Simple BBD circuit with MN3007

Started by HeaD, April 10, 2013, 01:48:36 PM

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HeaD

Hey there,

I've got a MN3007 and I'm looking to build a simple circuit to delay a line level signal by a short adjustable amount of time.

My idea is to use this "tool" in order to achieve an adjustable phase calibration during a tape studio recording with two microphones.

I don't want to hear the original signal, but only the delayed one. Is it possible to do that with the MN3007?

Thank you so much.

A
Sorry for my english :|

artifus

#1
http://sound.westhost.com/pcmm.htm

stumbled upon this recently: http://www.rolls.com/pdf/M_PT102.pdf

can't help with the mn3007 i'm afraid - think it needs a clock and will be noisey.

how far apart are your mics?! would this not be better done in a daw post recording?

*edit* just spotted the word 'tape'

also: http://www.soundonsound.com/sos/apr08/articles/phasedemystified.htm

and: http://www.soundonsound.com/sos/jan09/articles/loudelectricguitar.htm

HeaD

#2
Thank you for your reply artifus,

I usually put one mic on the front and the second on the back. I've to use an 8 track tape recorder, so I cannot use a daw.

A


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Oh ok, just read your edit :)
Sorry for my english :|

artifus

#3
with one mic front, one mic back equidistant from the cone you may just need to reverse the polarity - invert the phase - of one of the mics.

a simple way to phase align mics at an amp is to play white or pink noise - or even just a loud hiss or hum - thru the amp, match the gain of mics on meters by eye and then move one mic by ear (with both signals mixed equally and centre in headphones) for the fullest sound.

HeaD

Thank you!

And what if I would like to delay one of the two signals in order to create a kind of reverb-like sound? Not just to adjust phase...

I'd need a short time delay in that case? or you think is there another way to do that?

Thanks again
Sorry for my english :|

artifus

#5
the difference in sound you hear when mixing the two signals is caused by the comb filtering effect of the phase of the two signals - its kinda like weird eq for want of a better phrase, and is most noticeable as a lack of bottom end or an odd sounding upper mid range depending on where the constructive and destructive phase alignment occurs.

delaying one of the signals separates them further until you move out of the haas effect region and into slap back/early reflection reverb/echo territory.

read thru the above linked articles a few times - they make more sense than i can.

*edit* you may want to play with panning your two signals hard left and hard right for fun and profit but be aware of what happens to the sound when listening in mono.