question about the vtb1

[buryher17]

what does the function "reverse polarity" mean and do??

thats th eonly thing i really dont know/understand about the preamp

that and....


on the back it has the 200 and 50 mic impendence to choose form. please explain that too.

thanks

[Echelon]

reverse polarity... I'm under the impression that it when you have two microphones pointed at each other the sound will be recorded quite garbled because the sound vibrations mess with each other. By having one of the mics on reverse polarity, it changes the spectrum (or something) that the microphone picks up so that you can get a good sound. For instance... When I record drums, I will have one mic on the inside of the bass drum, and on on the outside by the place that the kick meets the drum (to get the click sound). Since both mics are pointed at each other, I would have one with reverse polarity. If this isn't the right answer, hopefully someone else can help you out.

[pikingrin]

In regards to mic impedance, this might be a good place to start, or just do a search through the mic forum here (check out Harvey Gerst's stuff, it's usually on top day after day in the mic forum, and extremely informative), or do a google search.

As far as reverse polarity, also known as phase reverse, when you have two mics recording at the same time they may, for some reason or another, start to cancel out certain frequencies. The source you record may sound "tinny" (you would know it if you heard it.).. That's because of all the frequencies that are being "cancelled out" by the other mic. If you hit the reverse polarity (or phase reverse) switch, it will clear all that up. I'm not by any means an expert, but it happens to the best of us along that lovely experimental road.

Either one of these questions are probably better answered by google or Harvey, so try a search as well. I am only a lowly HR amateur...

[MadMax]

Used to be really helpful when recording drums with multiple mics. For example; If you close mic the snare and you have overhead mics, the sound from the snare will arrive at the OH's a little later than the snare mic hears it. Your recorded waveforms will be out of phase and the resulting snare sound will be thin. You reverse the phase on the snare mic-or the OH's- and your fat snare sound is back. This only works if you have the capability to monitor your sources. Or you could try a test recording, listen, adjust and then rerecord once you have your sources "phase aligned".

This is kind of old school advice now that we have waveform editing capability in our DAW's, but that's what the phase button is for.
I don't even think about phase reversal on my pre's anymore.

[buryher17]

thanks a lot guys.


i know you guys are right about the polarity because when i recorded with 2 mxl 990's at the same time it was horirble and tiny and just nto right


now im gona try and use the reverse polarity feature, also when im doing double bass too.

thanks guys. helped me a lot.

[j-boy]

Another useful application of the polarity reverse is if you record your guitar amp using two mic's, one in the front at the speaker grille and one in the rear. This gives great results with open-back amps like the Fender Deluxe Reverb, for instance. But you have to flip the phase on one of them since the "push" phase of the front will be the "pull" phase of the back with relation to the speaker movement, and vice versa.

[buryher17]

Originally Posted by j-boy

Another useful application of the polarity reverse is if you record your guitar amp using two mic's, one in the front at the speaker grille and one in the rear. This gives great results with open-back amps like the Fender Deluxe Reverb, for instance. But you have to flip the phase on one of them since the "push" phase of the front will be the "pull" phase of the back with relation to the speaker movement, and vice versa.

does it matter which mike has the polarity device on??

i onyl have 1 pre amp. so which mic would i put it on?

[drossfile]

Originally Posted by buryher17

does it matter which mike has the polarity device on??

i onyl have 1 pre amp. so which mic would i put it on?

Makes no difference at all. In fact, all your "polarity reverse" button does is reverse pins 2 and 3 on your xlr plug (or, on a 1/4" balanced TRS plug, reverses "hot" and "cold"). You don't even need a button to do this for you if you don't have one--you can just rewire your microphone cables to achieve the same result (although certainly a button is easier). Picture your mic diaphragms: soundwaves are hitting your capsules at different times or from different directions, which is where your "phase cancellation" comes into play. If you reverse the polarity of one or the other of the two mics that are cancelling each other out, that cancellation is now eliminated by virtue of time-aligning/reversing the voltage signal that translates the sound waves into electric impulses.
So, in short, if one mic is cancelling the other out, and you reverse the phase on either one, your phase cancellation problem goes away. Good luck!

[buryher17]

Originally Posted by drossfile

Makes no difference at all. In fact, all your "polarity reverse" button does is reverse pins 2 and 3 on your xlr plug (or, on a 1/4" balanced TRS plug, reverses "hot" and "cold"). You don't even need a button to do this for you if you don't have one--you can just rewire your microphone cables to achieve the same result (although certainly a button is easier). Picture your mic diaphragms: soundwaves are hitting your capsules at different times or from different directions, which is where your "phase cancellation" comes into play. If you reverse the polarity of one or the other of the two mics that are cancelling each other out, that cancellation is now eliminated by virtue of time-aligning/reversing the voltage signal that translates the sound waves into electric impulses.
So, in short, if one mic is cancelling the other out, and you reverse the phase on either one, your phase cancellation problem goes away. Good luck!

awesome. thanks a lot. i already have the button, so definately easier than rewiring, but if it comes ot a point where i need to and dont have a button, ill have that saved.

[travelin travis]

Originally Posted by j-boy

Another useful application of the polarity reverse is if you record your guitar amp using two mic's, one in the front at the speaker grille and one in the rear. This gives great results with open-back amps like the Fender Deluxe Reverb, for instance. But you have to flip the phase on one of them since the "push" phase of the front will be the "pull" phase of the back with relation to the speaker movement, and vice versa.

I've got to try that. Are there any general mic positions for the rear mic?

[The Flame]

wow, is there any way i can flip the phase on my mics? I am using the firepod, and recording live drums and intruments, and i might be afraid i have this problem. I dont see any polarity switches anywhere, so is there another way to fix this?

[Jackrip]

I got a problem with my VTB1 as well... it seems like when I turn the nob to the tube pre instead of the solid state, my vocals get weird, real distorted and just messed up. I dunno if my compressor has annything to do with it or not, but I am confused about ti.

[scrubs]

Originally Posted by The Flame

wow, is there any way i can flip the phase on my mics? I am using the firepod, and recording live drums and intruments, and i might be afraid i have this problem. I dont see any polarity switches anywhere, so is there another way to fix this?

Yes, if you're using Cubase that came with the firepod, you can reverse the polarity in the software (under Audio-->Edit-->Reverse Polarity, or something similar).

[scrubs]

Originally Posted by Jackrip

I got a problem with my VTB1 as well... it seems like when I turn the nob to the tube pre instead of the solid state, my vocals get weird, real distorted and just messed up. I dunno if my compressor has annything to do with it or not, but I am confused about ti.

The "tube" of the VTB-1 adds distortion. That's it's purpose. You should set the gain using the input level, then, if desired, dial in a little bit of "toob." If you don't go past about 11 o'clock on the dial, the tube gain can actually sound kind of cool. Past that, and it gets dirty and nasty fast.

[Dogbreath]

cool. That's good to know Scrubby...

[gbondo9]

Originally Posted by Jackrip

I got a problem with my VTB1 as well... it seems like when I turn the nob to the tube pre instead of the solid state, my vocals get weird, real distorted and just messed up. I dunno if my compressor has annything to do with it or not, but I am confused about ti.

I use the "tube" switch for alot of stuff - but never vox.

[buryher17]

Originally Posted by gbondo9

I use the "tube" switch for alot of stuff - but never vox.

any specific reason why you dont????

i would think it would be better since it has a tube to add sound/flavor to the vox

i've yet to expeiriement in detail with this preamp when it comes to vox so im still veyr sketchy about it.

i wish i could sing... would amke things a lto easier lol

[Jackrip]

Originally Posted by scrubs

The "tube" of the VTB-1 adds distortion. That's it's purpose. You should set the gain using the input level, then, if desired, dial in a little bit of "toob." If you don't go past about 11 o'clock on the dial, the tube gain can actually sound kind of cool. Past that, and it gets dirty and nasty fast.

I thought the tube was supposed to fatten up the vocals, which is what I was trying to do. Because even though the vocals were good, they were a little thin I guess, I dont wanna say that even, but I think they would sound better with more presence behind them, I was trying to fatten them up a bit with the tube, any advice?

[The Flame]

Thanks scubby, i am using cubase le, hopefully i can find that phase reverse. What would i use it on anyhow. Like reverse one of my drum overheads? You think this will greatly help the sound? I am miking up my whole drum kit, anything else i should reverse? The guitar amps and bass are miked with one amp so i dont think thats gonna be a problem. Sometimes i do record "live" with 2 guitar players, bass and drums. Will switching the phase help this at all since all the mics are not far from eachother?

[scrubs]

Originally Posted by Jackrip

I thought the tube was supposed to fatten up the vocals, which is what I was trying to do. Because even though the vocals were good, they were a little thin I guess, I dont wanna say that even, but I think they would sound better with more presence behind them, I was trying to fatten them up a bit with the tube, any advice?

From Studio Projects Website:

Originally Posted by studioprojectsusa.com

For best Tube-Sound results:

The tube operates best when provided with a solid signal. The best way to accomplish this is to use the on-board metering to set the internal levels. Press the Meter Select switch IN, the meter will now display the signal level within the preamp, just before the tube stage. Adjust the GAIN control to get a meter reading within the 0 to +8 range. With the OUTPUT control at "0", start turning the BLEND control clockwise until the desired sound is heard. Depending on the source material, more or less BLEND will be needed. If the output level is too high or low for your following equipment, adjust the OUTPUT control to compensate. This won’t change the sound of the blended signal, just the overall level.

[scrubs]

Originally Posted by The Flame

Thanks scrubby, i am using cubase le, hopefully i can find that phase reverse. What would i use it on anyhow. Like reverse one of my drum overheads? You think this will greatly help the sound? I am miking up my whole drum kit, anything else i should reverse? The guitar amps and bass are miked with one amp so i dont think thats gonna be a problem. Sometimes i do record "live" with 2 guitar players, bass and drums. Will switching the phase help this at all since all the mics are not far from eachother?

Only use it if you hear phasing problems. For example, on your drum mics, if you have the overheads soloed and you add the snare track and the resulting sound of the snare drum gets worse (thin, weak, etc.), then try reversing the phase/polarity of the snare track, since it is probably out of phase with the overheads. Or, if you mic the top and bottom of the snare, you may need to reverse the polarity on the bottom mic. I wouldn't reverse the phase/polarity of your overheads, in general. Just focus on good mic placement.