Banzai's KM84 DIY Body & PCB kit build thread

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fsalter

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As an experiment, i built Banzai's circuit into a cheap BM-300 body with a JLI TSB-2550 capsule. I always really liked this capsule and i'm quite impressed with the sound with that circuit. Although it does'nt have that KM-84 "sweetness", it is nonetheless very impressive. The output is quite low though. Should i use a JFET with a higher Idss, or rebias? (i adjusted it to 10V, like my other 84 builds, which have a higher output)
 

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Banzai

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fsalter said:
As an experiment, i built Banzai's circuit into a cheap BM-300 body with a JLI TSB-2550 capsule.
* Graeme's circuit  :)
 

Whoops

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Hi everyone,
I never did this project and will do it in the near future.

I'm trying to decide which transformer to buy for this cricuit so I would like to ask you guys opinions on which transformers to use.

What are your experiencies with any of these transformers?
3U audio GZT-84, Cinemag, AMI or Haufe?

Anyone has great experience with a specific one and bad with any other?

Anyone ever did comparisons between the different transformers for this circuit?

Thank you so much
 

TillM

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Berlin - Germany
I used Cinemag and Haufe.
The Haufe and Cinemag had the same Sound in my opinion.
I can’t hear any difference, besides that, in my opinion the cinemag had a bit better build quality.
 

JerryPbury

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Charlotte, NC
Anybody have a source for these nylon pieces? I need at least 2. Also, I need an MXL capsule for parts.

Thank you,

Jerry
 

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iturnknobs

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Whoops said:
Hi everyone,
I never did this project and will do it in the near future.

I'm trying to decide which transformer to buy for this cricuit so I would like to ask you guys opinions on which transformers to use.

What are your experiencies with any of these transformers?
3U audio GZT-84, Cinemag, AMI or Haufe?

Anyone has great experience with a specific one and bad with any other?

Anyone ever did comparisons between the different transformers for this circuit?

Thank you so much

The Haufe transformers that I received literally fell apart. I applied just a little acetone to soften the factory lamination and then painted around the outside with some clear nail polish. The lamination process must have not been performed properly and the plates literally separated. Also, if none are available, a group purchase is/was required for a large enough run for Haufe to retool and start-up their winding machine. They seem a bit "sterile" compared to AMI. This might not be a bad thing.

AMI seems to sound as if they have a bit more "body". They are assembled very well and Dennis is fantastic over there. Expensive.

USPS lost my Cinemag order(CM-5722x4). David over at Cinemag offered to send me 2 new ones free of charge. I had no more bodies to put them in, so I declined his offer. It wasn't their fault that they were lost, anyway. The take away here is excellent customer service.

Hope this helps.
 

waltzingbear

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Jan 30, 2006
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Portland, Oregon
any one have a source for the standoffs? Mouser is back ordered til the end of May.
534-11322
STAND-OFFS
11322
.110 x .180, Solder
Keystone Circuit Board Hardware - PCB

cheers
Alan
 

JerryPbury

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waltzingbear said:
any one have a source for the standoffs? Mouser is back ordered til the end of May.
534-11322
STAND-OFFS
11322
.110 x .180, Solder
Keystone Circuit Board Hardware - PCB

cheers
Alan
[/
I bought a bunch from Digi-Key a couple of weeks ago. ‎36-11322-ND‎
 

Whoops

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iturnknobs said:
The Haufe transformers that I received literally fell apart.  They seem a bit "sterile" compared to AMI. This might not be a bad thing.

AMI seems to sound as if they have a bit more "body". They are assembled very well and Dennis is fantastic over there. Expensive.

USPS lost my Cinemag order(CM-5722x4). David over at Cinemag offered to send me 2 new ones free of charge. I had no more bodies to put them in, so I declined his offer. It wasn't their fault that they were lost, anyway. The take away here is excellent customer service.

Hope this helps.

TillM said:
I used Cinemag and Haufe.
The Haufe and Cinemag had the same Sound in my opinion.
I can’t hear any difference, besides that, in my opinion the cinemag had a bit better build quality.

Thank you so much iturnknobs and TillM for sharing your opinions and experience.
I would be more inclined for the Cinemag transformers.

How about the 3U audio GZT-84? Any opinions or experience with that one?

Thanks

 

Zim

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Feb 18, 2020
Messages
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I’ve just ordered a couple of kits from Banzai’s latest run but as a relative noob to DIY had a couple questions which I’d appreciate more learned advice on...

I’m totally comfortable with the build, but was initially a little put off by the calibration process as I don’t have the tools.  I figure I can use REW as a scope for now but would need a signal generator. I’ve seen the Feeltech fy6900 and fy8300s recommended as being a pretty good option for the price.  I’m clueless on this stuff though - Would this be worth having and/or are the any other options anyone would recommend?

Second question - I was thinking of leaving the body of the mic in it’s raw state, but is there any benefit to getting it powder coated other than the aesthetic. E.g. does powder coating give additional shielding against RFI for example  vs bare metal.  Plenty of mics have metal bodies, so I’m guessing  it wouldn’t be an issue but similarly could see how metal might act better as an antenna so thought it was worth asking the question just in case.

Appreciate any input

Thanks

Zim
 

oongbac

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Joined
Apr 16, 2021
Messages
5
waltzingbear said:
any one have a source for the standoffs? Mouser is back ordered til the end of May.
534-11322
STAND-OFFS
11322
.110 x .180, Solder
Keystone Circuit Board Hardware - PCB

cheers
Alan

I ordered 11302 instead of that. I cut lower part of teflon, there’s a small metal post can be used for soldering capacitor. I hope it’ll work.
 

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Zim

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oongbac said:
I ordered 11302 instead of that. I cut lower part of teflon, there’s a small metal post can be used for soldering capacitor. I hope it’ll work.

Could well be wrong, but this doesn’t de-couple the parts from the board does it? which (I think) was the purpose of the specced posts.
 

oongbac

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Zim said:
Could well be wrong, but this doesn’t de-couple the parts from the board does it? which (I think) was the purpose of the specced posts.

I choose this because remained teflon part has same radius with 11322(.125 maybe). I might apply some glue to fix this thing on the board, and also there’s still big risk of failure with this component. But I’m a really impatient one  ;D ;D
 

Strat96

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Nov 14, 2010
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Location
Motown
Thank you so much iturnknobs and TillM for sharing your opinions and experience.
I would be more inclined for the Cinemag transformers.

How about the 3U audio GZT-84? Any opinions or experience with that one?

Thanks
I have two kits from Banzai and will be buying the 3Us. Seems a lot of other people went that route. They are readily available and affordable.

I can let you know how they turn out, but won't have much of anything compare them against.
 
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