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SE 2200a modification of the internal input circuitry
Old 21st January 2019
  #61
Here for the gear
 

Thank you for all this great work, Jean.

I found out one of my sE2200A mics is actually ok. After changing a lot of the wiring in my studio to balanced cables and clean power the hum and noise it had went away, there is just some low background noise from the pre-amp. The second sE2200A is now also ok, but has a much much higher noise-floor. What do you think could be causing this in the stock circuit? I swapped the capsules over on the units and there was no difference, so it must be present in the electronics somewhere...
Old 26th January 2019
  #62
Gear Head
 

May be a lot of things
1) Probleme if the capsule is not used in a dry place (I'm taking about the water in the air)
2) some condenser is dead
3) some jfet or transistor is out of order or malfunction
4) 1 Gohm high value resistor has changed because of water
5) bad soldering

without special mesurings devices, you can only change one element and control if the problem is over or not

If you had some suspicious external wirings, you could have some problems with phantom power (short circuit between mass and hot or return wire)
In this case, have a look first close to the output components

If you have $$, just buy a Rode NT1, it's very good and transformerless circuitry
Old 15th July 2019
  #63
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Could anyone re-upload the archive again please?
Old 21st July 2019 | Show parent
  #64
Gear Head
 

Hello, this link, version with transformerless option

https://we.tl/t-LhMg44sP1M
Old 2nd October 2019 | Show parent
  #65
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Hi Jean, great work! Hate to be a pest, but that link from July expired. Could you please repost? Many thanks!
Old 3rd October 2019
  #66
Gear Head
 

No problem

available 7 days

https://we.tl/t-fegvC4xNN0
Old 12th October 2019 | Show parent
  #67
Here for the gear
 

Thanks Jean, sorry but one more time please? (Somehow I didn't get the alert that you'd replied and it just expired.. argh!!)
Old 10th December 2019
  #69
Here for the gear
 

Hi Jean

Im new here but found this post while looking at solving a issue with my SE2200a, it has a low level noise (sounds like wind blowing on the capsule). I was thinking of following your modification guide to improve the sound of my mic and as a by product resolve my issues.

I was assuming the noise was cap related so thought it was a good start, would you be good enough to please repost the pictures?

Thanks

Simon
Old 19th December 2019 | Show parent
  #70
Gear Head
 

Not sure it will solve your problem, maybe a capacitor but also the capsule FET transistor

New Link

https://wetransfer.com/downloads/9cb...9092245/05c7b8
Old 19th December 2019 | Show parent
  #71
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Hi Jean,

Thanks for the upload, can you give me the part number of the FET? id like to replace it.

Regards

Simon
Old 19th December 2019
  #72
Here for the gear
 

Sorry Jean, i see its a K30, ive not done much electronic work in the last 20 years!

Sorry

Simon
Old 19th December 2019
  #73
Here for the gear
 

Hi Jean,

So on serching RS components and Farnell i dont seem to be able to find the k30, and on looking for an equivelent i cant seem to find that ether, do you have a recomendation that is still in production?

Thanks
Simon
Old 20th December 2019
  #75
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thanks i have bought these

https://www.ebay.co.uk/itm/5x-2SK30A...72.m2749.l2649

Fingers crossed, ill post here once fitted

Thanks

Simon
Old 24th December 2019 | Show parent
  #76
Gear Head
 

Excellent, it's the last one in the Galaxy.
May the force be with you !!!
Old 7th January 2020
  #77
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Nope, still faulty, seems that the mods have made a difference, it sounds much better while it works, but when you speak into the mic at a reasonable level its almost as if it over loads the FET and shuts down, and then after a while it clears and the mic works again until there is another reasonably loud noise.

Any thoughts advice would be appreciated.

Regards

Simon
Old 8th January 2020 | Show parent
  #78
Gear Head
 

Hello, it seems to be an insulation problem in the FET or one of the external components wich is close to the FET

In the original circuitry, you have a 1nF capacitor between the capsule and the input of the FET, that's why the sound is not very good (certainly because of the quality or the value of the capacitor), BUT, there is an advantage of that when the capsule has insulation problem like humidity.

Try to insert this capacitor in serial with one of the wires of the capsule. You could loose some sound quality but you will test if the problem is caused by the capsule. If there is no more problem, then, replace the original 1nF capacitor with a very good quality capacitor and a greater value than the original, 2.2 nF for exemple, and you will not have quality loss and the problem will be solved.

If the problem persists, it can be the FET or the insulation of the 1Gohm resistor
I don't know how FET can be replaced by another component, perhaps searthing in the other circuitry wich component can be used.

In the original circuitry, you have 2 X 1Gohm resistor, if you already have the one wich was take off, you can replace the 1Gohm resistor by the second or test another one :
https://fr.farnell.com/ohmite/sm1020...g-1/dp/1550765

Hope you will solve the problem
Old 26th June 2020
  #79
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Anyone got these schematic images and photos saved??
Old 28th June 2020
  #80
Old 29th June 2020 | Show parent
  #81
Here for the gear
 

Quote:
Originally Posted by Jean30 View Post
FIrst of all, thanks for the new link and the pictures. I have oredered all parts to try it onmy Se2200a but I'm a bit concerned how you add in parallel of C9 ?
On pic 18 I can see only one point of soldering to the right (top) side but On the board, I do not find the left point you used to solder (Pic 12 clearly show a missing point).

This i s th nonly one doubt I have. Could you guide on that please?
regards
Old 30th June 2020 | Show parent
  #82
Gear Head
 

Ha Ha, its because of the shadow in the picture 12 and also because I created a soldering point to correctly put the capacitor

There is a soldering point but not at the good place

So you are right, there was no point in the origin and you have to create it

It's the mass
Old 30th June 2020
  #83
Gear Head
 

If you compare picture 12, picture 13 and picture 18, you will certainly understand, if not, no problem, I will try to explain with other words
Old 30th June 2020 | Show parent
  #84
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Adding C9 in parallel

Quote:
Originally Posted by Jean30 View Post
If you compare picture 12, picture 13 and picture 18, you will certainly understand, if not, no problem, I will try to explain with other words
Appreciate too much your support and patience. What I'm a bit lost is the lack of a soldering point on shown on the attached pics. I believe I can add in parallel of C9 on the opposite side, on the same way you addded C3 and C4. is it possible?

https://www.mediafire.com/file/8gvyr...2200a.rar/file

Regards
Old 2nd July 2020 | Show parent
  #85
Gear Head
 

Do it if you have some place.
Take care of the short circuit, the metal external cylinder of C9 has to be isolated from the additional 220nF.
Take care to maintain C9 on the board when you solder, it's CMS
When you add stain/Pb, don't solder with the external part of C9

That's why I soldered 220nF on the other face, its less risky
Old 3rd July 2020 | Show parent
  #86
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Quote:
Originally Posted by Jean30 View Post
Do it if you have some place.
Take care of the short circuit, the metal external cylinder of C9 has to be isolated from the additional 220nF.
Take care to maintain C9 on the board when you solder, it's CMS
When you add stain/Pb, don't solder with the external part of C9

That's why I soldered 220nF on the other face, its less risky
I'm awaiting some the components coming from Germany and will post you the results. Thanks for Your attention. Appreciate too much your support.
Old 6th July 2020 | Show parent
  #87
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Quote:
Originally Posted by Jean30 View Post
Do it if you have some place.
Take care of the short circuit....
I just finish it and I'm pleased with how it sounds now. Thanks for the pictures and advices, Jean30.
I'm going to buy another one to do with more audiophile graded components.
Old 15th July 2020
  #88
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Hey, does anyone have a schematic for the SE2200A? I am trying to troubleshoot one for a friend and assumed that it would be similar to the SE2000, however one side of the capsule seems to be connected to ground, so think the circuit must be different. Any help appreciated, Cheers/Jason
Old 29th October 2020 | Show parent
  #89
Here for the gear
 

Quote:
Originally Posted by Jean30 View Post
Hi, can you please share again your guide? I'm planning to try your mod on my 2200a.
Thank you a lot.
Old 4 weeks ago | Show parent
  #90
Gear Head
 

Hello
New link available 7 days, we are 30/10/2020
https://we.tl/t-eTIV2oTUWC
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