analogguru

Re: TF11
« Reply #20 on: October 01, 2020, 04:21:15 PM »
Now let's assume that "they" use some sort of µ-Amp or so - nothing really to be curious about.
But ..... how is the capsule polarized ?  With 35V - 38V from the phantom power ?   Or is it a very big electret capsule ?  That's something interesting....
« Last Edit: October 01, 2020, 04:24:55 PM by analogguru »


Re: TF11
« Reply #21 on: October 02, 2020, 02:21:51 AM »
But ..... how is the capsule polarized ?  With 35V - 38V from the phantom power ?   Or is it a very big electret capsule ?  That's something interesting....

Looks like just a straight 45V-47М from phantom power. There are no signs of any voltage oscillators or doublers of more typical 70V for CK12.

Gus

Re: TF11
« Reply #22 on: October 02, 2020, 07:34:28 PM »
I posted this more about the use of what looks like a dual fet. 

I would assume the power is from a center tap on the secondary side because I don't see two matched resistors like you see in a KM8x or U87.

Look at the picture at the company web site I see some different resistor band colors than people have posted.
https://www.telefunken-elektroakustik.com/microphones/tf11

No current draw given that would help with the capsule voltage and operating points

14Mv/Pa

 



« Last Edit: October 03, 2020, 07:59:33 PM by Gus »

Spencerleehorton

Re: TF11
« Reply #23 on: October 03, 2020, 01:08:50 AM »
I would think its along the lines of a c414 eb p48 sort of circuit?
Centre tap of secondary to a 2.2k through a 1M, through a 22nf cap to capsule?
Anyone traced this yet?
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

Spencerleehorton

Re: TF11
« Reply #24 on: October 03, 2020, 09:16:38 PM »
Could it be something along these lines?

https://tapeop.com/interviews/37/diy-jfet-mic-pre/
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

Spencerleehorton

Re: TF11
« Reply #25 on: October 03, 2020, 09:29:03 PM »
Also the lsk489 datasheet has a few diagrams which maybe helpful?
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

analogguru

Re: TF11
« Reply #26 on: October 03, 2020, 11:14:27 PM »
Could it be something along these lines?

https://tapeop.com/interviews/37/diy-jfet-mic-pre/
No.  The two FETs are in parallel ...

Spencerleehorton

Re: TF11
« Reply #27 on: October 03, 2020, 11:23:25 PM »
Do you ha e an idea on the schematic?

I'd be quite interested in building the circuit
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

analogguru

Re: TF11
« Reply #28 on: October 03, 2020, 11:36:28 PM »
.....
I would assume the power is from a center tap on the secondary side ....
That's right....

No current draw given that would help with the capsule voltage and operating points
And no noise specs.....

The current draw will be about 1mA which means with this current the capsule voltage is about 42V and the output transformer will be a step down transformer ..... (reducing the signal level to:)

14mV/Pa


analogguru

Re: TF11
« Reply #29 on: October 03, 2020, 11:42:48 PM »
Do you ha e an idea on the schematic?

I'd be quite interested in building the circuit
Since I don't like body-strippers who occupy the brand name of inactive companies for their own profit I have contacted my chinese friends and they promised me to send me a prototype of a clone - we will see.....


Spencerleehorton

Re: TF11
« Reply #30 on: October 04, 2020, 12:17:37 AM »
Sounds interesting,  I await your prognosis.
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

Gus

Re: TF11
« Reply #31 on: October 04, 2020, 08:26:15 AM »
Why do you want the schematic?

You have 9 resistors, 6 caps , a transformer and what looks like it might be a dual JFET. If it is a dual JFET how do they handle the substrate?

You can see some of the cap values looking at the different images you can find and take a guess at the others.

The black PCB makes it hard to see the traces from the images you can find on the web.

« Last Edit: October 04, 2020, 08:29:23 AM by Gus »

Khron

Re: TF11
« Reply #32 on: October 04, 2020, 08:37:59 AM »
Why do you want the schematic?

You have 9 resistors, 6 caps , a transformer and what looks like it might be a dual JFET. If it is a dual JFET how do they handle the substrate?

You can see some of the cap values looking at the different images you can find and take a guess at the others.

The black PCB makes it hard to see the traces from the images you can find on the web.

Am I the only one that's skeptical about how such mic electronics (ahem) "sound"?  ???

I mean, outside of clipping situations... How different can they really sound, really?  :o Obviously, discounting confirmation bias...

Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans

Spencerleehorton

Re: TF11
« Reply #33 on: October 04, 2020, 10:22:06 AM »
I think if I guess the arrangement of how it should work I'll be there for months before I get any results.
I'll just go and buy it, much cheaper!!
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

analogguru

Re: TF11
« Reply #34 on: October 04, 2020, 10:50:31 AM »
I think if I guess the arrangement of how it should work I'll be there for months before I get any results.
I'll just go and buy it, much cheaper!!
You must have much money .... (- feel free to give me some of it.)

Personally I would not inwaste one cent of my hard earned money for body-stripping money-makers.

BTW, when my chinese friends saw this schematic they said: "hey, I think we already had this, this looks similar to an overpriced Zvex SHO guitar pedal....."


« Last Edit: October 04, 2020, 10:58:29 AM by analogguru »

RuudNL

Re: TF11
« Reply #35 on: October 04, 2020, 11:42:15 AM »
I think if I guess the arrangement of how it should work I'll be there for months before I get any results.
I'll just go and buy it, much cheaper!!

The advantage of purchasing is that it works the first time!  ;)
There is a solution for every problem!

http://www.vansteenisaudio.nl

Spencerleehorton

Re: TF11
« Reply #36 on: October 04, 2020, 02:37:43 PM »
Sorry I was trying to be funny,  I'll wait for the schematic then build!!
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

Spencerleehorton

Re: TF11
« Reply #37 on: October 04, 2020, 07:39:07 PM »
What is that red component then? Resistor or diode or something else?
website: www.mohawkstudios.co.uk
email: [email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!

analogguru

Re: TF11
« Reply #38 on: October 04, 2020, 08:16:48 PM »
What is that red component then? Resistor or diode or something else?
Hmmm.... as far as I could determine it is marked as "R3" on the pcb...

Spencerleehorton

Re: TF11
« Reply #39 on: October 04, 2020, 09:47:05 PM »
Looks more like a capacitor if I'm honest?
website: www.mohawkstudios.co.uk
email: in[email protected]

If it hisses its probably the wrong impedance!!!
Or a snake!!!