Beyer TG D57c Help to identfy component!

[angelothewolf]

hi!
Im working on this beyer condenser drumkit mics, i have six of them with the same component shorted, and I have one working perfectly so I could compare and Im shure this component is bad. the thing is i dont know what it is>
Itīs a SOT363 or SOT26 6 pin package
I mesured the working component and it doesnt have any low resistance betwen any pins. with the diode test it seems to have two parallel diodes in the first two pins going the cathodes to a common pin, and another diode from one pin to another, very strange arrangement to be a diode package I thing.

[angelothewolf]

I forgot, the marking on the component is T4

[Enzo]

Here is the data sheet:
http://north-america.beyerdynamic.co...D57c_EN_A2.pdf

WHy not contact Beyer and ask them?

[angelothewolf]

Here is the data sheet:
http://north-america.beyerdynamic.co...D57c_EN_A2.pdf

WHy not contact Beyer and ask them?

hi Enzo, theres not to much info on that datasheet. already contact Beyer but they do not like not autorized people to repair their products. I just need to identify that component.
any ideas?

[Enzo]

The data sheet does not identify parts, but it does show the internal circuit, which appears to be a JFET in the element and a bipolar in the preamp. A small signal bipolar is what I suspect you have there, someone may know. There is a list of sm parts codes somewhere, I don;t have it.

You traced out the diode test results of your part, but why not trace out the circuit? There are not that many parts to it. And looking at the data sheet circuit, you might be able to fill in the blanks. I bet we could sub a lot of things into that spot.

[angelothewolf]

yep, Im afraid i will have to do that. the jfet is the one inside the capsule, and on the board there is two SOT23 bipolar transistors, so, im thinking this is a strange diode may be for protection, I dont know... I searched a lot of part code lists and the first result for "T4" is a double 4148 diode package, and other diode packages.
I also try to fit 3 4148 diodes in that manner but it doesnt work. So I think you are right, I will have to draw the maze...

[dmeek]

The Turuta SMD Code Book suggests it's an IMT4 dual pnp.



http://music-electronics-forum.com/a...1&d=1467939109

[angelothewolf]

The Turuta SMD Code Book suggests it's an IMT4 dual pnp.



http://music-electronics-forum.com/a...1&d=1467939109

Alright!!!
Fit a couple of 2n4403 just to test and it work like a charm! Do you think I need a 120v transistor in there?

[dmeek]

If the circuit is similar to the Apex 180, there would be 48 volts from the phantom power.
Maybe the 120v rating gives it a little extra leeway though it looks like it may need more
protection than that.

Doug



http://music-electronics-forum.com/a...1&d=1467990198

[Leo_Gnardo]

Alright!!!
Fit a couple of 2n4403 just to test and it work like a charm! Do you think I need a 120v transistor in there?

I've been watching this thread and thrilled to see you've found what looks like a good solution. Given there's a 48V phantom power (right?) it wouldn't hurt to have transistors that won't break down at or beyond that level. If 120V rated parts are what you have, and they're working well for you, I'd go for it.

[Jazz P Bass]

As usual, a lack of data is cunfusing things,

The -120Vdc rating is for the original dual pnp part.

The 2n4403 is rated at -40Vdc/ 600ma's.
Agilent (Hewlett-Packard) - datasheet pdf

I wouldn't use it as a permanent fix.

[Enzo]

MPSA42/43 maybe then.

[Jazz P Bass]

That will certainly meet the specs.

200Vdc

http://www.onsemi.com/pub_link/Collateral/MPSA42-D.PDF

[angelothewolf]

That will certainly meet the specs.

200Vdc

http://www.onsemi.com/pub_link/Collateral/MPSA42-D.PDF

I ended up putting a couple of MPSA92 in there. That was what I have on hand, and I think is a good choice. So far so good!

Thanks!