Troubleshooting a vintage ribbon Mic

[frans]

If in europe, you should contact this guy:
Xaudia Elektrik - Extinct Audio Equipment, Microphones & Information

[emrr]

Putting a multimeter on a ribbon mic is a good way to insure the ribbon is dead.

[Richard Crowley]

Please complete your user profile to at least reveal what country you are in. Your possible options depend on where you are.

[enginefire]

does the voltage from the DMM rip the ribbon?

for the profile... sending it away for repair is not an option, sending out for parts (and pizza) is possible.

so far I got it to pass sound, but the quality is terrible, it sounds like an old telephone, a lot of midrange resonance. maybe it needs a new ribbon? maybe a new transformer?

[Richard Crowley]

Transformers don't just "go bad" like that. It is possible that the ribbon is damaged (distended, ripped, etc.) Can you visibly examine the ribbon?

If you can't send it out for repair, your questions would suggest that you aren't up to the extremely delicate task of replacing the ribbon yourself, assuming you can even find one of the appropriate specs, etc. Maybe you can trade it for a pizza pie.

[enginefire]

I think I might surprise you Mr. Crowley!
I can inspect the ribbon, it does not look ideal.
I suspect the magnets are not as strong as they used to be.

maybe I get some pizza after the mic is fixed, nothing like special delivery.

the way i see it, if the mic already does not work as it should, I have nothing to lose by repairing it myself, at the end of the day I might end up with a mic that needs to be sent for repair, or I might end up with a fine working mic. Too many people feel themselves incapable, probably from being told for so long that they cant accomplish things that they set their minds too. Everything is a learning experience, the man (or woman who can profit from his experiences is a wealthy man indeed. The only thing of real value that we have is our time, and it is up to each one of us to decide how best to spend it. Personally, I like spending some of my free time fixing broken things and creating solutions... seems like there are problems all abound these days.

[Richard Crowley]

Don't get me wrong, nobody here is as big a supporter of fix it not toss it as I am. But the ribbon in a microphone is an extraordinarily delicate thing. You must wear a mask to avoid even breathing on it. And then there is the matter of finding, modifying or making the ribbon to begin with. There are purveyors of replacement ribbons for some microphones.

It seems unlikely that the magnets would go bad as the microphone can't be that old. And there are ribbon mics that were born early in the previous century that are still working fine.

[enginefire]

thanks for the mask tip, i will be extra careful. I have ordered some imitation leaf and will practice on a mic that I know already has a busted ribbon, at least this one passes sound as it is... not that I could sell it to someone and not let them know that it sounds terrible as far a usable mic goes.

I will try the fake stuff, and if after I get the hand of it, if i am not satisfied with the sound I will go for the "real deal" foil.

[enginefire]

I poked around a little today into the existing ribbon element (it sounds bad and I am going to replace it anyways, so I figured i couldnt really do any real damage....right?

I took some pictures. it looked saggy to me so i tightened it a little. actually i ended up removing it completely and finding that the assembly it was attached to was broken, I crazy glued the plastic back together and reassembled the element and mic.

I will test it tonight!

here are some pics, the ribbon still looks a little weird to me:

[Led]

Has it got the original 3 pin socket on it, or has it had an xlr put on - have you checked the wiring to the socket is all good and correctly wired?

[Richard Crowley]

If the socket wiring were incorrect, he likely wouldn't hear any signal, and probably a lot of hum. His description of the problem could easily account for the low (but still present) audio signal.

[enginefire]

I had to hook up the alligator clips to get any signal at all. it has the old socket and matching end with a mono quarter inch cable, it was wired for hi z previously.

sent from my m-3500 using the gearslutz app

[Genkin]

Originally Posted by enginefire

here are some pics, the ribbon still looks a little weird to me:
Attachment 321898
Attachment 321899

All the ribbons I saw are corrugated, but this one looks flat. I'd contact real ribbon gurus. If you are in Europe try Xaudia, or in US Samar Audio Design.

Cheers,
Paul

[Analok]

Agree that the ribbon looks in sad shape. Possibly over-tensioned and out of alignment as well. Is it rubbing along the gap's edges? Many times these old mic's magnets collect metal fragments over the years, clogging up the gap and restricting the ribbon from moving, thus low or zero output. Looks a rebuild is in order, cause the motor has damaging filth that current ribbon won't survive during the cleansing process. Putting a new ribbon on in the mic's current state is foolish. Clean it, re-ribbon it, hope for the best. Good Luck!!

[zebra50]

Yes, it certainly needs a good clean.

The ribbon is not original, and looks like it has been made from cigarette packet foil. We see quite a few like that. Live sound engineers used to do this to get through a gig if the ribbon popped. They sound pretty terrible like that, but can be nice mics when working well.

Drop me a line if you need any parts etc.

Stewart
Xaudia

[enginefire]

Now that you mention it, it looks exactly like cig pack foil! I was wondering where I had seen it before. No corrugation in the ribbon either.

I picked up some gears and ordered a bit of foil so I will attempt to replace the ribbon this January. I will clean up the magnets with some sticky tack to remove any metal bits. if this all goes well I will think about replacing the transformer too with a edcor or cinemag or maybe lundall... I am guessing that they are potato/potaato in terms of sound.

sent from my m-3500 using the gearslutz app

[Analok]

I'd try keeping the original iron first. Not that Reslo made anything laced in voodoo or such, I just personally like authenticity. Take a couple resistance measurements across the coils to rule out open/shorted windings (disconnected from the motor of course). Anything around 3 ohms should be OK. If truly dead then go on & swap it out.

[ShinyBox]

Originally Posted by rcrowley

But the ribbon in a microphone is an extraordinarily delicate thing. You must wear a mask to avoid even breathing on it.

I'll agree that they are delicate things, but the "you can't even breathe on it" part is a little overblown...

Handling ribbons for a skilled technician is a non-issue. If you are just messin around, you'll have bigger issues to worry about than holding your breathe

Ribbons are fun in that you can pretty much throw anything in there and get something to "make a sound" (I reribboned an Altec once that had kitchen foil as the ribbon), but getting it right takes time, experience, and attention to detail.