John Curl's Blowtorch preamplifier part III

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In addition all microphones makes/models responded very favourably to my 'treatment', especially passive dynamic Shure models with internal matching transformer, but also all condensor types....sensitivity and clarity increases markedly.

Sensitivity is an easily measurable quantity, nothing magnetic in a condensor mic (most modern ones). I guarantee gooping a capsule will not improve it.
 
Maybe cheaper compression drivers are an option for testing because they are designed to have user-replacable diaphragm assemblies and everything is quite large in terms of dimensions.
Definitely agreed. The D205TI's I replaced in the past were 2 inch dia and ffluid cooled.
But when I was getting materials for a line array setup, I purchased about 5 pieces of some tweet, don't remember what pedigree befor I committed to 200 units, so I've a few to waste in my feeble attempt.


Ed, thanks for the gum out hint, may try it. Was thinking heat on a flat exacto, and then bonding a blade to a handheld ultrasonic piezo stack feed horn. But was undecided as I couldn't be sure the hearing protection would protect my ears or that the acrylic goggles would prevent ultrasonic pass through from the eyes to my brain. No need to do a self imposed sonic attack thing.
Is this OK?
RMMGA/RAP postings on mics for recording/amplifying acoustic guitars (2001)

I’m more certain about this one (jn)
YouTube



It’s the proper moment to use your pencil to sketch it for us, John

George
He was so annoying, she on the other hand, wasn't.;)

Will do.
John
 
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Sensitivity is an easily measurable quantity
Sure. I'm commenting from subjective viewpoint using standard mixer/pre and headphones or speakers.



nothing magnetic in a condensor mic (most modern ones)
I think all the condensor mics I have dealt with run output coupling/matching transformer.



I guarantee gooping a capsule will not improve it.
Consensor capsules and dynamic pickups improved, ditto output transformers.
I'm not winding you up Scott, with real sounds these changes are strongly evident, with sinewave excitation probably not.


Dan.
 
One of the major differences is phase.
Dynamic mikes deliver max output at zero crossings, condensors at max excursion. Therefore, you cannot mix the two types when miking an instrument (book knowledge, don't know how it pans out in real life).

If I may, the most beautiful acoustic guitar I had recorded in a studio was taken with three microphones. I think a dynamic and two electrostatics.
As they were not placed in the same places/distances, the phases are doing their own thing: just give them something to smoke ;-)

nb: The owner of the mastering/cutting room asked-me if he could add the mix of this tune to his demo disk in project.
I was proud as a porn star receiving an Oscar.
 
I think all the condensor mics I have dealt with run output coupling/matching transformer.

Like Schoeps?

alice%20mic%20cirucuit.jpg
 
It’s the proper moment to use your pencil to sketch it for us, John

George
Here are both.

The top is the normal diff drive. I have neglected to draw in the Ls/Rs, as we all know what is meant now by the circuit.

In the second one, the pickup coil is half the turns, so shows only half the dB/dt. So I double it at the summer, and subtract it from the vout. The net effect is the same, the output of the summer will be Rs of the drive coil. (was unable to easily find the greek symbol for summation in this version of visio..sigh)

John
 

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Then Dan, a recording with/ without your goop would be a trivial thing for you to do from the line-out feed of the console, no?
Yes, or with my soundcard at home would be better....the experiments I ran were at work on the fly when the boss wasn't looking ;).
To this end I bought one of these CM-H8C Large Diaphram True Condensor Microphone the other week.....same mic but different nameplate (Bock BK-1100C) from a pawnshop $25.00 but have not listened to it yet.
View attachment CM-H8C-Data-Sheet.pdf
There are a bunch of AB loop recording experiments for me to run in the near future now that I am subjectively happy with the sounds of a range of 'goop' mixtures.
NYE experimental mixture was on a Jamaican DJ friend's decent DJ system in a marina large pub/beer garden venue running Reggae all night..... peace, love and happiness all round ;).
When I have sets of formal test recordings (ie when I extract the digit) Scott's band filtered signal noise floor modulation analysis ought to be useful.
Previous critical listening to AB difference signal residual is informative and correlates with subjective impressions/findings....the difference signal sounds truly 'nasty' and weirdly/wrongly dynamic in nature.


Dan.











 
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