Neumann TLM circuits

[jpmtv]

Hi,

I'm new in this fotum and I'm french, so sorry mor my English !

I'm looking for the schematic diagram for a Neumann TLM103.

The link in this topic doesn't work anymore.

Is anyone can help me ?

Thanks a lot

 

[emrr]

Yes!  Back from the dead. 

I sent Gus a bunch of pictures of the TLM67 circuit boards, but I've no idea how much luck he'll have with photos of SMD layout. 

 

[opacheco]

I have searched that schematic long time ago and I have found nothing about!!....if somebody can help me will be a great gift for me and us in this intense searching process!

Why is so difficult to get this schematic??

Opacheco.

 

[emrr]

Because Neumann doesn't fix these, they swap the entire board.  Thus, no one needs it from a service standpoint. 

 

[opacheco]

Because Neumann doesn't fix these, they swap the entire board.  Thus, no one needs it from a service standpoint.

But they must have a schematic for!!....and someone must have it, the question is who??

 

[radardoug]

Neumann will have it, but why should they just give it to you?
They will have spent a long time developing it, maybe there are proprietary parts to the schematic.
How much are you prepared to pay them for this info?

 

[RuudNL]

I got the impression that Gus (the first post in this topic) once tried to trace the TLM103 circuit?
Maybe he can help. I know he is an expert in reverse engineering!

 

[Gus]

Tracing the the 103 is not going to happen. I lent my 103  years ago and is has not been returned.

I gave up on the 67 trace from pictures. It has epoxy on some parts
If people want to trace this circuit two ways to try come to  mind
One apply a signal to the amp boards and measure the output frequency response and maybe even distortion then design a circuit to fit that.
Two remove the epoxy and trace and measure all the parts this could be be destructive and you could be left with a non working board.

Now if you want a solid state 67 circuit do what I have done.
Design a 120VDC powered solid state M269 like microphone.
I have built a 120VDC solid state 47 inspired microphone with a solid state gain section.  One of the next things  to build will be solid state M49c like circuit and solid state M269 circuit.

 

[gyraf]

Came across this at some time - it may form the basis of someone's reverseengineering?

Absolutely no idea about accuracy...

Jakob E.

 

[RuudNL]

Interesting! Just an observation: the combination C4 (10uF)/R12 (1K) looks at bit low to me. (LF loss?)

 

[abbey road d enfer]

Interesting! Just an observation: the combination C4 (10uF)/R12 (1K) looks at bit low to me. (LF loss?)

-1dB at 30Hz, who's gonna notice? 

 

[opacheco]

Came across this at some time - it may form the basis of someone's reverseengineering?

Absolutely no idea about accuracy...

Jakob E.

gyraf,
Thanks a lot for share with us your file!!

I will need to check it with my TLM103 now!...I let you know when I got it.

Opacheco.

 

[bockaudio]

The two output caps on mine are marked 47uf 50V. 
  AKG, mackie,neumann,rode and ? use this type of balanced drive.

Certainly the output caps on my tlm170 weren't great, changing them was monumental (sonically).

 

[opacheco]

Certainly the output caps on my tlm170 weren't great, changing them was monumental (sonically).

bockaudio, what kind of caps did you use (type, brand and values)?
Thanks
opacheco

 

[soliloqueen]

sorry to bump an old thread but it seems someone DID do this, I found this. Most values are missing, but everything seems traced?

 

[soliloqueen]

crazy to think there's only signal on pin 2...? if this schematic is right, the tlm 103 isn't a balanced circuit?

 

[abbey road d enfer]

crazy to think there's only signal on pin 2...? if this schematic is right, the tlm 103 isn't a balanced circuit?

It is actually impedance-balanced.
Balance has nothing to do with having signal split between the two outputs.

 

[soliloqueen]

It is actually impedance-balanced.
Balance has nothing to do with having signal split between the two outputs.

Oh of course

 

[Monte McGuire]

It is actually impedance-balanced.
Balance has nothing to do with having signal split between the two outputs.

It's still deeply impolite to put half of the signal onto the mike amp as a common mode error - this is what single ended drive means. Some mike amp circuit common mode behavior is not all that clean - have you ever seen a truly flat CMRR curve? Asking for trouble IMHO.

 

[abbey road d enfer]

It's still deeply impolite to put half of the signal onto the mike amp as a common mode error - this is what single ended drive means. Some mike amp circuit common mode behavior is not all that clean - have you ever seen a truly flat CMRR curve? Asking for trouble IMHO.

So, according to that, any unbalanced stage is asking for trouble?