AKG Perception 220 mod -does this look right???

[mikes425]

Hi, I sent my AKG 220 off to an engineer late last year to perform the mod that @kingkorg discussed
in another thread for a cap change. As mentioned in the forum I questioned whether it was done
when I saw no evidence of a new cap on the surface where the mod is supposed to be done.

I returned it to him and he sent me this photo 'confirming' the work done. I don't even
know where this cap is located -or why it would require placement on the top side of the board -
or...how it was wired - or if it is in fact done properly (?). I had event sent him the photos from the
forum.. Now I am being billed for a disassembly of the mic to confirm the mod. Just curious if
this looks right. It is said to be a 510 pF cap. Thanks for any insights!

Mike

 

[Khron]

Now I am being billed for a disassembly of the mic to confirm the mod.

Well, not that you couldn't have removed a couple Philips screws to see for yourself...

 

[mikes425]

Referencing my initial correspondence with the tech back in October: I had provided the link to the mod details.
>>
It's a fairly straightforward mic mod of an AKG Perception P220 condenser which
entails replacing the mics original 220pF capacitor with a .680pF capacitor. It's described in the very first post of a DIY forum thread, linked below, with photos.

https://groupdiy.com/threads/akg-perception-p220-to-neumann-u87-5-min-mod-p200-p100-p400-p420.67473/

That said, I don't know how I could've been much more clear on what the task was. Depending on how this
goes from here, i may be better off to cut my losses, get another cheap 220 and find someone else to do it.
I would out the cost of the donor mic and 100 bucks for the swap out of the wrong capacitor.

Thanks!

 

[mikes425]

The tech has responded that:

>>The capacitor was installed in the same spot in the circuit as the original part as requested, only on the opposite side of the board<<

 

[Khron]

"Same spot in the circuit"? I wonder which one that is and how he determined that... Especially since the cap he removed was definitely NOT even 220pF...

 

[mikes425]

Such a dilemma. The mic is now 'hostage' with an additional bench fee being invoiced for taking it apart to 'confirm' the job was done. Doesn't appear they are willing to acknowledge it to be wrong.
For the same amount as the new 'charge' - i can buy another donor mic and try to DIY it at this point.

 

[mikes425]

"Same spot in the circuit"? I wonder which one that is and how he determined that... Especially since the cap he removed was definitely NOT even 220pF...

Well...when i've pointed out multiple times, the simple instructions from korg's OP on this mod...and they are replying that the job was done..i'm just like. WTF !?? There's a 3 minute YT video i even sent showing precisely this mod. It's like...they aren't even LOOKING at these references I've sent.

The "same spot in the circuit" reply is so vague. If what was performed does not 'equal' the result intended - and presumably you're saying it simply does not, based on the photo showing the cap that WAS replaced, then i guess it's a lost cause.

 

[cholmes777]

that sucks!
Since they wont acknowledge the links and video you sent as a reference for the mod that you wanted done, id say ask for a refund maybe?
Let them keep that mic and grab another one and get the mod done correctly.

 

[mikes425]

that sucks!
Since they wont acknowledge the links and video you sent as a reference for the mod that you wanted done, id say ask for a refund maybe?
Let them keep that mic and grab another one and get the mod done correctly.

Yeah it's a shame. This was a Perception 220. If i get another 'donor' mic - is there any particular advantage in the newer "P220" over the original 220? Just curious...as i recall there's no major difference. Thanks!

 

[micolas]

Yeah it's a shame. This was a Perception 220. If i get another 'donor' mic - is there any particular advantage in the newer "P220" over the original 220? Just curious...as i recall there's no major difference. Thanks!

Both 220 models should sound identical. But the Perception220 is older, the components, the capsule, have aged, the sound may be affected. Theoretically, the P220
being newer should sound closer to what you want.
In the picture, isn't the 510pF capacitor wrongly connected to the input of the circuit and not to the de-emphasis side?
I have the P420, it's different, maybe someone recognizes the 220 circuit.

 

[Khron]

In the picture, isn't the 510pF capacitor wrongly connected to the input of the circuit and not to the de-emphasis side?

Yep, looks like it replaced the stock little yellow ceramic capacitor that's between the front diaphragm and the JFET gate. Nowhere near the de-emphasis capacitor that was "contracted" to be replaced.

 

[micolas]

Yep, looks like it replaced the stock little yellow ceramic capacitor that's between the front diaphragm and the JFET gate. Nowhere near the de-emphasis capacitor that was "contracted" to be replaced.

That's how it seemed to me too.
Or connected 510pF styro in parallel with that yellow ceramic coupling capacitor
The picture is not very clear.

 

[Khron]

That's how it seemed to me too.
Or connected 510pF styro in parallel with that yellow ceramic coupling capacitor
The picture is not very clear.

That remaining yellow one is likely the pad capacitor.

https://audioimprov.com/AudioImprov/Mics/Entries/2013/2/26_AKG_Perception_220.html

 

[micolas]

That remaining yellow one is likely the pad capacitor.

https://audioimprov.com/AudioImprov/Mics/Entries/2013/2/26_AKG_Perception_220.html

Anyway,the most reprehensible is not the professionalism of the person who modified the microphone, but his attitude, the lack of correctness.

 

[mikes425]

Anyway,the most reprehensible is not the professionalism of the person who modified the microphone, but his attitude, the lack of correctness.

Yeah, I am truly astonished that when I specifically referenced photos and this thread --and i get a single line response that what he did was what was requested?? That's just ... kind of psychotic to me.

 

[Khron]

Is that some little boutique company, or just some guy in his workshop?

 

[Khron]

Well, especially if it's a business, and there's clear record of the communications between you two, worst case he can be sued or something. Or, well, some sort of official-ish recourse...