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

[micolas]

@joulupukki
Be very careful when trying to fold the capacitor, it has very short and hard terminals, not to peel the PCB traces.
I experienced it many years ago, I was impatient.
Use tweezers to immobilize the terminals.

 

[Khron]

That, or desolder it first and resolder it already-laying-down

 

[joulupukki]

I will likely leave it untouched, maybe a couple dabs of superglue at the most. I'll just check to see if laying it down would be possible, for the sake of academics.

 

[micolas]

I will likely leave it untouched, maybe a couple dabs of superglue at the most. I'll just check to see if laying it down would be possible, for the sake of academics.

Leave it. Even @Khron posted a picture in which the capacitors are nicely in place.

 

[joulupukki]

And doesn't fit folded down in the other direction?

Confirmed. It could fit folded down in the opposite direction and admittedly that'd be a better plan with maybe a tiny dab of clear silicone caulk for some extra security.

 

[Khron]

Leave it. Even @Khron posted a picture in which the capacitors are nicely in place.

In my defense, i did that quite a number of years ago, when i was a slight wee bit less wise than i am nowadays

(Not that i've evolved THAT far beyond my previous state, but... that's a whole different conversation right there )

 

[micolas]

@Khron
I admit that I am even more guilty.
I like to build according to the point-to-point method, in the air, without a traditional PCB, or on a metal plate with a few solders in the GND points.
Maybe the rigidity of the assembly is lower, but in decades I have never had problems. I make very robust solders and in general the resulting structure absorbs shocks and vibrations well.
The big advantage is that I don't have to work a lot to manufacture the PCB (I do it completely manually: drilling, drawing, corrosion with hydrochloric acid with perhydrol/perogen, pickling, etc.) or I don't have to buy it elsewhere (price, taxes, transport , waiting time, etc.). When changing some components I don't have to make improvisations on the PCB.
So I just enjoy it, build quickly, with finer, temporary solders like a spider's web, if necessary shield everything in a bare metal cd player case, and experiment until I like the result, often making dozens of changes , without the risk of damaging the PCB or components. When I am satisfied, I draw the new diagram, with the new measured values.
Experimenting gives me great satisfaction, especially when I push things to the extreme.
If I decide to keep the circuit then I robustly rebuild it all p2p, using the same components from the experimental prototype.
Many years ago, during the communist dictatorship, the national TV program (the only one) lasted 2 hours! It contained only propaganda. Manipulation, indoctrination.
So I built huge Yagi antennas, or phased array antenna systems, and very high gain/low noise VHF/UHF amplifiers. We managed to receive programs from Hungary, Yugoslavia, Bulgaria (from hundreds of km away) and sometimes when the atmosphere was strongly ionized, we received Nordic countries, through reflections on the ionosphere, troposphere (thousands of km away: TV-DX). We build all the HF amplifiers p2p in metal cases and position them on the antenna, close to the vibrator/dipole/simetrizer for best S/N ratio.
The antennas vibrated strongly from the wind being placed on the roofs of the blocks as high as possible to improve the electromagnetic horizon, but I never had any problems with mechanical resistance.
In the mid-80s, I built satellite receivers and LNC/LNB, also using the p2p method, the requirements being even stricter with the increase in frequency.
In circuits with tubes as well, I preferred p2p montages even if it was a bass, guitar combo amplifier that vibrates strongly.

In conclusion, I'm perfectly fine with any way to solve the problems, if it's reliable.

 

[Papa Tango Charly]

Hello my friend, is there a way of lowering the self noise of this p220?

 

[MicMaven]

perhaps even tack it down with a drop of glue,

Sidebar Question: What sort of glue? / James

 

[Khron]

Sidebar Question: What sort of glue? / James

Doubt it matters much, as long as it's kept far enough away from other components & solder joints.

 

[micolas]

Hello my friend, is there a way of lowering the self noise of this p220?

Neumann's original goal when he introduced de-emphasis was to bring back noise.
The stock P220 has 16dBA self-noise, and after modification, depending on how far you went with the capacitor, you probably get 14...15dBA noise, which is very good for real-world use. I know that Neumann not long ago recreated the famous M49 in version V, with a noise of 20..21dBA.
If it's good for Neumann standards, then it's ok for us.

 

[mikes425]

Neumann's original goal when he introduced de-emphasis was to bring back noise.
The stock P220 has 16dBA self-noise, and after modification, depending on how far you went with the capacitor, you probably get 14...15dBA noise, <

Hi, Just curious, does the same apply to the older Perception 220...or does the P220 have lower self-noise? Wondering since
I have a 220 and if i do another mod, trying to decide if i should try to get a P220 instead. Thanks!

 

[micolas]

Hi, Just curious, does the same apply to the older Perception 220...or does the P220 have lower self-noise? Wondering since
I have a 220 and if i do another mod, trying to decide if i should try to get a P220 instead. Thanks!

From the manufacturer's documentation:
Noise: (stock)
16dBA for all 220 and Perception420
15dBA for P420

 

[mikes425]

From the manufacturer's documentation:
Noise: (stock)
16dBA for all 220 and Perception420
15dBA for P420

Thanks!

 

[micolas]

Hello my friend, is there a way of lowering the self noise of this p220?

My sweetest, velvety, silky, warm microphone for female vocals, the Sterling ST-77 (Made in Germany) is a true underrated gem.
It does not have a DC/DC converter, the voltage polarization being 34..35v, so it has a noise of 18..19 dBA.
When I use many layers on the voice, the noise in the solo bothers me, but in the mix the instrumentation masks it. I'm used to Rodes with insanely low noise figures, but I'm aware that adding an oscillator to the Sterling and increasing the capsule voltage will ruin the tonal balance, introduce distortion, more saturation, reduce headroom, etc. In a word I will lose its magical character.
So I learned to live with it and enjoy the good parts.

 

[cholmes777]

Im back
My brand new (black) perception 420 came in today plus my 680pf capacitors from mouser.

Ok lets try this again,this time leaving in the 220pf smd
And soldering in parallel on to it the 680pf for a total of
900pf

I thought I wouldn’t like this, I LOVE IT!! Super mid rangy creaminess!! Im guessing im in the tlm67/ u89 territory?..

My 470pf will deliver tomorrow but i think im going to leave this as is for now since i own a real u87ai. I think it compliments it well in the mic collection

Oh and im still using my blue housing from my p420 i destroyed
I dont like the new black housing.

 

[Khron]

You might wanna trim down the legs of that, and have it sit as close to the board as you can get it, maybe even glue it down, just for (mechanical) reliability's sake

 

[micolas]

Im back
My brand new (black) perception 420 came in today plus my 680pf capacitors from mouser.

Ok lets try this again,this time leaving in the 220pf smd
And soldering in parallel on to it the 680pf for a total of
900pf

I thought I wouldn’t like this, I LOVE IT!! Super mid rangy creaminess!! Im guessing im in the tlm67/ u89 territory?..

My 470pf will deliver tomorrow but i think im going to leave this as is for now since i own a real u87ai. I think it compliments it well in the mic collection

Oh and im still using my blue housing from my p420 i destroyed
I dont like the new black housing.

You got the same sound as me. It's delicious. Yep, looks like it's somewhere
towards TLM67.
Have you dressed the new P420 black with Perception420's blue clothes?
Could you do a comparative sound test between U87ai and P420 mod, possibly a test with Pink noise to see graphically the frequency response differences?
I repeat myself, but the damaged microphone needs to be fixed, made to sound good.

 

[cholmes777]

You might wanna trim down the legs of that, and have it sit as close to the board as you can get it, maybe even glue it down, just for (mechanical) reliability's sake

Will do khron!

 

[MicMaven]

Doubt it matters much, as long as it's kept far enough away from other components & solder joints.

Roger.

And yet, ... er ... um ... I suspect a glop of hot glue is more likely reversible than, say, an equal portion of CA (cyanoacrylic) "super") glue. James