Gbout2

AKG Perception 420 Mod
« on: September 03, 2016, 07:08:23 PM »
Rook mistake of desoldering backplate, front and back diaphragm wires without "clearly" marking where the new wires return for solder. Anybody perform this mod that can show pics of where to solder the new capsule wires? Thanks in advance!


ln76d

Re: AKG Perception 420 Mod
« Reply #1 on: September 03, 2016, 07:10:45 PM »
Put the pic and i will mark on it.
There's few options to mod the circuit capsule is the last since it have deemphasis network and pretty good K67 copy.

Gbout2

Re: AKG Perception 420 Mod
« Reply #2 on: September 03, 2016, 09:21:34 PM »
Side A

Gbout2

Re: AKG Perception 420 Mod
« Reply #3 on: September 03, 2016, 09:22:49 PM »
Side B

Khron

Re: AKG Perception 420 Mod
« Reply #4 on: September 03, 2016, 09:32:43 PM »
The wire from the rear diaphragm, goes through that little hole (between the 6-pin header and the 1G resistor, in the Side B view), and solders to the bottom of that white insulator (to which the middle leg of the pattern selector goes).

The wire from the front diaphragm goes through the little hole next to the JFET, and solders to the bottom of the white insulated pin between the pin header and the pad switch.

The backplate wire goes to that lone hole/pad right in the middle of the board, with a little solder blob sticking out of it, in-between the pad & high-pass filter switch, right next to the padding cap.
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Gbout2

Re: AKG Perception 420 Mod
« Reply #5 on: September 03, 2016, 09:36:48 PM »
I appreciate it, about to try it out.

Khron

Re: AKG Perception 420 Mod
« Reply #6 on: September 03, 2016, 09:51:35 PM »
Just going by the U87Ai schematic, and what i remember from modding my Perception 200's, plus a bit of logic / common sense :)
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Re: AKG Perception 420 Mod
« Reply #7 on: September 04, 2016, 11:42:59 AM »
Rook mistake of desoldering backplate, front and back diaphragm wires without "clearly" marking where the new wires return for solder. Anybody perform this mod that can show pics of where to solder the new capsule wires? Thanks in advance!

Maybe this post help ...

http://microphone-parts.com/pages/akg-perception-capsule-swap-tutorial

Regards

Khron

Re: AKG Perception 420 Mod
« Reply #8 on: September 04, 2016, 11:53:48 AM »
Those photos are from a Perception 200/220, the cardioid-only version :) 420's the multipattern one.

Rook mistake of desoldering backplate, front and back diaphragm wires without "clearly" marking where the new wires return for solder. Anybody perform this mod that can show pics of where to solder the new capsule wires? Thanks in advance!

Maybe this post help ...

http://microphone-parts.com/pages/akg-perception-capsule-swap-tutorial

Regards
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

ln76d

Re: AKG Perception 420 Mod
« Reply #9 on: September 04, 2016, 02:40:05 PM »
I followed mparts link and i wonder what's the sense of replacing original capsule to RK87...


Khron

Re: AKG Perception 420 Mod
« Reply #10 on: September 04, 2016, 02:43:10 PM »
They've got capsules to sell ;D

I followed mparts link and i wonder what's the sense of replacing original capsule to RK87...
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JessJackson

Re: AKG Perception 420 Mod
« Reply #11 on: September 05, 2016, 03:04:25 AM »
If anyone has their original capsule from their 220 or 400 series i will gladly buy it from you. cheers

jess

bxt403

Re: AKG Perception 420 Mod
« Reply #12 on: October 24, 2018, 11:37:35 AM »
I'm wondering what the decoupling capacitor value is (the ceramic capacitor that's replaced with a polystyrene one in the Microphone Parts Perception mod kit).  The photo on the Micparts site shows a photo of a P220 and later photo of a ceramic marked 212 (so 2100pF).  Is that the same value found in the 420 and what's the capacitance used for a polystyrene? 

Also- there's another post about modding the Perception 220 to be like a U87 where a 220pF SMD capacitor's replaced to 680pF (found on the underside of the switch PCB) that's responsible for the circuit's de-emphasis EQ.  Would that imply I'd need anything from an open to 470pF for a CK12 type capsule and (for a K47 type) open to 220pF? 
« Last Edit: October 24, 2018, 11:42:39 AM by bxt403 »

Re: AKG Perception 420 Mod
« Reply #13 on: October 24, 2018, 05:59:19 PM »
If you are going for c12 sound you don't need any cap there with rk12, maybe something like 100pf for elam-ish sound.

For k47 nothing as well.

However i would personally use original capsule with that 680pf as it is scary close to real u87.
I just did a shootout with some mics yesterday and p420 i modded on drum overhead. It's crazy good mic.

bxt403

Re: AKG Perception 420 Mod
« Reply #14 on: November 02, 2018, 10:53:01 PM »
So after getting a P420: I realized that it's not like the Perception 420.  The P420 I got ended up having all the parts that need to be replaced being surface mount.  There's little to no room to install a 470pF (or 1000pF)  polystyrene cap: the 470pF surface mount capacitor's on the underside of the switch board. 

The only mod I could do was replace the 220pF capacitor with a 680pF WIMA one I had leftover from building a MicParts S3-87.
The location is different than for the P220 but it's still easy to access.  I decided to keep the stock capsule installed but I'm  seriously impressed how great the mic sounds by simply changing out the 220pF capacitor with a 680pF one.

The only problem is that the capacitor I used needs to be desoldered if I ever need to disassemble the mic any further (like to access the top-side of the switchboard).  Considering how good mic sounds now: I doubt I ever will.

Khron

Re: AKG Perception 420 Mod
« Reply #15 on: November 03, 2018, 08:09:07 AM »
I'm not 100% sure what the news / surprise is - i have three Perception 200's and they're (or rather, were) all surface-mount "already". Well, apart from the JFET and transformer.

Perception 220 inside shots  (identical to the 200 save one capacitor value) - http://audioimprov.com/AudioImprov/Mics/Entries/2013/2/26_AKG_Perception_220.html

So after getting a P420: I realized that it's not like the Perception 420.  The P420 I got ended up having all the parts that need to be replaced being surface mount. 
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Re: AKG Perception 420 Mod
« Reply #16 on: November 03, 2018, 11:08:59 AM »
So after getting a P420: I realized that it's not like the Perception 420.  The P420 I got ended up having all the parts that need to be replaced being surface mount.  There's little to no room to install a 470pF (or 1000pF)  polystyrene cap: the 470pF surface mount capacitor's on the underside of the switch board. 

The only mod I could do was replace the 220pF capacitor with a 680pF WIMA one I had leftover from building a MicParts S3-87.
The location is different than for the P220 but it's still easy to access.  I decided to keep the stock capsule installed but I'm  seriously impressed how great the mic sounds by simply changing out the 220pF capacitor with a 680pF one.

The only problem is that the capacitor I used needs to be desoldered if I ever need to disassemble the mic any further (like to access the top-side of the switchboard).  Considering how good mic sounds now: I doubt I ever will.

I find the capsule phenomenal. Coupling is just fine if you ask me. The only further mod i did, which made it realy shine, is custom headbasket which got rid of all internal reflections. I got crazy smooth response from the mic. Without random dips in the high end. I can post measurements later.  Sound samples as well. However it left me with very ugly mic. I use it as mono overhead on drums, so the looks are not that important.

Khron

Re: AKG Perception 420 Mod
« Reply #17 on: November 03, 2018, 11:26:14 AM »
I made my Perception 200's into multipattern mics ;D The DC-DC converter was already made for that too, i just added the pattern switch.

On the other hand, the capsules were assembled from the "active" halves of sE 2200A capsules, put together. Haven't run any measurements on them yet, though.
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Re: AKG Perception 420 Mod
« Reply #18 on: November 03, 2018, 06:16:49 PM »
These are my replicas and modded Perception p420. Mics are placed over the shoulder of drummer. These are different takes, so there is some variation, but the sound difference is obvious. There is one Shure KSM44 which i like, just as a stock mic reference.

U67 with 797 capsule
https://app.box.com/s/pyxd2wpz4iodwoy2u2oiidtlv0uldjf3

U47 with Dale's M7 capsule
https://app.box.com/s/gp95jbg2sf542nyjx81z0qmoodeu5831

U47 with selected OEM k47 capsule
https://app.box.com/s/352xob1c0lv14s6oitdxbxm75q2eis3o

C12 with Tim Campbell's CT12
https://app.box.com/s/wlmx3bhgkqdxro9ndf004qcadlqvyiax

Shure ksm 44 stock
https://app.box.com/s/57nx0jdspe21wdfxq0dzpqphoet2tyim

Perception p420 with modded circuit and grille
https://app.box.com/s/2pljm7xvwrldru1792hj9wsm2thbmwx3

And just for the hell of it, as ''Chinese Mic'' sound reference - Stock Studio Projects C1
https://app.box.com/s/uxhrujd7y7wt6jdiidq74ksrtho3ekjg
« Last Edit: November 03, 2018, 06:24:52 PM by kingkorg »

bxt403

Re: AKG Perception 420 Mod
« Reply #19 on: November 04, 2018, 09:25:24 AM »
I find the capsule phenomenal. Coupling is just fine if you ask me. The only further mod i did, which made it realy shine, is custom headbasket which got rid of all internal reflections. I got crazy smooth response from the mic. Without random dips in the high end. I can post measurements later.  Sound samples as well. However it left me with very ugly mic. I use it as mono overhead on drums, so the looks are not that important.

Since I also have a MicParts S3-87 as a reference:  I decided to leave the head basket intact.

Comparing the two microphones: it looks like they both use two layer mesh but the S3 has wider gaps than the P420.  I'd rather have full EM shielding and physical protection from any contamination with the way the stock head basket is than risking anything by removing any of the mesh. 

Here's the video that initially made me want to install the RK-12 (or C12 type capsule):

https://www.youtube.com/watch?v=jsO4iJFAYjY

"Cuomo tragico..."
« Last Edit: November 04, 2018, 12:00:19 PM by bxt403 »