Mod tube power supply to work with Rode K2

[caluamar]

Shouldn't be hard. Basically reverse diodes and capacitors + switch out stabs. I've changed the heater this way in a t.bone Retro Tube II supply.

Hi, would be nice if you explain How did you mod the PSU a t.bone Retro Tube II to work with a K2 Rodé or NTK, please could you share this Information?

 

[evil grill]

I have not modified a supply to work with any Röde mics. If you want -V instead of +V just reverse diodes and capacitors and change voltage stabilizers and transistors + be careful with pinout. The retro Tube II supply has a 7806 & diode for heater supply if I remember it right. I changed it to 7906 and did some small changes since the pinout is different.

 

[caluamar]

Hi, would be nice if you explain How did you mod the PSU a t.bone Retro Tube II to work with a K2 Rodé or NTK, please could you share this Information?

Thanks! I already mod the pinout but I got. Pin 1 - 6,6, I have no Idea to Reverse capacitors and Transistors, I thought That You did it,
Anyways thanks, if you have some links or Data would be nice too.

 

[caluamar]

I have not modified a supply to work with any Röde mics. If you want -V instead of +V just reverse diodes and capacitors and change voltage stabilizers and transistors + be careful with pinout. The retro Tube II supply has a 7806 & diode for heater supply if I remember it right. I changed it to 7906 and did some small changes since the pinout is different.

I have tried changing the diode to the 7906 but I still don't understand why the T. Bone Retro II doesn't work with the Rode K2.
I have reversed the pins, and I have come to this conclusion:


K2 Retro Bone II

1 . 0,7 0
2. 0,1 0
3. 0,1 0
4. 148,5 140
5. 143,5 150
6 . 29,1 0
7. 0 - 120. 0-120


Does anyone know why pin 6 has no voltage ?
And pin 1?

 

[deniz]

Hi Andreas, So the -125V and -5.8V on the board read as they should...actually the -125V was more like -120V...but I did use an analog meter, so...However, still no voltage reading off 7 pin. This unit is relatively new to me and I hadn't even listened to the mic through this PSU yet. So with getting no reading on pin 7, I plugged in the PSU to a preamp to do a listening test and see if the pattern knob had any affect. Low and behold, turning the pattern knob did NOT affect the mics pickup behavior. Then to rule out the potential of the mic itself being the source of the issue, I plugged in my other K2 and the result was the same. So..it's starting too look like my amateurish understanding of electronics may not be the biggest problem with this PSU! (-;.

Hi, where you able to fix it? I'm having the same issue.

 

[deniz]

I managed to fix it. It was probably a cold joint. I desoldered the pot and tested it with alligator clips and it worked. I soldered it again and it's fine now.
By the way the pot is 100k linear. If you want the same pot style it's made by Vishay.

 

[Bassking]

@Ricardus,
the PCBs are in the mic are not the same (see attached Pics). BUT: I have two NTKs, and on one PCB it says NTK, on the other one it says K2. PCBs are clearly not the same (you can see that some resistors and caps are in other places/omitted. Capsules aren't the same either (but it says NTK on both mics) I just contacted Rode out of curiosity, let's see what they say...
Max

 

[Ricardus]

@Ricardus,
the PCBs are in the mic are not the same (see attached Pics). BUT: I have two NTKs, and on one PCB it says NTK, on the other one it says K2. PCBs are clearly not the same (you can see that some resistors and caps are in other places/omitted. Capsules aren't the same either (but it says NTK on both mics) I just contacted Rode out of curiosity, let's see what they say...
Max

They might have different revs but my boards absolutely doubled for both mics. And yes the capsules are different because they ship a one-sided capsule of the NTK so it can only be cardioid.

There is absolutely no need to have the extra contacts on the board of the NTK unless it doubled for the K2.

 

[Ricardus]

@Ricardus,
the PCBs are in the mic are not the same (see attached Pics). BUT: I have two NTKs, and on one PCB it says NTK, on the other one it says K2. PCBs are clearly not the same (you can see that some resistors and caps are in other places/omitted. Capsules aren't the same either (but it says NTK on both mics) I just contacted Rode out of curiosity, let's see what they say...
Max

Even boards from later years/revs of the same mic often are different in terms of look and layout, but it's the same circuit/mic.

 

[Bassking]

Yeah, my "NTK" with the K2-board has the two-sided capsule (with only one side wired up), the real NTK one has a one-sided capsule. And the "NTK" with K2-board has all 7 wires of the mic-cable connected, the real NTK only 6. They also sound slightly different (not a difference you would hear in a mix, though). I can hardly believe that a firm like Rode would "run out of boards" and jumble up a mic with different board and different capsule (which are more expensive!) and plonk it in a package with the "wrong/cheaper" PSU and sell it as an NTK, surely that would be noticed immediately. I bought both mics second hand, so there's no guarantee that my mics were built that way. But why would anyone "downgrade" the K2 to an NTK???

 

[MusoGreg70]

Late to this but the last NTK I opened had a K2 mic pcb and psu ( minus the potentiometer). It never occurred to me to check the capsule though! 2018 build.