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

[k brown]

The cap is so lightweight, the leads so short, and AKG boards are of sufficient quality, that I wouldn't think that cap is in any danger of coming loose, unless you pound nails with your mics . . .

 

[AdamFrisen]

A post how the capsule looks like front and back in AKG P420 would be great. I've heard it has Takstar inside but I cannot find any picture of the capsule inside P420.

 

[MicMaven]

I'm sure that @Khron would recommend you to fix it preventively with some glue, against shocks, vibrations, etc.

There are two schools of thought: Mr. Micolas properly cites Mr. Khron, representing the School-of-Common-Sense-Caution; while others advocate the "Don't-Fix-What-Is-Not-Broken" school of thought, which advances the time honored adage: "If you fix something long enough, ... you will, eventually, break it." (popularly known as Richards' Corollary of Murphy's Law)

You, Weed-Hopper, must decide which school to follow.

But, seriously folks, it depends on whether it will receive rough handling. A great many components are merely soldered in place in all sorts of gear. Why would this particular part face greater risk than similarly situated components? While a dab of glue may assure logevity, it may also impede future modification, manifesting a true dilemma. You must consider future handling and the potential for change, weighing the relative risks. Oddly, it is not an easy decision! Just MY take. Good luck. James

 

[stepanparkan]

Hello everyone, thank you for the amazing well of knowledge. I've decided to pursue this mic mod and am looking to buy a donor.

I live in Asia, so my options after shipping and importing are:

1. P420 from ebay (black) – new, 200 USD
2. Perception 420 (blue) from ebay – beat up externally, 150 USD
3. Perception 400 (blue, first gen I assume, BNIB) locally for 150 USD

Any reason to choose one over another? I would lean to go for a local deal and get it today instead of in two weeks, but is 400 in any way different?

 

[Khron]

is 400 in any way different?

"Only" has a -10dB pad instead of -20dB on the later models, and the JFET / switch board is more likely to use more through-hole components (JFET and possibly 1G resistors, can't recall exactly right now).

 

[stepanparkan]

Thank you Khron!
Can anyone please confirm if this is the correct cap?

 

[joulupukki]

Thank you Khron!
Can anyone please confirm if this is the correct cap?

Yes, that looks to be a 680pF cap. Should work if you remove and replace the original with that. It's much easier to just add on a 470pF capacitor if you have one of those.

 

[Paul W]

Yes, that looks to be a 680pF cap. Should work if you remove and replace the original with that. It's much easier to just add on a 470pF capacitor if you have one of those.

But as discussed upthread, the easiest way to do it is with a surface mount capacitor, 0805 (imperial) size (NP0 or C0G ceramic), which just sits right on the existing capacitor, and you can solder the corresponding ends together with a dab of solder.

Edited to add: 0805 imperial size is also known as 2012 metric size.

 

[baroquee]

It's closer to the U67, for a U87i Vintage sound @kingkorg used 680pF.
But you can use more values and a miniature dip switch inside the microphone.
It would be a very versatile multi-voice microphone

Hi all,
Thanks for all that Knowledge and modding of the akg perceptions mics. Has anyone integrated one of those dip switches already or has thoughts on where to place it? I‘d really like to move between say 680pf and 900pf. Is there even a chance to have a dip switch or similar accessible from the outside? Maybe like a 3way-switch-knob or so. To be able to even switch between original p420/220 to U87like to u67like?

Best

 

[RumHam726]

Is there a reason folks are using through-hole mount capacitors instead of replacing the stock cap with a new surface mount one? Is it just the difficulty of removing the smd stuff making it more likely to cause damage?

 

[Paul W]

Is there a reason folks are using through-hole mount capacitors instead of replacing the stock cap with a new surface mount one? Is it just the difficulty of removing the smd stuff making it more likely to cause damage?

It seems that everyone who has compared the two approaches thinks it’s easier to replace the capacitor with another surface mount one, and still easier to just piggyback another 0805 SMT (a.k.a. metric 2012 size) cap on top of the one that’s there.

I suspect that some people are just using what they have around, and others didn’t read enough of the thread to realize SMT is easier.

 

[joulupukki]

For sure if I would have had a SMT cap to piggy back, I would have just done that. But small ceramics are plentiful and simple enough to just tack on.

 

[stepanparkan]

I swapped the capacitor and the mic indeed sounds more tame and controlled on my voice.

Is there any benefit to midding it rurther? I was looking at mayeb using AU Flat47 in it. I am not trying to go for a neumann clone or anything, just want as flat sounding mic as I can get for some non-voice related recordings, wherer I want to keep things as tue to life as I can.

 

[Khron]

Is there any benefit to midding it rurther? I was looking at mayeb using AU Flat47 in it

If you go that route, you'll want to disconnect the feedback network entirely (unless you DO want to roll off the high frequencies in a flat K47 as well)...

 

[k brown]

I swapped the capacitor and the mic indeed sounds more tame and controlled on my voice.

Is there any benefit to midding it rurther? I was looking at mayeb using AU Flat47 in it. I am not trying to go for a neumann clone or anything, just want as flat sounding mic as I can get for some non-voice related recordings, wherer I want to keep things as tue to life as I can.

I suppose you could try JLI-3412; it's not as high quality as the AKG, but is a bit flatter; with the modded AKG EQ, probably quite flat.
https://www.jlielectronics.com/microphone-capsules/jli-3412/

 

[RumHam726]

I had ordered these caps from Digikey. I'm not too experienced with all the ratings for parts like this, and the caps that showed up were much smaller than a lot of what I'm seeing in photos, though that might be a good thing. Will these work to add to the existing cap? Thanks for any guidance!

 

[kingkorg]

I had ordered these caps from Digikey. I'm not too experienced with all the ratings for parts like this, and the caps that showed up were much smaller than a lot of what I'm seeing in photos, though that might be a good thing. Will these work to add to the existing cap? Thanks for any guidance!View attachment 135480View attachment 135481

Sure, you can just add it to the existing one.

 

[RumHam726]

Got the mod done on a P420 the other day - added a 470pf cap onto the original - not the cleanest but I've never soldered anything this small. I practiced on an old broken tuner to get a feel for it. Anyway - I think it seems solid enough.

Definitely much warmer and richer sounding mic compared to stock. Thanks @kingkorg and everyone else for the idea and the tips!

One thing that just occured to me - does the orientation of the leads matter in this - is there a positive and negative? I didn't even consider it! It seems to have worked out but I have another one on deck and want to be sure.

EDIT - looking at the data sheet for the capacitor and says it's a "non-polar device", so I'm guess that answers my question and it doesn't matter which way it's installed. Please correct me if I'm wrong.

 

[k brown]

Got the mod done on a P420 the other day - added a 470pf cap onto the original - not the cleanest but I've never soldered anything this small. I practiced on an old broken tuner to get a feel for it. Anyway - I think it seems solid enough.

Definitely much warmer and richer sounding mic compared to stock. Thanks @kingkorg and everyone else for the idea and the tips!

One thing that just occured to me - does the orientation of the leads matter in this - is there a positive and negative? I didn't even consider it! It seems to have worked out but I have another one on deck and want to be sure.

EDIT - looking at the data sheet for the capacitor and says it's a "non-polar device", so I'm guess that answers my question and it doesn't matter which way it's installed. Please correct me if I'm wrong.
View attachment 135716

Correct - they are non-polar.

 

[k brown]

Caps with a much lower voltage rating will have thinner leads that are rather easier to deal with (no need for 100V).