Reslo RB Ribbon mic, Info, Wiring, Mods.

[quote author="Marik"]
Are you sure the original Reslos had 3um ribbons? Also, they were ribboned with duralum, which after many years most likely got hardened and lost compliance (unless was kept in vacuum).
[/quote]

No! :razz:

That was an estimate, hence the ~ symbol. If this was Klaus Heyne's mic lab then I would have been sent to microphone prison!

I have had some 2 micron ribbon in the past, and the Reslo material appears to feel slightly thicker, hence my guess. It can't have been much thicker since it begins to sound very bad after you get over a certain thickness (I have tried this). Reslo also changed ribbon design in the 50's or 60's when they introduced the RB models.

I have one new old stock Reslo and the ribbon material looks brand new - it is still shiny and flexible (it was sealed though). I know what Duralum looks like when it hardens - it goes grey due to oxidisation and breaks. The original ribbons were pressed into a square-wave which is strange! It looks like they were put in some sort of clamp...

You guys rock! thanks a lot Mark and Rod.

My ribbon was very grey indeed, no shine left (so I guess thats how it broke), in fact I'm going to clean the entire assemble as its pretty tarnished. I suppose this mic is 50-60 yrs old, its a black label, the casing outside however is perfect.

Any ideas if triangular corrugation will effect the sound (piston behaviour) compared to the duralum squares?

Cheers again
Tom

[quote author="TomWaterman"]
Any ideas if triangular corrugation will effect the sound (piston behaviour) compared to the duralum squares?
[/quote]

Triangular will be fine. I suppose the original square pattern may have reduced resonances to a certain degree, but a normal fine wave is fine.

There is talk about corrugation types in the BBC ribbon microphone monograph.

I am considering replacing the torn ribbon on an old RB Reslo. Does anyone have any definitive information as the width of the ribbbon - its never mentioned in YouTube fixing videos? I have measured mine as 2.3mm width but this may not be accurate. Also when fitting the ribbon is there a specification for the gap between the ribbon and the magnet plates - this seems to be adjustable to a limited extent? Incidentally the corrugations seem to be a square wave with each indentation being 1/8" long.