good recordings with it, then it _is_ good". Knowing it is "U47-like" just indicates what type of things you might try using it for, but should not limit your imagination, nor should it be expected to really be exactly like a real U47. If you like the sound of a mic and can use it effectively, for example, the WA-47, then use it for what it is without tying to make it into something else. Without some miraculous source of new parts, most of us will never really know what a "real U47" sounds like, but that should not stop us from building/buying/modding other microphones that perform well in their own ways.

For myself, I like the sound of my WA-47 with the GE 5751, but I have over a dozen mics I would prefer to it in most situations. If I had any sense, I would sell all of the mics that I don't use, but I still enjoy collecting and comparing them.

 

[McIrish]

I have worked with a number of U47s as well as owning a Wunder CM7GTS/M7. To me, the sound of the U47 varies by what capsule is installed (M7 or K47), but still the sonic character is there. Big round low end and a mid bump that pushes vocals forward without becoming harsh. Due to the grill design, there is a slight dip in the sibilance frequencies. To my ears, the K47 has a bit more open top end while the M7 is a bit smoother. With all of the ones I worked with, I could get a similar sound with 1-2dB EQ changes. (usually in the top end) They all gave me what I was looking for.

On a side note, another really great mic is the Miktek CV4 IF you swap the capsule. The basic design of the circuit is super similar to Oliver's U47 design with an EF800. I absolutely hated it stock but after tossing in a Beesneez K7, it became one of my main go to vocal mics.

 

[doqmemory]

I have worked with a number of U47s as well as owning a Wunder CM7GTS/M7. To me, the sound of the U47 varies by what capsule is installed (M7 or K47), but still the sonic character is there. Big round low end and a mid bump that pushes vocals forward without becoming harsh. Due to the grill design, there is a slight dip in the sibilance frequencies. To my ears, the K47 has a bit more open top end while the M7 is a bit smoother. With all of the ones I worked with, I could get a similar sound with 1-2dB EQ changes. (usually in the top end) They all gave me what I was looking for.

On a side note, another really great mic is the Miktek CV4 IF you swap the capsule. The basic design of the circuit is super similar to Oliver's U47 design with an EF800. I absolutely hated it stock but after tossing in a Beesneez K7, it became one of my main go to vocal mics.

Miktek makes some quality microphones, but they need to use "better" capsules (better matched to their circuits). I think their C7e is a much better "U87"-style microphone than either the WA-87 or WA-87R2 (I own all 3). I would love to compare the CV4 with my own versions based on the Oliver Archut design (or @poctop's D-EF47).

 

[Purplenoise]

Personally I'm a bit confused or not really sure what is actually the sound of an U47, I don't know if you guys feel the same or not.

I've only tried 4 original U47s until now, the one I had in the studio I worked in had a Nuvistor tube it sounded good in his own way, then I had another from other studio with the original VF14 but that mic was not serviced for a long time and I was not sure if the tube was still up to the task, it sounded different than the U47 we had.
Then I used 2x U47s when I produced a record in Abbey Road Studio 3, I used them on top of the drum kit in a Glyn Johns 3 mic technique, they sounded good but I think any good LDC mics would work well for that application.

Then because the VF14M is long gone, all the many U47 clones I tried from different brands all of them have different tubes (than the VF14 and between them) and because of that the electronic circuit is also different than the original U47 circuit.
Most of them sound good to me but all sound different from each other.

So what is the U47 sound?
I really don't know

For me the u47 sound is…very realistic in a very coloured way haha…if that makes any sense at all. There is a very holographic quality in the way original k47 and m7 sound…something I haven’t found in other clone capsules so much.
Also one thing to remember is that u47 are not dark mics as most people believe. A well maintained u47 has a really nice air sheen, especially with a k47. I think ef800 mics are a little shy in the “air” region and they don’t do justice to original k47. M7 clones or brighter k47 clones work better I think with ef800

 

[soliloqueen]

you guys sure it's the capsules? i put a third party capsule in a real u47 for fun and that 3d quality appeared...