Nady TCM 1050 mods

[kingkorg]

Nope, not at all.

 

[Icantthinkofaname]

The tube arrived today, just ordered the K47 capsule. The other mods seem easy enough since it's just removing or replacing capacitors.

 

[Icantthinkofaname]

Got my K47 capsule in the mail today. Is there a recommended socket I can add to the circuit, or should any 9 pin socket that fits work?

 

[kingkorg]

I cant say for sure, but you need to make sure you have enough room for the tube after installing the socket.  So it doesnt hit the transformer at the bottom. If your tube is soldered to the pcb, which i reckon, you really need to plan well how to remove it. It is soldered on both sides of the pcb, and almost impossible to remove without damaging either tube, or PCB. I used combination of air gun, pump, vacuum cleaner with  extension, soldering gun and barely made it.

Or you can just break the tube (CAREFULLY) and take out pin, by pin . I never liked that idea.

 

[Khron]

When desoldering "factory" stuff, whenever possible, it's probably a good idea to remove as much of the stock solder (lead-free, high melting point) as possible, within reason, and adding in some leaded solder (lower melting point, and to aid with thermal transfer to both sides of the board).

With a 9-pin device like a tube, i'd blob on a healthy dose of leaded solder and blast the solder-side with a hot-air station (or in a pinch, a hot-air gun / paint-stripper).

 

[Icantthinkofaname]

Will I also need to replace the diodes in the PSU? This is the only part I'm actually worried about doing.

 

[Khron]

Any particular reason? Both for replacing them, and for worrying about it.

 

[Icantthinkofaname]

Any particular reason? Both for replacing them, and for worrying about it.

It's more the warnings about the voltage the PSU uses being potentially lethal that worry me, because I'm not too experienced with DIY electronics work. I'm sure just replacing the diodes is simple enough though (I'm pretty sure those warnings are about wiring the whole thing and more about the wiring the entire PSU though).

As for the reason to replace them, that's just what Advanced Audio and Fox Audio Research recommend, so you get the 60v or so the capsules are designed for, rather than the 70v the stock PSU puts out. Is an extra 10v enough the cause any real problems for the capsule?

 

[Khron]

https://groupdiy.com/index.php?topic=65159.0

And regarding PSU voltages being on the "interesting" side of things... I trust you're not planning on doing any soldering / modding with the thing plugged in and powered on, are you?

 

[tchgtr]

So the stock transformer doesn't roll off too much high end for a K47 capsule?

I have a 1050 in which I installed a 47-type capsule bought from a group buy here many years ago. I love it. Very lovely, dark mic with great clean high end. Really nice for percussion and bright voices. Didn't do too much to the circuit other than upgrade caps and some of the Fox mods. I think I put a 12AT7 in it. Probably a JJ.
To my ear, the original circuits sound much better with a C12 copy than the original capsule. 
If you want open and brighter(tho not as bright as a C12 mic)...C12 copy. Dark and rich...47.
I have another with the original capsule and some simple mods. I hate those 67 copies, but I'm trying to make it work.

 

[Papa Tango Charly]

12AX7 est le choix typique de nombreux fabricants de microphones chinois.
Personnellement, je n'ai jamais obtenu de bons résultats avec ce tube.
Tous les 12AX7 que j'ai testés étaient tous bruyants.
J'ai obtenu de bien meilleurs résultats avec le EF806S (EF86)

Hello Ruud do you have a Schematic to mod the Apex a 460 Microphone with a C12 capsule an EF806S (EF86) Tube. i have read on few forums that the original transformer is good. Thank you best.

 

[vmanj]

I tried to remake this microphone according to the schemes U-67 (without frequency correction), C-12.
Tried different capsule polarization connections.
I use AA AK-47 capsule.
I also tried different tubes (12A...7, EF86, E88CC) for greater variability of experiments.
The transformer left stock, only reduced the wire winding and ratio. I also tried the transformer from the OCTAVA MK-319 microphone.
Now I settled on the ELA M-250 scheme, while I like it more ..