Neumann M49 DIY Bodykits – CLOSED

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
RuudNL said:
My arm is getting tired holding the M49 all the time...  :p
Any suggestions for a shockmount or swivel?

I really like the m600 from enhanced audio
 
does anybody have an idea, how one could mount the poctop pcb in Banzais bodykit ?
I attach a pic, where you can see, that the pcb is a bit too small.
I thought about buying an acrylic glass with diameter of 66mm, drill the necessary holes and use this as an adapter-plate.
But maybe the whole construction get's too high ?
Never did this before.

Every idea is welcome !

http://www.ebay.de/itm/Acrylglas-Rund-3mm-10-100mm-Scheibe-Kreis-Zuschnitt-Plexiglas-/201705737623?var=&hash=item2ef6994d97:m:mfhDfz79y7XzEfgAqnSTbVw
 

Attachments

  • Poctop vs Banzai.JPG
    Poctop vs Banzai.JPG
    252.9 KB · Views: 50
I could be wrong, but I think Neumann used an adapter made of rubber.
That way, the "guts" of the mic will have no  metal to metal contact with the body.
That will hopefully reduce vibrations from the floor and the mic stand a bit, especially when you use a swirvel mount.
If you use an adaptor made from rubber, I think you also need to put some sort of soft rubber ring around one of the upper PCBs, to keep the PCBs away from the body tube. 
 
thanks for the suggestion.
useme2305 gave me the idea to order a 67mm/3mm plexiglas disc, which is very cheap (1€) and I'll see, where this is going.
Rubber is very interesting, but I can imagine, that it's not easy to work with.
Another idea would be a 3d printed part.

I also shot a mail to Andriejus, wether he sells his whole mounting construct alone.
 
I finished the first one and I'm deeply impressed by the quality of this mic.
I used the K47 from Banzai, poctops M49c pcb and ioaidio's BV11 transformer in combination with 6S6B tube.
This mic is so smooth and : very quiet !!!
I love it.

It was a bit tricky to install the pcb into the body, but in the end, I got everything in.
Next steps now: different TX, Cinemag CM6511.
 
some pasted pics. You can see on the lower left picture, that poctops transformer pcb sits on a 3mm plexiglass disc, which itself is screwed to the body. Next time, I will leave out the transformer pcb and raise the plexiglass disc about 15mm higher.
I also had to modify the diameter of the uppermost capsule-holder pcb, took away about 1mm, that it fits into the mic basket.
 

Attachments

  • M49c.jpg
    M49c.jpg
    1.8 MB · Views: 166
Funny that you ask, I was just about posting this question on poctops thread.
I took the 1,6V cathode voltage from the orig M49c schematic as reference. To reach this, I have about 47V on the plate.
I don't know, wether this is he proper way to do this, but the Mic sounds fantastic. And the noise is very low, which is important to me. I ordered 5 6s6b and took the first without testing it.
 
kosi said:
Funny that you ask, I was just about posting this question on poctops thread.
I took the 1,6V cathode voltage from the orig M49c schematic as reference. To reach this, I have about 47V on the plate.
I don't know, wether this is he proper way to do this, but the Mic sounds fantastic. And the noise is very low, which is important to me. I ordered 5 6s6b and took the first without testing it.

If your B+ is set to 120V, then you have the perfect recommended 0.73mA plate current:

120V B+
47V plate voltage
100K plate resistor
I = V/R

(120 - 47) = 73 / 100 = 0.73mA

With 116V B+, you'll want around 43V plate voltage:
(116 - 43) = 73 / 100 = 0.73mA

The recommended I and V values are marked on the M49C schematic, right above the plate.
 
kosi said:
Funny that you ask, I was just about posting this question on poctops thread.
I took the 1,6V cathode voltage from the orig M49c schematic as reference. To reach this, I have about 47V on the plate.
I don't know, wether this is he proper way to do this, but the Mic sounds fantastic. And the noise is very low, which is important to me. I ordered 5 6s6b and took the first without testing it.

You didn't change anything else in the circuit? So the 6S6B is really a "drop in" replacement except for the heater voltage?
 
Murdock said:
You didn't change anything else in the circuit? So the 6S6B is really a "drop in" replacement except for the heater voltage?

correct. I didn't change anything.
I will build a second one over the next weeks, where I will use an  AC701, which I luckily still own. I also have access to some real M49, so I plan to do a nice comparison .
 
kosi said:
correct. I didn't change anything.
I will build a second one over the next weeks, where I will use an  AC701, which I luckily still own. I also have access to some real M49, so I plan to do a nice comparison .

Yes, please do! That sounds promising!
 
kosi said:
thank you very much for the explanation !
I have 120 V B+ btw.

And just in case, I simplified the calculation from:

73 (plate resistor voltage drop) / 100'000 (plate resistor value) = 0.00073A = 0.73mA
 
Tight, but works.
But I wouldn't recommend it, cause the mic is too heavy, and the clamping mechanism from Rycote is, ahm, not so good....
 

Attachments

  • IMG_6099.JPG
    IMG_6099.JPG
    761.3 KB · Views: 49
I finished both my kits, one with BV11 and one with the Cinemag.
I have the feeling, that the Cinemag has more air. This is a first impression, I only have one mic holder, so on my tests, both were laying side by side on my couch...
But the sound is fantastic. I compared it with a TLM49, a Chunger C12 with Haun capsule/ CInemag tx and a Schoeps CMC5 w cardiod capsule for reference, I know it very well.
TLM sounds very clean and boring, but has the lowest noisefloor of them all, the C12 is a bit strange, sound seems to be processed somehow... Schoeps sounds like Schoeps, business as usual.
Both M49 have really incredible nice midrange, I love it !
 

Attachments

  • IMG_6103.JPG
    IMG_6103.JPG
    923.4 KB · Views: 64
kosi said:
Tight, but works.
But I wouldn't recommend it, cause the mic is too heavy, and the clamping mechanism from Rycote is, ahm, not so good....

Hey Kosi,

Did you sign up for shockmounts from the new batch?

They'll be here in a few weeks  ;)
 
Back
Top