Impedance switching box with mic booster

[Nen'O]

Sorry, mic booster + impedance switch is for Metric Halo 2882 with Mic Inputs: 200 kOhms (Balanced).

*I just mentioned Phoenix audio as an example of mic pre with very high impedance of 10K.

 

[abbey road d enfer]

Sorry, mic booster + impedance switch is for Metric Halo 2882 with Mic Inputs: 200 kOhms (Balanced).

These are very strange specs for mic inputs.
Of course there is no phantom power...

 

[kags]

These are very strange specs for mic inputs.
Of course there is no phantom power...

Strange, indeed!

 

[abbey road d enfer]

Strange, indeed!

Looks like a very bad compromise to make a "universal" input.
In this context, a step-up transformer would make sense.
If phantom is needed, not much.

 

[ccaudle]

Looks like a very bad compromise to make a "universal" input.

The description of the microphone amps is "Utility Mic Preamps" so Metric Halo does not seem to be making any great claims. If you just wanted some reasonable inputs that could handle a mic in front of a guitar amp they would be fine.

 

[Nen'O]

OK, i'm confused now. So is there any use of using putting +10db transformer before preamp?

 

[ccaudle]

is there any use of using putting +10db transformer before preamp?

A 10dB transformer is probably not useful before an existing preamp, but would be useful if you control the circuit, e.g. in front of a tube or jfet circuit with very high impedance.

 

[Dylan W]

In most cases, reducing the impedance the mic sees results in deterioration of sound.
As the posted video says, it is shocking how it changes the sound, but he neglects to say that reducing the impedance always results in worse sound.
It has been clearly demonstrated that dynamic and ribbon mics benefit from the largest possible impedance; this has been known since the inception of ribbon mics in the 1930's.
Condenser mics may not be as sensitive to loading than other types, but in any case, there is a common consequence: the level drops, thus reducing S/N ratio.
This kind of variable load acts only in one direction, it does not "open" the microphone. It is only capable of choking it.
I find it pathetic this trend to sabotage sound with that kind of device or introducing distortion, when generations of engineers have pulled hairs to improve objectively the performance of equipment.

This seems a little strong… it doesn’t seem out of the realm of possibility to me that some ears prefer some mics with a lower load impedance. In particular, some people think the SM57/58 sounds better into ~600 ohms. IIRC it has to do with damping midrange resonances.

https://web.archive.org/web/2008120...dingmag.com/resources/resourceDetail/330.html

This doesn’t have much to do with what OP is looking for though - why not build a Cloudlifter?

 

[abbey road d enfer]

This seems a little strong… it doesn’t seem out of the realm of possibility to me that some ears prefer some mics with a lower load impedance. In particular, some people think the SM57/58 sounds better into ~600 ohms. IIRC it has to do with damping midrange resonances.

https://web.archive.org/web/2008120...dingmag.com/resources/resourceDetail/330.html

That's an interesting article, although it somehow misses the point.
The test would have been complete if it had included EQ, in order to include the whole sound-shaping process.
Using dynamic mics with a light load (high loadimpedance) has an effect on sound that needs to be EQ'd, but all dynamic mics need EQ anyway.

This doesn’t have much to do with what OP is looking for though - why not build a Cloudlifter?

IINM, the OP proposes to build a load box. Mic booster comes later in the discussion, showing he already has one.

 

[Nen'O]

This doesn’t have much to do with what OP is looking for though - why not build a Cloudlifter?

Does anyone sells DIY kits for Cloudlifter aka mic booster?

 

[rogs]

Does anyone sells DIY kits for Cloudlifter aka mic booster?

There are a couple of Cloudlifter 'clones' that cost a lot less than the original -- so cheap in fact that it's probably not worth trying to build one !
This one perhaps? : https://www.gear4music.com/Recording-and-Computers/SubZero-Single-Channel-Microphone-Booster/2BNB

Or maybe the Alctron MA-1 which you can find at various online sites (includng Aliexpress)
I believe the Alctron uses a very similar circuit to the original Cloudlifter. (Copy of the Alctron MA-1 schematic attached here for interest).
As I say, it's probably cheaper to actually buy one! .....

N.B. don't forget that this kind of booster needs phantom power to function -- which it doesn't pass through to the input.

 

[abbey road d enfer]

Does anyone sells DIY kits for Cloudlifter aka mic booster?

I suggest you search in this group for cloudlifter. there are at least 3 extensive threads about them.

 

[zzzzz]

Here are the guts of one of the AliExpress Cloudlifter clones. Four transistors (probably JFET like the original) but way more parts otherwise!

 

[abbey road d enfer]

Here are the guts of one of the AliExpress Cloudlifter clones. Four transistors (probably JFET like the original) but way more parts otherwise!

Apparently, it uses a front end that's very similar to Cloudlifter/FetHead, combined with a Schoeps output arrangement.

 

[zzzzz]

Apparently, it uses a front end that's very similar to Cloudlifter/FetHead, combined with a Schoeps output arrangement.

ha go figure, looks like someone knew what they were going for?!

looks like those tantalums might be in a signal path? honestly I have barely even looked at the thing let alone those photos I attached.

we have a couple of legit Cloudlifter boxes -- the standard ones. Will shoot them out eventually.