AKG Perception P220 to Neumann u87 5 min mod ( p200, p100, p400, p420? )

[micolas]

Hi @s wave ,

This circle in which we float, called Groupdiy, operates with technical terms, with clearly defined parameters, we make measurements, our approach is scientific, objective.
Otherwise, we end up contradicting each other permanently for subjective reasons, for beliefs, individual psychoacoustic perceptions, personal preferences, very different aesthetic, artistic, cultural orientations.

Edit:
Let's not pollute this thread with @kingkorg 's excellent mod with off topic discussion.

 

[s wave]

I don't think it is off topic ~ when discussing the high end frequency of a specific mod vs it's targeted model. (I think your posted definition uses very subjective words btw) I wanted to hear, from those who have made mods, and how they compare the high ends; in terms of that classic 'Neumann air'. Does a dual diaphragm inherently have a tidbit of smear/phase shift vs a single?

 

[micolas]

Does a dual diaphragm inherently have a tidbit of smear/phase shift vs a single?

That's a really good question, and since it's not specific to a particular microphone brand or model, I think it deserves a separate thread. At least in the case of capsules with a central screw, I am convinced that a capsule with a double diaphragm has a different spectral and polar behavior compared to a simple capsule. I think that in the case of a dual capsule, the central screw influences the amplitude and the way the rear diaphragm vibrates, resonates, damps, rejects, etc.
It is possible that @kingkorg studied this aspect, and knowing that he is very pedantic and objective, he may have made measurements.
On the other hand, phase shifts are ubiquitous in acoustic reality.

 

[Masiusima13]

I just got a new p420 for really cheap and im going to mod it soon, is there any sonic benefits to using a wima or a nicer 680pf cap instead of a smd 0805 equivalent, im leaning towards using the smd one because its a drop in equivalent and no risk having a bulky cap hanging by its leads inside the mic but if the wima sounds better i might go in that direction, any help?
Ive read that the cap is not in the signal path and only in the feedback network so every same value cap would sound the same.

Also what voltage is appropriate? I was thinking of using 63v caps. Thanks.

 

[k brown]

That's a really good question, and since it's not specific to a particular microphone brand or model, I think it deserves a separate thread. At least in the case of capsules with a central screw, I am convinced that a capsule with a double diaphragm has a different spectral and polar behavior compared to a simple capsule. I think that in the case of a dual capsule, the central screw influences the amplitude and the way the rear diaphragm vibrates, resonates, damps, rejects, etc.
It is possible that @kingkorg studied this aspect, and knowing that he is very pedantic and objective, he may have made measurements.
On the other hand, phase shifts are ubiquitous in acoustic reality.

But, of course the majority of people use dual-diaphragm capsule mics in cardioid most of the time; then the rear diaphragm is doing nothing. A notable exeption is the Neumann M 49, where the most accurate card pattern is produced with a small amount of voltage to the rear.

 

[Khron]

is there any sonic benefits to using a wima or a nicer 680pf cap instead of a smd 0805 equivalent,

Unlikely, as long as you make sure the new SMD cap is C0G / NP0 material.

 

[Emmathom]

Ive read that the cap is not in the signal path and only in the feedback network so every same value cap would sound the same.

Is it sure that the feedback signal does not influence the main one in terms of quality ?
Isn't it "melted" with the "main" signal ? I would say yes to that question...

 

[ccaudle]

in cardioid most of the time; then the rear diaphragm is doing nothing.

I would not say it is doing nothing, it is the rear diaphragm which is driving the delay network through the backplate. A dual diaphragm capsule will be different than a single diaphragm capsule in the extent that air vibrating the diaphragm which then vibrates the air behind the backplate is different then vibrating air directly hitting the backplate. Guy Torio at Shure wrote one or two papers on differences between single and dual diaphragm designs. If I remember correctly the most noticeable differences were in proximity behavior.