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Author Topic: Question for Klaus [Klaus Heyne Modified u67]  (Read 5851 times)

Je55

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Question for Klaus [Klaus Heyne Modified u67]
« on: October 06, 2012, 04:20:19 am »

Hi Klaus,

I've been renting a great u67 recently, I've been using it every day on my most important lead vocal tracking... not going to mention the artists.

I then shot it out against another vintage u67 offered for sale and noticed how much more open and clear it sounded in comparison. It didn't have that De-essing type sound most u67's have.

This made me open them both up to see what was going on. Low and behold... the pics below...

Can I ask you on your detailed thought process behind this modification? I'm sure theres a great back story. You replaced most of the circuit with an oversized styrene and you threw what looks like a 0.5uf rel cap coupling output capacitor which I found interesting as I remembered reading a thread by you about how you bought into the whole rel-cap hype and then realized later on that you should have stuck with pio's.

It also looks like (judging by the two serial numbers), you modified or worked on this mic at two different times.

The mic I shot it against for sale was true to the original schematic but all caps other than the filter wima cap had been replaced with yellow poly's currently available on mouser etc.. They sounded very similar, Your modded u67 having slightly less lower mids (which i would have subtracted in post anyway) and a much more open and clearer top end.

I'll take some better high res images out of the studio later.

I'm in the market for a couple vintage u67's and i'm also currently building one of Dany's circuits over on the groupdiy forums but now I want them to sound like this one... or better

cheers

J









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klaus

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Re: Question for Klaus [Mod on u67]
« Reply #1 on: October 06, 2012, 05:03:01 am »

Thanks for the compliments! I am sure you will understand that any form of promotion, including self-promotion, is against the ground rules on this forum, for the obvious reason that it contaminates sincere, unbiased discussions.
So, please contact me privately if you have any questions relating to my work.

One thing though, needs correction here:
I have never "bought into Rel-Cap hype" and then abandoned it. If you mean the company's products: I have, without interruption used that brand from the very beginning of my career (though not exclusively) and do so, to this day. I rate Rel-Cap's build quality and sonic performance among the best in any of the capacitor types they make. Types and values I use have evolved through the years (the company currently makes a special 1 mfd. film and foil version for me, which is what you see in the picture). 

What you may have confused with the above is my 180║ reversal, about 15 years ago, in thinking that piggybacking coupling capacitors makes sense and improves the sound. The hypothesis: by using parallel capacitors the electron flow of specific frequency ranges would self-select to pass through the most suitable capacitor value, thereby reducing smear and improving time-alignment of the audio signal.

Rel Cap indeed makes an expensive version of parallel cap which it markets as "MIT/MultiCap". After I tried them and found them to be smeared and ugly sounding in the extreme- at least in microphones- I went back and listened to my own versions of this piggyback arrangement, dating back a decade before Rel Cap commercialized it. After repeated listening, I realized that my logical brain had outsmarted my ears in judging that this must be better, because the idea was so compelling. Out went that theory, and out went the piggybacked caps.
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Klaus Heyne
German Masterworks«
www.GermanMasterworks.com

Je55

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Re: Question for Klaus [Klaus Heyne Modified u67]
« Reply #2 on: October 06, 2012, 08:31:53 am »

Thanks Klaus,

A very humble reply. I emailed you regarding the modification. I disagree that it would be self promotion though. I ran into a mic circuit you designed in an off chance and complimented you on your work. This was sincere and unbiased as it gets as it was a blind test (Your modification markings were only on the inside of the mic)

I stand corrected regarding rel caps, your previous comments were regarding the MIT caps.

Cheers

J
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Jim Williams

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Re: Question for Klaus [Klaus Heyne Modified u67]
« Reply #3 on: October 08, 2012, 12:44:58 pm »

Bas Lim of Reliable Capacitors states clearly in their apps notes that the multi-stage self bypassed designs of their MIT cap line requires at least a 50 hour break in or the sonics will sound strident. Many have not done that before evaluating them.

I have found his RTX series polystyrene MIT caps to sound excellent, with a bit more detail than their single stage RT polystyrene caps. The major construction difference is the MIT's use aluminum foil (unless tin is requested) and the RT series use tin foil construction. Tin tends to have a softer sound quality. Bas can also wind caps with high purity copper foil, worth checking out as well.

Other brands are also excellent like the Mundorf silver foil caps, but you will pay dearly for those.
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klaus

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Re: Question for Klaus [Klaus Heyne Modified u67]
« Reply #4 on: October 08, 2012, 02:00:23 pm »

You are not implying, Jim, that when I came to my conclusion about the unpleasant sound of the MIT multi caps, that I did not break them in properly?
I never release a mic to its owner unless its new capacitors have been broken in for at least 3 solid days, often seven. (By the way: I do the same with the cables I provide.)

You mention copper foil: Yes, very nice, but not necessarily superior to tin in mics, (aside of being unaffordable to 99% of the public, let alone OEMs).
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Klaus Heyne
German Masterworks«
www.GermanMasterworks.com

Jim Williams

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Re: Question for Klaus [Klaus Heyne Modified u67]
« Reply #5 on: October 09, 2012, 11:57:12 am »

You will be hard pressed to find current manufacturers that will spend the extra $ for Rel Caps, MIT's, Mundorf or any of the other high end capacitors.

Dropping twenty bucks or more on a single capacitor is the domain of the experimenter or audiophile playback crowd. You will not find these parts in currently available in commercial pro audio gear, with perhaps Manley being an exception in some products.

As good as some of these capacitors are, none compare to a bare wire for sonics. That is why I take out as many as I can here. My custom mics only have one capacitor in the audio path, it's an MIT poly cap that does sound very good. Removing the coupling caps off the capsules did more for the sonics that any other modification. Yes, even Rel Cap RT's at 1000pf/600V sound clogged to me compared to a wire.
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klaus

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Re: Question for Klaus [Klaus Heyne Modified u67]
« Reply #6 on: October 09, 2012, 12:38:30 pm »

Agree with your conclusions: less components with their time-alignment and filtering issues in the audio path always leads to more fidelity
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Klaus Heyne
German Masterworks«
www.GermanMasterworks.com
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