How To Simply Measure and Evaluate Microphone Tubes

Before what?

Rubbing it on your face.

Moving/jostling it around, if possible.

sorry... not trying to be funny... What's that about? never heard that... Are you saying that they are somehow more vulnerable to damage while they are hot?

I'm not any sort of tube expert, but somewhere along it became engrained in my head that it is good practice to not disturb or bump a tube mic during 10-15 minutes of warm-up as well as cool-down.

It obviously requires no effort, so I've been doing this with all my tube mics for a long time.

Aside from the idea that tubes are somewhat vulnerable to physical impact at any temperature, can anyone comment more authoritatively on this? Klaus?

The heater of tubes is somewhat similar to a filament of a light bulp - so yes, it's better to wait a few minutes before you put your mic back into storage after use.

thanks! I know what filaments are but never heard that they were more sensitive when hot, about tubes or lightbulbs...

Let's rock and roll with those sound samples gurlz ok?

I want to hear the sound of Neumann kicking themselves for a lost business opportunity. Or having a private laugh. Whichever.

When will the vintage U87 mods be available? And how much? Sorry if this was answered already

The U87 to U67 mod variation prototype is working on my bench. I'll be receiving a (vintage) U87 in the next couple of days to try if everything works and fits, so i expect to have them on sale within two weeks or less.

-Max

Out of curiosity, how can you tell whether a body is an Ai or old U87? Other than markings of course....

As it goes I have a basket, bodytube and bottom screw bit, so would only need to buy the capsule and the white plastic bit to mount on with the pattern selector, plus the bits you mentioned earlier Max. All those bits are not exactly for free from Neumann, but it would be cheaper than a donor mic. Only, how do I know which version would work? Is it only capsule dependent (as they differ) and the rest is the same as all the guts comes out anyway?

The only non-ai 87s I've seen have the small "window" in the body is for the battery compartment. I think there are even earlier 87s that don't have the comparment but those are afaik quite rare.

I think the outer body parts are interchangeable between all models.

Best is to talk to neumann spares to find out. The only difference crucial to the mod is the capsule and capsule-head related parts. The (vintage) U87 uses a different capsule with four wires and a different cicuit in the head-switch part.

What I figured, so I'd have to get the Ai part from Neumann and go from there I suspect. Thank you, chaps.

The next batch of TLM67/U87Ai modules is nearing completition, shipping will start on wednesday 1.7.15
Most of the batch is already spoken for, but a few modules are still availble - check the first post and email me if interested.


thanks,
Max

Hi max, will you still have more in 3 months or is there a limited run on this ? Thanks.

After examining everything very carefully I have ordered one of the batch of kits.

Everything looks exactly as it should. I'm pretty excited.

Like Dr Bill, I no longer have more than one 87 (I actually sold my vintage one), so I'd like to have a quick swap to standard when needed. So far I've struck out on the side rails. It would be ideal be able to swap the guts in under 30 seconds, so another bottom and rails is the plan.

[QUOTE=It would be ideal be able to swap the guts in under 30 seconds, so another bottom and rails is the plan.[/QUOTE]
Do you can buy?

Let us know on how you get on. I might be keen to do the same.
I've just installed the U67 kit I received from Max. Gonna have a play...

Hi, how does it sound compared to your original? any sound samples ?

Anyone with a U87AI or a TLM67 in London/Essex want to do a comparison with one of my U67's at mine?

Yup. That's a deal breaker for me until that gets sorted out. If I had a second 87 I might consider it, but at this point I need it to be a quick swap too. Between the Innertube mod, the stock 87 topology and the Max 67 mod - this could make an 87 perhaps the most iconic and useful mic on the planet. Hope Max figures it all out. But, like you say, it needs to be quickly swappable.

Hey Bill,

i do have a solution, did you read my answer #108 ?

I received this pic from Neumann spares, you need to order:
the threaded base unit #27
two side rails #17
screws #14 , 15 and two of each #25 and #26

The module can be mounted in this assembly and than changed within seconds.

-Max

One down, one to go!

https://drive.google.com/file/d/0B0O...ew?usp=sharing

Anyone want to report any sonic joys yet....?

Installing was straightforward, although it took me longer than the quoted 3 min, partly because my screwdriver wasn't a perfect match and also I wanted to be careful to not yank any wires, as the rails were pretty tight.

I haven't got a U67 to compare to, nor have I recorded my voice on one before but I will say that I was wanting a tube mic with a smooth, somewhat subdued high end for recording classic sounding soul and rock vocals and this is definitely that, when I compare it to my more C12 styled Stellar CM5. I dispise sibilence and this seems to be smooth as butter in that range and that pleases me!

I wasn't using my U87ai (2001 model) that much and had been interested in the Cathedral Guitars CG67 which the late Oliver Archut was working on which obviously got put on hold, so the time was right to give this a go.

I can say that it works and it sounds good to me, but I'm not the right person to say how close it sounds to a prime condition U67, because I don't have access to one.

Neumann Spares have contacted me and they now listed all the required parts:
U87Ai - Sennheiser Pro Spares - Purchase Online