Mic Capsule question / Latvian Blue Baby Bottle output differences

[Baltimore]

I have two early made in Lavtia Blue Baby Bottle mics - one i believe is the first version of the mic with a plastic ring as the capsule mount, and the other is slightly later with 2 pins and a screw holding the capsule in place. I'm working on tracing the circuits to be sure, but the circuit boards are the same, and at a quick glance components appear the same other than a couple caps are slightly smaller values / different types.

The most obvious difference in these mics is that one has a sputtered rear diaphragm, and the other does not have any gold on the rear diaphragm. Capsules appear quite similar other than this.

These mics sound wildly different. The older plastic ring mic is darker and sounds excellent on guitar cabs, but not great on vocals or as an overhead mic. It has hot but manageable output. The other is brighter, sounds great on vocals and as an overhead. It has ~20dB+ hotter output than the first mic and is easily overloaded. Very loud vocalists will clip it, loud drummers clip it, guitar amp use is pretty much out of the question for most of the work I do.

Can some or all of these differences be attributed to the rear diaphragm? I've ordered a capacitance meter to measure each capsule, but I'm just trying to learn what can make such a dramatic impact on the output of these mics, and to a lesser extent the tone

 

[kingkorg]

I have two early made in Lavtia Blue Baby Bottle mics - one i believe is the first version of the mic with a plastic ring as the capsule mount, and the other is slightly later with 2 pins and a screw holding the capsule in place. I'm working on tracing the circuits to be sure, but the circuit boards are the same, and at a quick glance components appear the same other than a couple caps are slightly smaller values / different types.

The most obvious difference in these mics is that one has a sputtered rear diaphragm, and the other does not have any gold on the rear diaphragm. Capsules appear quite similar other than this.

These mics sound wildly different. The older plastic ring mic is darker and sounds excellent on guitar cabs, but not great on vocals or as an overhead mic. It has hot but manageable output. The other is brighter, sounds great on vocals and as an overhead. It has ~20dB+ hotter output than the first mic and is easily overloaded. Very loud vocalists will clip it, loud drummers clip it, guitar amp use is pretty much out of the question for most of the work I do.

Can some or all of these differences be attributed to the rear diaphragm? I've ordered a capacitance meter to measure each capsule, but I'm just trying to learn what can make such a dramatic impact on the output of these mics, and to a lesser extent the tone

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Are you sure about that 20db difference figure? If so, i'm quite sure one of these mics is broken, no difference in functioning capsule design should explain 20db of difference in level. Try comparing both to a known functioning mic and see which of the two deviate the most in level.

 

[vintagelove]

I really liked the first versions (no screw holes in the headbasket). It was definitely darker and had an interesting/different character. Very nice on acoustic instruments as well. The second version as you pointed out was brighter, and while still good, just wasn't as unique a mic anymore.


Not much help, but I definitely don't remember there being a 20db difference in output. I can't say for sure because it's been a long time, but I have to think I would have noticed that much of a difference.

 

[Baltimore]

Are you sure about that 20db difference figure? If so, i'm quite sure one of these mics is broken, no difference in functioning capsule design should explain 20db of difference in level. Try comparing both to a known functioning mic and see which of the two deviate the most in leve

Yes, I'm sure.
One mic might be technically broken, but you'd never know by listening to it. it sounds excellent and is still as hot as a typical modern condenser mic. the other is unusually high output. a friend has a latvian baby bottle with the pin/screw mount like my later one that is also very high output.

If it can't be the capsules, I'll work on a schematic and compare voltages to see what is going on. there might be circuit changes that i didn't pick up on on first glance, or maybe something is amiss.