Switchable circuit mic

[untamedfrontier]

Perhaps this is a dumb suggestion, but has anyone ever seen or attempted a mic build with multiple circuits in the same body, that can be selected via switch?

My thought was prompted because I'm getting a full size 47 body, but don't think I'm going to fill it's guts up with a tube yet, and if there's enough space in there to put in something like a 47fet and then an Alice circuit and have them be switchable by a 4pdt (or 3pdt, I haven't thought far enough ahead to know which would be more appropriate, if at all), could be an interesting way to play around and switch between different circuits with only needing 1 capsule.

Anyone ever tried something like this?

 

[Rob Flinn]

New mic mnufacturer AIM has a mic which has switchable solid state & transformer based outputs.

https://aimaudio.com/inspire/

 

[kingkorg]

Perhaps this is a dumb suggestion, but has anyone ever seen or attempted a mic build with multiple circuits in the same body, that can be selected via switch?

My thought was prompted because I'm getting a full size 47 body, but don't think I'm going to fill it's guts up with a tube yet, and if there's enough space in there to put in something like a 47fet and then an Alice circuit and have them be switchable by a 4pdt (or 3pdt, I haven't thought far enough ahead to know which would be more appropriate, if at all), could be an interesting way to play around and switch between different circuits with only needing 1 capsule.

Anyone ever tried something like this?

Bock Audio IFet. Fet47 and km84 circuits.

 

[garp]

The EMI also has such a stuff as i have read .

 

[SubSpec]

New mic mnufacturer AIM has a mic which has switchable solid state & transformer based outputs.

https://aimaudio.com/inspire/

My gosh if that doesn't look like a TV remote. Cool stuff though, interested to check it out more!

 

[Barry Hufker]

United Studio Technologies' Twin87 has two circuits in one body. The first for a vintage sound and the second for modern.
https://unitedstudiotech.com/en/products/ut-twin87

 

[Khron]

United Studio Technologies' Twin87 has two circuits in one body.

Does it, physically? I remember the mic being discussed around here somewhere, but not sure there were any gut shots...

 

[Barry Hufker]

This is a screenshot of their brochure...
I believe two circuits are being discussed but I could be wrong in my understanding.

 

[TwentyTrees]

The Lewitt LCT940 goes one step further - it has both FET and tube circuits, continuously variable through a pot on the power supply. Thought it might be a bit of a gimmick, but I've found it surprisingly useful in changing the voicing of the mic.

 

[Khron]

I believe two circuits are being discussed but I could be wrong in my understanding.

Exactly - that's a (marketing) BROCHURE "Truth in advertising" is a concept that's been long lost in the mists of time...

TL;DR - I trust absolutely nothing coming straight from the manufacturer, especially in fields as "esoteric" as audio.

 

[RuudNL]

Here are some inside pictures of the UT87 twin.:

 

[Khron]

That would be very interesting to reverse-engineer then. Definitely wouldn't call that "two discrete circuit topologies", unless that's supposed to mean "one circuit that happens to be built with discrete components, to which the capsule gets connected in two different ways". I really wouldn't dare call this "twin circuit", but then again, i'm not a marketing person with no shame or scruples...

I see no "-60" test-pad on the bias oscillator board, so... Considering this is multipattern, is this (only) a U87 non-A capsule wiring (isolated backplates, single bias voltage), and they're only altering the bias voltage level, between "modern (60v)" and "vintage (46v-ish)"?

Maybe not, if the description is to be believed?

In Vintage Mode, the capsule is polarized simply by normal phantom power voltages (+48v, optimal), and utilizes an insulated backplate design to polarize the front and back sides separately. In Modern Mode, the capsule backplates are connected, and the polarization voltage is raised (slowly, and gently) up to about 63 volts using a specially designed boost circuit.

Also switching in an extra capacitor in the HF feedback, going by the frequency plots...

 

[Accelerator]

My thought was prompted because I'm getting a full size 47 body, but don't think I'm going to fill it's guts up with a tube yet, and if there's enough space in there

Well, if you have this Horror vacui (art)

about this full size 47 body, you can consider for something like EMI-Chandler Limited REDD Microphone with all of these “bell and whistles” switches…

https://chandlerlimited.com/redd-microphone/

 

[Accelerator]

The Lewitt LCT940 goes one step further - it has both FET and tube circuits, continuously variable through a pot on the power supply. Thought it might be a bit of a gimmick, but I've found it surprisingly useful in changing the voicing of the mic.

And then, after all of these “bells and whistles” and the high prices of the Lewitt LCT 940 and the Lewitt LCT 1040, the minimalistic and affordable Lewitt Pure Tube be the winner in any audio term…

What a shame, what a shame...

 

[pasarski]

Could it be a good way to implement a "pad"? Two circuits with different sensitivities and headroom instead of a pad implemented by capacitive divider/lowering the polarization voltage? One could dodge the distortion/noise penalties associated with the traditional methods. Not that noise is a big problem in situations where you need a pad though. Also it probably wouldn't be as sexy and marketable as a "modern + vintage mojo circuit in one" that seems to be the usual case with mics marketed as twin circuit.

 

[Khron]

Could it be a good way to implement a "pad"?

... But why? Or rather, why "two circuits" as opposed to one with some tonal options? Or, at the very least, what would be the goal, at the end of the day?

 

[Migs 31]

Very Interesting idea.

But should’t contemporary companies concentrate R&D in making just ONE microphone in a metal tube, that actually sounds real GOOD! As in: just right for most vocals Male or Female (Music or VO) and or for a variety of instruments?
And that at decent (not extortionary) prices. Maybe too much asking?!?


M

 

[thomasdf]

Here are some inside pictures of the UT87 twin.:

View attachment 132902

View attachment 132903

Some sort of bias preset ? Switching from high to lower = playing with headroom and tone / freq response of the mic ? Or maybe some with capsule polarisation ?

 

[pasarski]

... But why? Or rather, why "two circuits" as opposed to one with some tonal options? Or, at the very least, what would be the goal, at the end of the day?

AFAIK a capacitive pad introduces more distortion at lower levels and lowering the polarization voltage has a negative effect on S/N ratio. It would probably count as over engineering of course, considering the real life situations where one needs a pad.

 

[Khron]

AFAIK a capacitive pad introduces more distortion at lower levels

That's true.

lowering the polarization voltage has a negative effect on S/N ratio

If you're in a situation where you need a pad, the noise floor is very unlikely to be any sort of issue.

But nothing in your reply is an actual answer to any of my questions, i think..?