Help with capsule choice

[skyy7]

Hello, I am having difficulty choosing a capsule for my next build (most likely a multipattern k67 in a schoeps circuit with a u87 style deemphasis).

I have been debating between the 3 manufacturers: 797 audio, Arienne Audio, or 3u. I was wondering if anyone had any experience with these manufacturers and would have any advice to which capsule I should purchase.

I have heard wonderful things about all 3 manufacturers and I would to purchase a capsule under the 200 dollar mark so if anyone has an suggestions it would be much appreciated.

On a side note, I have noticed that some k67 type dual sided capsules only have one black wire connected to one of the 2 back plates. How would I go about applying a negative and positive polarizing voltage to each side of the capsule to create a multipattern mic?

 

[Khron]

How would I go about applying a negative and positive polarizing voltage to each side of the capsule to create a multipattern mic?

https://audioimprov.com/AudioImprov/Mics/Entries/2015/12/20_Modding_a_BM-800_Mic.html

a schoeps circuit with a u87 style deemphasis

Got a schematic? Because that sounds... a bit confusing to me, but i may well be misunderstanding your intention.

 

[skyy7]

https://audioimprov.com/AudioImprov/Mics/Entries/2015/12/20_Modding_a_BM-800_Mic.html


Got a schematic? Because that sounds... a bit confusing to me, but i may well be misunderstanding your intention.

Oh, so the capsule is polarized using the redwire and the black goes to the gate.

Regarding the circuit...
https://audioimprov.com/AudioImprov/Mics/Entries/2014/2/8_EQ_Pt.3_-_Transformerless_Mics.html

 

[Khron]

Regarding the circuit...

As some users have found, that apparently adds noticeably to the mic's noise floor.

I would rather suggest a capacitor (or series capacitor-resistor) in parallel with the JFET drain resistor, to achive basically the same effect.

 

[kingkorg]

Hello, I am having difficulty choosing a capsule for my next build (most likely a multipattern k67 in a schoeps circuit with a u87 style deemphasis).

I have been debating between the 3 manufacturers: 797 audio, Arienne Audio, or 3u. I was wondering if anyone had any experience with these manufacturers and would have any advice to which capsule I should purchase.

I have heard wonderful things about all 3 manufacturers and I would to purchase a capsule under the 200 dollar mark so if anyone has an suggestions it would be much appreciated.

On a side note, I have noticed that some k67 type dual sided capsules only have one black wire connected to one of the 2 back plates. How would I go about applying a negative and positive polarizing voltage to each side of the capsule to create a multipattern mic?

Arienne's is confirmed 1:1 Neumann replica.

 

[skyy7]

As some users have found, that apparently adds noticeably to the mic's noise floor.

I would rather suggest a capacitor (or series capacitor-resistor) in parallel with the JFET drain resistor, to achive basically the same effect.

So in the context of this circuit would it be a series capacitor and resistor in parallel with r7? I've never heard of something like this before so what values would I go about choosing?

 

[skyy7]

Arienne's is confirmed 1:1 Neumann replica.

Thats amazing. I think I'm gonna buy Arienne. But just gotta wait for stock...

 

[Khron]

So in the context of this circuit would it be a series capacitor and resistor in parallel with r7? I've never heard of something like this before so what values would I go about choosing?

Indeed. Start with 4.7nF, perhaps 6.8nF, and a 10k trimpot in series with that capacitor - set that to minimum resistance, so your starting point cuts the most amount of top-end. Then you can trim that back to restore as much top-end as you want; unsolder and measure what resistance you ended up with, and permanently solder in the closest standard-value fixed resistor you have in your stash.

 

[kingkorg]

Or if you want to go crazy, and do the true feedback de-emphasis, you can add this part to the circuit. Thanks to marvelous @RuudNL for this solution.

 

[oscarhuang]

Or if you want to go crazy, and do the true feedback de-emphasis, you can add this part to the circuit. Thanks to marvelous @RuudNL for this solution.

It seems that this is a really good idea. Like u87, it uses reverse signal injection into the capsule.

 

[skyy7]

As some users have found, that apparently adds noticeably to the mic's noise floor.

I would rather suggest a capacitor (or series capacitor-resistor) in parallel with the JFET drain resistor, to achive basically the same effect.

Wait, sorry.

In a TL/C type circuit where would I add the series capacitor resistor? Would it be at the bias of the JFET still at R5? Or at the bias of the PNP phase splitter at R4?

 

[Khron]

Wait, sorry.

In a TL/C type circuit where would I add the series capacitor resistor? Would it be at the bias of the JFET still at R5? Or at the bias of the PNP phase splitter at R4?

"Bias" is not the name of any transistor terminal
https://en.wikipedia.org/wiki/Biasing
In the schematic in your post, it would go in parallel with R5, the drain resistor of the JFET. You'll probably want to measure "before" and "after" things - REW is great for that.

 

[micolas]

Arienne's is confirmed 1:1 Neumann replica.

Kingkorg,
I apologize for bothering you, but I have great confidence in your experience and objectivity. I think we all want to know your opinion.
Have you managed to measure all versions of the Arienne K87, including v2.0?
How do they compare?
Which one is closest to Neumann?

 

[skyy7]

Indeed. Start with 4.7nF, perhaps 6.8nF, and a 10k trimpot in series with that capacitor - set that to minimum resistance, so your starting point cuts the most amount of top-end. Then you can trim that back to restore as much top-end as you want; unsolder and measure what resistance you ended up with, and permanently solder in the closest standard-value fixed resistor you have in your stash.

Sorry, but I was messing around with this and noticed that it works as intended but causes the signal to become unbalanced. Is this a problem?

 

[Khron]

Define the "become unbalanced" part.

 

[kingkorg]

Kingkorg,
I apologize for bothering you, but I have great confidence in your experience and objectivity. I think we all want to know your opinion.
Have you managed to measure all versions of the Arienne K87, including v2.0?
How do they compare?
Which one is closest to Neumann?

I actually don't know. She sent me random samples and most of the time i couldn't figure out myself what the difference was supposed to be. They all pretty much measured and performed as the originals.

In my opinion Arienne is so pedantic and transparent about her process that it could confuse regular DIYer, because she points to so miniscule parameter changes within the production. Things like screw design, wire materials, material and labour sourcing... you get the point.

All the "improvements" went from exceptional first one i ever got to beyond exceptional with the latest ones i received. I am wondering if she is trying to beat Neumann when it comes to consistency, quality, durability...

I am sure the first ones are really as good as the latest ones, and they can be used interchangeably, but @soliloqueen can say herself if there is any significant difference in the sound.

I don't receive any capsules right now, as i will be spending 6 months a year in Spain in future, and i'm really caught up in the moving process. She nailed the measurement setup her self, and i dont think she really needs my help regarding that part, besides occasional quality double check.

My first post on the capsules still stands, i've never had any financial gain from our interaction, never even spoken to her on a phone. During my written interchange with her on the forum i got a glimpse of what she has gone through to make these capsules, and i can tell you she went to the hell and back to make this work. Almost masochistic. I would never invest that much time, work, and effort into anything, and i truly admire what she has achieved.

 

[capacitor]

+1000 to the above. I know this might be an unpopular position to some, but I think she should revise her pricing to make it worth her while

Thanks @soliloqueen and Happy New Year everyone!

 

[skyy7]

Define the "become unbalanced" part.

If I understood correctly, in a Schoeps circuit, the JFET also acts as a phase splitter, sending the same AC signal, one flipped out of phase, out of the drain, and the source. The 2 signals are then sent through PNP output transistors. The 2 signals get sent out of pin 2 and pin 3 and summed in order to remove any noise. This is my understanding of a balanced circuit.

In Spice, when I added in the series resistor and capacitor in parallel with the drain resistor, the signal that gets outputted from the drain gets an LPF as desired but the signal from the source does not which creates what I believe is an unbalanced signal... I've heard of people saying that this doesn't matter but I really don't fully understand everything....

 

[micolas]

Kingkorg,
thank you for honesty, altruism, for all the efforts made for the benefit of the diy community.
We all realized that Arienne is a perfectionist, professional, generous person who wants to deliver products of the highest level, no matter how much hard work and sacrifices are required.
The results are absolutely remarkable.
We are all grateful and happy to benefit from her amazing products.

Thanks Soliloqueen!

 

[Khron]

which creates what I believe is an unbalanced signal...

https://sound-au.com/articles/balanced-2.htm#s1

SIGNAL SYMMETRY HAS ABSOLUTELY NOTHING TO DO WITH NOISE REJECTION - IMPEDANCE IS WHAT MATTERS!
...
The impedances, with respect to ground, of the two lines is what defines an interface as balanced or unbalanced.