mic modifications

donkeystyle said:
hey. i've been considering maybe trying to mod my at3035's. i've never even looked inside them though. has anyone worked with them before?
Click to expand...

I haven't modded my AT3060; one looked convinced me otherwise. The circuit board is mounted laterally rather than longitudinally, and there is very little clearance for all of its surface mount caps. But this is the tube mic, so maybe the AT3035 has some more room inside.
 
mic mods done

Hi,
I finished the mic mod on the apex 180. There are definate improvements, less self noise, more clarity ( especially in the low end) and a less accentuated high end. So thx Marik.

The caps I used were ones I found at the local electronics store and to be honest were choosen cause they fit in the limited space inside the small body.

So Marik, would you like to take a shot at the apex 430?
Thx for your time, I appreciatte it.
A
 
Andybot said:
Hi,
im having trouble finding the caps i need in a size that will fit. The mic is oktava size just to give you an idea.

I need 1000pF polystyrene and 1-2.2 uF polypropylene, does anyone have an idea where I may find these in a smaller size.

What type do people use for the oktava mods?...
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I just started reading this thread - sorry for the delay.

C13 needs to be a 820pF - 1000pF polystyrene. Accept NO substitutes! :D You can get them at Mouser Electronics.

For the C3 and C4, the Panasonic "V" series miniature metallized polys from Digi-Key will work just fine and sound excellent IMHO. I'd also choose the ones with the lowest voltage rating (50-100V) for both a smaller size and a thinner dielectric.
 
mic mods

Thx Flatpicker,
I will post a pic of the circuit board when my cam decides to work. Thx for the
info on parts suppliers, I would like to try out other caps as im sure the ones I used, although an improvement, could be improved upon.

Im up in Canada so I can order direct from Solen in Quebec, but theres are too large for this pencil condenser. Its an apex by the way.

Ill post the pic as soon as possible.
Thx
 
Hi Flatpicker,
heres a pic of the board, I hope this is what you need, if not I will take others.

Is there a part number for any v series panasonic cap you could give me, Im having a few problems navigating the digikey site. Thx for the help.
Andy
 
Andybot said:
...heres a pic of the board...
Click to expand...
Thanks. Are the big blue caps the ones you added?

Andybot said:
Is there a part number for any v series panasonic cap you could give me...
Click to expand...
P4675-ND is the 1uF/50V "V" series cap.

Since you need to get the polystyrenes from Mouser, the CDE 1uF/100V may do just fine. Their Mouser part # is 5989-100V

The 1000pf polystyrene # is 23PS210 for the axial and # 23PW210 for the radial. The radial would probably be a better fit.
 
mic mods

Thx Flatpicker,
yes the blue caps are the new ones, just noname electronics store metal film etc just goes to show what must have been in there before. And thanks for the digikey numbers those will help.

I also have an apex 420 large condenser mic I would like to work on. If anyone is willing to look at the schematic and suggest improvements I will post the schematic.

Thx, Andybot
 
Andybot said:
...the blue caps are the new ones, just noname electronics store metal film etc...
Click to expand...
Those may be ok, but I'd still try the Panasonics. Changing C13 to a 1000pf polystyrene will make the biggest difference, though.

Andybot said:
I also have an apex 420 large condenser mic I would like to work on. If anyone is willing to look at the schematic and suggest improvements I will post the schematic.
Click to expand...
Yes!
 
mic mods

Thx Flatpicker, I will start a new thread for the apex 420. I am going to try those panasonic caps for sure.

If you have the time could you explain the function of the 1000pF polystyrene cap? Thx, A
 
Andybot said:
...If you have the time could you explain the function of the 1000pF polystyrene cap?...
Click to expand...
It's used to couple the capsule to the FET and is the first thing the audio signal passes through before the FET can convert it to a useable signal. This is the reason that it's characteristics are extremely critical.

Feel free to try different caps here, as they all impart a different sound, but the polystyrene is the most transparent and unobtrusive to my ears. Most mics use monolithics here, but they don’t sound as smooth and natural as a polystyrene.
 
Andybot said:
If you have the time could you explain the function of the 1000pF polystyrene cap? Thx, A
Click to expand...
It carries the signal from the condenser to the gate of the FET. This is a very low current signal (very few electrons, relatively speaking), going into a very high impedance, and is very sensitive to any circuit irregularities or abberations. Any distortion introduced at this point will be amplified along with the signal up the signal chain, so you should use the best capacitor possible.

Here's an article on choosing caps in audio circuits if you haven't seen it.
http://www.capacitors.com/picking_capacitors/pickcap.htm
 
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