AKG Perception 420 Mod

[Khron]

Could even be a fake one...

 

[AUDIO FREQ]

Could even be a fake one...

This is my fear .

 

[AUDIO FREQ]

The reviews on this one I bought, looks like im not the only one experiencing this issue.

 

[Khron]

Then again, these "328" component testers are all(?) clones of clones of a design. If you have a suitable programmer, i wonder if a more "official" firmware (update) might help. At least then you'd be more sure whether it's the firmware, or a hardware issue...

https://www.google.com/search?q=328...Ouk-AE&udm=&oq=328+component+tester+schematic
A convenient collection of source material:
http://claudiuradu.blogspot.com/2013/04/component-tester.html

 

[AUDIO FREQ]

The TSC-2 Capsule should be here tomorrow. So that is exciting. I will let you guys know how it goes. By the way, does anyone know if the Perception series is a 1:1 with the U87ai circuit? Do we know what ratio the transformer is used in the perception series? It sounds really good.

 

[micolas]

The TSC-2 Capsule should be here tomorrow. So that is exciting. I will let you guys know how it goes. By the way, does anyone know if the Perception series is a 1:1 with the U87ai circuit? Do we know what ratio the transformer is used in the perception series? It sounds really good.

You will be delighted with the tsc-2 capsule and modified microphone.
The AKG Perception is inspired by the U87 input topology, but the feedback network is a little different, not as pronounced. Perception uses an additional bipolar transistor to drive a cheaper output transformer with a lower ratio (about 2:1) unlike of U87 which uses a 9.5:1 ratio transformer, harder to build and therefore more expensive. The shape of the headbasket also makes a difference.

 

[AUDIO FREQ]

You will be delighted with the tsc-2 capsule and modified microphone.
The AKG Perception is inspired by the U87 input topology, but the feedback network is a little different, not as pronounced. Perception uses an additional bipolar transistor to drive a cheaper output transformer with a lower ratio (about 2:1) unlike of U87 which uses a 9.5:1 ratio transformer, harder to build and therefore more expensive. The shape of the headbasket also makes a difference.

Hey Micolas, I did as you said and put the 2n3819 on the bottom part, and the K30A on the top part near the switches. How much more noise does the 2n3819 produce? Is there a better alternative than the K30A or 2n3819?

 

[micolas]

Hey Micolas, I did as you said and put the 2n3819 on the bottom part, and the K30A on the top part near the switches. How much more noise does the 2n3819 produce? Is there a better alternative than the K30A or 2n3819?

2SK30A has ultra low noise (typically 0.5dB), which is why it was chosen by AKG engineers for the input circuit). In the oscillator (dc/dc converter) jFET noise
( 2N3819 has low noise, <3dB) it doesn't affect the final mic noise which is normal:
Perception 420 (blue) 16dB
P420 (black - new one) 15dB
If after modding you have higher output noise than the stock microphone, but it works, then you need to clean the modified areas very well. A cold, imperfect solder can also induce noise.
Or damage (even partial) through overheating of 2SK30A or other components.
A reBias may be required because jFET transistors have a large parameter dispersion.
KingKorg's mod is brilliant, I'd say the microphone noise is even lower than the stock version (I think due to the more pronounced negative feedback the distortions are also reduced), so in the real world it becomes an excellent microphone.

 

[AUDIO FREQ]

2SK30A has ultra low noise (typically 0.5dB), which is why it was chosen by AKG engineers for the input circuit). In the oscillator (dc/dc converter) jFET noise
( 2N3819 has low noise, <3dB) it doesn't affect the final mic noise which is normal:
Perception 420 (blue) 16dB
P420 (black - new one) 15dB
If after modding you have higher output noise than the stock microphone, but it works, then you need to clean the modified areas very well. A cold, imperfect solder can also induce noise.
Or damage (even partial) through overheating of 2SK30A or other components.
A reBias may be required because jFET transistors have a large parameter dispersion.
KingKorg's mod is brilliant, I'd say the microphone noise is even lower than the stock version (I think due to the more pronounced negative feedback the distortions are also reduced), so in the real world it becomes an excellent microphone.

I think I should clean it better than, because mine sounds pretty noisy. Any tips or advice on cleaning circuits and stuff?

 

[Khron]

I think I should clean it better than, because mine sounds pretty noisy. Any tips or advice on cleaning circuits and stuff?

Isopropyl alcohol, q-tips, elbow-grease. Just try not to get any onto the capsule.

 

[AUDIO FREQ]

Isopropyl alcohol, q-tips, elbow-grease. Just try not to get any onto the capsule.

What happens if i get alcohol or elbow grease onto the capsule? Where do I buy elbow grease? I looked on mouser and digikey, amazon...ebay....nothing.

 

[kingkorg]

What happens if i get alcohol or elbow grease onto the capsule? Where do I buy elbow grease? I looked on mouser and digikey, amazon...ebay....nothing.

I once asked a friend to buy me some cerumen wax at a pharmacy. I was pretty wasted and he was on the way to join the party. He didn't speak to me rest of the night, and refused to tell me about pharmacist's reaction. No idea why i said all this, i guess elbow grease somehow reminded me of cerumen...

 

[Khron]

What happens if i get alcohol or elbow grease onto the capsule? Where do I buy elbow grease? I looked on mouser and digikey, amazon...ebay....nothing.

https://en.wikipedia.org/wiki/Elbow_grease

 

[AUDIO FREQ]

Reminds me of my days in the Army, when we used to make the privates go get a can of blinker fluid for the humvees. Or go ask the comms nco for a prick e7. PRC-E7.

 

[AUDIO FREQ]

Just got the TSC-2 capsule in, and im a bit disappointed. There seems to be a smudge mark on it and the center termination screw wax got stuck to the lid. Im contemplating, should I send it back?

 

[kingkorg]

Just got the TSC-2 capsule in, and im a bit disappointed. There seems to be a smudge mark on it and the center termination screw wax got stuck to the lid. Im contemplating, should I send it back?

Nope, i wouldn't worry about that.

 

[AUDIO FREQ]

Nope, i wouldn't worry about that.

I know we were all being sarcastic just recently, but are you being serious or sarcastic? Wouldn't the smudge, especially if its some sort of chemical or adhesive, be a detriment to the mobility/function?

 

[micolas]

Just got the TSC-2 capsule in, and im a bit disappointed. There seems to be a smudge mark on it and the center termination screw wax got stuck to the lid. Im contemplating, should I send it back?

Just move the central wire (red) away from the surface of the diaphragm and choose for the Front (for this use the cardioid mode) the half of the capsule that you like the most how it sounds.

 

[micolas]

I know we were all being sarcastic just recently, but are you being serious or sarcastic? Wouldn't the smudge, especially if its some sort of chemical or adhesive, be a detriment to the mobility/function?

It seems to be just surplus solder material

 

[AUDIO FREQ]

Just move the central wire (red) away from the surface of the diaphragm and choose for the Front (for this use the cardioid mode) the half of the capsule that you like the most how it sounds.

Thats true. Ok, ill just keep it. Thanks