Need some capsule advice (SOLVED)

Just bought a t-bone SCT-800 (SE5500) valve condenser mic 2nd hand. Noticed that when I gently swayed the microphone backwards and forwards that the sound peaks and cut-outs momentarily. I thought this might be the cable, but holding the mike steady and moving the cable does nothing.

So I took it apart and had a look at the capsule:



Notice the crease in the upper right and centre right. Doesn't look good to me, but could this be the cause of the problems I'm noticing?

I don't want to spend hundreds of pounds modding it, so I'm wondering if a re-skin might be in order. I'm based in UK so any recommendations would be gratefully received.

solderspongebob said:

I don't want to spend hundreds of pounds modding it, so I'm wondering if a re-skin might be in order. I'm based in UK so any recommendations would be gratefully received.

Click to expand...

Reskinning a capsule is very skilled work and there are few who can do it well.  Consequently the work is not cheap.  I can't imagine it ever being worthwhile to reskin a chinese capsule, you could buy a replacement a lot more cost effectively.

Good luck fixing the issue.

Cheers,
Ruairi

That will definitely cause the problem. Sadly problems like these are really common to see on those capsules. Ruairi is right - it won't be worth the cost of reskinning.

I may still have a spare one - let me look on Monday and get back to you. I sold another one recently to a forum member and I can't remember if there were any left.

Cheers!

Stewart

Ruairio, Stewart, thankyou very much for your replies.

I would be happy to replace the capsule for a better one, but only if someone has used said capsule with the same mic (or chinese clone) with positive results. Microphone DIY is new to me so there is a lot of ground for me to make up researching the many threads that talented members have written on the subject. I note from the ones that I've read that the headbasket can have a significant effect on the sound, so there maybe only so far this mic can go; having said that, I can't afford a U87 so this will be the *closest* I get for a long time!

The seller supplied a Groove Tubes 12AX7 with the mic (as well as the original chinese tube). From one of the threads I found about this mic, it was suggested that a Tung-Sol yielded lower noise floor and better clarity - once the capsule is sorted/replaced I may try this too.

Bob,

Can you please measure across your capsule so I can check for size?

Cheers!

Stewart

Hi Stewart,

Outside diameter is: 32.2mm
Inside diameter: 25.80mm
Thickness (excl. screw heads): 12.65mm
Thickness (incl. screw heads): 14.80mm

Cheers!

I've found one that should fit. It is used but does / did work.

It's single sided, cardioid only.

If you want it then drop me a pm with your address.

Stewart

Happy ending:

zebra50 sorted me out with a replacement capsule (used, but works fine).

The mic now has a nice sparkly top-end and handling noise has diminished.

Next step is to replace the tube with a nice Tung-Sol and see if that helps the noise floor. Also got a Groove Tubes one designated for microphone use so I'll compare it with that too.

Big thanks to zebra50 for your help with this.

solderspongebob said:

The seller supplied a Groove Tubes 12AX7 with the mic (as well as the original chinese tube). From one of the threads I found about this mic, it was suggested that a Tung-Sol yielded lower noise floor and better clarity - once the capsule is sorted/replaced I may try this too.

Click to expand...

You know, this mic (same circuit as in Apex 460 and others, but with single sided capsule) is really ment to be used with 12AT7. They usually come with 12AX7 though. I have not tried to swap the tube to other 12AX7 but I can confirm that putting in a 12AT7 makes a big difference. It makes the mic less grainy sounding, more "hi-fi". You may or may not like it. I had good luck with used 12AT7's from e-bay.

Superb! Thanks for the advice - I shall source a nice quality 12AT7 tube to try out.

Hi,


  I am not an expert, but I believe it could actually be a 12aY7, or 6072, preferably five star GE version. This was MUCH quieter and sounded loads better than stock tube, and better imho than the NOS 12at7s I tried.


  kindest regards,


    ANdyP

I'm not an expert myself, but yes 12AY7 works also and sounds better than the stock tube. What comes to GE 5 star version I would hesitate to use a tube that costs almost as much as the mic itself. And I haven't bumped into any noise issues with "regular" tubes with this circuit. Maybe it's the cathode follower, someone more experienced might want to comment on this.