GroupDIY

Project Specific Discussions => Microphones => Topic started by: manulaudic on November 09, 2011, 06:47:59 AM

Title: U47 Clone Build Thread based on T-bone sct2000
Post by: manulaudic on November 09, 2011, 06:47:59 AM
Hello !!

I have this T-bone SCT2000 Tube microphone and i would like to modify it and get a u47 clone or so.
This thread is so that we can all contribute to what Capsule to choose along with Modifying the circuit and Transformer.

I've already upgraded the tube for a JJ EC881 or 12at7.

On a french forum i also found those mods :

Change C4 ->  Styroflex 1000pF 630V
Change C3 & C5 -> polypropylene 22 nF 1000V (Arcotronics 1000V 0.022uF)
Change  C7 C10 C9 -> 100 nF 100V MKP2 Wima
Change C8 -> polypropylene metallise SCR PB100 1uF 400V

I believe this T-bone is also seen with Apex, Nady or other chinese copies.

Here are the pictures of my microphone :
(https://dl-web.dropbox.com/get/Photos/126_2469.JPG?w=95a6070a)
(https://dl-web.dropbox.com/get/Photos/126_2473.JPG?w=8cf9fd71)
(https://dl-web.dropbox.com/get/Photos/126_2475.JPG?w=4c1443fe)
(https://dl-web.dropbox.com/get/Photos/126_2476.JPG?w=156e235c)
(https://dl-web.dropbox.com/get/Photos/126_2477.JPG?w=d4a50cbb)
(https://dl-web.dropbox.com/get/Photos/126_2478.JPG?w=487ae280)

Thank you for Helping and make this mod Happen !
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Gus on November 09, 2011, 06:57:28 AM
You want free design work from this forum?

Read the threads at this forum a lot has been posted over the years about the questions you are asking.

Look for the MK47 threads the MK7 threads u47 threads etc.
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: manulaudic on November 09, 2011, 07:00:29 AM
I've read the forums, i was just thinking i could mod this mic real time and post pictures.

I guess, i can rely on one MK47 mod and try it out. !

Do you recommend a specific Capsule?
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: KrIVIUM2323 on November 09, 2011, 07:20:32 AM
For capsule M7 or K47 copy?

Many to choose from... Which one is the best? The best for what? Every copy is different and coupling with headbasket acoustic for 'that 47' sound is not negligible. And STC is not the same as a 47ish headbasket (as well as mic body and some  resonance from it) so you would probably not beeing in that kind of '47' sound

Transformer is imho important too, as biasing method.

Well, better than a '47 copy' why not try to make a good mic with his own character with what you've got?

By the way Gus gave many many infos about mic design and build over years... He's really an 'expert' in the domain. Maybe a search about his previous post could be relevant.  ;)
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Hank Dussen on November 09, 2011, 08:40:22 AM
Thiersch are absolutely top notch!http://www.thiersch-mic.de/en/estm_produkte.html (http://www.thiersch-mic.de/en/estm_produkte.html)
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: KrIVIUM2323 on November 09, 2011, 09:11:37 AM
Or Beezneez K7 or K47, Dale M7(Chucks batch currently in White market), Equinox 47, ADK, Violet design,... or an original Neumann K47... Probably many other to choose from!
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: manulaudic on November 09, 2011, 09:23:20 AM
KrIVIUM2323 You are right !

I forget the idea of trying to get a U47 clone. I would need to start from scratch and get good Mic case and all. I actually found on the black market different sellers for Both Mic Body and Mic PCB etc...

Though i am trying to get this mic for Vocal purposes, i would like to get rid of the Harsh High-end and have a more flaten response.

Is there any components i should upgrade on the PCB?

Here is a link to my music, that kind of style, pretty Fresh ! http://www.youtube.com/watch?v=otoWoq_5gBY (http://www.youtube.com/watch?v=otoWoq_5gBY)
By the way Vocals were done with SCT2000 -> Mbox2pro. Pretty Basic and Ok for a first Song, Not clear enough in my opinion for our futur projects..

I will take a look at Gus previous post and find what could work.
Thank you all.

Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: mich on November 09, 2011, 10:07:00 AM
its been mentioned many times - and its true : the capsule will determine mostly the sound of the mic (i would say 75-80%) and the rest - the circuit,the body,component choices.
so dont wait for a BIG change replacing capacitors...
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: KrIVIUM2323 on November 09, 2011, 10:10:03 AM
Manu,
great song!

OT: I like the way your voices blends together, maybe sometime you're a bit upfront vs Eva for my taste. Well this record is not so bad. For your future project i think you'll be in major studios in Paris (Taratata will bring you to light i'm sure!) or elsewhere with massive amount of gear and mics to choose from...  8) 

But for your preprod work i'll be ok to mod your mic for something better it's sure. I'm sure a  change in capsule for a more serious one will bring your mic to next level. Second eventually change the capacitors as you mentionned earlier. Last but not least the out transformer for one dedicated to ECC81 (Marik of Samar audio have some for this purpose, check White market).

But overall it will cost money (and time) and probably as many as if you decided to go for a commercialy availlable one... But less fun to go to store and plug and play than to mod one.  ::)   :)
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: manulaudic on November 09, 2011, 10:28:51 AM
Thank you !

I'm happy you took a listen, we are coming up with an album soon, got to sing in a real u47 for the record, that's nice ! It's true my voice is a bit too upfront. It's good to hear feedback, thanks.
Though i love DIY, it's like a passion. It's good to be able to relax.

Anyway, i think i will then upgrade the Capsule and will see what happen.


Manu
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: KrIVIUM2323 on November 09, 2011, 10:45:11 AM
Manu last few things about mix/mastering,
 on my laptop there's some distorded peaks all along the songs (need to bring back volume on Youtub player) and overall i feel the song to be a little bit overcompressed. Don't be obsessed with subjective volume, your style of songs need some dynamics and 'breath'. Yours voices/music will bring listener 'captive' no need for high average volume in the style you do, i think.

About capsule change be aware that some kind of capsule need de-emphasis (K87/K67) as they brings highs foreward (inherently/ by design). If you change capsule for M7/K47 type and your mic had 87/67 capsule without modifying circuit you will end up with dull sound.

You'll probably have to reverse enginneer the circuit to be sure.   
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Moby on February 17, 2012, 07:50:53 AM
its been mentioned many times - and its true : the capsule will determine mostly the sound of the mic (i would say 75-80%) and the rest - the circuit,the body,component choices.
so dont wait for a BIG change replacing capacitors...
Making U47 clone and ignoring capsule-headgrill effect is just making Chinese microphone to sound different from stock. As I mentioned under U47 body thread I'm working on such a details for more than 6 months. So, my advice is not to bother with wrong designed head-grills . You can see the measuring results with correct mesh size. Wrong dimensions (most of U47 body clones) looks and sounds quite different.
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: bezen4uk on February 19, 2012, 03:08:58 AM
Hi Moby,
Accordingly your graph the grill changes freq.response up to 13dB. It is not true.
Compare M7 capsule FR for U47 and CMV563(lollipop).
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Moby on February 19, 2012, 07:35:49 AM
Hi Moby,
Accordingly your graph the grill changes freq.response up to 13dB. It is not true.
Compare M7 capsule FR for U47 and CMV563(lollipop).
No, take a better look. Measuring is not normalized. So, difference is +2 /-6 db. And yes, it's like this, with wrong mesh sizes (3 layer mesh) acoustics coloration is different.
Cheers
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: bezen4uk on February 20, 2012, 03:31:39 AM
Yep, my fault - grid is 1dB.
Anyway, 8db difference is too much. How did you measured?
Regards, Vladimir.
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Moby on February 20, 2012, 07:59:09 AM
Yep, my fault - grid is 1dB.
Anyway, 8db difference is too much. How did you measured?
Regards, Vladimir.
Well, too much but that's the reason why I chime about it. I measured with calibrated microphone in omni mode , so all sides of basket are included. Software used is Fuzzmeasure.
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: pasarski on February 20, 2012, 02:40:10 PM
http://mixguides.com/microphones/vintage_products/audio_vintage_microphones_part/

Here's a same kind of graph by late guru Stephen Paul. Hard to read but seems like the bumps and dips are not as deep and in different places, but there's a strong resemblance. Differences could easily be explained by cardioid vs. omni, and/or a measurement mic vs. a K47 capsule + holder in the head basket.
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Moby on February 20, 2012, 07:18:59 PM
This measuring looks like heavy smoothed. Something like1/3 oct (mine is 48/oct) . BTW, point was not to show capsule response but response of head basket with correct mesh size. When I finish my investigation expect new thread about it. Especially about BV8 :)
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: bezen4uk on February 22, 2012, 04:54:09 AM
When I finish my investigation expect new thread about it. Especially about BV8 :)
Hi Moby,
Such thread will be appreciated!
Good luck.
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: Moby on February 22, 2012, 07:01:03 AM
When I finish my investigation expect new thread about it. Especially about BV8 :)
Hi Moby,
Such thread will be appreciated!
Good luck.
Yes Sir :)
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: manulaudic on May 08, 2012, 05:16:59 AM
Hello,

It's been a while.

I have been finishing my album and haven't had the time to mod my microphone, actually i recorded all female vocals with the stock T-bone sct2000 that i have and it was pretty good for that purpose.

I noticed at one point a ringing tone from the mic : There was some sort of electric hum that was ringing like a certain note, i actually recorded it and i could post it for you guys to hear it if anybody is interested...

I've been in touch with Dave Thomas, who was very kind to explain to me the circuit and what change to be done including Capsule, Transformer, Tube and Zener diode to get the right voltage to the new tube circuit.

I guess i will start from that and order with him. I've been wondering though if i should get a second T-bone sct2000 to mod since i quite like the one i have.

One last question :

- How can i know which type of capsule i have in my t-bone, could it be the 797 one? or some other chinese?
Any sign to look for?

Thank you all for your help and whenever i decide to mod it i will keep posted !

Manu
Title: Re: U47 Clone Build Thread based on T-bone sct2000
Post by: manulaudic on May 08, 2012, 05:20:49 AM
Here is the sound i noticed during recording :

http://dl.dropbox.com/u/680387/T-bone%20Sct2000%20High%20Noise%20sound.wav

I realized that turning off the power supply and back on would eventually remove the hiss...

Manu