Re: Sontronics STC-2 Microphone repair help

[maxkriza]

Hi
Got this mic with a damaged capsule which I'm trying to fix. Looking for a reasonable
replacement one or maybe fix the damaged one. Any tips will be appreciated.
Thanks
Max

 

[mista min]

Man, this is my third time trying to post... Uggh!!
Stupid cellphone :/

It's a Chinese 32 mm, K67 copy, that according to my experience and that of others isn't very nice.  Since it's broken, why not replace it with something better

Maybe even build a new mic in the body.

Cheers,
Marcos

 

[pucho812]

what is wrong with the capsule?

 

[maxkriza]

capsule is damaged. someone tried to unscrew the central screw and the Mylar is torn. I am considering to try and rebuild the capsule or maybe change it to a similar one. not sure where to get one. Emailed Sontronics but they haven't replied. I'm in London UK, anyone selling these?
Thanks for any suggestion.

 

[zebra50]

Hi!

Can you post a picture and measure across the capsule? I might have something.

Cheers!

Stewart

 

[maxkriza]

sure thanks.
here is a link to photos http://www.flickr.com/photos/31913729@N04/sets/72157626606657846/with/5668883673/
capsule size 32mm external 1" internal.
cheers
Max

 

[zebra50]

Hi Max,

I'm pretty sure I have one - it might be a double sided one with one good side.

Is that any use to you?

Stewart

 

[maxkriza]

SURE, that will be great!

 

[zebra50]

Hi Max,

I'll have a look for you today.

I'll be on holiday next week so would be good to get it posted out before I leave (assuming I have one!).
Can you pm me your address?

How does £10 sound, including postage?

Cheers

Stewart

 

[maxkriza]

Thanks, will email you my details.
cheers

 

[maxkriza]

new capsule is fitted now, mic is dead.
Fet measures: D 2.83v S 2.74v G 0.24v
Capsule hot side 0.4v other side is earthed. are these make sense at all?
thanks for any help
max

 

[maxkriza]

Anyone has a schematic for this microphone?
tnx

 

[volker]

A search might have revealed this .

And your voltages are pretty off. I measured

D  13,8V
S  1,3V
G  0,76V

 

[maxkriza]

Thanks Volker, I did search for it again and it doesn't come up. only my previous posts.
How did it go for you and are you happy with the mic?

 

[volker]

As I wrote in the other thread, I bought it (rather cheap) with the intention to toy around
and put something else in. It works, so much I can say ;D. But I didn't really test it out.
It's been sitting there ever since, too much other things with higher priority on the desk.

 

[maxkriza]

voltages on the 3DJ7F FET are way out. which other fet can I substitute this obscure fet ?

 

[maxkriza]

will 2SK170 work here?
is there a way to determine the fet is faulty?
"Fet measures: D 2.83v S 2.74v G 0.24v"  
drain resistor 27k measures 18v before, 2.83v after.
thanks
Max  

 

[maxkriza]

tried a few different fets, no luck.
anyone can help with this?
thanks

 

[zebra50]

Capsule hot side 0.4v other side is earthed. are these make sense at all?

Hi Max,

It should be higher but you can't really measure these very high impedance voltages with a standard multimeter - the meter input loads down the circuit!

Are you getting sensible voltages elsewhere around the circuit? For example at R10/R11, and at C8?

 

[maxkriza]

I think so, r11 35v, 22.5v, r10 20.66v, C8 35v. my phantom supply is a bit low at about 36v.
Volker said he measured 13.8v at the drain.

thanks