Ribbon mic foil sources

[seavote]

Ribbon mic foil sources

http://www.lebowcompany.com/index.htm
http://www.alfa.com/alf/index.htm
http://www.goodfellow.com/
http://www.advent-rm.com
http://www.dickblick.com/zz270/12a/

 

[Kit]

Thanks. :thumb:

 

[drummerguy]

you can get 4 micron ribbon in small amounts here:
http://www.audiocdmasters.com/ribbon.htm

 

[Marik]

you can get 4 micron ribbon in small amounts here:
http://www.audiocdmasters.com/ribbon.htm

Why wouldn't you tell straight that you sell that ribbon? In any case, 4 micron is way too thick for use in ribbon microphones.

Best, M

 

[drummerguy]

actually they sound great when replacing the chinese ribbons. That's what most people buy them for.
and...
how more direct do i need to be?  ???

 

[mac]

Hello all,
I have enjoyed emesely the ribbon mic discussions here on DIY, and have been entertaining my first excursion into a DIY ribbon mic. This evening, curiosity got the better of me - so I pulled apart an old metal foil cap to see the insides. Two layers of very thin foil with a plastic sheet between each two layers was what I found.

Question i have is, how on earth do you tell how thin a material is when you source it like this? I mean, it is clearly much thinner than normal food grade foil, but how can I measure or test the material to see if I should bother playing with it any further?

Mac

 

[Jonte Knif]

Simply fold it multiple times and measure. 16 or 32 layers is fine if you have a micrometer.

The foil is likely to be about 6 microns. At least I haven't been able to find anything thinner from caps. OTOH I haven't done searching too much.

Lebow company sells thin Japanese made foils for modest price, don't waste you time with caps. (And surely even 4 microns is way too thick.)

-Jonte

 

[pyjaman]

Hi,
Mac,
What I did once was to go in a technical school in my town ( I don't know how you call it but where they learn mechanics and industrial processes, stuffs like that...) .They had very accurate tools for mesuring of such things.

Laurent.

 

[Marik]

Hello all,
I have enjoyed emesely the ribbon mic discussions here on DIY, and have been entertaining my first excursion into a DIY ribbon mic. This evening, curiosity got the better of me - so I pulled apart an old metal foil cap to see the insides. Two layers of very thin foil with a plastic sheet between each two layers was what I found.

Question i have is, how on earth do you tell how thin a material is when you source it like this? I mean, it is clearly much thinner than normal food grade foil, but how can I measure or test the material to see if I should bother playing with it any further?

Is it laminated, or you can separate the foil from the plastic? The thinnest capacitor foil I ever saw was 4um in old Illinois paper-in-oil. You can roll it down with a wide enough ball bearing. Use very thin lubricating oil and roll it on a piece of glass. It is very hard to measure thickness of the material even with a clutch type micrometer. Layering can give you much better ballpark. Usually, for precise measurement they do it by weighing the bigger piece and then calculating the thickness from mass and dimention.  Also, you can calculate the foil thickness from from its resistance (which is not very precise way), but again, you have to have means of measurements of those small values--usual DMM won't do it. I use GenRad 1650 bridge and HP3457A multimeter, with Kelvin probes.

As a side note, 4um indeed is very thick for ribbon mics. It is what many Chinese mics use, so I don't quite see how it would be any better (or any worse, for that matter) than Chinese stuff. The only good thing about them is they theoretically have lower resistance and potentially lower noise. However, Chinese don't use it to advantage, as with quite poor quality of clamping they get pretty high resistance at the termination. I get the similar overall resistance with more than twice as thin of the ribbon (I usually use 1.5um). Also, the Chinese transformer has very high copper resistance, so with 1:55 step ratio they get extremely high noise--much higher than their potential.
Needless to mention much higher mass in 4um and since the mic sensitivity is directly proportional to the ribbon mass the sensitivity drops dramatically (we are talking about at least 6db). Another thing is thicker ribbons prone to much nastier resonant modes, so it is very hard (read: nearly impossible) to damp them effectively, even electronically. If anything, they can be only used in "piston-like" fashion, but this is completely different can of worms.
All in all, I don't quite see what can be so great about them.

Best, M

 

[mac]

Thanks everyone...

I had started down the resistance measuring track, but I think that given the efforts to obtain the material (and the excellent advice given here) - I would be better off purchasing appropriate materials to begin with.

Wow - if only multinational call centers provided the same level of accurate advice and customer service as this Forum!!!

Cheers,
Mac.

 

[drummerguy]

(And surely even 4 microns is way too thick.)

royer finds 4 microns perfectly fine in their r-121 ribbon mic.
http://www.royerlabs.com/R-121Live.html

 

[Jonte Knif]

royer finds 4 microns perfectly fine in their r-121 ribbon mic.

That is a live mic, made to be abused and surely has been carefully designed to work _almost_ as well as their "studio" range mics. And what ever Chinese use is unlikely to be an optimal solution.

Marik said it all.

I wonder how much better the Chinese mics would perform/sound with thinner ribbons. That would be a nice test.

Best,

Jonte

 

[gemini86]

just throwing this out here, i'd bet the general recording hobbyist would still be pleased with the sound and performance of 4 micron ribbon, even if it's not optimal.

 

[rodabod]

Thinner ribbons sound better in my opinion. Might be a difficulty with the Chinese models if they lack inductance on the transformer, also the output impedance increases. The Chinese foil I've seen is crap. The Oktava foil isn't great either.

 

[mac]

Others may have already seen (or know) this site, but I found it informative read;

http://www.lkmusic.co.nz/ribbonfix.htm

Mac.

 

[Kingston]

I wonder how much better the Chinese mics would perform/sound with thinner ribbons. That would be a nice test.

I would certainly be up for it. I've a heavily modded RB500 (the standard long foil chinese model) that I'm already very satisfied with, but improvements won't hurt this "lofi" mic.

I already switched to lundahl transformer, tuned the ribbon and removed much of the excess damping and protection "socks".

It's already my favourite mic of all time, and I'll be getting another one soon for a stereo pair.

 

[Marik]

(And surely even 4 microns is way too thick.)

royer finds 4 microns perfectly fine in their r-121 ribbon mic.
http://www.royerlabs.com/R-121Live.html

Any design is a set of compromises. As Jonte has pointed out, this is a Live mic, specifically designed, tuned, and all the parameters and parts optimised for this specific application. As such, some characteristics are inevitably compromised. For example, as it (diplomatically) mentions, the high end is more rolled off. In reality, I'd expect them to sound different from the studio version, as the main purpose of the mic is to hold an on road abuse.
Another difference is in the precision of manufacturing. Excuse me, but cutting foil with scissors, vs. cutting with computerized cutter are different, as there is a "slight" difference between corrugation made with a super precision corrugator vs. using a comb and spunge.

But the main question remains the same, i.e. what makes the material you sell be an upgrade from the usual Chinese stuff?

Best, M

 

[Svart]

how thick is aluminum leaf?  I tried some of that in a homemade ribbon mic and it worked but it was much easier to break than the ribbons in my chinese mics.

 

[Marik]

how thick is aluminum leaf?  I tried some of that in a homemade ribbon mic and it worked but it was much easier to break than the ribbons in my chinese mics.

It is around 0.6um. Big PITA to work with, and has high DCR. Nevertheless, once paired with right transformer can sound wonderful.

Best, M

 

[pyjaman]

Hi,

I've been overtaken by Marik, so just to confirm:
Svart,
I remember I've read somewhere those "singwriter silver leafs" were 0.6 micron thick, so not surprisingly highly breakable...

Laurent.