Replacement capsule for Rode NT1a
« on: May 05, 2020, 07:15:58 PM »
Hello from France.
The capsule of my Rode NT1a is dead, I want to replace it, but I ask myself the question :  with which capsule, Type K47 or K67 or K12 ?
The new capsule at Rode costs € 150 in France... The cricuit is in CMS and relatively effective, I only want to replace the capsule.
Do you have any recommendations ? 
I looked at the RK47 and RK12 at MP, the AK47, AK12 at AA, the Maiku are a bit expensive, I found a supplier on Alibaba who seems to make quality capsules, but I don't want to order 10! Thank you in advance.
I would like that my budget will not be disproportionate to the price and the original quality of the microphone. This is also an opportunity to test, I already have some large diaphragm condensers : Gefell um70s with an M7 rebuilt by Thiersch & Grosser, Oktava MK219, Rode NT1 mkI, Tbone SCT700...
Thank you in advance.


dima_k85

Re: Replacement capsule for Rode NT1a
« Reply #1 on: May 05, 2020, 08:15:27 PM »

rogs

Re: Replacement capsule for Rode NT1a
« Reply #2 on: May 05, 2020, 09:15:42 PM »
I looked at the RK47 and RK12 at MP, the AK47, AK12 at AA, the Maiku are a bit expensive, I found a supplier on Alibaba who seems to make quality capsules, but I don't want to order 10! ..............

You can now buy edge individual terminated capsules  from AliExpress :  https://tinyurl.com/aliexedgeterm

Normally the edge terminated  style are only from Alibaba - in 10 off minimum quantities.
www.amx.jp137.com - A DIY RF condenser mic project

Re: Replacement capsule for Rode NT1a
« Reply #3 on: May 06, 2020, 01:52:54 AM »
Thanks!
Maybe I'll buy a type 47 and a k12 type capsule and I can compare!

Re: Replacement capsule for Rode NT1a
« Reply #4 on: May 06, 2020, 04:49:44 AM »
Hey !

I do have change the capsule in mine.
I have put a ck12 capsule from beesneez, and change the capacitor to some vintage yellow mustard as well
It sounds awesome !

I would recommand the maiku ones ! They’re bang for the bucks !!

Greetings from France ! ;)

Re: Replacement capsule for Rode NT1a
« Reply #5 on: May 06, 2020, 05:07:57 AM »
Thanks! Which cap do you replace ?

Re: Replacement capsule for Rode NT1a
« Reply #6 on: May 06, 2020, 05:17:28 AM »
Thanks! Which cap do you replace ?

I do have the old one, the creamy grey version.

Which one is yours? Old one or the metal grey one ?

If so I guess their is no mod to make on the circuitry.

Here is a post from Jim Williams on GS

« Lucky boy. You have an original NT-1A.

I designed it with super low noise Hitachi transistors and a Siliconix rf jfet. As you can see it has German Roederstein metal film resistors and Wima polypropylene film caps. As it is there is little to do to improve it. It was built "modified". Peter Freedman did try to use lesser quality parts after the design but elected to use the quality parts I designated as they also heard the improved sonics from those parts. The NT-2 was repriced from $699 to $749 to include the quality parts.
Since then, competition has been fierce. Peter elected to lower the production costs of the Rode line so that's when the good stuff was chucked for all low cost surface mount parts. Those are the Rode mics you see today.

There are no frequency feedback nets in that design. There are a pair of 470 pf caps at the base of each Hitachi output transistor to ground that you can increase the value of to lower hf bandwidth. Try 1500 or 2200 pf.

The capsule is an odd duck with it's metal disc. It has no coating on the rear so it's cardiode only and has very low self noise.

The same design and circuit was also used in the original NT-2 mics but only that capsule is different. It also had a switch to add the rear diaphram for omni patterns.

Jim Williams
Audio Upgrades

Re: Replacement capsule for Rode NT1a
« Reply #7 on: May 06, 2020, 05:37:07 AM »
It's a NT1a for which I need a new capsule. It's a later version than the white one (I've got one too). It's a CMS circuit version, so it's difficult to upgrade the components...

rogs

Re: Replacement capsule for Rode NT1a
« Reply #8 on: May 06, 2020, 09:01:00 AM »
If my memory serves me right, the Rode NT1a includes a centre terminated 'K67' type capsule.. and uses a polarisation voltage of around 70V.
(EDIT: my memory does not serve me right ! -- the NT1a has an edge terminated K67 type capsule - see here: http://recordinghacks.com/microphones/Rode/NT1-A

If you substitute that for a 'standard' Chinese edge terminated capsule, that polarisation voltage maybe too high?

I have a couple of  edge terminated  capsules -which I bought from Ebay and were specified as having 3 micron membranes - which would tend to collapse  if more than about 50V was applied  as a polarisation voltage. 
(They seemed to recover OK once the voltage was removed and then reduced )

Some Chinese edge terminated capsules are specified with 4 - or even 6 - micron membranes, and these don't seem to mind  higher polarisation voltages.

The HF6 capsule fitted to my Rode NT1 (the current issue black version) is itself an edge terminated capsule polarised at c.75V.
(I believe  that the HF6 is a 6 micron capsule).

I have used K47 type capsules - which tend to be less 'bright' than the more common K67 type - with 60V polarisation, but I haven't tried them with anything higher.

I think there maybe be an element of  experimentation required in your project ! :)
« Last Edit: May 06, 2020, 09:49:04 AM by rogs »
www.amx.jp137.com - A DIY RF condenser mic project

RuudNL

Re: Replacement capsule for Rode NT1a
« Reply #9 on: May 06, 2020, 09:37:48 AM »
The choice of a center terminated capsule ('K67') in the NT1, without any frequency compensation is a bit 'strange', to put it mildly...
« Last Edit: May 06, 2020, 11:54:03 AM by RuudNL »
There is a solution for every problem!

http://www.vansteenisaudio.nl


rogs

Re: Replacement capsule for Rode NT1a
« Reply #10 on: May 06, 2020, 09:54:56 AM »
The choice of a center terminated capsule ('K67') in the NT1, without any frequency compensation it a bit 'strange', to put it mildly...

As I recall - the original NT1 used a centre terminated 'K67 type' capsule, and I believe it was often  considered to be an 'over bright' mic?
The new (black) NT1 uses a specially deveopled HF6 edge terminated capsule, which is less 'bright' .

The NT1a seems to be somewhere between the two (Edge terminated capsule - but with a  K67 style backplate ..
www.amx.jp137.com - A DIY RF condenser mic project

RuudNL

Re: Replacement capsule for Rode NT1a
« Reply #11 on: May 06, 2020, 11:55:23 AM »
To be really honest: I never heard a Rode microphone that sounded 'good'...

It is not my intention to insult Rode microphone owners, but the microphones I use sound a lot better...
« Last Edit: May 06, 2020, 03:36:31 PM by RuudNL »
There is a solution for every problem!

http://www.vansteenisaudio.nl

rogs

Re: Replacement capsule for Rode NT1a
« Reply #12 on: May 06, 2020, 04:34:16 PM »
I don't think  the Rode range can compete with some of the best Neumanns and AKGs etc, but then the prices are a LOT less!

I use one of the new NT1  mics - and find it a useful workhorse - as well as a useful tool for comparing to some of my own DIY mics.

I don't think it fares too badly in this comparison clip:  https://www.youtube.com/watch?v=VnrXFC5Pyhs

Not quite in the same league (or price bracket!) as the U47, but holds it own quite well? 
If you do download the 32 bit master clips, you can hear where the Neumann has a hi-mid 'silkyness' that the Rode doesn't have.
It's not quite so obvious with the original You Tube  audio....

That is the trouble with many mics though... once you get into the realms of the 'law of diminishing returns',  you need to spend a LOT more money for  sometimes tiny improvements in performance.
www.amx.jp137.com - A DIY RF condenser mic project

Re: Replacement capsule for Rode NT1a
« Reply #13 on: May 06, 2020, 04:42:33 PM »
The strange thing is that the dead capsule on my NT1a is a K67 type identical to the capsule inside my old white NT1 ... Both are center terminated .

rogs

Re: Replacement capsule for Rode NT1a
« Reply #14 on: May 06, 2020, 05:07:00 PM »
It does look as if it's not quite so clear cut ...
According to these notes from mic mod specialist Michael Joly (on the Recording Hacks page I linked to above) there are three variations of capsule fitted to the early NT1 and NT1A..

"The NT1 and NT1a mics use three different capsule variations based around the K67-type backplates. One of them is center-terminated and is basically a K67 recreation (intentional 8kHz boost). Another … has a HF resonator plate for even more HF [boost]. And the third type of capsule uses the K67 backplate pattern, but the diaphragm is edge-terminated and has a very unusual drilled aluminum plate on the back side instead of the usual back diaphragm".

So a centre terminated 'K67' type capsule seems possible for an NT1a

www.amx.jp137.com - A DIY RF condenser mic project

Re: Replacement capsule for Rode NT1a
« Reply #15 on: May 06, 2020, 05:09:28 PM »
Ok, So it's not so strange!!

RuudNL

Re: Replacement capsule for Rode NT1a
« Reply #16 on: May 18, 2020, 03:27:52 PM »
K67 without correction: "some like it bright!"  ;D
There is a solution for every problem!

http://www.vansteenisaudio.nl


 

Related Topics

  Subject / Started by Replies Last post
32 Replies
16662 Views
Last post December 17, 2018, 09:57:56 AM
by gyraf
6 Replies
5345 Views
Last post December 22, 2008, 07:57:37 AM
by evil grill
8 Replies
2896 Views
Last post November 03, 2011, 01:40:00 AM
by baadc0de
5 Replies
4876 Views
Last post May 11, 2012, 04:25:14 AM
by The Voice